Reland "Move webrtc/{base => rtc_base}" (https://codereview.webrtc.org/2877023002)

Reland the base->rtc_base without adding stub headers (will be
done in follow-up CL). This preserves git blame history of all files.

BUG=webrtc:7634
NOTRY=True
TBR=kwiberg@webrtc.org

Change-Id: Iea3bb6f3f67b8374c96337b63e8f5aa3e6181012
Reviewed-on: https://chromium-review.googlesource.com/554611
Reviewed-by: Henrik Kjellander <kjellander@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#18821}

webrtc/rtc_base/DEPS

@@ -0,0 +1,15 @@
+include_rules = [
+  "+base/third_party/libevent",
+  "+json",
+  "+third_party/jsoncpp",
+  "+webrtc/system_wrappers",
+]
+
+specific_include_rules = {
+  "gunit_prod.h": [
+    "+gtest",
+  ],
+  "protobuf_utils.h": [
+    "+third_party/protobuf",
+  ],
+}

webrtc/rtc_base/OWNERS

@@ -0,0 +1,19 @@
+henrika@webrtc.org
+henrikg@webrtc.org
+hta@webrtc.org
+juberti@webrtc.org
+mflodman@webrtc.org
+perkj@webrtc.org
+pthatcher@webrtc.org
+sergeyu@chromium.org
+tommi@webrtc.org
+deadbeef@webrtc.org
+kwiberg@webrtc.org
+
+# These are for the common case of adding or renaming files. If you're doing
+# structural changes, please get a review from a reviewer in this file.
+per-file *.gn=*
+per-file *.gni=*
+
+per-file rate_statistics*=sprang@webrtc.org
+per-file rate_statistics*=stefan@webrtc.org

webrtc/rtc_base/applefilesystem.mm

@@ -0,0 +1,53 @@
+/*
+ *  Copyright 2014 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+// This file only exists because various iOS and macOS system APIs are only
+// available from Objective-C. See unixfilesystem.cc for the only use
+// (enforced by a lack of a header file).
+
+#import <Foundation/NSPathUtilities.h>
+#import <Foundation/NSProcessInfo.h>
+#include <string.h>
+
+#include "webrtc/base/checks.h"
+#include "webrtc/base/pathutils.h"
+
+// Return a new[]'d |char*| copy of the UTF8 representation of |s|.
+// Caller owns the returned memory and must use delete[] on it.
+static char* copyString(NSString* s) {
+  const char* utf8 = [s UTF8String];
+  size_t len = strlen(utf8) + 1;
+  char* copy = new char[len];
+  // This uses a new[] + strcpy (instead of strdup) because the
+  // receiver expects to be able to delete[] the returned pointer
+  // (instead of free()ing it).
+  strcpy(copy, utf8);
+  return copy;
+}
+
+// Return a (leaked) copy of a directory name suitable for application data.
+char* AppleDataDirectory() {
+  NSArray* paths = NSSearchPathForDirectoriesInDomains(
+      NSApplicationSupportDirectory, NSUserDomainMask, YES);
+  RTC_DCHECK([paths count] == 1);
+  return copyString([paths objectAtIndex:0]);
+}
+
+// Return a (leaked) copy of a directory name suitable for use as a $TEMP.
+char* AppleTempDirectory() {
+  return copyString(NSTemporaryDirectory());
+}
+
+// Return the binary's path.
+void AppleAppName(rtc::Pathname* path) {
+  NSProcessInfo* pInfo = [NSProcessInfo processInfo];
+  NSString* argv0 = [[pInfo arguments] objectAtIndex:0];
+  path->SetPathname([argv0 UTF8String]);
+}

webrtc/rtc_base/array_view.h

@@ -0,0 +1,253 @@
+/*
+ *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_ARRAY_VIEW_H_
+#define WEBRTC_RTC_BASE_ARRAY_VIEW_H_
+
+#include "webrtc/base/checks.h"
+#include "webrtc/base/type_traits.h"
+
+namespace rtc {
+
+// Many functions read from or write to arrays. The obvious way to do this is
+// to use two arguments, a pointer to the first element and an element count:
+//
+//   bool Contains17(const int* arr, size_t size) {
+//     for (size_t i = 0; i < size; ++i) {
+//       if (arr[i] == 17)
+//         return true;
+//     }
+//     return false;
+//   }
+//
+// This is flexible, since it doesn't matter how the array is stored (C array,
+// std::vector, rtc::Buffer, ...), but it's error-prone because the caller has
+// to correctly specify the array length:
+//
+//   Contains17(arr, arraysize(arr));     // C array
+//   Contains17(arr.data(), arr.size());  // std::vector
+//   Contains17(arr, size);               // pointer + size
+//   ...
+//
+// It's also kind of messy to have two separate arguments for what is
+// conceptually a single thing.
+//
+// Enter rtc::ArrayView<T>. It contains a T pointer (to an array it doesn't
+// own) and a count, and supports the basic things you'd expect, such as
+// indexing and iteration. It allows us to write our function like this:
+//
+//   bool Contains17(rtc::ArrayView<const int> arr) {
+//     for (auto e : arr) {
+//       if (e == 17)
+//         return true;
+//     }
+//     return false;
+//   }
+//
+// And even better, because a bunch of things will implicitly convert to
+// ArrayView, we can call it like this:
+//
+//   Contains17(arr);                             // C array
+//   Contains17(arr);                             // std::vector
+//   Contains17(rtc::ArrayView<int>(arr, size));  // pointer + size
+//   Contains17(nullptr);                         // nullptr -> empty ArrayView
+//   ...
+//
+// ArrayView<T> stores both a pointer and a size, but you may also use
+// ArrayView<T, N>, which has a size that's fixed at compile time (which means
+// it only has to store the pointer).
+//
+// One important point is that ArrayView<T> and ArrayView<const T> are
+// different types, which allow and don't allow mutation of the array elements,
+// respectively. The implicit conversions work just like you'd hope, so that
+// e.g. vector<int> will convert to either ArrayView<int> or ArrayView<const
+// int>, but const vector<int> will convert only to ArrayView<const int>.
+// (ArrayView itself can be the source type in such conversions, so
+// ArrayView<int> will convert to ArrayView<const int>.)
+//
+// Note: ArrayView is tiny (just a pointer and a count if variable-sized, just
+// a pointer if fix-sized) and trivially copyable, so it's probably cheaper to
+// pass it by value than by const reference.
+
+namespace impl {
+
+// Magic constant for indicating that the size of an ArrayView is variable
+// instead of fixed.
+enum : std::ptrdiff_t { kArrayViewVarSize = -4711 };
+
+// Base class for ArrayViews of fixed nonzero size.
+template <typename T, std::ptrdiff_t Size>
+class ArrayViewBase {
+  static_assert(Size > 0, "ArrayView size must be variable or non-negative");
+
+ public:
+  ArrayViewBase(T* data, size_t size) : data_(data) {}
+
+  static constexpr size_t size() { return Size; }
+  static constexpr bool empty() { return false; }
+  T* data() const { return data_; }
+
+ protected:
+  static constexpr bool fixed_size() { return true; }
+
+ private:
+  T* data_;
+};
+
+// Specialized base class for ArrayViews of fixed zero size.
+template <typename T>
+class ArrayViewBase<T, 0> {
+ public:
+  explicit ArrayViewBase(T* data, size_t size) {}
+
+  static constexpr size_t size() { return 0; }
+  static constexpr bool empty() { return true; }
+  T* data() const { return nullptr; }
+
+ protected:
+  static constexpr bool fixed_size() { return true; }
+};
+
+// Specialized base class for ArrayViews of variable size.
+template <typename T>
+class ArrayViewBase<T, impl::kArrayViewVarSize> {
+ public:
+  ArrayViewBase(T* data, size_t size)
+      : data_(size == 0 ? nullptr : data), size_(size) {}
+
+  size_t size() const { return size_; }
+  bool empty() const { return size_ == 0; }
+  T* data() const { return data_; }
+
+ protected:
+  static constexpr bool fixed_size() { return false; }
+
+ private:
+  T* data_;
+  size_t size_;
+};
+
+}  // namespace impl
+
+template <typename T, std::ptrdiff_t Size = impl::kArrayViewVarSize>
+class ArrayView final : public impl::ArrayViewBase<T, Size> {
+ public:
+  using value_type = T;
+  using const_iterator = const T*;
+
+  // Construct an ArrayView from a pointer and a length.
+  template <typename U>
+  ArrayView(U* data, size_t size)
+      : impl::ArrayViewBase<T, Size>::ArrayViewBase(data, size) {
+    RTC_DCHECK_EQ(size == 0 ? nullptr : data, this->data());
+    RTC_DCHECK_EQ(size, this->size());
+    RTC_DCHECK_EQ(!this->data(),
+                  this->size() == 0);  // data is null iff size == 0.
+  }
+
+  // Construct an empty ArrayView. Note that fixed-size ArrayViews of size > 0
+  // cannot be empty.
+  ArrayView() : ArrayView(nullptr, 0) {}
+  ArrayView(std::nullptr_t) : ArrayView() {}
+  ArrayView(std::nullptr_t, size_t size)
+      : ArrayView(static_cast<T*>(nullptr), size) {
+    static_assert(Size == 0 || Size == impl::kArrayViewVarSize, "");
+    RTC_DCHECK_EQ(0, size);
+  }
+
+  // Construct an ArrayView from an array.
+  template <typename U, size_t N>
+  ArrayView(U (&array)[N]) : ArrayView(array, N) {
+    static_assert(Size == N || Size == impl::kArrayViewVarSize,
+                  "Array size must match ArrayView size");
+  }
+
+  // (Only if size is fixed.) Construct an ArrayView from any type U that has a
+  // static constexpr size() method whose return value is equal to Size, and a
+  // data() method whose return value converts implicitly to T*. In particular,
+  // this means we allow conversion from ArrayView<T, N> to ArrayView<const T,
+  // N>, but not the other way around. We also don't allow conversion from
+  // ArrayView<T> to ArrayView<T, N>, or from ArrayView<T, M> to ArrayView<T,
+  // N> when M != N.
+  template <typename U,
+            typename std::enable_if<
+                Size != impl::kArrayViewVarSize &&
+                HasDataAndSize<U, T>::value>::type* = nullptr>
+  ArrayView(U& u) : ArrayView(u.data(), u.size()) {
+    static_assert(U::size() == Size, "Sizes must match exactly");
+  }
+
+  // (Only if size is variable.) Construct an ArrayView from any type U that
+  // has a size() method whose return value converts implicitly to size_t, and
+  // a data() method whose return value converts implicitly to T*. In
+  // particular, this means we allow conversion from ArrayView<T> to
+  // ArrayView<const T>, but not the other way around. Other allowed
+  // conversions include
+  // ArrayView<T, N> to ArrayView<T> or ArrayView<const T>,
+  // std::vector<T> to ArrayView<T> or ArrayView<const T>,
+  // const std::vector<T> to ArrayView<const T>,
+  // rtc::Buffer to ArrayView<uint8_t> or ArrayView<const uint8_t>, and
+  // const rtc::Buffer to ArrayView<const uint8_t>.
+  template <
+      typename U,
+      typename std::enable_if<Size == impl::kArrayViewVarSize &&
+                              HasDataAndSize<U, T>::value>::type* = nullptr>
+  ArrayView(U& u) : ArrayView(u.data(), u.size()) {}
+
+  // Indexing and iteration. These allow mutation even if the ArrayView is
+  // const, because the ArrayView doesn't own the array. (To prevent mutation,
+  // use a const element type.)
+  T& operator[](size_t idx) const {
+    RTC_DCHECK_LT(idx, this->size());
+    RTC_DCHECK(this->data());
+    return this->data()[idx];
+  }
+  T* begin() const { return this->data(); }
+  T* end() const { return this->data() + this->size(); }
+  const T* cbegin() const { return this->data(); }
+  const T* cend() const { return this->data() + this->size(); }
+
+  ArrayView<T> subview(size_t offset, size_t size) const {
+    return offset < this->size()
+               ? ArrayView<T>(this->data() + offset,
+                              std::min(size, this->size() - offset))
+               : ArrayView<T>();
+  }
+  ArrayView<T> subview(size_t offset) const {
+    return subview(offset, this->size());
+  }
+};
+
+// Comparing two ArrayViews compares their (pointer,size) pairs; it does *not*
+// dereference the pointers.
+template <typename T, std::ptrdiff_t Size1, std::ptrdiff_t Size2>
+bool operator==(const ArrayView<T, Size1>& a, const ArrayView<T, Size2>& b) {
+  return a.data() == b.data() && a.size() == b.size();
+}
+template <typename T, std::ptrdiff_t Size1, std::ptrdiff_t Size2>
+bool operator!=(const ArrayView<T, Size1>& a, const ArrayView<T, Size2>& b) {
+  return !(a == b);
+}
+
+// Variable-size ArrayViews are the size of two pointers; fixed-size ArrayViews
+// are the size of one pointer. (And as a special case, fixed-size ArrayViews
+// of size 0 require no storage.)
+static_assert(sizeof(ArrayView<int>) == 2 * sizeof(int*), "");
+static_assert(sizeof(ArrayView<int, 17>) == sizeof(int*), "");
+static_assert(std::is_empty<ArrayView<int, 0>>::value, "");
+
+template <typename T>
+inline ArrayView<T> MakeArrayView(T* data, size_t size) {
+  return ArrayView<T>(data, size);
+}
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_ARRAY_VIEW_H_

webrtc/rtc_base/array_view_unittest.cc

@@ -0,0 +1,411 @@
+/*
+ *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <algorithm>
+#include <string>
+#include <vector>
+
+#include "webrtc/base/array_view.h"
+#include "webrtc/base/buffer.h"
+#include "webrtc/base/checks.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/test/gmock.h"
+
+namespace rtc {
+
+namespace {
+
+using ::testing::ElementsAre;
+using ::testing::IsEmpty;
+
+template <typename T>
+void Call(ArrayView<T>) {}
+
+}  // namespace
+
+TEST(ArrayViewTest, TestConstructFromPtrAndArray) {
+  char arr[] = "Arrr!";
+  const char carr[] = "Carrr!";
+  Call<const char>(arr);
+  Call<const char>(carr);
+  Call<char>(arr);
+  // Call<char>(carr);  // Compile error, because can't drop const.
+  // Call<int>(arr);  // Compile error, because incompatible types.
+  ArrayView<int*> x;
+  EXPECT_EQ(0u, x.size());
+  EXPECT_EQ(nullptr, x.data());
+  ArrayView<char> y = arr;
+  EXPECT_EQ(6u, y.size());
+  EXPECT_EQ(arr, y.data());
+  ArrayView<char, 6> yf = arr;
+  static_assert(yf.size() == 6, "");
+  EXPECT_EQ(arr, yf.data());
+  ArrayView<const char> z(arr + 1, 3);
+  EXPECT_EQ(3u, z.size());
+  EXPECT_EQ(arr + 1, z.data());
+  ArrayView<const char, 3> zf(arr + 1, 3);
+  static_assert(zf.size() == 3, "");
+  EXPECT_EQ(arr + 1, zf.data());
+  ArrayView<const char> w(arr, 2);
+  EXPECT_EQ(2u, w.size());
+  EXPECT_EQ(arr, w.data());
+  ArrayView<const char, 2> wf(arr, 2);
+  static_assert(wf.size() == 2, "");
+  EXPECT_EQ(arr, wf.data());
+  ArrayView<char> q(arr, 0);
+  EXPECT_EQ(0u, q.size());
+  EXPECT_EQ(nullptr, q.data());
+  ArrayView<char, 0> qf(arr, 0);
+  static_assert(qf.size() == 0, "");
+  EXPECT_EQ(nullptr, qf.data());
+#if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
+  // DCHECK error (nullptr with nonzero size).
+  EXPECT_DEATH(ArrayView<int>(static_cast<int*>(nullptr), 5), "");
+#endif
+  // These are compile errors, because incompatible types.
+  // ArrayView<int> m = arr;
+  // ArrayView<float> n(arr + 2, 2);
+}
+
+TEST(ArrayViewTest, TestCopyConstructorVariable) {
+  char arr[] = "Arrr!";
+  ArrayView<char> x = arr;
+  EXPECT_EQ(6u, x.size());
+  EXPECT_EQ(arr, x.data());
+  ArrayView<char> y = x;  // Copy non-const -> non-const.
+  EXPECT_EQ(6u, y.size());
+  EXPECT_EQ(arr, y.data());
+  ArrayView<const char> z = x;  // Copy non-const -> const.
+  EXPECT_EQ(6u, z.size());
+  EXPECT_EQ(arr, z.data());
+  ArrayView<const char> w = z;  // Copy const -> const.
+  EXPECT_EQ(6u, w.size());
+  EXPECT_EQ(arr, w.data());
+  // ArrayView<char> v = z;  // Compile error, because can't drop const.
+}
+
+TEST(ArrayViewTest, TestCopyConstructorFixed) {
+  char arr[] = "Arrr!";
+  ArrayView<char, 6> x = arr;
+  static_assert(x.size() == 6, "");
+  EXPECT_EQ(arr, x.data());
+
+  // Copy fixed -> fixed.
+  ArrayView<char, 6> y = x;  // Copy non-const -> non-const.
+  static_assert(y.size() == 6, "");
+  EXPECT_EQ(arr, y.data());
+  ArrayView<const char, 6> z = x;  // Copy non-const -> const.
+  static_assert(z.size() == 6, "");
+  EXPECT_EQ(arr, z.data());
+  ArrayView<const char, 6> w = z;  // Copy const -> const.
+  static_assert(w.size() == 6, "");
+  EXPECT_EQ(arr, w.data());
+  // ArrayView<char, 6> v = z;  // Compile error, because can't drop const.
+
+  // Copy fixed -> variable.
+  ArrayView<char> yv = x;  // Copy non-const -> non-const.
+  EXPECT_EQ(6u, yv.size());
+  EXPECT_EQ(arr, yv.data());
+  ArrayView<const char> zv = x;  // Copy non-const -> const.
+  EXPECT_EQ(6u, zv.size());
+  EXPECT_EQ(arr, zv.data());
+  ArrayView<const char> wv = z;  // Copy const -> const.
+  EXPECT_EQ(6u, wv.size());
+  EXPECT_EQ(arr, wv.data());
+  // ArrayView<char> vv = z;  // Compile error, because can't drop const.
+}
+
+TEST(ArrayViewTest, TestCopyAssignmentVariable) {
+  char arr[] = "Arrr!";
+  ArrayView<char> x(arr);
+  EXPECT_EQ(6u, x.size());
+  EXPECT_EQ(arr, x.data());
+  ArrayView<char> y;
+  y = x;  // Copy non-const -> non-const.
+  EXPECT_EQ(6u, y.size());
+  EXPECT_EQ(arr, y.data());
+  ArrayView<const char> z;
+  z = x;  // Copy non-const -> const.
+  EXPECT_EQ(6u, z.size());
+  EXPECT_EQ(arr, z.data());
+  ArrayView<const char> w;
+  w = z;  // Copy const -> const.
+  EXPECT_EQ(6u, w.size());
+  EXPECT_EQ(arr, w.data());
+  // ArrayView<char> v;
+  // v = z;  // Compile error, because can't drop const.
+}
+
+TEST(ArrayViewTest, TestCopyAssignmentFixed) {
+  char arr[] = "Arrr!";
+  char init[] = "Init!";
+  ArrayView<char, 6> x(arr);
+  EXPECT_EQ(arr, x.data());
+
+  // Copy fixed -> fixed.
+  ArrayView<char, 6> y(init);
+  y = x;  // Copy non-const -> non-const.
+  EXPECT_EQ(arr, y.data());
+  ArrayView<const char, 6> z(init);
+  z = x;  // Copy non-const -> const.
+  EXPECT_EQ(arr, z.data());
+  ArrayView<const char, 6> w(init);
+  w = z;  // Copy const -> const.
+  EXPECT_EQ(arr, w.data());
+  // ArrayView<char, 6> v(init);
+  // v = z;  // Compile error, because can't drop const.
+
+  // Copy fixed -> variable.
+  ArrayView<char> yv;
+  yv = x;  // Copy non-const -> non-const.
+  EXPECT_EQ(6u, yv.size());
+  EXPECT_EQ(arr, yv.data());
+  ArrayView<const char> zv;
+  zv = x;  // Copy non-const -> const.
+  EXPECT_EQ(6u, zv.size());
+  EXPECT_EQ(arr, zv.data());
+  ArrayView<const char> wv;
+  wv = z;  // Copy const -> const.
+  EXPECT_EQ(6u, wv.size());
+  EXPECT_EQ(arr, wv.data());
+  // ArrayView<char> v;
+  // v = z;  // Compile error, because can't drop const.
+}
+
+TEST(ArrayViewTest, TestStdVector) {
+  std::vector<int> v;
+  v.push_back(3);
+  v.push_back(11);
+  Call<const int>(v);
+  Call<int>(v);
+  // Call<unsigned int>(v);  // Compile error, because incompatible types.
+  ArrayView<int> x = v;
+  EXPECT_EQ(2u, x.size());
+  EXPECT_EQ(v.data(), x.data());
+  ArrayView<const int> y;
+  y = v;
+  EXPECT_EQ(2u, y.size());
+  EXPECT_EQ(v.data(), y.data());
+  // ArrayView<double> d = v;  // Compile error, because incompatible types.
+  const std::vector<int> cv;
+  Call<const int>(cv);
+  // Call<int>(cv);  // Compile error, because can't drop const.
+  ArrayView<const int> z = cv;
+  EXPECT_EQ(0u, z.size());
+  EXPECT_EQ(nullptr, z.data());
+  // ArrayView<int> w = cv;  // Compile error, because can't drop const.
+}
+
+TEST(ArrayViewTest, TestRtcBuffer) {
+  rtc::Buffer b = "so buffer";
+  Call<const uint8_t>(b);
+  Call<uint8_t>(b);
+  // Call<int8_t>(b);  // Compile error, because incompatible types.
+  ArrayView<uint8_t> x = b;
+  EXPECT_EQ(10u, x.size());
+  EXPECT_EQ(b.data(), x.data());
+  ArrayView<const uint8_t> y;
+  y = b;
+  EXPECT_EQ(10u, y.size());
+  EXPECT_EQ(b.data(), y.data());
+  // ArrayView<char> d = b;  // Compile error, because incompatible types.
+  const rtc::Buffer cb = "very const";
+  Call<const uint8_t>(cb);
+  // Call<uint8_t>(cb);  // Compile error, because can't drop const.
+  ArrayView<const uint8_t> z = cb;
+  EXPECT_EQ(11u, z.size());
+  EXPECT_EQ(cb.data(), z.data());
+  // ArrayView<uint8_t> w = cb;  // Compile error, because can't drop const.
+}
+
+TEST(ArrayViewTest, TestSwapVariable) {
+  const char arr[] = "Arrr!";
+  const char aye[] = "Aye, Cap'n!";
+  ArrayView<const char> x(arr);
+  EXPECT_EQ(6u, x.size());
+  EXPECT_EQ(arr, x.data());
+  ArrayView<const char> y(aye);
+  EXPECT_EQ(12u, y.size());
+  EXPECT_EQ(aye, y.data());
+  using std::swap;
+  swap(x, y);
+  EXPECT_EQ(12u, x.size());
+  EXPECT_EQ(aye, x.data());
+  EXPECT_EQ(6u, y.size());
+  EXPECT_EQ(arr, y.data());
+  // ArrayView<char> z;
+  // swap(x, z);  // Compile error, because can't drop const.
+}
+
+TEST(FixArrayViewTest, TestSwapFixed) {
+  const char arr[] = "Arr!";
+  char aye[] = "Aye!";
+  ArrayView<const char, 5> x(arr);
+  EXPECT_EQ(arr, x.data());
+  ArrayView<const char, 5> y(aye);
+  EXPECT_EQ(aye, y.data());
+  using std::swap;
+  swap(x, y);
+  EXPECT_EQ(aye, x.data());
+  EXPECT_EQ(arr, y.data());
+  // ArrayView<char, 5> z(aye);
+  // swap(x, z);  // Compile error, because can't drop const.
+  // ArrayView<const char, 4> w(aye, 4);
+  // swap(x, w);  // Compile error, because different sizes.
+}
+
+TEST(ArrayViewTest, TestIndexing) {
+  char arr[] = "abcdefg";
+  ArrayView<char> x(arr);
+  const ArrayView<char> y(arr);
+  ArrayView<const char, 8> z(arr);
+  EXPECT_EQ(8u, x.size());
+  EXPECT_EQ(8u, y.size());
+  EXPECT_EQ(8u, z.size());
+  EXPECT_EQ('b', x[1]);
+  EXPECT_EQ('c', y[2]);
+  EXPECT_EQ('d', z[3]);
+  x[3] = 'X';
+  y[2] = 'Y';
+  // z[1] = 'Z';  // Compile error, because z's element type is const char.
+  EXPECT_EQ('b', x[1]);
+  EXPECT_EQ('Y', y[2]);
+  EXPECT_EQ('X', z[3]);
+#if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
+  EXPECT_DEATH(z[8], "");  // DCHECK error (index out of bounds).
+#endif
+}
+
+TEST(ArrayViewTest, TestIterationEmpty) {
+  // Variable-size.
+  ArrayView<std::vector<std::vector<std::vector<std::string>>>> av;
+  EXPECT_EQ(av.begin(), av.end());
+  EXPECT_EQ(av.cbegin(), av.cend());
+  for (auto& e : av) {
+    EXPECT_TRUE(false);
+    EXPECT_EQ(42u, e.size());  // Dummy use of e to prevent unused var warning.
+  }
+
+  // Fixed-size.
+  ArrayView<std::vector<std::vector<std::vector<std::string>>>, 0> af;
+  EXPECT_EQ(af.begin(), af.end());
+  EXPECT_EQ(af.cbegin(), af.cend());
+  for (auto& e : af) {
+    EXPECT_TRUE(false);
+    EXPECT_EQ(42u, e.size());  // Dummy use of e to prevent unused var warning.
+  }
+}
+
+TEST(ArrayViewTest, TestIterationVariable) {
+  char arr[] = "Arrr!";
+  ArrayView<char> av(arr);
+  EXPECT_EQ('A', *av.begin());
+  EXPECT_EQ('A', *av.cbegin());
+  EXPECT_EQ('\0', *(av.end() - 1));
+  EXPECT_EQ('\0', *(av.cend() - 1));
+  char i = 0;
+  for (auto& e : av) {
+    EXPECT_EQ(arr + i, &e);
+    e = 's' + i;
+    ++i;
+  }
+  i = 0;
+  for (auto& e : ArrayView<const char>(av)) {
+    EXPECT_EQ(arr + i, &e);
+    // e = 'q' + i;  // Compile error, because e is a const char&.
+    ++i;
+  }
+}
+
+TEST(ArrayViewTest, TestIterationFixed) {
+  char arr[] = "Arrr!";
+  ArrayView<char, 6> av(arr);
+  EXPECT_EQ('A', *av.begin());
+  EXPECT_EQ('A', *av.cbegin());
+  EXPECT_EQ('\0', *(av.end() - 1));
+  EXPECT_EQ('\0', *(av.cend() - 1));
+  char i = 0;
+  for (auto& e : av) {
+    EXPECT_EQ(arr + i, &e);
+    e = 's' + i;
+    ++i;
+  }
+  i = 0;
+  for (auto& e : ArrayView<const char, 6>(av)) {
+    EXPECT_EQ(arr + i, &e);
+    // e = 'q' + i;  // Compile error, because e is a const char&.
+    ++i;
+  }
+}
+
+TEST(ArrayViewTest, TestEmpty) {
+  EXPECT_TRUE(ArrayView<int>().empty());
+  const int a[] = {1, 2, 3};
+  EXPECT_FALSE(ArrayView<const int>(a).empty());
+
+  static_assert(ArrayView<int, 0>::empty(), "");
+  static_assert(!ArrayView<int, 3>::empty(), "");
+}
+
+TEST(ArrayViewTest, TestCompare) {
+  int a[] = {1, 2, 3};
+  int b[] = {1, 2, 3};
+
+  EXPECT_EQ(ArrayView<int>(a), ArrayView<int>(a));
+  EXPECT_EQ((ArrayView<int, 3>(a)), (ArrayView<int, 3>(a)));
+  EXPECT_EQ(ArrayView<int>(a), (ArrayView<int, 3>(a)));
+  EXPECT_EQ(ArrayView<int>(), ArrayView<int>());
+  EXPECT_EQ(ArrayView<int>(), ArrayView<int>(a, 0));
+  EXPECT_EQ(ArrayView<int>(a, 0), ArrayView<int>(b, 0));
+  EXPECT_EQ((ArrayView<int, 0>(a, 0)), ArrayView<int>());
+
+  EXPECT_NE(ArrayView<int>(a), ArrayView<int>(b));
+  EXPECT_NE((ArrayView<int, 3>(a)), (ArrayView<int, 3>(b)));
+  EXPECT_NE((ArrayView<int, 3>(a)), ArrayView<int>(b));
+  EXPECT_NE(ArrayView<int>(a), ArrayView<int>());
+  EXPECT_NE(ArrayView<int>(a), ArrayView<int>(a, 2));
+  EXPECT_NE((ArrayView<int, 3>(a)), (ArrayView<int, 2>(a, 2)));
+}
+
+TEST(ArrayViewTest, TestSubViewVariable) {
+  int a[] = {1, 2, 3};
+  ArrayView<int> av(a);
+
+  EXPECT_EQ(av.subview(0), av);
+
+  EXPECT_THAT(av.subview(1), ElementsAre(2, 3));
+  EXPECT_THAT(av.subview(2), ElementsAre(3));
+  EXPECT_THAT(av.subview(3), IsEmpty());
+  EXPECT_THAT(av.subview(4), IsEmpty());
+
+  EXPECT_THAT(av.subview(1, 0), IsEmpty());
+  EXPECT_THAT(av.subview(1, 1), ElementsAre(2));
+  EXPECT_THAT(av.subview(1, 2), ElementsAre(2, 3));
+  EXPECT_THAT(av.subview(1, 3), ElementsAre(2, 3));
+}
+
+TEST(ArrayViewTest, TestSubViewFixed) {
+  int a[] = {1, 2, 3};
+  ArrayView<int, 3> av(a);
+
+  EXPECT_EQ(av.subview(0), av);
+
+  EXPECT_THAT(av.subview(1), ElementsAre(2, 3));
+  EXPECT_THAT(av.subview(2), ElementsAre(3));
+  EXPECT_THAT(av.subview(3), IsEmpty());
+  EXPECT_THAT(av.subview(4), IsEmpty());
+
+  EXPECT_THAT(av.subview(1, 0), IsEmpty());
+  EXPECT_THAT(av.subview(1, 1), ElementsAre(2));
+  EXPECT_THAT(av.subview(1, 2), ElementsAre(2, 3));
+  EXPECT_THAT(av.subview(1, 3), ElementsAre(2, 3));
+}
+
+}  // namespace rtc

webrtc/rtc_base/arraysize.h

@@ -0,0 +1,31 @@
+/*
+ *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_ARRAYSIZE_H_
+#define WEBRTC_RTC_BASE_ARRAYSIZE_H_
+
+#include <stddef.h>
+
+// This file defines the arraysize() macro and is derived from Chromium's
+// base/macros.h.
+
+// The arraysize(arr) macro returns the # of elements in an array arr.
+// The expression is a compile-time constant, and therefore can be
+// used in defining new arrays, for example.  If you use arraysize on
+// a pointer by mistake, you will get a compile-time error.
+
+// This template function declaration is used in defining arraysize.
+// Note that the function doesn't need an implementation, as we only
+// use its type.
+template <typename T, size_t N> char (&ArraySizeHelper(T (&array)[N]))[N];
+
+#define arraysize(array) (sizeof(ArraySizeHelper(array)))
+
+#endif  // WEBRTC_RTC_BASE_ARRAYSIZE_H_

webrtc/rtc_base/asyncinvoker-inl.h

@@ -0,0 +1,56 @@
+/*
+ *  Copyright 2014 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_ASYNCINVOKER_INL_H_
+#define WEBRTC_RTC_BASE_ASYNCINVOKER_INL_H_
+
+#include "webrtc/base/atomicops.h"
+#include "webrtc/base/bind.h"
+#include "webrtc/base/criticalsection.h"
+#include "webrtc/base/messagehandler.h"
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/thread.h"
+#include "webrtc/base/thread_annotations.h"
+
+namespace rtc {
+
+class AsyncInvoker;
+
+// Helper class for AsyncInvoker. Runs a task and triggers a callback
+// on the calling thread if necessary.
+class AsyncClosure {
+ public:
+  explicit AsyncClosure(AsyncInvoker* invoker) : invoker_(invoker) {}
+  virtual ~AsyncClosure();
+  // Runs the asynchronous task, and triggers a callback to the calling
+  // thread if needed. Should be called from the target thread.
+  virtual void Execute() = 0;
+
+ protected:
+  AsyncInvoker* invoker_;
+};
+
+// Simple closure that doesn't trigger a callback for the calling thread.
+template <class FunctorT>
+class FireAndForgetAsyncClosure : public AsyncClosure {
+ public:
+  explicit FireAndForgetAsyncClosure(AsyncInvoker* invoker,
+                                     const FunctorT& functor)
+      : AsyncClosure(invoker), functor_(functor) {}
+  virtual void Execute() {
+    functor_();
+  }
+ private:
+  FunctorT functor_;
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_ASYNCINVOKER_INL_H_

webrtc/rtc_base/asyncinvoker.cc

@@ -0,0 +1,119 @@
+/*
+ *  Copyright 2014 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/asyncinvoker.h"
+
+#include "webrtc/base/atomicops.h"
+#include "webrtc/base/checks.h"
+#include "webrtc/base/logging.h"
+
+namespace rtc {
+
+AsyncInvoker::AsyncInvoker() : invocation_complete_(false, false) {}
+
+AsyncInvoker::~AsyncInvoker() {
+  destroying_ = true;
+  // Messages for this need to be cleared *before* our destructor is complete.
+  MessageQueueManager::Clear(this);
+  // And we need to wait for any invocations that are still in progress on
+  // other threads.
+  while (AtomicOps::AcquireLoad(&pending_invocations_)) {
+    // If the destructor was called while AsyncInvoke was being called by
+    // another thread, WITHIN an AsyncInvoked functor, it may do another
+    // Thread::Post even after we called MessageQueueManager::Clear(this). So
+    // we need to keep calling Clear to discard these posts.
+    MessageQueueManager::Clear(this);
+    invocation_complete_.Wait(Event::kForever);
+  }
+}
+
+void AsyncInvoker::OnMessage(Message* msg) {
+  // Get the AsyncClosure shared ptr from this message's data.
+  ScopedMessageData<AsyncClosure>* data =
+      static_cast<ScopedMessageData<AsyncClosure>*>(msg->pdata);
+  // Execute the closure and trigger the return message if needed.
+  data->inner_data().Execute();
+  delete data;
+}
+
+void AsyncInvoker::Flush(Thread* thread, uint32_t id /*= MQID_ANY*/) {
+  if (destroying_) return;
+
+  // Run this on |thread| to reduce the number of context switches.
+  if (Thread::Current() != thread) {
+    thread->Invoke<void>(RTC_FROM_HERE,
+                         Bind(&AsyncInvoker::Flush, this, thread, id));
+    return;
+  }
+
+  MessageList removed;
+  thread->Clear(this, id, &removed);
+  for (MessageList::iterator it = removed.begin(); it != removed.end(); ++it) {
+    // This message was pending on this thread, so run it now.
+    thread->Send(it->posted_from, it->phandler, it->message_id, it->pdata);
+  }
+}
+
+void AsyncInvoker::DoInvoke(const Location& posted_from,
+                            Thread* thread,
+                            std::unique_ptr<AsyncClosure> closure,
+                            uint32_t id) {
+  if (destroying_) {
+    LOG(LS_WARNING) << "Tried to invoke while destroying the invoker.";
+    return;
+  }
+  AtomicOps::Increment(&pending_invocations_);
+  thread->Post(posted_from, this, id,
+               new ScopedMessageData<AsyncClosure>(std::move(closure)));
+}
+
+void AsyncInvoker::DoInvokeDelayed(const Location& posted_from,
+                                   Thread* thread,
+                                   std::unique_ptr<AsyncClosure> closure,
+                                   uint32_t delay_ms,
+                                   uint32_t id) {
+  if (destroying_) {
+    LOG(LS_WARNING) << "Tried to invoke while destroying the invoker.";
+    return;
+  }
+  AtomicOps::Increment(&pending_invocations_);
+  thread->PostDelayed(posted_from, delay_ms, this, id,
+                      new ScopedMessageData<AsyncClosure>(std::move(closure)));
+}
+
+GuardedAsyncInvoker::GuardedAsyncInvoker() : thread_(Thread::Current()) {
+  thread_->SignalQueueDestroyed.connect(this,
+                                        &GuardedAsyncInvoker::ThreadDestroyed);
+}
+
+GuardedAsyncInvoker::~GuardedAsyncInvoker() {
+}
+
+bool GuardedAsyncInvoker::Flush(uint32_t id) {
+  rtc::CritScope cs(&crit_);
+  if (thread_ == nullptr)
+    return false;
+  invoker_.Flush(thread_, id);
+  return true;
+}
+
+void GuardedAsyncInvoker::ThreadDestroyed() {
+  rtc::CritScope cs(&crit_);
+  // We should never get more than one notification about the thread dying.
+  RTC_DCHECK(thread_ != nullptr);
+  thread_ = nullptr;
+}
+
+AsyncClosure::~AsyncClosure() {
+  AtomicOps::Decrement(&invoker_->pending_invocations_);
+  invoker_->invocation_complete_.Set();
+}
+
+}  // namespace rtc

webrtc/rtc_base/asyncinvoker.h

@@ -0,0 +1,221 @@
+/*
+ *  Copyright 2014 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_ASYNCINVOKER_H_
+#define WEBRTC_RTC_BASE_ASYNCINVOKER_H_
+
+#include <memory>
+#include <utility>
+
+#include "webrtc/base/asyncinvoker-inl.h"
+#include "webrtc/base/bind.h"
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/base/event.h"
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/thread.h"
+
+namespace rtc {
+
+// Invokes function objects (aka functors) asynchronously on a Thread, and
+// owns the lifetime of calls (ie, when this object is destroyed, calls in
+// flight are cancelled). AsyncInvoker can optionally execute a user-specified
+// function when the asynchronous call is complete, or operates in
+// fire-and-forget mode otherwise.
+//
+// AsyncInvoker does not own the thread it calls functors on.
+//
+// A note about async calls and object lifetimes: users should
+// be mindful of object lifetimes when calling functions asynchronously and
+// ensure objects used by the function _cannot_ be deleted between the
+// invocation and execution of the functor. AsyncInvoker is designed to
+// help: any calls in flight will be cancelled when the AsyncInvoker used to
+// make the call is destructed, and any calls executing will be allowed to
+// complete before AsyncInvoker destructs.
+//
+// The easiest way to ensure lifetimes are handled correctly is to create a
+// class that owns the Thread and AsyncInvoker objects, and then call its
+// methods asynchronously as needed.
+//
+// Example:
+//   class MyClass {
+//    public:
+//     void FireAsyncTaskWithResult(Thread* thread, int x) {
+//       // Specify a callback to get the result upon completion.
+//       invoker_.AsyncInvoke<int>(RTC_FROM_HERE,
+//           thread, Bind(&MyClass::AsyncTaskWithResult, this, x),
+//           &MyClass::OnTaskComplete, this);
+//     }
+//     void FireAnotherAsyncTask(Thread* thread) {
+//       // No callback specified means fire-and-forget.
+//       invoker_.AsyncInvoke<void>(RTC_FROM_HERE,
+//           thread, Bind(&MyClass::AnotherAsyncTask, this));
+//
+//    private:
+//     int AsyncTaskWithResult(int x) {
+//       // Some long running process...
+//       return x * x;
+//     }
+//     void AnotherAsyncTask() {
+//       // Some other long running process...
+//     }
+//     void OnTaskComplete(int result) { result_ = result; }
+//
+//     AsyncInvoker invoker_;
+//     int result_;
+//   };
+class AsyncInvoker : public MessageHandler {
+ public:
+  AsyncInvoker();
+  ~AsyncInvoker() override;
+
+  // Call |functor| asynchronously on |thread|, with no callback upon
+  // completion. Returns immediately.
+  template <class ReturnT, class FunctorT>
+  void AsyncInvoke(const Location& posted_from,
+                   Thread* thread,
+                   const FunctorT& functor,
+                   uint32_t id = 0) {
+    std::unique_ptr<AsyncClosure> closure(
+        new FireAndForgetAsyncClosure<FunctorT>(this, functor));
+    DoInvoke(posted_from, thread, std::move(closure), id);
+  }
+
+  // Call |functor| asynchronously on |thread| with |delay_ms|, with no callback
+  // upon completion. Returns immediately.
+  template <class ReturnT, class FunctorT>
+  void AsyncInvokeDelayed(const Location& posted_from,
+                          Thread* thread,
+                          const FunctorT& functor,
+                          uint32_t delay_ms,
+                          uint32_t id = 0) {
+    std::unique_ptr<AsyncClosure> closure(
+        new FireAndForgetAsyncClosure<FunctorT>(this, functor));
+    DoInvokeDelayed(posted_from, thread, std::move(closure), delay_ms, id);
+  }
+
+  // Synchronously execute on |thread| all outstanding calls we own
+  // that are pending on |thread|, and wait for calls to complete
+  // before returning. Optionally filter by message id.
+  // The destructor will not wait for outstanding calls, so if that
+  // behavior is desired, call Flush() before destroying this object.
+  void Flush(Thread* thread, uint32_t id = MQID_ANY);
+
+ private:
+  void OnMessage(Message* msg) override;
+  void DoInvoke(const Location& posted_from,
+                Thread* thread,
+                std::unique_ptr<AsyncClosure> closure,
+                uint32_t id);
+  void DoInvokeDelayed(const Location& posted_from,
+                       Thread* thread,
+                       std::unique_ptr<AsyncClosure> closure,
+                       uint32_t delay_ms,
+                       uint32_t id);
+  volatile int pending_invocations_ = 0;
+  Event invocation_complete_;
+  bool destroying_ = false;
+  friend class AsyncClosure;
+
+  RTC_DISALLOW_COPY_AND_ASSIGN(AsyncInvoker);
+};
+
+// Similar to AsyncInvoker, but guards against the Thread being destroyed while
+// there are outstanding dangling pointers to it. It will connect to the current
+// thread in the constructor, and will get notified when that thread is
+// destroyed. After GuardedAsyncInvoker is constructed, it can be used from
+// other threads to post functors to the thread it was constructed on. If that
+// thread dies, any further calls to AsyncInvoke() will be safely ignored.
+class GuardedAsyncInvoker : public sigslot::has_slots<> {
+ public:
+  GuardedAsyncInvoker();
+  ~GuardedAsyncInvoker() override;
+
+  // Synchronously execute all outstanding calls we own, and wait for calls to
+  // complete before returning. Optionally filter by message id. The destructor
+  // will not wait for outstanding calls, so if that behavior is desired, call
+  // Flush() first. Returns false if the thread has died.
+  bool Flush(uint32_t id = MQID_ANY);
+
+  // Call |functor| asynchronously with no callback upon completion. Returns
+  // immediately. Returns false if the thread has died.
+  template <class ReturnT, class FunctorT>
+  bool AsyncInvoke(const Location& posted_from,
+                   const FunctorT& functor,
+                   uint32_t id = 0) {
+    rtc::CritScope cs(&crit_);
+    if (thread_ == nullptr)
+      return false;
+    invoker_.AsyncInvoke<ReturnT, FunctorT>(posted_from, thread_, functor, id);
+    return true;
+  }
+
+  // Call |functor| asynchronously with |delay_ms|, with no callback upon
+  // completion. Returns immediately. Returns false if the thread has died.
+  template <class ReturnT, class FunctorT>
+  bool AsyncInvokeDelayed(const Location& posted_from,
+                          const FunctorT& functor,
+                          uint32_t delay_ms,
+                          uint32_t id = 0) {
+    rtc::CritScope cs(&crit_);
+    if (thread_ == nullptr)
+      return false;
+    invoker_.AsyncInvokeDelayed<ReturnT, FunctorT>(posted_from, thread_,
+                                                   functor, delay_ms, id);
+    return true;
+  }
+
+  // Call |functor| asynchronously, calling |callback| when done. Returns false
+  // if the thread has died.
+  template <class ReturnT, class FunctorT, class HostT>
+  bool AsyncInvoke(const Location& posted_from,
+                   const Location& callback_posted_from,
+                   const FunctorT& functor,
+                   void (HostT::*callback)(ReturnT),
+                   HostT* callback_host,
+                   uint32_t id = 0) {
+    rtc::CritScope cs(&crit_);
+    if (thread_ == nullptr)
+      return false;
+    invoker_.AsyncInvoke<ReturnT, FunctorT, HostT>(
+        posted_from, callback_posted_from, thread_, functor, callback,
+        callback_host, id);
+    return true;
+  }
+
+  // Call |functor| asynchronously calling |callback| when done. Overloaded for
+  // void return. Returns false if the thread has died.
+  template <class ReturnT, class FunctorT, class HostT>
+  bool AsyncInvoke(const Location& posted_from,
+                   const Location& callback_posted_from,
+                   const FunctorT& functor,
+                   void (HostT::*callback)(),
+                   HostT* callback_host,
+                   uint32_t id = 0) {
+    rtc::CritScope cs(&crit_);
+    if (thread_ == nullptr)
+      return false;
+    invoker_.AsyncInvoke<ReturnT, FunctorT, HostT>(
+        posted_from, callback_posted_from, thread_, functor, callback,
+        callback_host, id);
+    return true;
+  }
+
+ private:
+  // Callback when |thread_| is destroyed.
+  void ThreadDestroyed();
+
+  CriticalSection crit_;
+  Thread* thread_ GUARDED_BY(crit_);
+  AsyncInvoker invoker_ GUARDED_BY(crit_);
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_ASYNCINVOKER_H_

webrtc/rtc_base/asyncpacketsocket.cc

@@ -0,0 +1,29 @@
+/*
+ *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/asyncpacketsocket.h"
+
+namespace rtc {
+
+PacketTimeUpdateParams::PacketTimeUpdateParams()
+    : rtp_sendtime_extension_id(-1),
+      srtp_auth_tag_len(-1),
+      srtp_packet_index(-1) {
+}
+
+PacketTimeUpdateParams::~PacketTimeUpdateParams() = default;
+
+AsyncPacketSocket::AsyncPacketSocket() {
+}
+
+AsyncPacketSocket::~AsyncPacketSocket() {
+}
+
+};  // namespace rtc

webrtc/rtc_base/asyncpacketsocket.h

@@ -0,0 +1,143 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_ASYNCPACKETSOCKET_H_
+#define WEBRTC_RTC_BASE_ASYNCPACKETSOCKET_H_
+
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/base/dscp.h"
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/socket.h"
+#include "webrtc/base/timeutils.h"
+
+namespace rtc {
+
+// This structure holds the info needed to update the packet send time header
+// extension, including the information needed to update the authentication tag
+// after changing the value.
+struct PacketTimeUpdateParams {
+  PacketTimeUpdateParams();
+  ~PacketTimeUpdateParams();
+
+  int rtp_sendtime_extension_id;    // extension header id present in packet.
+  std::vector<char> srtp_auth_key;  // Authentication key.
+  int srtp_auth_tag_len;            // Authentication tag length.
+  int64_t srtp_packet_index;        // Required for Rtp Packet authentication.
+};
+
+// This structure holds meta information for the packet which is about to send
+// over network.
+struct PacketOptions {
+  PacketOptions() : dscp(DSCP_NO_CHANGE), packet_id(-1) {}
+  explicit PacketOptions(DiffServCodePoint dscp) : dscp(dscp), packet_id(-1) {}
+
+  DiffServCodePoint dscp;
+  int packet_id;  // 16 bits, -1 represents "not set".
+  PacketTimeUpdateParams packet_time_params;
+};
+
+// This structure will have the information about when packet is actually
+// received by socket.
+struct PacketTime {
+  PacketTime() : timestamp(-1), not_before(-1) {}
+  PacketTime(int64_t timestamp, int64_t not_before)
+      : timestamp(timestamp), not_before(not_before) {}
+
+  int64_t timestamp;   // Receive time after socket delivers the data.
+
+  // Earliest possible time the data could have arrived, indicating the
+  // potential error in the |timestamp| value, in case the system, is busy. For
+  // example, the time of the last select() call.
+  // If unknown, this value will be set to zero.
+  int64_t not_before;
+};
+
+inline PacketTime CreatePacketTime(int64_t not_before) {
+  return PacketTime(TimeMicros(), not_before);
+}
+
+// Provides the ability to receive packets asynchronously. Sends are not
+// buffered since it is acceptable to drop packets under high load.
+class AsyncPacketSocket : public sigslot::has_slots<> {
+ public:
+  enum State {
+    STATE_CLOSED,
+    STATE_BINDING,
+    STATE_BOUND,
+    STATE_CONNECTING,
+    STATE_CONNECTED
+  };
+
+  AsyncPacketSocket();
+  ~AsyncPacketSocket() override;
+
+  // Returns current local address. Address may be set to null if the
+  // socket is not bound yet (GetState() returns STATE_BINDING).
+  virtual SocketAddress GetLocalAddress() const = 0;
+
+  // Returns remote address. Returns zeroes if this is not a client TCP socket.
+  virtual SocketAddress GetRemoteAddress() const = 0;
+
+  // Send a packet.
+  virtual int Send(const void *pv, size_t cb, const PacketOptions& options) = 0;
+  virtual int SendTo(const void *pv, size_t cb, const SocketAddress& addr,
+                     const PacketOptions& options) = 0;
+
+  // Close the socket.
+  virtual int Close() = 0;
+
+  // Returns current state of the socket.
+  virtual State GetState() const = 0;
+
+  // Get/set options.
+  virtual int GetOption(Socket::Option opt, int* value) = 0;
+  virtual int SetOption(Socket::Option opt, int value) = 0;
+
+  // Get/Set current error.
+  // TODO: Remove SetError().
+  virtual int GetError() const = 0;
+  virtual void SetError(int error) = 0;
+
+  // Emitted each time a packet is read. Used only for UDP and
+  // connected TCP sockets.
+  sigslot::signal5<AsyncPacketSocket*, const char*, size_t,
+                   const SocketAddress&,
+                   const PacketTime&> SignalReadPacket;
+
+  // Emitted each time a packet is sent.
+  sigslot::signal2<AsyncPacketSocket*, const SentPacket&> SignalSentPacket;
+
+  // Emitted when the socket is currently able to send.
+  sigslot::signal1<AsyncPacketSocket*> SignalReadyToSend;
+
+  // Emitted after address for the socket is allocated, i.e. binding
+  // is finished. State of the socket is changed from BINDING to BOUND
+  // (for UDP and server TCP sockets) or CONNECTING (for client TCP
+  // sockets).
+  sigslot::signal2<AsyncPacketSocket*, const SocketAddress&> SignalAddressReady;
+
+  // Emitted for client TCP sockets when state is changed from
+  // CONNECTING to CONNECTED.
+  sigslot::signal1<AsyncPacketSocket*> SignalConnect;
+
+  // Emitted for client TCP sockets when state is changed from
+  // CONNECTED to CLOSED.
+  sigslot::signal2<AsyncPacketSocket*, int> SignalClose;
+
+  // Used only for listening TCP sockets.
+  sigslot::signal2<AsyncPacketSocket*, AsyncPacketSocket*> SignalNewConnection;
+
+ private:
+  RTC_DISALLOW_COPY_AND_ASSIGN(AsyncPacketSocket);
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_ASYNCPACKETSOCKET_H_

webrtc/rtc_base/asyncresolverinterface.cc

@@ -0,0 +1,20 @@
+/*
+ *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/asyncresolverinterface.h"
+
+namespace rtc {
+
+AsyncResolverInterface::AsyncResolverInterface() {
+}
+
+AsyncResolverInterface::~AsyncResolverInterface() = default;
+
+};  // namespace rtc

webrtc/rtc_base/asyncresolverinterface.h

@@ -0,0 +1,47 @@
+/*
+ *  Copyright 2013 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_ASYNCRESOLVERINTERFACE_H_
+#define WEBRTC_RTC_BASE_ASYNCRESOLVERINTERFACE_H_
+
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/socketaddress.h"
+
+namespace rtc {
+
+// This interface defines the methods to resolve the address asynchronously.
+class AsyncResolverInterface {
+ public:
+  AsyncResolverInterface();
+  virtual ~AsyncResolverInterface();
+
+  // Start address resolve process.
+  virtual void Start(const SocketAddress& addr) = 0;
+  // Returns top most resolved address of |family|
+  virtual bool GetResolvedAddress(int family, SocketAddress* addr) const = 0;
+  // Returns error from resolver.
+  virtual int GetError() const = 0;
+  // Delete the resolver.
+  virtual void Destroy(bool wait) = 0;
+  // Returns top most resolved IPv4 address if address is resolved successfully.
+  // Otherwise returns address set in SetAddress.
+  SocketAddress address() const {
+    SocketAddress addr;
+    GetResolvedAddress(AF_INET, &addr);
+    return addr;
+  }
+
+  // This signal is fired when address resolve process is completed.
+  sigslot::signal1<AsyncResolverInterface*> SignalDone;
+};
+
+}  // namespace rtc
+
+#endif

webrtc/rtc_base/asyncsocket.cc

@@ -0,0 +1,127 @@
+/*
+ *  Copyright 2010 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/asyncsocket.h"
+#include "webrtc/base/checks.h"
+
+namespace rtc {
+
+AsyncSocket::AsyncSocket() {
+}
+
+AsyncSocket::~AsyncSocket() {
+}
+
+AsyncSocketAdapter::AsyncSocketAdapter(AsyncSocket* socket) : socket_(nullptr) {
+  Attach(socket);
+}
+
+AsyncSocketAdapter::~AsyncSocketAdapter() {
+  delete socket_;
+}
+
+void AsyncSocketAdapter::Attach(AsyncSocket* socket) {
+  RTC_DCHECK(!socket_);
+  socket_ = socket;
+  if (socket_) {
+    socket_->SignalConnectEvent.connect(this,
+                                        &AsyncSocketAdapter::OnConnectEvent);
+    socket_->SignalReadEvent.connect(this, &AsyncSocketAdapter::OnReadEvent);
+    socket_->SignalWriteEvent.connect(this, &AsyncSocketAdapter::OnWriteEvent);
+    socket_->SignalCloseEvent.connect(this, &AsyncSocketAdapter::OnCloseEvent);
+  }
+}
+
+SocketAddress AsyncSocketAdapter::GetLocalAddress() const {
+  return socket_->GetLocalAddress();
+}
+
+SocketAddress AsyncSocketAdapter::GetRemoteAddress() const {
+  return socket_->GetRemoteAddress();
+}
+
+int AsyncSocketAdapter::Bind(const SocketAddress& addr) {
+  return socket_->Bind(addr);
+}
+
+int AsyncSocketAdapter::Connect(const SocketAddress& addr) {
+  return socket_->Connect(addr);
+}
+
+int AsyncSocketAdapter::Send(const void* pv, size_t cb) {
+  return socket_->Send(pv, cb);
+}
+
+int AsyncSocketAdapter::SendTo(const void* pv,
+                               size_t cb,
+                               const SocketAddress& addr) {
+  return socket_->SendTo(pv, cb, addr);
+}
+
+int AsyncSocketAdapter::Recv(void* pv, size_t cb, int64_t* timestamp) {
+  return socket_->Recv(pv, cb, timestamp);
+}
+
+int AsyncSocketAdapter::RecvFrom(void* pv,
+                                 size_t cb,
+                                 SocketAddress* paddr,
+                                 int64_t* timestamp) {
+  return socket_->RecvFrom(pv, cb, paddr, timestamp);
+}
+
+int AsyncSocketAdapter::Listen(int backlog) {
+  return socket_->Listen(backlog);
+}
+
+AsyncSocket* AsyncSocketAdapter::Accept(SocketAddress* paddr) {
+  return socket_->Accept(paddr);
+}
+
+int AsyncSocketAdapter::Close() {
+  return socket_->Close();
+}
+
+int AsyncSocketAdapter::GetError() const {
+  return socket_->GetError();
+}
+
+void AsyncSocketAdapter::SetError(int error) {
+  return socket_->SetError(error);
+}
+
+AsyncSocket::ConnState AsyncSocketAdapter::GetState() const {
+  return socket_->GetState();
+}
+
+int AsyncSocketAdapter::GetOption(Option opt, int* value) {
+  return socket_->GetOption(opt, value);
+}
+
+int AsyncSocketAdapter::SetOption(Option opt, int value) {
+  return socket_->SetOption(opt, value);
+}
+
+void AsyncSocketAdapter::OnConnectEvent(AsyncSocket* socket) {
+  SignalConnectEvent(this);
+}
+
+void AsyncSocketAdapter::OnReadEvent(AsyncSocket* socket) {
+  SignalReadEvent(this);
+}
+
+void AsyncSocketAdapter::OnWriteEvent(AsyncSocket* socket) {
+  SignalWriteEvent(this);
+}
+
+void AsyncSocketAdapter::OnCloseEvent(AsyncSocket* socket, int err) {
+  SignalCloseEvent(this, err);
+}
+
+}  // namespace rtc

webrtc/rtc_base/asyncsocket.h

@@ -0,0 +1,83 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_ASYNCSOCKET_H_
+#define WEBRTC_RTC_BASE_ASYNCSOCKET_H_
+
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/socket.h"
+
+namespace rtc {
+
+// TODO: Remove Socket and rename AsyncSocket to Socket.
+
+// Provides the ability to perform socket I/O asynchronously.
+class AsyncSocket : public Socket {
+ public:
+  AsyncSocket();
+  ~AsyncSocket() override;
+
+  AsyncSocket* Accept(SocketAddress* paddr) override = 0;
+
+  // SignalReadEvent and SignalWriteEvent use multi_threaded_local to allow
+  // access concurrently from different thread.
+  // For example SignalReadEvent::connect will be called in AsyncUDPSocket ctor
+  // but at the same time the SocketDispatcher maybe signaling the read event.
+  // ready to read
+  sigslot::signal1<AsyncSocket*,
+                   sigslot::multi_threaded_local> SignalReadEvent;
+  // ready to write
+  sigslot::signal1<AsyncSocket*,
+                   sigslot::multi_threaded_local> SignalWriteEvent;
+  sigslot::signal1<AsyncSocket*> SignalConnectEvent;     // connected
+  sigslot::signal2<AsyncSocket*, int> SignalCloseEvent;  // closed
+};
+
+class AsyncSocketAdapter : public AsyncSocket, public sigslot::has_slots<> {
+ public:
+  // The adapted socket may explicitly be null, and later assigned using Attach.
+  // However, subclasses which support detached mode must override any methods
+  // that will be called during the detached period (usually GetState()), to
+  // avoid dereferencing a null pointer.
+  explicit AsyncSocketAdapter(AsyncSocket* socket);
+  ~AsyncSocketAdapter() override;
+  void Attach(AsyncSocket* socket);
+  SocketAddress GetLocalAddress() const override;
+  SocketAddress GetRemoteAddress() const override;
+  int Bind(const SocketAddress& addr) override;
+  int Connect(const SocketAddress& addr) override;
+  int Send(const void* pv, size_t cb) override;
+  int SendTo(const void* pv, size_t cb, const SocketAddress& addr) override;
+  int Recv(void* pv, size_t cb, int64_t* timestamp) override;
+  int RecvFrom(void* pv,
+               size_t cb,
+               SocketAddress* paddr,
+               int64_t* timestamp) override;
+  int Listen(int backlog) override;
+  AsyncSocket* Accept(SocketAddress* paddr) override;
+  int Close() override;
+  int GetError() const override;
+  void SetError(int error) override;
+  ConnState GetState() const override;
+  int GetOption(Option opt, int* value) override;
+  int SetOption(Option opt, int value) override;
+
+ protected:
+  virtual void OnConnectEvent(AsyncSocket* socket);
+  virtual void OnReadEvent(AsyncSocket* socket);
+  virtual void OnWriteEvent(AsyncSocket* socket);
+  virtual void OnCloseEvent(AsyncSocket* socket, int err);
+
+  AsyncSocket* socket_;
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_ASYNCSOCKET_H_

webrtc/rtc_base/asynctcpsocket.cc

@@ -0,0 +1,331 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/asynctcpsocket.h"
+
+#include <string.h>
+
+#include <algorithm>
+#include <memory>
+
+#include "webrtc/base/byteorder.h"
+#include "webrtc/base/checks.h"
+#include "webrtc/base/logging.h"
+
+#if defined(WEBRTC_POSIX)
+#include <errno.h>
+#endif  // WEBRTC_POSIX
+
+namespace rtc {
+
+static const size_t kMaxPacketSize = 64 * 1024;
+
+typedef uint16_t PacketLength;
+static const size_t kPacketLenSize = sizeof(PacketLength);
+
+static const size_t kBufSize = kMaxPacketSize + kPacketLenSize;
+
+// The input buffer will be resized so that at least kMinimumRecvSize bytes can
+// be received (but it will not grow above the maximum size passed to the
+// constructor).
+static const size_t kMinimumRecvSize = 128;
+
+static const int kListenBacklog = 5;
+
+// Binds and connects |socket|
+AsyncSocket* AsyncTCPSocketBase::ConnectSocket(
+    rtc::AsyncSocket* socket,
+    const rtc::SocketAddress& bind_address,
+    const rtc::SocketAddress& remote_address) {
+  std::unique_ptr<rtc::AsyncSocket> owned_socket(socket);
+  if (socket->Bind(bind_address) < 0) {
+    LOG(LS_ERROR) << "Bind() failed with error " << socket->GetError();
+    return nullptr;
+  }
+  if (socket->Connect(remote_address) < 0) {
+    LOG(LS_ERROR) << "Connect() failed with error " << socket->GetError();
+    return nullptr;
+  }
+  return owned_socket.release();
+}
+
+AsyncTCPSocketBase::AsyncTCPSocketBase(AsyncSocket* socket, bool listen,
+                                       size_t max_packet_size)
+    : socket_(socket),
+      listen_(listen),
+      max_insize_(max_packet_size),
+      max_outsize_(max_packet_size) {
+  if (!listen_) {
+    // Listening sockets don't send/receive data, so they don't need buffers.
+    inbuf_.EnsureCapacity(kMinimumRecvSize);
+  }
+
+  RTC_DCHECK(socket_.get() != nullptr);
+  socket_->SignalConnectEvent.connect(
+      this, &AsyncTCPSocketBase::OnConnectEvent);
+  socket_->SignalReadEvent.connect(this, &AsyncTCPSocketBase::OnReadEvent);
+  socket_->SignalWriteEvent.connect(this, &AsyncTCPSocketBase::OnWriteEvent);
+  socket_->SignalCloseEvent.connect(this, &AsyncTCPSocketBase::OnCloseEvent);
+
+  if (listen_) {
+    if (socket_->Listen(kListenBacklog) < 0) {
+      LOG(LS_ERROR) << "Listen() failed with error " << socket_->GetError();
+    }
+  }
+}
+
+AsyncTCPSocketBase::~AsyncTCPSocketBase() {}
+
+SocketAddress AsyncTCPSocketBase::GetLocalAddress() const {
+  return socket_->GetLocalAddress();
+}
+
+SocketAddress AsyncTCPSocketBase::GetRemoteAddress() const {
+  return socket_->GetRemoteAddress();
+}
+
+int AsyncTCPSocketBase::Close() {
+  return socket_->Close();
+}
+
+AsyncTCPSocket::State AsyncTCPSocketBase::GetState() const {
+  switch (socket_->GetState()) {
+    case Socket::CS_CLOSED:
+      return STATE_CLOSED;
+    case Socket::CS_CONNECTING:
+      if (listen_) {
+        return STATE_BOUND;
+      } else {
+        return STATE_CONNECTING;
+      }
+    case Socket::CS_CONNECTED:
+      return STATE_CONNECTED;
+    default:
+      RTC_NOTREACHED();
+      return STATE_CLOSED;
+  }
+}
+
+int AsyncTCPSocketBase::GetOption(Socket::Option opt, int* value) {
+  return socket_->GetOption(opt, value);
+}
+
+int AsyncTCPSocketBase::SetOption(Socket::Option opt, int value) {
+  return socket_->SetOption(opt, value);
+}
+
+int AsyncTCPSocketBase::GetError() const {
+  return socket_->GetError();
+}
+
+void AsyncTCPSocketBase::SetError(int error) {
+  return socket_->SetError(error);
+}
+
+int AsyncTCPSocketBase::SendTo(const void *pv, size_t cb,
+                               const SocketAddress& addr,
+                               const rtc::PacketOptions& options) {
+  const SocketAddress& remote_address = GetRemoteAddress();
+  if (addr == remote_address)
+    return Send(pv, cb, options);
+  // Remote address may be empty if there is a sudden network change.
+  RTC_DCHECK(remote_address.IsNil());
+  socket_->SetError(ENOTCONN);
+  return -1;
+}
+
+int AsyncTCPSocketBase::SendRaw(const void * pv, size_t cb) {
+  if (outbuf_.size() + cb > max_outsize_) {
+    socket_->SetError(EMSGSIZE);
+    return -1;
+  }
+
+  RTC_DCHECK(!listen_);
+  outbuf_.AppendData(static_cast<const uint8_t*>(pv), cb);
+
+  return FlushOutBuffer();
+}
+
+int AsyncTCPSocketBase::FlushOutBuffer() {
+  RTC_DCHECK(!listen_);
+  int res = socket_->Send(outbuf_.data(), outbuf_.size());
+  if (res <= 0) {
+    return res;
+  }
+  if (static_cast<size_t>(res) > outbuf_.size()) {
+    RTC_NOTREACHED();
+    return -1;
+  }
+  size_t new_size = outbuf_.size() - res;
+  if (new_size > 0) {
+    memmove(outbuf_.data(), outbuf_.data() + res, new_size);
+  }
+  outbuf_.SetSize(new_size);
+  return res;
+}
+
+void AsyncTCPSocketBase::AppendToOutBuffer(const void* pv, size_t cb) {
+  RTC_DCHECK(outbuf_.size() + cb <= max_outsize_);
+  RTC_DCHECK(!listen_);
+  outbuf_.AppendData(static_cast<const uint8_t*>(pv), cb);
+}
+
+void AsyncTCPSocketBase::OnConnectEvent(AsyncSocket* socket) {
+  SignalConnect(this);
+}
+
+void AsyncTCPSocketBase::OnReadEvent(AsyncSocket* socket) {
+  RTC_DCHECK(socket_.get() == socket);
+
+  if (listen_) {
+    rtc::SocketAddress address;
+    rtc::AsyncSocket* new_socket = socket->Accept(&address);
+    if (!new_socket) {
+      // TODO(stefan): Do something better like forwarding the error
+      // to the user.
+      LOG(LS_ERROR) << "TCP accept failed with error " << socket_->GetError();
+      return;
+    }
+
+    HandleIncomingConnection(new_socket);
+
+    // Prime a read event in case data is waiting.
+    new_socket->SignalReadEvent(new_socket);
+  } else {
+    size_t total_recv = 0;
+    while (true) {
+      size_t free_size = inbuf_.capacity() - inbuf_.size();
+      if (free_size < kMinimumRecvSize && inbuf_.capacity() < max_insize_) {
+        inbuf_.EnsureCapacity(std::min(max_insize_, inbuf_.capacity() * 2));
+        free_size = inbuf_.capacity() - inbuf_.size();
+      }
+
+      int len =
+          socket_->Recv(inbuf_.data() + inbuf_.size(), free_size, nullptr);
+      if (len < 0) {
+        // TODO(stefan): Do something better like forwarding the error to the
+        // user.
+        if (!socket_->IsBlocking()) {
+          LOG(LS_ERROR) << "Recv() returned error: " << socket_->GetError();
+        }
+        break;
+      }
+
+      total_recv += len;
+      inbuf_.SetSize(inbuf_.size() + len);
+      if (!len || static_cast<size_t>(len) < free_size) {
+        break;
+      }
+    }
+
+    if (!total_recv) {
+      return;
+    }
+
+    size_t size = inbuf_.size();
+    ProcessInput(inbuf_.data<char>(), &size);
+
+    if (size > inbuf_.size()) {
+      LOG(LS_ERROR) << "input buffer overflow";
+      RTC_NOTREACHED();
+      inbuf_.Clear();
+    } else {
+      inbuf_.SetSize(size);
+    }
+  }
+}
+
+void AsyncTCPSocketBase::OnWriteEvent(AsyncSocket* socket) {
+  RTC_DCHECK(socket_.get() == socket);
+
+  if (outbuf_.size() > 0) {
+    FlushOutBuffer();
+  }
+
+  if (outbuf_.size() == 0) {
+    SignalReadyToSend(this);
+  }
+}
+
+void AsyncTCPSocketBase::OnCloseEvent(AsyncSocket* socket, int error) {
+  SignalClose(this, error);
+}
+
+// AsyncTCPSocket
+// Binds and connects |socket| and creates AsyncTCPSocket for
+// it. Takes ownership of |socket|. Returns null if bind() or
+// connect() fail (|socket| is destroyed in that case).
+AsyncTCPSocket* AsyncTCPSocket::Create(
+    AsyncSocket* socket,
+    const SocketAddress& bind_address,
+    const SocketAddress& remote_address) {
+  return new AsyncTCPSocket(AsyncTCPSocketBase::ConnectSocket(
+      socket, bind_address, remote_address), false);
+}
+
+AsyncTCPSocket::AsyncTCPSocket(AsyncSocket* socket, bool listen)
+    : AsyncTCPSocketBase(socket, listen, kBufSize) {
+}
+
+int AsyncTCPSocket::Send(const void *pv, size_t cb,
+                         const rtc::PacketOptions& options) {
+  if (cb > kBufSize) {
+    SetError(EMSGSIZE);
+    return -1;
+  }
+
+  // If we are blocking on send, then silently drop this packet
+  if (!IsOutBufferEmpty())
+    return static_cast<int>(cb);
+
+  PacketLength pkt_len = HostToNetwork16(static_cast<PacketLength>(cb));
+  AppendToOutBuffer(&pkt_len, kPacketLenSize);
+  AppendToOutBuffer(pv, cb);
+
+  int res = FlushOutBuffer();
+  if (res <= 0) {
+    // drop packet if we made no progress
+    ClearOutBuffer();
+    return res;
+  }
+
+  rtc::SentPacket sent_packet(options.packet_id, rtc::TimeMillis());
+  SignalSentPacket(this, sent_packet);
+
+  // We claim to have sent the whole thing, even if we only sent partial
+  return static_cast<int>(cb);
+}
+
+void AsyncTCPSocket::ProcessInput(char * data, size_t* len) {
+  SocketAddress remote_addr(GetRemoteAddress());
+
+  while (true) {
+    if (*len < kPacketLenSize)
+      return;
+
+    PacketLength pkt_len = rtc::GetBE16(data);
+    if (*len < kPacketLenSize + pkt_len)
+      return;
+
+    SignalReadPacket(this, data + kPacketLenSize, pkt_len, remote_addr,
+                     CreatePacketTime(0));
+
+    *len -= kPacketLenSize + pkt_len;
+    if (*len > 0) {
+      memmove(data, data + kPacketLenSize + pkt_len, *len);
+    }
+  }
+}
+
+void AsyncTCPSocket::HandleIncomingConnection(AsyncSocket* socket) {
+  SignalNewConnection(this, new AsyncTCPSocket(socket, false));
+}
+
+}  // namespace rtc

webrtc/rtc_base/asynctcpsocket.h

@@ -0,0 +1,108 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_ASYNCTCPSOCKET_H_
+#define WEBRTC_RTC_BASE_ASYNCTCPSOCKET_H_
+
+#include <memory>
+
+#include "webrtc/base/asyncpacketsocket.h"
+#include "webrtc/base/buffer.h"
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/base/socketfactory.h"
+
+namespace rtc {
+
+// Simulates UDP semantics over TCP.  Send and Recv packet sizes
+// are preserved, and drops packets silently on Send, rather than
+// buffer them in user space.
+class AsyncTCPSocketBase : public AsyncPacketSocket {
+ public:
+  AsyncTCPSocketBase(AsyncSocket* socket, bool listen, size_t max_packet_size);
+  ~AsyncTCPSocketBase() override;
+
+  // Pure virtual methods to send and recv data.
+  int Send(const void *pv, size_t cb,
+                   const rtc::PacketOptions& options) override = 0;
+  virtual void ProcessInput(char* data, size_t* len) = 0;
+  // Signals incoming connection.
+  virtual void HandleIncomingConnection(AsyncSocket* socket) = 0;
+
+  SocketAddress GetLocalAddress() const override;
+  SocketAddress GetRemoteAddress() const override;
+  int SendTo(const void* pv,
+             size_t cb,
+             const SocketAddress& addr,
+             const rtc::PacketOptions& options) override;
+  int Close() override;
+
+  State GetState() const override;
+  int GetOption(Socket::Option opt, int* value) override;
+  int SetOption(Socket::Option opt, int value) override;
+  int GetError() const override;
+  void SetError(int error) override;
+
+ protected:
+  // Binds and connects |socket| and creates AsyncTCPSocket for
+  // it. Takes ownership of |socket|. Returns null if bind() or
+  // connect() fail (|socket| is destroyed in that case).
+  static AsyncSocket* ConnectSocket(AsyncSocket* socket,
+                                    const SocketAddress& bind_address,
+                                    const SocketAddress& remote_address);
+  virtual int SendRaw(const void* pv, size_t cb);
+  int FlushOutBuffer();
+  // Add data to |outbuf_|.
+  void AppendToOutBuffer(const void* pv, size_t cb);
+
+  // Helper methods for |outpos_|.
+  bool IsOutBufferEmpty() const { return outbuf_.size() == 0; }
+  void ClearOutBuffer() { outbuf_.Clear(); }
+
+ private:
+  // Called by the underlying socket
+  void OnConnectEvent(AsyncSocket* socket);
+  void OnReadEvent(AsyncSocket* socket);
+  void OnWriteEvent(AsyncSocket* socket);
+  void OnCloseEvent(AsyncSocket* socket, int error);
+
+  std::unique_ptr<AsyncSocket> socket_;
+  bool listen_;
+  Buffer inbuf_;
+  Buffer outbuf_;
+  size_t max_insize_;
+  size_t max_outsize_;
+
+  RTC_DISALLOW_COPY_AND_ASSIGN(AsyncTCPSocketBase);
+};
+
+class AsyncTCPSocket : public AsyncTCPSocketBase {
+ public:
+  // Binds and connects |socket| and creates AsyncTCPSocket for
+  // it. Takes ownership of |socket|. Returns null if bind() or
+  // connect() fail (|socket| is destroyed in that case).
+  static AsyncTCPSocket* Create(AsyncSocket* socket,
+                                const SocketAddress& bind_address,
+                                const SocketAddress& remote_address);
+  AsyncTCPSocket(AsyncSocket* socket, bool listen);
+  ~AsyncTCPSocket() override {}
+
+  int Send(const void* pv,
+           size_t cb,
+           const rtc::PacketOptions& options) override;
+  void ProcessInput(char* data, size_t* len) override;
+  void HandleIncomingConnection(AsyncSocket* socket) override;
+
+ private:
+  RTC_DISALLOW_COPY_AND_ASSIGN(AsyncTCPSocket);
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_ASYNCTCPSOCKET_H_

webrtc/rtc_base/asynctcpsocket_unittest.cc

@@ -0,0 +1,50 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <memory>
+#include <string>
+
+#include "webrtc/base/asynctcpsocket.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/virtualsocketserver.h"
+
+namespace rtc {
+
+class AsyncTCPSocketTest
+    : public testing::Test,
+      public sigslot::has_slots<> {
+ public:
+  AsyncTCPSocketTest()
+      : vss_(new rtc::VirtualSocketServer()),
+        socket_(vss_->CreateAsyncSocket(SOCK_STREAM)),
+        tcp_socket_(new AsyncTCPSocket(socket_, true)),
+        ready_to_send_(false) {
+    tcp_socket_->SignalReadyToSend.connect(this,
+                                           &AsyncTCPSocketTest::OnReadyToSend);
+  }
+
+  void OnReadyToSend(rtc::AsyncPacketSocket* socket) {
+    ready_to_send_ = true;
+  }
+
+ protected:
+  std::unique_ptr<VirtualSocketServer> vss_;
+  AsyncSocket* socket_;
+  std::unique_ptr<AsyncTCPSocket> tcp_socket_;
+  bool ready_to_send_;
+};
+
+TEST_F(AsyncTCPSocketTest, OnWriteEvent) {
+  EXPECT_FALSE(ready_to_send_);
+  socket_->SignalWriteEvent(socket_);
+  EXPECT_TRUE(ready_to_send_);
+}
+
+}  // namespace rtc

webrtc/rtc_base/asyncudpsocket.cc

@@ -0,0 +1,130 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/asyncudpsocket.h"
+#include "webrtc/base/checks.h"
+#include "webrtc/base/logging.h"
+
+namespace rtc {
+
+static const int BUF_SIZE = 64 * 1024;
+
+AsyncUDPSocket* AsyncUDPSocket::Create(
+    AsyncSocket* socket,
+    const SocketAddress& bind_address) {
+  std::unique_ptr<AsyncSocket> owned_socket(socket);
+  if (socket->Bind(bind_address) < 0) {
+    LOG(LS_ERROR) << "Bind() failed with error " << socket->GetError();
+    return nullptr;
+  }
+  return new AsyncUDPSocket(owned_socket.release());
+}
+
+AsyncUDPSocket* AsyncUDPSocket::Create(SocketFactory* factory,
+                                       const SocketAddress& bind_address) {
+  AsyncSocket* socket =
+      factory->CreateAsyncSocket(bind_address.family(), SOCK_DGRAM);
+  if (!socket)
+    return nullptr;
+  return Create(socket, bind_address);
+}
+
+AsyncUDPSocket::AsyncUDPSocket(AsyncSocket* socket)
+    : socket_(socket) {
+  size_ = BUF_SIZE;
+  buf_ = new char[size_];
+
+  // The socket should start out readable but not writable.
+  socket_->SignalReadEvent.connect(this, &AsyncUDPSocket::OnReadEvent);
+  socket_->SignalWriteEvent.connect(this, &AsyncUDPSocket::OnWriteEvent);
+}
+
+AsyncUDPSocket::~AsyncUDPSocket() {
+  delete [] buf_;
+}
+
+SocketAddress AsyncUDPSocket::GetLocalAddress() const {
+  return socket_->GetLocalAddress();
+}
+
+SocketAddress AsyncUDPSocket::GetRemoteAddress() const {
+  return socket_->GetRemoteAddress();
+}
+
+int AsyncUDPSocket::Send(const void *pv, size_t cb,
+                         const rtc::PacketOptions& options) {
+  rtc::SentPacket sent_packet(options.packet_id, rtc::TimeMillis());
+  int ret = socket_->Send(pv, cb);
+  SignalSentPacket(this, sent_packet);
+  return ret;
+}
+
+int AsyncUDPSocket::SendTo(const void *pv, size_t cb,
+                           const SocketAddress& addr,
+                           const rtc::PacketOptions& options) {
+  rtc::SentPacket sent_packet(options.packet_id, rtc::TimeMillis());
+  int ret = socket_->SendTo(pv, cb, addr);
+  SignalSentPacket(this, sent_packet);
+  return ret;
+}
+
+int AsyncUDPSocket::Close() {
+  return socket_->Close();
+}
+
+AsyncUDPSocket::State AsyncUDPSocket::GetState() const {
+  return STATE_BOUND;
+}
+
+int AsyncUDPSocket::GetOption(Socket::Option opt, int* value) {
+  return socket_->GetOption(opt, value);
+}
+
+int AsyncUDPSocket::SetOption(Socket::Option opt, int value) {
+  return socket_->SetOption(opt, value);
+}
+
+int AsyncUDPSocket::GetError() const {
+  return socket_->GetError();
+}
+
+void AsyncUDPSocket::SetError(int error) {
+  return socket_->SetError(error);
+}
+
+void AsyncUDPSocket::OnReadEvent(AsyncSocket* socket) {
+  RTC_DCHECK(socket_.get() == socket);
+
+  SocketAddress remote_addr;
+  int64_t timestamp;
+  int len = socket_->RecvFrom(buf_, size_, &remote_addr, &timestamp);
+  if (len < 0) {
+    // An error here typically means we got an ICMP error in response to our
+    // send datagram, indicating the remote address was unreachable.
+    // When doing ICE, this kind of thing will often happen.
+    // TODO: Do something better like forwarding the error to the user.
+    SocketAddress local_addr = socket_->GetLocalAddress();
+    LOG(LS_INFO) << "AsyncUDPSocket[" << local_addr.ToSensitiveString() << "] "
+                 << "receive failed with error " << socket_->GetError();
+    return;
+  }
+
+  // TODO: Make sure that we got all of the packet.
+  // If we did not, then we should resize our buffer to be large enough.
+  SignalReadPacket(
+      this, buf_, static_cast<size_t>(len), remote_addr,
+      (timestamp > -1 ? PacketTime(timestamp, 0) : CreatePacketTime(0)));
+}
+
+void AsyncUDPSocket::OnWriteEvent(AsyncSocket* socket) {
+  SignalReadyToSend(this);
+}
+
+}  // namespace rtc

webrtc/rtc_base/asyncudpsocket.h

@@ -0,0 +1,67 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_ASYNCUDPSOCKET_H_
+#define WEBRTC_RTC_BASE_ASYNCUDPSOCKET_H_
+
+#include <memory>
+
+#include "webrtc/base/asyncpacketsocket.h"
+#include "webrtc/base/socketfactory.h"
+
+namespace rtc {
+
+// Provides the ability to receive packets asynchronously.  Sends are not
+// buffered since it is acceptable to drop packets under high load.
+class AsyncUDPSocket : public AsyncPacketSocket {
+ public:
+  // Binds |socket| and creates AsyncUDPSocket for it. Takes ownership
+  // of |socket|. Returns null if bind() fails (|socket| is destroyed
+  // in that case).
+  static AsyncUDPSocket* Create(AsyncSocket* socket,
+                                const SocketAddress& bind_address);
+  // Creates a new socket for sending asynchronous UDP packets using an
+  // asynchronous socket from the given factory.
+  static AsyncUDPSocket* Create(SocketFactory* factory,
+                                const SocketAddress& bind_address);
+  explicit AsyncUDPSocket(AsyncSocket* socket);
+  ~AsyncUDPSocket() override;
+
+  SocketAddress GetLocalAddress() const override;
+  SocketAddress GetRemoteAddress() const override;
+  int Send(const void* pv,
+           size_t cb,
+           const rtc::PacketOptions& options) override;
+  int SendTo(const void* pv,
+             size_t cb,
+             const SocketAddress& addr,
+             const rtc::PacketOptions& options) override;
+  int Close() override;
+
+  State GetState() const override;
+  int GetOption(Socket::Option opt, int* value) override;
+  int SetOption(Socket::Option opt, int value) override;
+  int GetError() const override;
+  void SetError(int error) override;
+
+ private:
+  // Called when the underlying socket is ready to be read from.
+  void OnReadEvent(AsyncSocket* socket);
+  // Called when the underlying socket is ready to send.
+  void OnWriteEvent(AsyncSocket* socket);
+
+  std::unique_ptr<AsyncSocket> socket_;
+  char* buf_;
+  size_t size_;
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_ASYNCUDPSOCKET_H_

webrtc/rtc_base/asyncudpsocket_unittest.cc

@@ -0,0 +1,53 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <memory>
+#include <string>
+
+#include "webrtc/base/asyncudpsocket.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/physicalsocketserver.h"
+#include "webrtc/base/virtualsocketserver.h"
+
+namespace rtc {
+
+class AsyncUdpSocketTest
+    : public testing::Test,
+      public sigslot::has_slots<> {
+ public:
+  AsyncUdpSocketTest()
+      : pss_(new rtc::PhysicalSocketServer),
+        vss_(new rtc::VirtualSocketServer(pss_.get())),
+        socket_(vss_->CreateAsyncSocket(SOCK_DGRAM)),
+        udp_socket_(new AsyncUDPSocket(socket_)),
+        ready_to_send_(false) {
+    udp_socket_->SignalReadyToSend.connect(this,
+                                           &AsyncUdpSocketTest::OnReadyToSend);
+  }
+
+  void OnReadyToSend(rtc::AsyncPacketSocket* socket) {
+    ready_to_send_ = true;
+  }
+
+ protected:
+  std::unique_ptr<PhysicalSocketServer> pss_;
+  std::unique_ptr<VirtualSocketServer> vss_;
+  AsyncSocket* socket_;
+  std::unique_ptr<AsyncUDPSocket> udp_socket_;
+  bool ready_to_send_;
+};
+
+TEST_F(AsyncUdpSocketTest, OnWriteEvent) {
+  EXPECT_FALSE(ready_to_send_);
+  socket_->SignalWriteEvent(socket_);
+  EXPECT_TRUE(ready_to_send_);
+}
+
+}  // namespace rtc

webrtc/rtc_base/atomicops.h

@@ -0,0 +1,87 @@
+/*
+ *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_ATOMICOPS_H_
+#define WEBRTC_RTC_BASE_ATOMICOPS_H_
+
+#if defined(WEBRTC_WIN)
+// Include winsock2.h before including <windows.h> to maintain consistency with
+// win32.h.  We can't include win32.h directly here since it pulls in
+// headers such as basictypes.h which causes problems in Chromium where webrtc
+// exists as two separate projects, webrtc and libjingle.
+#include <winsock2.h>
+#include <windows.h>
+#endif  // defined(WEBRTC_WIN)
+
+namespace rtc {
+class AtomicOps {
+ public:
+#if defined(WEBRTC_WIN)
+  // Assumes sizeof(int) == sizeof(LONG), which it is on Win32 and Win64.
+  static int Increment(volatile int* i) {
+    return ::InterlockedIncrement(reinterpret_cast<volatile LONG*>(i));
+  }
+  static int Decrement(volatile int* i) {
+    return ::InterlockedDecrement(reinterpret_cast<volatile LONG*>(i));
+  }
+  static int AcquireLoad(volatile const int* i) {
+    return *i;
+  }
+  static void ReleaseStore(volatile int* i, int value) {
+    *i = value;
+  }
+  static int CompareAndSwap(volatile int* i, int old_value, int new_value) {
+    return ::InterlockedCompareExchange(reinterpret_cast<volatile LONG*>(i),
+                                        new_value,
+                                        old_value);
+  }
+  // Pointer variants.
+  template <typename T>
+  static T* AcquireLoadPtr(T* volatile* ptr) {
+    return *ptr;
+  }
+  template <typename T>
+  static T* CompareAndSwapPtr(T* volatile* ptr, T* old_value, T* new_value) {
+    return static_cast<T*>(::InterlockedCompareExchangePointer(
+        reinterpret_cast<PVOID volatile*>(ptr), new_value, old_value));
+  }
+#else
+  static int Increment(volatile int* i) {
+    return __sync_add_and_fetch(i, 1);
+  }
+  static int Decrement(volatile int* i) {
+    return __sync_sub_and_fetch(i, 1);
+  }
+  static int AcquireLoad(volatile const int* i) {
+    return __atomic_load_n(i, __ATOMIC_ACQUIRE);
+  }
+  static void ReleaseStore(volatile int* i, int value) {
+    __atomic_store_n(i, value, __ATOMIC_RELEASE);
+  }
+  static int CompareAndSwap(volatile int* i, int old_value, int new_value) {
+    return __sync_val_compare_and_swap(i, old_value, new_value);
+  }
+  // Pointer variants.
+  template <typename T>
+  static T* AcquireLoadPtr(T* volatile* ptr) {
+    return __atomic_load_n(ptr, __ATOMIC_ACQUIRE);
+  }
+  template <typename T>
+  static T* CompareAndSwapPtr(T* volatile* ptr, T* old_value, T* new_value) {
+    return __sync_val_compare_and_swap(ptr, old_value, new_value);
+  }
+#endif
+};
+
+
+
+}
+
+#endif  // WEBRTC_RTC_BASE_ATOMICOPS_H_

webrtc/rtc_base/atomicops_unittest.cc

@@ -0,0 +1,12 @@
+/*
+ *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+// TODO(pbos): Move AtomicOps tests to here from
+// webrtc/base/criticalsection_unittest.cc.

webrtc/rtc_base/base64.cc

@@ -0,0 +1,278 @@
+
+//*********************************************************************
+//* Base64 - a simple base64 encoder and decoder.
+//*
+//*     Copyright (c) 1999, Bob Withers - bwit@pobox.com
+//*
+//* This code may be freely used for any purpose, either personal
+//* or commercial, provided the authors copyright notice remains
+//* intact.
+//*
+//* Enhancements by Stanley Yamane:
+//*     o reverse lookup table for the decode function
+//*     o reserve string buffer space in advance
+//*
+//*********************************************************************
+
+#include "webrtc/base/base64.h"
+
+#include <string.h>
+
+#include "webrtc/base/checks.h"
+
+using std::vector;
+
+namespace rtc {
+
+static const char kPad = '=';
+static const unsigned char pd = 0xFD;  // Padding
+static const unsigned char sp = 0xFE;  // Whitespace
+static const unsigned char il = 0xFF;  // Illegal base64 character
+
+const char Base64::Base64Table[] =
+    // 0000000000111111111122222222223333333333444444444455555555556666
+    // 0123456789012345678901234567890123456789012345678901234567890123
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+// Decode Table gives the index of any valid base64 character in the
+// Base64 table
+// 65 == A, 97 == a, 48 == 0, 43 == +, 47 == /
+
+const unsigned char Base64::DecodeTable[] = {
+    // 0  1  2  3  4  5  6  7  8  9
+    il, il, il, il, il, il, il, il, il, sp,  //   0 -   9
+    sp, sp, sp, sp, il, il, il, il, il, il,  //  10 -  19
+    il, il, il, il, il, il, il, il, il, il,  //  20 -  29
+    il, il, sp, il, il, il, il, il, il, il,  //  30 -  39
+    il, il, il, 62, il, il, il, 63, 52, 53,  //  40 -  49
+    54, 55, 56, 57, 58, 59, 60, 61, il, il,  //  50 -  59
+    il, pd, il, il, il, 0,  1,  2,  3,  4,   //  60 -  69
+    5,  6,  7,  8,  9,  10, 11, 12, 13, 14,  //  70 -  79
+    15, 16, 17, 18, 19, 20, 21, 22, 23, 24,  //  80 -  89
+    25, il, il, il, il, il, il, 26, 27, 28,  //  90 -  99
+    29, 30, 31, 32, 33, 34, 35, 36, 37, 38,  // 100 - 109
+    39, 40, 41, 42, 43, 44, 45, 46, 47, 48,  // 110 - 119
+    49, 50, 51, il, il, il, il, il, il, il,  // 120 - 129
+    il, il, il, il, il, il, il, il, il, il,  // 130 - 139
+    il, il, il, il, il, il, il, il, il, il,  // 140 - 149
+    il, il, il, il, il, il, il, il, il, il,  // 150 - 159
+    il, il, il, il, il, il, il, il, il, il,  // 160 - 169
+    il, il, il, il, il, il, il, il, il, il,  // 170 - 179
+    il, il, il, il, il, il, il, il, il, il,  // 180 - 189
+    il, il, il, il, il, il, il, il, il, il,  // 190 - 199
+    il, il, il, il, il, il, il, il, il, il,  // 200 - 209
+    il, il, il, il, il, il, il, il, il, il,  // 210 - 219
+    il, il, il, il, il, il, il, il, il, il,  // 220 - 229
+    il, il, il, il, il, il, il, il, il, il,  // 230 - 239
+    il, il, il, il, il, il, il, il, il, il,  // 240 - 249
+    il, il, il, il, il, il                   // 250 - 255
+};
+
+bool Base64::IsBase64Char(char ch) {
+  return (('A' <= ch) && (ch <= 'Z')) || (('a' <= ch) && (ch <= 'z')) ||
+         (('0' <= ch) && (ch <= '9')) || (ch == '+') || (ch == '/');
+}
+
+bool Base64::GetNextBase64Char(char ch, char* next_ch) {
+  if (next_ch == nullptr) {
+    return false;
+  }
+  const char* p = strchr(Base64Table, ch);
+  if (!p)
+    return false;
+  ++p;
+  *next_ch = (*p) ? *p : Base64Table[0];
+  return true;
+}
+
+bool Base64::IsBase64Encoded(const std::string& str) {
+  for (size_t i = 0; i < str.size(); ++i) {
+    if (!IsBase64Char(str.at(i)))
+      return false;
+  }
+  return true;
+}
+
+void Base64::EncodeFromArray(const void* data,
+                             size_t len,
+                             std::string* result) {
+  RTC_DCHECK(nullptr != result);
+  result->clear();
+  result->resize(((len + 2) / 3) * 4);
+  const unsigned char* byte_data = static_cast<const unsigned char*>(data);
+
+  unsigned char c;
+  size_t i = 0;
+  size_t dest_ix = 0;
+  while (i < len) {
+    c = (byte_data[i] >> 2) & 0x3f;
+    (*result)[dest_ix++] = Base64Table[c];
+
+    c = (byte_data[i] << 4) & 0x3f;
+    if (++i < len) {
+      c |= (byte_data[i] >> 4) & 0x0f;
+    }
+    (*result)[dest_ix++] = Base64Table[c];
+
+    if (i < len) {
+      c = (byte_data[i] << 2) & 0x3f;
+      if (++i < len) {
+        c |= (byte_data[i] >> 6) & 0x03;
+      }
+      (*result)[dest_ix++] = Base64Table[c];
+    } else {
+      (*result)[dest_ix++] = kPad;
+    }
+
+    if (i < len) {
+      c = byte_data[i] & 0x3f;
+      (*result)[dest_ix++] = Base64Table[c];
+      ++i;
+    } else {
+      (*result)[dest_ix++] = kPad;
+    }
+  }
+}
+
+size_t Base64::GetNextQuantum(DecodeFlags parse_flags,
+                              bool illegal_pads,
+                              const char* data,
+                              size_t len,
+                              size_t* dpos,
+                              unsigned char qbuf[4],
+                              bool* padded) {
+  size_t byte_len = 0, pad_len = 0, pad_start = 0;
+  for (; (byte_len < 4) && (*dpos < len); ++*dpos) {
+    qbuf[byte_len] = DecodeTable[static_cast<unsigned char>(data[*dpos])];
+    if ((il == qbuf[byte_len]) || (illegal_pads && (pd == qbuf[byte_len]))) {
+      if (parse_flags != DO_PARSE_ANY)
+        break;
+      // Ignore illegal characters
+    } else if (sp == qbuf[byte_len]) {
+      if (parse_flags == DO_PARSE_STRICT)
+        break;
+      // Ignore spaces
+    } else if (pd == qbuf[byte_len]) {
+      if (byte_len < 2) {
+        if (parse_flags != DO_PARSE_ANY)
+          break;
+        // Ignore unexpected padding
+      } else if (byte_len + pad_len >= 4) {
+        if (parse_flags != DO_PARSE_ANY)
+          break;
+        // Ignore extra pads
+      } else {
+        if (1 == ++pad_len) {
+          pad_start = *dpos;
+        }
+      }
+    } else {
+      if (pad_len > 0) {
+        if (parse_flags != DO_PARSE_ANY)
+          break;
+        // Ignore pads which are followed by data
+        pad_len = 0;
+      }
+      ++byte_len;
+    }
+  }
+  for (size_t i = byte_len; i < 4; ++i) {
+    qbuf[i] = 0;
+  }
+  if (4 == byte_len + pad_len) {
+    *padded = true;
+  } else {
+    *padded = false;
+    if (pad_len) {
+      // Roll back illegal padding
+      *dpos = pad_start;
+    }
+  }
+  return byte_len;
+}
+
+bool Base64::DecodeFromArray(const char* data,
+                             size_t len,
+                             DecodeFlags flags,
+                             std::string* result,
+                             size_t* data_used) {
+  return DecodeFromArrayTemplate<std::string>(data, len, flags, result,
+                                              data_used);
+}
+
+bool Base64::DecodeFromArray(const char* data,
+                             size_t len,
+                             DecodeFlags flags,
+                             vector<char>* result,
+                             size_t* data_used) {
+  return DecodeFromArrayTemplate<vector<char>>(data, len, flags, result,
+                                               data_used);
+}
+
+bool Base64::DecodeFromArray(const char* data,
+                             size_t len,
+                             DecodeFlags flags,
+                             vector<uint8_t>* result,
+                             size_t* data_used) {
+  return DecodeFromArrayTemplate<vector<uint8_t>>(data, len, flags, result,
+                                                  data_used);
+}
+
+template <typename T>
+bool Base64::DecodeFromArrayTemplate(const char* data,
+                                     size_t len,
+                                     DecodeFlags flags,
+                                     T* result,
+                                     size_t* data_used) {
+  RTC_DCHECK(nullptr != result);
+  RTC_DCHECK(flags <= (DO_PARSE_MASK | DO_PAD_MASK | DO_TERM_MASK));
+
+  const DecodeFlags parse_flags = flags & DO_PARSE_MASK;
+  const DecodeFlags pad_flags = flags & DO_PAD_MASK;
+  const DecodeFlags term_flags = flags & DO_TERM_MASK;
+  RTC_DCHECK(0 != parse_flags);
+  RTC_DCHECK(0 != pad_flags);
+  RTC_DCHECK(0 != term_flags);
+
+  result->clear();
+  result->reserve(len);
+
+  size_t dpos = 0;
+  bool success = true, padded;
+  unsigned char c, qbuf[4];
+  while (dpos < len) {
+    size_t qlen = GetNextQuantum(parse_flags, (DO_PAD_NO == pad_flags), data,
+                                 len, &dpos, qbuf, &padded);
+    c = (qbuf[0] << 2) | ((qbuf[1] >> 4) & 0x3);
+    if (qlen >= 2) {
+      result->push_back(c);
+      c = ((qbuf[1] << 4) & 0xf0) | ((qbuf[2] >> 2) & 0xf);
+      if (qlen >= 3) {
+        result->push_back(c);
+        c = ((qbuf[2] << 6) & 0xc0) | qbuf[3];
+        if (qlen >= 4) {
+          result->push_back(c);
+          c = 0;
+        }
+      }
+    }
+    if (qlen < 4) {
+      if ((DO_TERM_ANY != term_flags) && (0 != c)) {
+        success = false;  // unused bits
+      }
+      if ((DO_PAD_YES == pad_flags) && !padded) {
+        success = false;  // expected padding
+      }
+      break;
+    }
+  }
+  if ((DO_TERM_BUFFER == term_flags) && (dpos != len)) {
+    success = false;  // unused chars
+  }
+  if (data_used) {
+    *data_used = dpos;
+  }
+  return success;
+}
+
+}  // namespace rtc

webrtc/rtc_base/base64.h

@@ -0,0 +1,123 @@
+
+//*********************************************************************
+//* C_Base64 - a simple base64 encoder and decoder.
+//*
+//*     Copyright (c) 1999, Bob Withers - bwit@pobox.com
+//*
+//* This code may be freely used for any purpose, either personal
+//* or commercial, provided the authors copyright notice remains
+//* intact.
+//*********************************************************************
+
+#ifndef WEBRTC_RTC_BASE_BASE64_H_
+#define WEBRTC_RTC_BASE_BASE64_H_
+
+#include <string>
+#include <vector>
+
+namespace rtc {
+
+class Base64 {
+ public:
+  enum DecodeOption {
+    DO_PARSE_STRICT = 1,  // Parse only base64 characters
+    DO_PARSE_WHITE = 2,   // Parse only base64 and whitespace characters
+    DO_PARSE_ANY = 3,     // Parse all characters
+    DO_PARSE_MASK = 3,
+
+    DO_PAD_YES = 4,  // Padding is required
+    DO_PAD_ANY = 8,  // Padding is optional
+    DO_PAD_NO = 12,  // Padding is disallowed
+    DO_PAD_MASK = 12,
+
+    DO_TERM_BUFFER = 16,  // Must termiante at end of buffer
+    DO_TERM_CHAR = 32,    // May terminate at any character boundary
+    DO_TERM_ANY = 48,     // May terminate at a sub-character bit offset
+    DO_TERM_MASK = 48,
+
+    // Strictest interpretation
+    DO_STRICT = DO_PARSE_STRICT | DO_PAD_YES | DO_TERM_BUFFER,
+
+    DO_LAX = DO_PARSE_ANY | DO_PAD_ANY | DO_TERM_CHAR,
+  };
+  typedef int DecodeFlags;
+
+  static bool IsBase64Char(char ch);
+
+  // Get the char next to the |ch| from the Base64Table.
+  // If the |ch| is the last one in the Base64Table then returns
+  // the first one from the table.
+  // Expects the |ch| be a base64 char.
+  // The result will be saved in |next_ch|.
+  // Returns true on success.
+  static bool GetNextBase64Char(char ch, char* next_ch);
+
+  // Determines whether the given string consists entirely of valid base64
+  // encoded characters.
+  static bool IsBase64Encoded(const std::string& str);
+
+  static void EncodeFromArray(const void* data,
+                              size_t len,
+                              std::string* result);
+  static bool DecodeFromArray(const char* data,
+                              size_t len,
+                              DecodeFlags flags,
+                              std::string* result,
+                              size_t* data_used);
+  static bool DecodeFromArray(const char* data,
+                              size_t len,
+                              DecodeFlags flags,
+                              std::vector<char>* result,
+                              size_t* data_used);
+  static bool DecodeFromArray(const char* data,
+                              size_t len,
+                              DecodeFlags flags,
+                              std::vector<uint8_t>* result,
+                              size_t* data_used);
+
+  // Convenience Methods
+  static inline std::string Encode(const std::string& data) {
+    std::string result;
+    EncodeFromArray(data.data(), data.size(), &result);
+    return result;
+  }
+  static inline std::string Decode(const std::string& data, DecodeFlags flags) {
+    std::string result;
+    DecodeFromArray(data.data(), data.size(), flags, &result, nullptr);
+    return result;
+  }
+  static inline bool Decode(const std::string& data,
+                            DecodeFlags flags,
+                            std::string* result,
+                            size_t* data_used) {
+    return DecodeFromArray(data.data(), data.size(), flags, result, data_used);
+  }
+  static inline bool Decode(const std::string& data,
+                            DecodeFlags flags,
+                            std::vector<char>* result,
+                            size_t* data_used) {
+    return DecodeFromArray(data.data(), data.size(), flags, result, data_used);
+  }
+
+ private:
+  static const char Base64Table[];
+  static const unsigned char DecodeTable[];
+
+  static size_t GetNextQuantum(DecodeFlags parse_flags,
+                               bool illegal_pads,
+                               const char* data,
+                               size_t len,
+                               size_t* dpos,
+                               unsigned char qbuf[4],
+                               bool* padded);
+  template <typename T>
+  static bool DecodeFromArrayTemplate(const char* data,
+                                      size_t len,
+                                      DecodeFlags flags,
+                                      T* result,
+                                      size_t* data_used);
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_BASE64_H_

webrtc/rtc_base/base64_unittest.cc

@@ -0,0 +1,999 @@
+/*
+ *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/base64.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/stringutils.h"
+
+#include "webrtc/base/testbase64.h"
+
+using namespace std;
+using namespace rtc;
+
+static struct {
+  size_t plain_length;
+  const char* plaintext;
+  const char* cyphertext;
+} base64_tests[] = {
+
+  // Basic bit patterns;
+  // values obtained with "echo -n '...' | uuencode -m test"
+
+  { 1, "\000", "AA==" },
+  { 1, "\001", "AQ==" },
+  { 1, "\002", "Ag==" },
+  { 1, "\004", "BA==" },
+  { 1, "\010", "CA==" },
+  { 1, "\020", "EA==" },
+  { 1, "\040", "IA==" },
+  { 1, "\100", "QA==" },
+  { 1, "\200", "gA==" },
+
+  { 1, "\377", "/w==" },
+  { 1, "\376", "/g==" },
+  { 1, "\375", "/Q==" },
+  { 1, "\373", "+w==" },
+  { 1, "\367", "9w==" },
+  { 1, "\357", "7w==" },
+  { 1, "\337", "3w==" },
+  { 1, "\277", "vw==" },
+  { 1, "\177", "fw==" },
+  { 2, "\000\000", "AAA=" },
+  { 2, "\000\001", "AAE=" },
+  { 2, "\000\002", "AAI=" },
+  { 2, "\000\004", "AAQ=" },
+  { 2, "\000\010", "AAg=" },
+  { 2, "\000\020", "ABA=" },
+  { 2, "\000\040", "ACA=" },
+  { 2, "\000\100", "AEA=" },
+  { 2, "\000\200", "AIA=" },
+  { 2, "\001\000", "AQA=" },
+  { 2, "\002\000", "AgA=" },
+  { 2, "\004\000", "BAA=" },
+  { 2, "\010\000", "CAA=" },
+  { 2, "\020\000", "EAA=" },
+  { 2, "\040\000", "IAA=" },
+  { 2, "\100\000", "QAA=" },
+  { 2, "\200\000", "gAA=" },
+
+  { 2, "\377\377", "//8=" },
+  { 2, "\377\376", "//4=" },
+  { 2, "\377\375", "//0=" },
+  { 2, "\377\373", "//s=" },
+  { 2, "\377\367", "//c=" },
+  { 2, "\377\357", "/+8=" },
+  { 2, "\377\337", "/98=" },
+  { 2, "\377\277", "/78=" },
+  { 2, "\377\177", "/38=" },
+  { 2, "\376\377", "/v8=" },
+  { 2, "\375\377", "/f8=" },
+  { 2, "\373\377", "+/8=" },
+  { 2, "\367\377", "9/8=" },
+  { 2, "\357\377", "7/8=" },
+  { 2, "\337\377", "3/8=" },
+  { 2, "\277\377", "v/8=" },
+  { 2, "\177\377", "f/8=" },
+
+  { 3, "\000\000\000", "AAAA" },
+  { 3, "\000\000\001", "AAAB" },
+  { 3, "\000\000\002", "AAAC" },
+  { 3, "\000\000\004", "AAAE" },
+  { 3, "\000\000\010", "AAAI" },
+  { 3, "\000\000\020", "AAAQ" },
+  { 3, "\000\000\040", "AAAg" },
+  { 3, "\000\000\100", "AABA" },
+  { 3, "\000\000\200", "AACA" },
+  { 3, "\000\001\000", "AAEA" },
+  { 3, "\000\002\000", "AAIA" },
+  { 3, "\000\004\000", "AAQA" },
+  { 3, "\000\010\000", "AAgA" },
+  { 3, "\000\020\000", "ABAA" },
+  { 3, "\000\040\000", "ACAA" },
+  { 3, "\000\100\000", "AEAA" },
+  { 3, "\000\200\000", "AIAA" },
+  { 3, "\001\000\000", "AQAA" },
+  { 3, "\002\000\000", "AgAA" },
+  { 3, "\004\000\000", "BAAA" },
+  { 3, "\010\000\000", "CAAA" },
+  { 3, "\020\000\000", "EAAA" },
+  { 3, "\040\000\000", "IAAA" },
+  { 3, "\100\000\000", "QAAA" },
+  { 3, "\200\000\000", "gAAA" },
+
+  { 3, "\377\377\377", "////" },
+  { 3, "\377\377\376", "///+" },
+  { 3, "\377\377\375", "///9" },
+  { 3, "\377\377\373", "///7" },
+  { 3, "\377\377\367", "///3" },
+  { 3, "\377\377\357", "///v" },
+  { 3, "\377\377\337", "///f" },
+  { 3, "\377\377\277", "//+/" },
+  { 3, "\377\377\177", "//9/" },
+  { 3, "\377\376\377", "//7/" },
+  { 3, "\377\375\377", "//3/" },
+  { 3, "\377\373\377", "//v/" },
+  { 3, "\377\367\377", "//f/" },
+  { 3, "\377\357\377", "/+//" },
+  { 3, "\377\337\377", "/9//" },
+  { 3, "\377\277\377", "/7//" },
+  { 3, "\377\177\377", "/3//" },
+  { 3, "\376\377\377", "/v//" },
+  { 3, "\375\377\377", "/f//" },
+  { 3, "\373\377\377", "+///" },
+  { 3, "\367\377\377", "9///" },
+  { 3, "\357\377\377", "7///" },
+  { 3, "\337\377\377", "3///" },
+  { 3, "\277\377\377", "v///" },
+  { 3, "\177\377\377", "f///" },
+
+  // Random numbers: values obtained with
+  //
+  //  #! /bin/bash
+  //  dd bs=$1 count=1 if=/dev/random of=/tmp/bar.random
+  //  od -N $1 -t o1 /tmp/bar.random
+  //  uuencode -m test < /tmp/bar.random
+  //
+  // where $1 is the number of bytes (2, 3)
+
+  { 2, "\243\361", "o/E=" },
+  { 2, "\024\167", "FHc=" },
+  { 2, "\313\252", "y6o=" },
+  { 2, "\046\041", "JiE=" },
+  { 2, "\145\236", "ZZ4=" },
+  { 2, "\254\325", "rNU=" },
+  { 2, "\061\330", "Mdg=" },
+  { 2, "\245\032", "pRo=" },
+  { 2, "\006\000", "BgA=" },
+  { 2, "\375\131", "/Vk=" },
+  { 2, "\303\210", "w4g=" },
+  { 2, "\040\037", "IB8=" },
+  { 2, "\261\372", "sfo=" },
+  { 2, "\335\014", "3Qw=" },
+  { 2, "\233\217", "m48=" },
+  { 2, "\373\056", "+y4=" },
+  { 2, "\247\232", "p5o=" },
+  { 2, "\107\053", "Rys=" },
+  { 2, "\204\077", "hD8=" },
+  { 2, "\276\211", "vok=" },
+  { 2, "\313\110", "y0g=" },
+  { 2, "\363\376", "8/4=" },
+  { 2, "\251\234", "qZw=" },
+  { 2, "\103\262", "Q7I=" },
+  { 2, "\142\312", "Yso=" },
+  { 2, "\067\211", "N4k=" },
+  { 2, "\220\001", "kAE=" },
+  { 2, "\152\240", "aqA=" },
+  { 2, "\367\061", "9zE=" },
+  { 2, "\133\255", "W60=" },
+  { 2, "\176\035", "fh0=" },
+  { 2, "\032\231", "Gpk=" },
+
+  { 3, "\013\007\144", "Cwdk" },
+  { 3, "\030\112\106", "GEpG" },
+  { 3, "\047\325\046", "J9Um" },
+  { 3, "\310\160\022", "yHAS" },
+  { 3, "\131\100\237", "WUCf" },
+  { 3, "\064\342\134", "NOJc" },
+  { 3, "\010\177\004", "CH8E" },
+  { 3, "\345\147\205", "5WeF" },
+  { 3, "\300\343\360", "wOPw" },
+  { 3, "\061\240\201", "MaCB" },
+  { 3, "\225\333\044", "ldsk" },
+  { 3, "\215\137\352", "jV/q" },
+  { 3, "\371\147\160", "+Wdw" },
+  { 3, "\030\320\051", "GNAp" },
+  { 3, "\044\174\241", "JHyh" },
+  { 3, "\260\127\037", "sFcf" },
+  { 3, "\111\045\033", "SSUb" },
+  { 3, "\202\114\107", "gkxH" },
+  { 3, "\057\371\042", "L/ki" },
+  { 3, "\223\247\244", "k6ek" },
+  { 3, "\047\216\144", "J45k" },
+  { 3, "\203\070\327", "gzjX" },
+  { 3, "\247\140\072", "p2A6" },
+  { 3, "\124\115\116", "VE1O" },
+  { 3, "\157\162\050", "b3Io" },
+  { 3, "\357\223\004", "75ME" },
+  { 3, "\052\117\156", "Kk9u" },
+  { 3, "\347\154\000", "52wA" },
+  { 3, "\303\012\142", "wwpi" },
+  { 3, "\060\035\362", "MB3y" },
+  { 3, "\130\226\361", "WJbx" },
+  { 3, "\173\013\071", "ews5" },
+  { 3, "\336\004\027", "3gQX" },
+  { 3, "\357\366\234", "7/ac" },
+  { 3, "\353\304\111", "68RJ" },
+  { 3, "\024\264\131", "FLRZ" },
+  { 3, "\075\114\251", "PUyp" },
+  { 3, "\315\031\225", "zRmV" },
+  { 3, "\154\201\276", "bIG+" },
+  { 3, "\200\066\072", "gDY6" },
+  { 3, "\142\350\267", "Yui3" },
+  { 3, "\033\000\166", "GwB2" },
+  { 3, "\210\055\077", "iC0/" },
+  { 3, "\341\037\124", "4R9U" },
+  { 3, "\161\103\152", "cUNq" },
+  { 3, "\270\142\131", "uGJZ" },
+  { 3, "\337\076\074", "3z48" },
+  { 3, "\375\106\362", "/Uby" },
+  { 3, "\227\301\127", "l8FX" },
+  { 3, "\340\002\234", "4AKc" },
+  { 3, "\121\064\033", "UTQb" },
+  { 3, "\157\134\143", "b1xj" },
+  { 3, "\247\055\327", "py3X" },
+  { 3, "\340\142\005", "4GIF" },
+  { 3, "\060\260\143", "MLBj" },
+  { 3, "\075\203\170", "PYN4" },
+  { 3, "\143\160\016", "Y3AO" },
+  { 3, "\313\013\063", "ywsz" },
+  { 3, "\174\236\135", "fJ5d" },
+  { 3, "\103\047\026", "QycW" },
+  { 3, "\365\005\343", "9QXj" },
+  { 3, "\271\160\223", "uXCT" },
+  { 3, "\362\255\172", "8q16" },
+  { 3, "\113\012\015", "SwoN" },
+
+  // various lengths, generated by this python script:
+  //
+  // from string import lowercase as lc
+  // for i in range(27):
+  //   print '{ %2d, "%s",%s "%s" },' % (i, lc[:i], ' ' * (26-i),
+  //                                     lc[:i].encode('base64').strip())
+
+  {  0, "abcdefghijklmnopqrstuvwxyz", "" },
+  {  1, "abcdefghijklmnopqrstuvwxyz", "YQ==" },
+  {  2, "abcdefghijklmnopqrstuvwxyz", "YWI=" },
+  {  3, "abcdefghijklmnopqrstuvwxyz", "YWJj" },
+  {  4, "abcdefghijklmnopqrstuvwxyz", "YWJjZA==" },
+  {  5, "abcdefghijklmnopqrstuvwxyz", "YWJjZGU=" },
+  {  6, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVm" },
+  {  7, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZw==" },
+  {  8, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZ2g=" },
+  {  9, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZ2hp" },
+  { 10, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZ2hpag==" },
+  { 11, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZ2hpams=" },
+  { 12, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZ2hpamts" },
+  { 13, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZ2hpamtsbQ==" },
+  { 14, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZ2hpamtsbW4=" },
+  { 15, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZ2hpamtsbW5v" },
+  { 16, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZ2hpamtsbW5vcA==" },
+  { 17, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZ2hpamtsbW5vcHE=" },
+  { 18, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZ2hpamtsbW5vcHFy" },
+  { 19, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZ2hpamtsbW5vcHFycw==" },
+  { 20, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZ2hpamtsbW5vcHFyc3Q=" },
+  { 21, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZ2hpamtsbW5vcHFyc3R1" },
+  { 22, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dg==" },
+  { 23, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnc=" },
+  { 24, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4" },
+  { 25, "abcdefghijklmnopqrstuvwxy",  "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eQ==" },
+  { 26, "abcdefghijklmnopqrstuvwxyz", "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXo=" },
+};
+#if 0
+static struct {
+  const char* plaintext;
+  const char* cyphertext;
+} base64_strings[] = {
+
+  // The first few Google quotes
+  // Cyphertext created with "uuencode - GNU sharutils 4.2.1"
+  {
+    "Everyone!  We're teetering on the brink of disaster."
+    " - Sergey Brin, 6/24/99, regarding the company's state "
+    "after the unleashing of Netscape/Google search",
+
+    "RXZlcnlvbmUhICBXZSdyZSB0ZWV0ZXJpbmcgb24gdGhlIGJyaW5rIG9mIGRp"
+    "c2FzdGVyLiAtIFNlcmdleSBCcmluLCA2LzI0Lzk5LCByZWdhcmRpbmcgdGhl"
+    "IGNvbXBhbnkncyBzdGF0ZSBhZnRlciB0aGUgdW5sZWFzaGluZyBvZiBOZXRz"
+    "Y2FwZS9Hb29nbGUgc2VhcmNo" },
+
+  {
+    "I'm not sure why we're still alive, but we seem to be."
+    " - Larry Page, 6/24/99, while hiding in the kitchenette "
+    "during the Netscape traffic overflow",
+
+    "SSdtIG5vdCBzdXJlIHdoeSB3ZSdyZSBzdGlsbCBhbGl2ZSwgYnV0IHdlIHNl"
+    "ZW0gdG8gYmUuIC0gTGFycnkgUGFnZSwgNi8yNC85OSwgd2hpbGUgaGlkaW5n"
+    "IGluIHRoZSBraXRjaGVuZXR0ZSBkdXJpbmcgdGhlIE5ldHNjYXBlIHRyYWZm"
+    "aWMgb3ZlcmZsb3c" },
+
+  {
+    "I think kids want porn."
+    " - Sergey Brin, 6/99, on why Google shouldn't prioritize a "
+    "filtered search for children and families",
+
+    "SSB0aGluayBraWRzIHdhbnQgcG9ybi4gLSBTZXJnZXkgQnJpbiwgNi85OSwg"
+    "b24gd2h5IEdvb2dsZSBzaG91bGRuJ3QgcHJpb3JpdGl6ZSBhIGZpbHRlcmVk"
+    "IHNlYXJjaCBmb3IgY2hpbGRyZW4gYW5kIGZhbWlsaWVz" },
+};
+#endif
+// Compare bytes 0..len-1 of x and y.  If not equal, abort with verbose error
+// message showing position and numeric value that differed.
+// Handles embedded nulls just like any other byte.
+// Only added because string.compare() in gcc-3.3.3 seems to misbehave with
+// embedded nulls.
+// TODO: switch back to string.compare() if/when gcc is fixed
+#define EXPECT_EQ_ARRAY(len, x, y, msg)                      \
+  for (size_t j = 0; j < len; ++j) {                           \
+    if (x[j] != y[j]) {                                     \
+        LOG(LS_ERROR) << "" # x << " != " # y                  \
+                   << " byte " << j << " msg: " << msg;     \
+      }                                                     \
+    }
+
+size_t Base64Escape(const unsigned char *src, size_t szsrc, char *dest,
+                    size_t szdest) {
+  std::string escaped;
+  Base64::EncodeFromArray((const char *)src, szsrc, &escaped);
+  memcpy(dest, escaped.data(), min(escaped.size(), szdest));
+  return escaped.size();
+}
+
+size_t Base64Unescape(const char *src, size_t szsrc, char *dest,
+                      size_t szdest) {
+  std::string unescaped;
+  EXPECT_TRUE(
+      Base64::DecodeFromArray(src, szsrc, Base64::DO_LAX, &unescaped, nullptr));
+  memcpy(dest, unescaped.data(), min(unescaped.size(), szdest));
+  return unescaped.size();
+}
+
+size_t Base64Unescape(const char *src, size_t szsrc, std::string *s) {
+  EXPECT_TRUE(Base64::DecodeFromArray(src, szsrc, Base64::DO_LAX, s, nullptr));
+  return s->size();
+}
+
+TEST(Base64, EncodeDecodeBattery) {
+  LOG(LS_VERBOSE) << "Testing base-64";
+
+  size_t i;
+
+  // Check the short strings; this tests the math (and boundaries)
+  for( i = 0; i < sizeof(base64_tests) / sizeof(base64_tests[0]); ++i ) {
+    char encode_buffer[100];
+    size_t encode_length;
+    char decode_buffer[100];
+    size_t decode_length;
+    size_t cypher_length;
+
+    LOG(LS_VERBOSE) << "B64: " << base64_tests[i].cyphertext;
+
+    const unsigned char* unsigned_plaintext =
+      reinterpret_cast<const unsigned char*>(base64_tests[i].plaintext);
+
+    cypher_length = strlen(base64_tests[i].cyphertext);
+
+    // The basic escape function:
+    memset(encode_buffer, 0, sizeof(encode_buffer));
+    encode_length = Base64Escape(unsigned_plaintext,
+                                 base64_tests[i].plain_length,
+                                 encode_buffer,
+                                 sizeof(encode_buffer));
+    //    Is it of the expected length?
+    EXPECT_EQ(encode_length, cypher_length);
+
+    //    Is it the expected encoded value?
+    EXPECT_STREQ(encode_buffer, base64_tests[i].cyphertext);
+
+    // If we encode it into a buffer of exactly the right length...
+    memset(encode_buffer, 0, sizeof(encode_buffer));
+    encode_length = Base64Escape(unsigned_plaintext,
+                                 base64_tests[i].plain_length,
+                                 encode_buffer,
+                                 cypher_length);
+    //    Is it still of the expected length?
+    EXPECT_EQ(encode_length, cypher_length);
+
+    //    And is the value still correct?  (i.e., not losing the last byte)
+    EXPECT_STREQ(encode_buffer, base64_tests[i].cyphertext);
+
+    // If we decode it back:
+    memset(decode_buffer, 0, sizeof(decode_buffer));
+    decode_length = Base64Unescape(encode_buffer,
+                                   cypher_length,
+                                   decode_buffer,
+                                   sizeof(decode_buffer));
+
+    //    Is it of the expected length?
+    EXPECT_EQ(decode_length, base64_tests[i].plain_length);
+
+    //    Is it the expected decoded value?
+    EXPECT_EQ(0,  memcmp(decode_buffer, base64_tests[i].plaintext, decode_length));
+
+    // Our decoder treats the padding '=' characters at the end as
+    // optional.  If encode_buffer has any, run some additional
+    // tests that fiddle with them.
+    char* first_equals = strchr(encode_buffer, '=');
+    if (first_equals) {
+      // How many equals signs does the string start with?
+      int equals = (*(first_equals+1) == '=') ? 2 : 1;
+
+      // Try chopping off the equals sign(s) entirely.  The decoder
+      // should still be okay with this.
+      std::string decoded2("this junk should also be ignored");
+      *first_equals = '\0';
+      EXPECT_NE(0U, Base64Unescape(encode_buffer, first_equals-encode_buffer,
+                           &decoded2));
+      EXPECT_EQ(decoded2.size(), base64_tests[i].plain_length);
+      EXPECT_EQ_ARRAY(decoded2.size(), decoded2.data(), base64_tests[i].plaintext, i);
+
+      size_t len;
+
+      // try putting some extra stuff after the equals signs, or in between them
+      if (equals == 2) {
+        sprintfn(first_equals, 6, " = = ");
+        len = first_equals - encode_buffer + 5;
+      } else {
+        sprintfn(first_equals, 6, " = ");
+        len = first_equals - encode_buffer + 3;
+      }
+      decoded2.assign("this junk should be ignored");
+      EXPECT_NE(0U, Base64Unescape(encode_buffer, len, &decoded2));
+      EXPECT_EQ(decoded2.size(), base64_tests[i].plain_length);
+      EXPECT_EQ_ARRAY(decoded2.size(), decoded2, base64_tests[i].plaintext, i);
+    }
+  }
+}
+
+// here's a weird case: a giant base64 encoded stream which broke our base64
+// decoding.  Let's test it explicitly.
+const char SpecificTest[] =
+  "/9j/4AAQSkZJRgABAgEASABIAAD/4Q0HRXhpZgAATU0AKgAAAAgADAEOAAIAAAAgAAAAngEPAAI\n"
+  "AAAAFAAAAvgEQAAIAAAAJAAAAwwESAAMAAAABAAEAAAEaAAUAAAABAAAAzAEbAAUAAAABAAAA1A\n"
+  "EoAAMAAAABAAIAAAExAAIAAAAUAAAA3AEyAAIAAAAUAAAA8AE8AAIAAAAQAAABBAITAAMAAAABA\n"
+  "AIAAIdpAAQAAAABAAABFAAAAsQgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgAFNPTlkA\n"
+  "RFNDLVAyMDAAAAAASAAAAAEAAABIAAAAAUFkb2JlIFBob3Rvc2hvcCA3LjAAMjAwNzowMTozMCA\n"
+  "yMzoxMDowNABNYWMgT1MgWCAxMC40LjgAAByCmgAFAAAAAQAAAmqCnQAFAAAAAQAAAnKIIgADAA\n"
+  "AAAQACAACIJwADAAAAAQBkAACQAAAHAAAABDAyMjCQAwACAAAAFAAAAnqQBAACAAAAFAAAAo6RA\n"
+  "QAHAAAABAECAwCRAgAFAAAAAQAAAqKSBAAKAAAAAQAAAqqSBQAFAAAAAQAAArKSBwADAAAAAQAF\n"
+  "AACSCAADAAAAAQAAAACSCQADAAAAAQAPAACSCgAFAAAAAQAAArqgAAAHAAAABDAxMDCgAQADAAA\n"
+  "AAf//AACgAgAEAAAAAQAAAGSgAwAEAAAAAQAAAGSjAAAHAAAAAQMAAACjAQAHAAAAAQEAAACkAQ\n"
+  "ADAAAAAQAAAACkAgADAAAAAQAAAACkAwADAAAAAQAAAACkBgADAAAAAQAAAACkCAADAAAAAQAAA\n"
+  "ACkCQADAAAAAQAAAACkCgADAAAAAQAAAAAAAAAAAAAACgAAAZAAAAAcAAAACjIwMDc6MDE6MjAg\n"
+  "MjM6MDU6NTIAMjAwNzowMToyMCAyMzowNTo1MgAAAAAIAAAAAQAAAAAAAAAKAAAAMAAAABAAAAB\n"
+  "PAAAACgAAAAYBAwADAAAAAQAGAAABGgAFAAAAAQAAAxIBGwAFAAAAAQAAAxoBKAADAAAAAQACAA\n"
+  "ACAQAEAAAAAQAAAyICAgAEAAAAAQAACd0AAAAAAAAASAAAAAEAAABIAAAAAf/Y/+AAEEpGSUYAA\n"
+  "QIBAEgASAAA/+0ADEFkb2JlX0NNAAL/7gAOQWRvYmUAZIAAAAAB/9sAhAAMCAgICQgMCQkMEQsK\n"
+  "CxEVDwwMDxUYExMVExMYEQwMDAwMDBEMDAwMDAwMDAwMDAwMDAwMDAwMDAwMDAwMDAwMAQ0LCw0\n"
+  "ODRAODhAUDg4OFBQODg4OFBEMDAwMDBERDAwMDAwMEQwMDAwMDAwMDAwMDAwMDAwMDAwMDAwMDA\n"
+  "wMDAz/wAARCABkAGQDASIAAhEBAxEB/90ABAAH/8QBPwAAAQUBAQEBAQEAAAAAAAAAAwABAgQFB\n"
+  "gcICQoLAQABBQEBAQEBAQAAAAAAAAABAAIDBAUGBwgJCgsQAAEEAQMCBAIFBwYIBQMMMwEAAhED\n"
+  "BCESMQVBUWETInGBMgYUkaGxQiMkFVLBYjM0coLRQwclklPw4fFjczUWorKDJkSTVGRFwqN0Nhf\n"
+  "SVeJl8rOEw9N14/NGJ5SkhbSVxNTk9KW1xdXl9VZmdoaWprbG1ub2N0dXZ3eHl6e3x9fn9xEAAg\n"
+  "IBAgQEAwQFBgcHBgU1AQACEQMhMRIEQVFhcSITBTKBkRShsUIjwVLR8DMkYuFygpJDUxVjczTxJ\n"
+  "QYWorKDByY1wtJEk1SjF2RFVTZ0ZeLys4TD03Xj80aUpIW0lcTU5PSltcXV5fVWZnaGlqa2xtbm\n"
+  "9ic3R1dnd4eXp7fH/9oADAMBAAIRAxEAPwDy7bKNTUXNLz9EaJPDWMjxH4ozhtpYwaACT8ShaaW\n"
+  "bW0uEc9/JFfjj0Q4Hk/PRDxwX7y47W9z/AN9Cv4+O3ILK2DcRqT2CaSvEbcl1Jbz37KG1dBldLo\n"
+  "qaS4l9xGjG9v6yoDAdYIaIjUk+AREgo4y5sapirb8Yl0NHHdKvBNm4yA1o5Pc+SPEFvCWqB3HZF\n"
+  "Hj2SbWQ/afGFP0bHP8ATY0uc4w1o1JPkkimGiS2KvqlnmBkOZQTyydzgPMM9v8A0lp4v1Nx9gF1\n"
+  "tpdqJaGtH/S3I0i3lISXW/8AMqnd/O2bfg2eUkqVYf/Q8zuncO4Bj7lZ+n7f5Mj5KsJcY8NUZ4d\n"
+  "uEDVo1HkeU0rg3Om4H2rabCWUN7DQuK1n5FWKW4uCwG92gDRJBS6exhxmMboQI+Cv4WFTQ42Bs2\n"
+  "fvnkkqEmy2YxoMMbpVzaz6jt+RbpHZs8lzkHqrasKkYOKP0jgDfZ4N/wDM1tNrcWfSPmRyq9uNV\n"
+  "DnFg2s97i7UkjxKVrq0eVz3spZsja+ASDzwsh9jnOk/JFzb3XZD3v1c4yT8UACTCniKDUnKz5Nj\n"
+  "G33XV1DV73BrT8dF23SejV4zg9g33cOsPb+SxVvqv9ViwNy8vS0iWs/daf8A0Y5dpTi1sADGxCR\n"
+  "K1o0YBEmInlXWYbDBcDLdPJXa8f71Yrx2jnUoAqLnfZK5hJaW2vdwEk5a/wD/0fN6Ia/e76IiVf\n"
+  "xavUL7CPpnT4LNbYXAVjuQt/AqDmNYO/Kjnoy4hr5J8SwMhrRMaeSvbsxrfUazcOw4UX0Cisem2\n"
+  "SBoD4+Kz8nC6llbSLCRrubJA8kwUWbUDa29X1PMa7aQWjuDC0MXMdbDbhI7eazBiUfZ6GOYRe1s\n"
+  "WvGgJ8Vbw2+m4Bx9s6JpNHuuGo1FF53r/SHYua61gLse0lzXeBP5rkvqx0o5vVWz7WY49QkiQSP\n"
+  "oN/tLoevW/ogxv0HA7tJ0AnhT+pdDGYVl/wCdcTPkGn2NU0JWNWvlgAbHV6fEqdu2gR/r2WlWwt\n"
+  "AA5VXAEsLXTqJafArQY5rRr9LiPBJiZsZCI1pJjxCi0j4oncSICSkWwzwkjeaSch//0vO7sP7Lm\n"
+  "enO9ogtd5FbPT3Q5pCpZVc4ld3Lmn3O8j9EI2BYdunKjOobMQIyI+rusc2wx4d0eutwGnHh/uQc\n"
+  "Ha7ladj6mVANGvcqOgz0Go7HJ12/GEHcwvB/dPY6ImbbaMaASGuIBjkN7qofs9Ubg9g7OI9p/t/\n"
+  "RTSmhTHr0v6eSz6UgCPP2/wAVu9Ex2V49dVY2iACB4BZeVXQ/AJ3gzGnnOi2+kACpru8flUsNmt\n"
+  "zHRf6xfWCnoeAfTh2ZaQKazx/Ke7+QxcKz61fWA2uuObaC4zGhaPJrXBL64ZFmR124O09ENraPK\n"
+  "N3/AH5GqxIrZVUyp2K2vfdkENsDnxuex9m4Ox9n82xSgNd9D+p/XR1npgseR9ppOy4Dx/NfH/CL\n"
+  "oQJGunmvMv8AFq3KHVcq3HkYQbD2nuSf0I/rMavSg6TLjLigQhJ7Z58v9QkmlsTOqSCn/9PzL7R\n"
+  "d6Qq3n0wZ2zotXpT9xLfFYvkr/S7jXeB8E0jRkhKpC3q8LcJ/kmCrTnkuAPCq4do9Q/ytVbuAeY\n"
+  "Gg5lQybQK+82GBqEQUA1kOHPYf3LLsoyN36G5w8iUfHxepbXE2l0cApALgLHzBq9UxhTXU5hMC1\n"
+  "ktnSCup6S4Ctk+C5XqVGcaHPfuiuHkeTTuWz0+9zaKiH6CC0/yXBSQ2a/MxojV57634rq+v2PLY\n"
+  "be1r2nsYG13/AFKxbfCBMcr0brGAzrGEwCG31ncx0SfBzf7S4+zoHUWWsJq3hz9oLfcBH77R9H+\n"
+  "0pA13u/qPgDp/Q6ri39JlfpXkDx+h/msWn1L6wdO6bSbcrIbU2Q0xLnSe21kuVejJspbVS5+4bd\n"
+  "ocBAkD/orG+tP1ar67Wy7GtZTm1SCXfRsb+a18fRe38x6SG3/44H1Z3f0y2I+l6DoSXD/8xPrDs\n"
+  "3enVu3bdnqN3R+//USSVo//1PLohhce+gRWS0Nsby3lRgFkKxQyW7SgUh3em5Tbq2uB9wWw1wey\n"
+  "J1XGV2XYdm5k7e4WzidXY9oMwo5RZ4T6Hd1ixwfp96PWbAJBVTHzK7O6Ky5oJB1HZMqmUEFlkGy\n"
+  "xpa4zI1Hkq31dy7bMN9BAc3HeWAnnbyxEycmuup1jiAGglZ31PyrmZ9tQg1WtNj54EHR3/S2qTH\n"
+  "1Yc5GgD1FFtzPdWGkd2AyflogZmRmsz6PSrbXbdo+txOrP337f3fzVo15DK2uyrTtqpBOnBKx6b\n"
+  "7MjJsz7tHWOAYP3WD6LU6cqGjFCNl1MmvLcxv6YtDTLSAqP27LrdtYHXFnJZI+Tp3MWg68OpDPv\n"
+  "UMUM2lkQBoouKQ6swjE9Nml+1sz1PW+z6xt27zuj+skrX2ZvqR5z8kkuOfdPt43/1fMm/grFG6f\n"
+  "Lss9JA7JG7tnZs/SfJUrfS3foJ9TvHCopJsV8nWx/t24bJn8Fo/5TjWJXMJIS+i+G36TsZ/7Q9P\n"
+  "8ATfzfeOFofVSZv2/zvt+O3X/v65dJPjt/BiyfN1/wn0zre79nVej/ADG8ep4x2/6Srjd6TdviF\n"
+  "52ko8m6/Ht9X1KnftEo+POwxzK8mSTF46vrH6T1/OEl5Okkl//Z/+0uHFBob3Rvc2hvcCAzLjAA\n"
+  "OEJJTQQEAAAAAAArHAIAAAIAAhwCeAAfICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgIAA\n"
+  "4QklNBCUAAAAAABD7Caa9B0wqNp2P4sxXqayFOEJJTQPqAAAAAB2wPD94bWwgdmVyc2lvbj0iMS\n"
+  "4wIiBlbmNvZGluZz0iVVRGLTgiPz4KPCFET0NUWVBFIHBsaXN0IFBVQkxJQyAiLS8vQXBwbGUgQ\n"
+  "29tcHV0ZXIvL0RURCBQTElTVCAxLjAvL0VOIiAiaHR0cDovL3d3dy5hcHBsZS5jb20vRFREcy9Q\n"
+  "cm9wZXJ0eUxpc3QtMS4wLmR0ZCI+CjxwbGlzdCB2ZXJzaW9uPSIxLjAiPgo8ZGljdD4KCTxrZXk\n"
+  "+Y29tLmFwcGxlLnByaW50LlBhZ2VGb3JtYXQuUE1Ib3Jpem9udGFsUmVzPC9rZXk+Cgk8ZGljdD\n"
+  "4KCQk8a2V5PmNvbS5hcHBsZS5wcmludC50aWNrZXQuY3JlYXRvcjwva2V5PgoJCTxzdHJpbmc+Y\n"
+  "29tLmFwcGxlLnByaW50aW5nbWFuYWdlcjwvc3RyaW5nPgoJCTxrZXk+Y29tLmFwcGxlLnByaW50\n"
+  "LnRpY2tldC5pdGVtQXJyYXk8L2tleT4KCQk8YXJyYXk+CgkJCTxkaWN0PgoJCQkJPGtleT5jb20\n"
+  "uYXBwbGUucHJpbnQuUGFnZUZvcm1hdC5QTUhvcml6b250YWxSZXM8L2tleT4KCQkJCTxyZWFsPj\n"
+  "cyPC9yZWFsPgoJCQkJPGtleT5jb20uYXBwbGUucHJpbnQudGlja2V0LmNsaWVudDwva2V5PgoJC\n"
+  "QkJPHN0cmluZz5jb20uYXBwbGUucHJpbnRpbmdtYW5hZ2VyPC9zdHJpbmc+CgkJCQk8a2V5PmNv\n"
+  "bS5hcHBsZS5wcmludC50aWNrZXQubW9kRGF0ZTwva2V5PgoJCQkJPGRhdGU+MjAwNy0wMS0zMFQ\n"
+  "yMjowODo0MVo8L2RhdGU+CgkJCQk8a2V5PmNvbS5hcHBsZS5wcmludC50aWNrZXQuc3RhdGVGbG\n"
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+  "YGRMqGx8BTB0eEjQhVSYnLxMyQ0Q4IWklMlomOywgdz0jXiRIMXVJMICQoYGSY2RRonZHRVN/Kj\n"
+  "s8MoKdPj84SUpLTE1OT0ZXWFlaW1xdXl9UZWZnaGlqa2xtbm9kdXZ3eHl6e3x9fn9zhIWGh4iJi\n"
+  "ouMjY6Pg5SVlpeYmZqbnJ2en5KjpKWmp6ipqqusra6vr/2gAMAwEAAhEDEQA/APBnplwPAdR+GB\n"
+  "KY6dYtNG1w39yh4+xb+zIksgEfFaRSSoIx8f7RPRRkSWQimM+lRmwWVXFWYigHxUUVoMiJM+Fj0\n"
+  "tg0RBegLE0Wu+3c+GTBazFCGI7HtSp9slbFYYzyoBsegw2hY1Afl3wqqRqahk+0tDgKpgu4DAUU\n"
+  "+HY+GRS2ePiMKtUB3G+KGuONq//Q8OzpFbW5WnxMop4k9crG5ZnZNJkEOn21utVRYw7HxZtz+OR\n"
+  "vdsrZ2lRtci4aVxFEQA0neg/ZXxJpTITNNuOFss0vSotYNvZ2qGRkPKSTqiU8Sdqk5SZU5Ix8XJ\n"
+  "NNZ8k6bp8TtM73OputUtYq0Unux/hkRkJOzZLCAN2KR+VpbtSkCBaDnIzdlWu59u+XeJTjeASk8\n"
+  "+juZOESEAVqx8BvU/PJibScTrTy09560hkWOGFd2YgFnPQKD19zhOSkxw2l8Vm6XAiYb8gg+k5O\n"
+  "9mnhoon9H3cs5s7WF5pp29OGGMFndyaAKBuTiEEPQLD8h/NDmNdYlttNkYjlbFjcXCr3LLH8II8\n"
+  "C2WUGviZvon/OPWkm3RNSv72SYllMkKxQRV67CQMSKYQAxMkR/wBC56d61P0heel4cYuVOXWvTp\n"
+  "h4Qjjf/9Hw5qBYyISaqjBV+QpvkAzKcki4HomnIxck/wBhtlR2bhunvlDywddMUl4zW+kQ9FQ8X\n"
+  "nfuSewrtmPkycPvc/DhMhvyegXOrWWhmLQPKlsj6xIAiLCoZkY96nv7npmJvI2XOjQFMl0fyRqM\n"
+  "NoxvZvrGt33wlATwiMnVnY1LEdSfuyXF3KIDmUu88w2XlnTl8raAlb2ZFfVL0jdYRtQnxc7BfDC\n"
+  "OaJR7nm3me5tdOtjbMvp3ZRXkV6chVQRX79hmVjgZG+jgZ5jHGhzecXF5LPL6jEjstSSaDM51Ka\n"
+  "6MZ9S1C0sEBe8uZo4YCBXdjxGw60wEWyEqfUHkT8vLXRJFuLdTcaqfhlvWUErtukZ3ABPUjIXTE\n"
+  "m3rGmeV2Tk5UKz/AG/E/wAcgZKya20C3b02kjYtH8AqCygbkUH0nLYlgUb+gbWtPbpXt/n2ybB/\n"
+  "/9Lw4oaVxGd+PxH3qBkGaY3KyiSP01IkiUclH8sg+LKydm6INvZvKsFu+kWtvD8LRoFNRup6moO\n"
+  "aqd277HsGW+XPLmn6XM17FF6l7vW4fd2Zuu+RFls2tmUNrLJb7TSBertGQGqetDkxE0na0pvtHs\n"
+  "QkszWyiGAG5laYlnkeMVHJj8sA5rPk+SvMepTalqlxd3B5zTOXdj/MxqafLpm5xioh5nPK5kpRG\n"
+  "pkcKAST0A6k5NpfUP5K/ki1ssHmHzF+71KRQ8Nud/Qibb/kYw6/yjbrXISlSH07YaHbWyxx2kXE\n"
+  "KACB2zHJtLI7XSelBRvH2xCpvaaTDHXkOTVBPcUG2479RlsdmJVPRtvV+ylenQ0y62FP/9PxRpo\n"
+  "WG5FxKKxKFDA+GVS5NsebLdFsRePc3siVW4f4QR0QVAGYeSXR2unhtZ6s60K6jt+MMSFwtF2+xX\n"
+  "wr7eGUGLlRPQMsE2vxQm7itxKg3VCfT2+nb8cDYaCDtfOXmCCcROrQrUhkkCHYn6emRMqZxjbLd\n"
+  "F1+W/4xajHzjNCtQKMffETWUdngX5p+QZ9A8xS6hbo0ui37NNDPT7DOalHpsCD08Rmyw5ARTpdV\n"
+  "gIPEF35MeRn80ed4S5EdrpKm9kZ15K0iH92hB7Me/tmS60vt/QrCYyekiBdgSTXcjqV9q9MokFD\n"
+  "N7S3aFVVR8RoK9zldqndvAY6nffr/AGYQqLhjdpCoIAZW22HavU/LJBUP9WblX0xTw7fOmWsX/9\n"
+  "Tw7FdvMqWkQ3Z1qfED+mQIbI77PX/LFis9vBajZm2Y+x65rMh3t30Bsze400aVaIbSLk6r8CMRT\n"
+  "l/NmOcllnGDD9Y8uecNfEEiXrMgDGWAyGOOu5WlB+vMrHODTlxZCdjsyFdB006VpVtLasurQxBL\n"
+  "64WiLI4/aFT1ANOXemV5piR2b9NiljB4yyHy9CLOVI5GJhB+CvXY9R8xmINzs5HNZ+Z96BZpbxA\n"
+  "fVJo39UFefwopYgL4nMiMd2qZoIn/AJx00u3t/Lt7qpp9Yv5GLf5MUTERqfbvmzBeezjd9H+VlL\n"
+  "wSQzBqsvOGQD7L12rXsemPNxmXQSxxIPU2nFV4HYqR1xEUWj4ZAxBryr2G+J2VGDZlLrxUH6KZA\n"
+  "Fkqb15VFelfwy+2FP8A/9Xxlf6AdA182Yk9eFeLxSjoVfcfSMo4uIOfkweFOnpvlWYrLEwNFAA+\n"
+  "nMOYdrhFvQLeSO7coBXiK8iKiv07Zj8Ac4QtNrW1njUcKcT+yAR/xGmR4WcsStLpTuPU9IFaEsV\n"
+  "BP3k4m2AgBzSwyQNcIwNTE1aI3wnam9O2Ug7s5Ckk/NDndeVXa2H78MqqV6jmeBp9+ZWKXqDjZ4\n"
+  "+gvVvy30qCy0qzsLRBCnBI2VdgUTqPvOZ7y+Q7pz+bn5q6d+VflZxZlJ/NN4ypptk5qtB9qRwDX\n"
+  "gn/AAx2y2ItpfKFv+eH5qNeTajJ5ovVaVywSqvEtTUKqupAA6D2y0BNPtv/AJx//M5PzL8mJeXT\n"
+  "L+ndPf6rqarSpkAqsnEAAeoN6DpkJRYci9lROSgSUUH9o9K5Tw0ztfSHnXkOtK9q+PHwydq//9b\n"
+  "yxrVoZNBtNSA5zRMPXmH8j0CLXuBmHE+qneamHpEuqYeV7pzFVTRgQK5XMNmnlb1vyyY5QA1OwJ\n"
+  "+eUF2seTOLu5s7azVIVAkpVn/hhnIALG73Yz5jvb1dICqzpDNIqyFD8SxH7R28cxibZCiWOsdJs\n"
+  "PTM6XNstPhnkjIhcHuJBVfvOCiUSn0TfWrTTLjyw8guA/PifTO3xcxxA8a5ZAbimvJP0m3p/kFF\n"
+  "WxhmpWQJ9NW3zZPHz5vlb/nIDVbrWfzO1RJhxGnpDaRL/khA1T7ktmSOTAJhZaAUtLawsbayl8v\n"
+  "xWi3Gpay0cF3HPcFRJJHJMXVrcJ8UaAFG5LWjF8tAYW9H/wCcOo9bTzxrt/owkTyksZW5gkIKvI\n"
+  "7k26nvyReRJHyyBWT7dWQyOWlbnK2526e1O1MqIUFE84uPLkOdK9RXI0E2/wD/1/DA1bURZLY/W\n"
+  "ZDZqwb0eXw7dMgIi7bjllVXsz7yNcfWC0Vd3Ip92Y2UOz0cnsPlwyx8xQ/u24sMxCadoJp9LOXk\n"
+  "VX/uwRUE0BI8cokbLMyoKouHu2MaKGXw7fLDwgoGSkbHpaNZyLLHRSKcFFQQRvUdMlwUFOQyLzr\n"
+  "ztpCaba6fPau4ijv4OURY8AjVFKV7ZZiO+7Vnh6XvXkSWNbW2WTb92KDxIFMzwHlZc3zX+fuizW\n"
+  "f5p3ty8XGDU4YLmCQiisyII3+4rvl8UB5ffEghRGvOm7AbnvWvjk1fen/ONPldPKP5aWOpPCfr2\n"
+  "uE31y6q2wbaMEn+VAMDSdyzrzj+avlHyTp0l/r2rxWFuHWJuIeacu4qFCRgsajfBwsty89/6Gr/\n"
+  "ACa9an+JL/hSnrfoubhXwpXpjwhaL//Q8E1AqtcAZMs8l6i1nqMa1oSVP0VynKLDmaWdSfQXl69\n"
+  "jF1Jv8MhDb5rpB3AO7INRRLhhGp4R05FgaGvTMU8200xS70zVDMRp2pTIOvBmB3PgQP15kxIcnD\n"
+  "LH/EEz0rRvOJhldr9pQtCqyd6VrShGTqw5d4ARv9jHfOGl+ZJNMluLkyenaFbiRdqFYW5nrWuwO\n"
+  "MKB5MdSMRxnhlu9N8p6lLFpti63FUjCtFJTrDKvse2bEDZ4XJ9RZB+YPli2/Mjy5bxoUi1a0YS2\n"
+  "85UOwIXiy9jRu+TBppfOF1+V3m22vrdpNPM8cs/oo0VJlUqQPjValR3+IZNNvtLS9Yu9Mi0/TJr\n"
+  "kyp6QhWVVCIWRATsKBemwwFrDzT87fybs/wA1bW21PRb+DTvNlgGSRp6iC8i3KJJx+y6n7D0Pwm\n"
+  "hxBZXT55/6Fi/Nf0PW+qWXq+t6X1X67F6vD/ftK04V/wBl344U8b//0fBapxheVh9ocV+nviqY2\n"
+  "/qQJDew/bioWHiuQ8m0bbvaPKGtQ6jaxSo9JloCK75gZI0Xb4sgkHo8MouoAvP94BsRmGY7uWJU\n"
+  "gzbypOQpNOvIdK4Nw2WCE2tXulTkjEEbdafgclxMhFBas93dwyQzsWDghlJFONKHJCZtjOFBJfy\n"
+  "j1y9vPL9zpbIs0WkXL2sUjA8hDXlGCRXtt07ZuYvL5KJeo6bfajbkzWkcToR8dqshZ6in2fhNK/\n"
+  "PDTUlXmHVvMdr5o0v9H2kdrqGpfu7m0nkY87Uf7tkKAU4/s03ynLkEBbfihx7dGT6va67LbRMNR\n"
+  "aKOBuUTKgIBXoK1BOYR1M3aQ0mOt9yxUeZNdtJhFapLqMluSXkg5oxJrUMW5KevQ9MmNXXNqOiH\n"
+  "Rr/Hmv8A1r9I/oj95w+r+j9Yf1+NP5+nXtTD+dF8tkfkOlv/0vC3ph7f0/alcVTbS4A8QibuKb5\n"
+  "RI05EBYRFpdX3ly79a2qYCavH/EY7TCYyMD5PSdD8+wXUSn1ArDqOhBzFlipz4ZwWbaV5htbsgF\n"
+  "qg9crMXKErGyYwajFGzxyHlGSePbbwyqg5UZlCaxrFpaWU95LIqrEjMAT4Dp9OShGy1ZslBhv/A\n"
+  "Dj9rd/a+aL+xUK+m38L3d0HrxRo2HFtu5D8c27y8t30raarbWkU+u6g4gsNORn+EcUaSh2Pc0/4\n"
+  "lgtAjezzbT9SutY1i782al8Nxdyotqh6xWybIg+jc5q8s+I27bFDgFPQp9RE+nrag70+L6crrZu\n"
+  "4jajokdv6LW/Dii1Wo61PXKQN3KPK0L+h4/rnD/K5V78a5LhXxd3/0/DMXXtwxVNtL9Xkaf3f7N\n"
+  "etfbKMjdjtkZ9D6ufrlK0+HpX8coF9HJ26sXvfqXrf7i/U+uften/d/wCyrmQL6uOav0pvpP8Ai\n"
+  "b1F+rV59+vH6a5XLhcjH4nRmY/xpxHP0/UptWvT6Mx/RbmjxWK+aP8AFf1M/pCv1Kvxen9inavf\n"
+  "MrFwXtzcLUeLXq5Mv/I3nz1b0v8AjofuKVry9KrUpTanOlf9jmQ68va/zH9b/COn/o7/AI431mP\n"
+  "65SvLh+zWvbl9rMfNfC34K4kmj9T6lD6FKclp/DNYXZx5srsPrHor6nXvkgxTPS/U+rv6dPU5mt\n"
+  "fngFN5ulv+l/pL/Lp/scerHo//2Q==\n";
+
+static std::string gCommandLine;
+
+TEST(Base64, LargeSample) {
+  LOG(LS_VERBOSE) << "Testing specific base64 file";
+
+  char unescaped[64 * 1024];
+
+  // unescape that massive blob above
+  size_t size = Base64Unescape(SpecificTest,
+                            sizeof(SpecificTest),
+                            unescaped,
+                            sizeof(unescaped));
+
+  EXPECT_EQ(size, sizeof(testbase64));
+  EXPECT_EQ(0, memcmp(testbase64, unescaped, sizeof(testbase64)));
+}
+
+bool DecodeTest(const char* encoded, size_t expect_unparsed,
+                const char* decoded, Base64::DecodeFlags flags)
+{
+  std::string result;
+  size_t consumed = 0, encoded_len = strlen(encoded);
+  bool success = Base64::DecodeFromArray(encoded, encoded_len, flags,
+                                         &result, &consumed);
+  size_t unparsed = encoded_len - consumed;
+  EXPECT_EQ(expect_unparsed, unparsed) << "\"" << encoded
+                                       << "\" -> \"" << decoded
+                                       << "\"";
+  EXPECT_STREQ(decoded, result.c_str());
+  return success;
+}
+
+#define Flags(x,y,z) \
+  Base64::DO_PARSE_##x | Base64::DO_PAD_##y | Base64::DO_TERM_##z
+
+TEST(Base64, DecodeParseOptions) {
+  // Trailing whitespace
+  EXPECT_TRUE (DecodeTest("YWJjZA== ", 1, "abcd", Flags(STRICT, YES, CHAR)));
+  EXPECT_TRUE (DecodeTest("YWJjZA== ", 0, "abcd", Flags(WHITE,  YES, CHAR)));
+  EXPECT_TRUE (DecodeTest("YWJjZA== ", 0, "abcd", Flags(ANY,    YES, CHAR)));
+
+  // Embedded whitespace
+  EXPECT_FALSE(DecodeTest("YWJjZA= =", 3, "abcd", Flags(STRICT, YES, CHAR)));
+  EXPECT_TRUE (DecodeTest("YWJjZA= =", 0, "abcd", Flags(WHITE,  YES, CHAR)));
+  EXPECT_TRUE (DecodeTest("YWJjZA= =", 0, "abcd", Flags(ANY,    YES, CHAR)));
+
+  // Embedded non-base64 characters
+  EXPECT_FALSE(DecodeTest("YWJjZA=*=", 3, "abcd", Flags(STRICT, YES, CHAR)));
+  EXPECT_FALSE(DecodeTest("YWJjZA=*=", 3, "abcd", Flags(WHITE,  YES, CHAR)));
+  EXPECT_TRUE (DecodeTest("YWJjZA=*=", 0, "abcd", Flags(ANY,    YES, CHAR)));
+
+  // Unexpected padding characters
+  EXPECT_FALSE(DecodeTest("YW=JjZA==", 7, "a",    Flags(STRICT, YES, CHAR)));
+  EXPECT_FALSE(DecodeTest("YW=JjZA==", 7, "a",    Flags(WHITE,  YES, CHAR)));
+  EXPECT_TRUE (DecodeTest("YW=JjZA==", 0, "abcd", Flags(ANY,    YES, CHAR)));
+}
+
+TEST(Base64, DecodePadOptions) {
+  // Padding
+  EXPECT_TRUE (DecodeTest("YWJjZA==",  0, "abcd", Flags(STRICT, YES, CHAR)));
+  EXPECT_TRUE (DecodeTest("YWJjZA==",  0, "abcd", Flags(STRICT, ANY, CHAR)));
+  EXPECT_TRUE (DecodeTest("YWJjZA==",  2, "abcd", Flags(STRICT, NO,  CHAR)));
+
+  // Incomplete padding
+  EXPECT_FALSE(DecodeTest("YWJjZA=",   1, "abcd", Flags(STRICT, YES, CHAR)));
+  EXPECT_TRUE (DecodeTest("YWJjZA=",   1, "abcd", Flags(STRICT, ANY, CHAR)));
+  EXPECT_TRUE (DecodeTest("YWJjZA=",   1, "abcd", Flags(STRICT, NO,  CHAR)));
+
+  // No padding
+  EXPECT_FALSE(DecodeTest("YWJjZA",    0, "abcd", Flags(STRICT, YES, CHAR)));
+  EXPECT_TRUE (DecodeTest("YWJjZA",    0, "abcd", Flags(STRICT, ANY, CHAR)));
+  EXPECT_TRUE (DecodeTest("YWJjZA",    0, "abcd", Flags(STRICT, NO,  CHAR)));
+}
+
+TEST(Base64, DecodeTerminateOptions) {
+  // Complete quantum
+  EXPECT_TRUE (DecodeTest("YWJj",      0, "abc",  Flags(STRICT, NO,  BUFFER)));
+  EXPECT_TRUE (DecodeTest("YWJj",      0, "abc",  Flags(STRICT, NO,  CHAR)));
+  EXPECT_TRUE (DecodeTest("YWJj",      0, "abc",  Flags(STRICT, NO,  ANY)));
+
+  // Complete quantum with trailing data
+  EXPECT_FALSE(DecodeTest("YWJj*",     1, "abc",  Flags(STRICT, NO,  BUFFER)));
+  EXPECT_TRUE (DecodeTest("YWJj*",     1, "abc",  Flags(STRICT, NO,  CHAR)));
+  EXPECT_TRUE (DecodeTest("YWJj*",     1, "abc",  Flags(STRICT, NO,  ANY)));
+
+  // Incomplete quantum
+  EXPECT_FALSE(DecodeTest("YWJ",       0, "ab",   Flags(STRICT, NO,  BUFFER)));
+  EXPECT_FALSE(DecodeTest("YWJ",       0, "ab",   Flags(STRICT, NO,  CHAR)));
+  EXPECT_TRUE (DecodeTest("YWJ",       0, "ab",   Flags(STRICT, NO,  ANY)));
+}
+
+TEST(Base64, GetNextBase64Char) {
+  // The table looks like this:
+  // "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
+  char next_char;
+  EXPECT_TRUE(Base64::GetNextBase64Char('A', &next_char));
+  EXPECT_EQ('B', next_char);
+  EXPECT_TRUE(Base64::GetNextBase64Char('Z', &next_char));
+  EXPECT_EQ('a', next_char);
+  EXPECT_TRUE(Base64::GetNextBase64Char('/', &next_char));
+  EXPECT_EQ('A', next_char);
+  EXPECT_FALSE(Base64::GetNextBase64Char('&', &next_char));
+  EXPECT_FALSE(Base64::GetNextBase64Char('Z', nullptr));
+}

webrtc/rtc_base/basictypes.h

@@ -0,0 +1,70 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_BASICTYPES_H_
+#define WEBRTC_RTC_BASE_BASICTYPES_H_
+
+#include <stddef.h>  // for NULL, size_t
+#include <stdint.h>  // for uintptr_t and (u)int_t types.
+
+// Detect compiler is for x86 or x64.
+#if defined(__x86_64__) || defined(_M_X64) || \
+    defined(__i386__) || defined(_M_IX86)
+#define CPU_X86 1
+#endif
+
+// Detect compiler is for arm.
+#if defined(__arm__) || defined(_M_ARM)
+#define CPU_ARM 1
+#endif
+
+#if defined(CPU_X86) && defined(CPU_ARM)
+#error CPU_X86 and CPU_ARM both defined.
+#endif
+
+#if !defined(RTC_ARCH_CPU_BIG_ENDIAN) && !defined(RTC_ARCH_CPU_LITTLE_ENDIAN)
+// x86, arm or GCC provided __BYTE_ORDER__ macros
+#if defined(CPU_X86) || defined(CPU_ARM) ||                             \
+  (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
+#define RTC_ARCH_CPU_LITTLE_ENDIAN
+#elif defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#define RTC_ARCH_CPU_BIG_ENDIAN
+#else
+#error RTC_ARCH_CPU_BIG_ENDIAN or RTC_ARCH_CPU_LITTLE_ENDIAN should be defined.
+#endif
+#endif
+
+#if defined(RTC_ARCH_CPU_BIG_ENDIAN) && defined(RTC_ARCH_CPU_LITTLE_ENDIAN)
+#error RTC_ARCH_CPU_BIG_ENDIAN and RTC_ARCH_CPU_LITTLE_ENDIAN both defined.
+#endif
+
+#if defined(WEBRTC_WIN)
+typedef int socklen_t;
+#endif
+
+// The following only works for C++
+#ifdef __cplusplus
+
+#ifndef ALIGNP
+#define ALIGNP(p, t)                                             \
+  (reinterpret_cast<uint8_t*>(((reinterpret_cast<uintptr_t>(p) + \
+  ((t) - 1)) & ~((t) - 1))))
+#endif
+
+#define RTC_IS_ALIGNED(p, a) (!((uintptr_t)(p) & ((a) - 1)))
+
+// Use these to declare and define a static local variable that gets leaked so
+// that its destructors are not called at exit.
+#define RTC_DEFINE_STATIC_LOCAL(type, name, arguments) \
+  static type& name = *new type arguments
+
+#endif  // __cplusplus
+
+#endif  // WEBRTC_RTC_BASE_BASICTYPES_H_

webrtc/rtc_base/basictypes_unittest.cc

@@ -0,0 +1,48 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/basictypes.h"
+
+#include "webrtc/base/gunit.h"
+
+namespace rtc {
+
+TEST(BasicTypesTest, Endian) {
+  uint16_t v16 = 0x1234u;
+  uint8_t first_byte = *reinterpret_cast<uint8_t*>(&v16);
+#if defined(RTC_ARCH_CPU_LITTLE_ENDIAN)
+  EXPECT_EQ(0x34u, first_byte);
+#elif defined(RTC_ARCH_CPU_BIG_ENDIAN)
+  EXPECT_EQ(0x12u, first_byte);
+#endif
+}
+
+TEST(BasicTypesTest, SizeOfConstants) {
+  EXPECT_EQ(8u, sizeof(INT64_C(0)));
+  EXPECT_EQ(8u, sizeof(UINT64_C(0)));
+  EXPECT_EQ(8u, sizeof(INT64_C(0x1234567887654321)));
+  EXPECT_EQ(8u, sizeof(UINT64_C(0x8765432112345678)));
+}
+
+// Test CPU_ macros
+#if !defined(CPU_ARM) && defined(__arm__)
+#error expected CPU_ARM to be defined.
+#endif
+#if !defined(CPU_X86) && (defined(WEBRTC_WIN) || defined(WEBRTC_MAC) && !defined(WEBRTC_IOS))
+#error expected CPU_X86 to be defined.
+#endif
+#if !defined(RTC_ARCH_CPU_LITTLE_ENDIAN) && \
+  (defined(WEBRTC_WIN) || defined(WEBRTC_MAC) && !defined(WEBRTC_IOS) || defined(CPU_X86))
+#error expected RTC_ARCH_CPU_LITTLE_ENDIAN to be defined.
+#endif
+
+// TODO(fbarchard): Test all macros in basictypes.h
+
+}  // namespace rtc

webrtc/rtc_base/bind.h

@@ -0,0 +1,284 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+// Bind() is an overloaded function that converts method calls into function
+// objects (aka functors). The method object is captured as a scoped_refptr<> if
+// possible, and as a raw pointer otherwise. Any arguments to the method are
+// captured by value. The return value of Bind is a stateful, nullary function
+// object. Care should be taken about the lifetime of objects captured by
+// Bind(); the returned functor knows nothing about the lifetime of a non
+// ref-counted method object or any arguments passed by pointer, and calling the
+// functor with a destroyed object will surely do bad things.
+//
+// To prevent the method object from being captured as a scoped_refptr<>, you
+// can use Unretained. But this should only be done when absolutely necessary,
+// and when the caller knows the extra reference isn't needed.
+//
+// Example usage:
+//   struct Foo {
+//     int Test1() { return 42; }
+//     int Test2() const { return 52; }
+//     int Test3(int x) { return x*x; }
+//     float Test4(int x, float y) { return x + y; }
+//   };
+//
+//   int main() {
+//     Foo foo;
+//     cout << rtc::Bind(&Foo::Test1, &foo)() << endl;
+//     cout << rtc::Bind(&Foo::Test2, &foo)() << endl;
+//     cout << rtc::Bind(&Foo::Test3, &foo, 3)() << endl;
+//     cout << rtc::Bind(&Foo::Test4, &foo, 7, 8.5f)() << endl;
+//   }
+//
+// Example usage of ref counted objects:
+//   struct Bar {
+//     int AddRef();
+//     int Release();
+//
+//     void Test() {}
+//     void BindThis() {
+//       // The functor passed to AsyncInvoke() will keep this object alive.
+//       invoker.AsyncInvoke(RTC_FROM_HERE,rtc::Bind(&Bar::Test, this));
+//     }
+//   };
+//
+//   int main() {
+//     rtc::scoped_refptr<Bar> bar = new rtc::RefCountedObject<Bar>();
+//     auto functor = rtc::Bind(&Bar::Test, bar);
+//     bar = nullptr;
+//     // The functor stores an internal scoped_refptr<Bar>, so this is safe.
+//     functor();
+//   }
+//
+
+#ifndef WEBRTC_RTC_BASE_BIND_H_
+#define WEBRTC_RTC_BASE_BIND_H_
+
+#include <tuple>
+#include <type_traits>
+
+#include "webrtc/base/scoped_ref_ptr.h"
+#include "webrtc/base/template_util.h"
+
+#define NONAME
+
+namespace rtc {
+namespace detail {
+// This is needed because the template parameters in Bind can't be resolved
+// if they're used both as parameters of the function pointer type and as
+// parameters to Bind itself: the function pointer parameters are exact
+// matches to the function prototype, but the parameters to bind have
+// references stripped. This trick allows the compiler to dictate the Bind
+// parameter types rather than deduce them.
+template <class T> struct identity { typedef T type; };
+
+// IsRefCounted<T>::value will be true for types that can be used in
+// rtc::scoped_refptr<T>, i.e. types that implements nullary functions AddRef()
+// and Release(), regardless of their return types. AddRef() and Release() can
+// be defined in T or any superclass of T.
+template <typename T>
+class IsRefCounted {
+  // This is a complex implementation detail done with SFINAE.
+
+  // Define types such that sizeof(Yes) != sizeof(No).
+  struct Yes { char dummy[1]; };
+  struct No { char dummy[2]; };
+  // Define two overloaded template functions with return types of different
+  // size. This way, we can use sizeof() on the return type to determine which
+  // function the compiler would have chosen. One function will be preferred
+  // over the other if it is possible to create it without compiler errors,
+  // otherwise the compiler will simply remove it, and default to the less
+  // preferred function.
+  template <typename R>
+  static Yes test(R* r, decltype(r->AddRef(), r->Release(), 42));
+  template <typename C> static No test(...);
+
+public:
+  // Trick the compiler to tell if it's possible to call AddRef() and Release().
+  static const bool value = sizeof(test<T>((T*)nullptr, 42)) == sizeof(Yes);
+};
+
+// TernaryTypeOperator is a helper class to select a type based on a static bool
+// value.
+template <bool condition, typename IfTrueT, typename IfFalseT>
+struct TernaryTypeOperator {};
+
+template <typename IfTrueT, typename IfFalseT>
+struct TernaryTypeOperator<true, IfTrueT, IfFalseT> {
+  typedef IfTrueT type;
+};
+
+template <typename IfTrueT, typename IfFalseT>
+struct TernaryTypeOperator<false, IfTrueT, IfFalseT> {
+  typedef IfFalseT type;
+};
+
+// PointerType<T>::type will be scoped_refptr<T> for ref counted types, and T*
+// otherwise.
+template <class T>
+struct PointerType {
+  typedef typename TernaryTypeOperator<IsRefCounted<T>::value,
+                                       scoped_refptr<T>,
+                                       T*>::type type;
+};
+
+template <typename T>
+class UnretainedWrapper {
+ public:
+  explicit UnretainedWrapper(T* o) : ptr_(o) {}
+  T* get() const { return ptr_; }
+
+ private:
+  T* ptr_;
+};
+
+}  // namespace detail
+
+template <typename T>
+static inline detail::UnretainedWrapper<T> Unretained(T* o) {
+  return detail::UnretainedWrapper<T>(o);
+}
+
+template <class ObjectT, class MethodT, class R, typename... Args>
+class MethodFunctor {
+ public:
+  MethodFunctor(MethodT method, ObjectT* object, Args... args)
+      : method_(method), object_(object), args_(args...) {}
+  R operator()() const {
+    return CallMethod(typename sequence_generator<sizeof...(Args)>::type());
+  }
+
+ private:
+  // Use sequence_generator (see template_util.h) to expand a MethodFunctor
+  // with 2 arguments to (std::get<0>(args_), std::get<1>(args_)), for
+  // instance.
+  template <int... S>
+  R CallMethod(sequence<S...>) const {
+    return (object_->*method_)(std::get<S>(args_)...);
+  }
+
+  MethodT method_;
+  typename detail::PointerType<ObjectT>::type object_;
+  typename std::tuple<typename std::remove_reference<Args>::type...> args_;
+};
+
+template <class ObjectT, class MethodT, class R, typename... Args>
+class UnretainedMethodFunctor {
+ public:
+  UnretainedMethodFunctor(MethodT method,
+                          detail::UnretainedWrapper<ObjectT> object,
+                          Args... args)
+      : method_(method), object_(object.get()), args_(args...) {}
+  R operator()() const {
+    return CallMethod(typename sequence_generator<sizeof...(Args)>::type());
+  }
+
+ private:
+  // Use sequence_generator (see template_util.h) to expand an
+  // UnretainedMethodFunctor with 2 arguments to (std::get<0>(args_),
+  // std::get<1>(args_)), for instance.
+  template <int... S>
+  R CallMethod(sequence<S...>) const {
+    return (object_->*method_)(std::get<S>(args_)...);
+  }
+
+  MethodT method_;
+  ObjectT* object_;
+  typename std::tuple<typename std::remove_reference<Args>::type...> args_;
+};
+
+template <class FunctorT, class R, typename... Args>
+class Functor {
+ public:
+  Functor(const FunctorT& functor, Args... args)
+      : functor_(functor), args_(args...) {}
+  R operator()() const {
+    return CallFunction(typename sequence_generator<sizeof...(Args)>::type());
+  }
+
+ private:
+  // Use sequence_generator (see template_util.h) to expand a Functor
+  // with 2 arguments to (std::get<0>(args_), std::get<1>(args_)), for
+  // instance.
+  template <int... S>
+  R CallFunction(sequence<S...>) const {
+    return functor_(std::get<S>(args_)...);
+  }
+
+  FunctorT functor_;
+  typename std::tuple<typename std::remove_reference<Args>::type...> args_;
+};
+
+#define FP_T(x) R (ObjectT::*x)(Args...)
+
+template <class ObjectT, class R, typename... Args>
+MethodFunctor<ObjectT, FP_T(NONAME), R, Args...> Bind(
+    FP_T(method),
+    ObjectT* object,
+    typename detail::identity<Args>::type... args) {
+  return MethodFunctor<ObjectT, FP_T(NONAME), R, Args...>(method, object,
+                                                          args...);
+}
+
+template <class ObjectT, class R, typename... Args>
+MethodFunctor<ObjectT, FP_T(NONAME), R, Args...> Bind(
+    FP_T(method),
+    const scoped_refptr<ObjectT>& object,
+    typename detail::identity<Args>::type... args) {
+  return MethodFunctor<ObjectT, FP_T(NONAME), R, Args...>(method, object.get(),
+                                                          args...);
+}
+
+template <class ObjectT, class R, typename... Args>
+UnretainedMethodFunctor<ObjectT, FP_T(NONAME), R, Args...> Bind(
+    FP_T(method),
+    detail::UnretainedWrapper<ObjectT> object,
+    typename detail::identity<Args>::type... args) {
+  return UnretainedMethodFunctor<ObjectT, FP_T(NONAME), R, Args...>(
+      method, object, args...);
+}
+
+#undef FP_T
+#define FP_T(x) R (ObjectT::*x)(Args...) const
+
+template <class ObjectT, class R, typename... Args>
+MethodFunctor<const ObjectT, FP_T(NONAME), R, Args...> Bind(
+    FP_T(method),
+    const ObjectT* object,
+    typename detail::identity<Args>::type... args) {
+  return MethodFunctor<const ObjectT, FP_T(NONAME), R, Args...>(method, object,
+                                                                args...);
+}
+template <class ObjectT, class R, typename... Args>
+UnretainedMethodFunctor<const ObjectT, FP_T(NONAME), R, Args...> Bind(
+    FP_T(method),
+    detail::UnretainedWrapper<const ObjectT> object,
+    typename detail::identity<Args>::type... args) {
+  return UnretainedMethodFunctor<const ObjectT, FP_T(NONAME), R, Args...>(
+      method, object, args...);
+}
+
+#undef FP_T
+#define FP_T(x) R (*x)(Args...)
+
+template <class R, typename... Args>
+Functor<FP_T(NONAME), R, Args...> Bind(
+    FP_T(function),
+    typename detail::identity<Args>::type... args) {
+  return Functor<FP_T(NONAME), R, Args...>(function, args...);
+}
+
+#undef FP_T
+
+}  // namespace rtc
+
+#undef NONAME
+
+#endif  // WEBRTC_RTC_BASE_BIND_H_

webrtc/rtc_base/bind_unittest.cc

@@ -0,0 +1,222 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <type_traits>
+
+#include "webrtc/base/bind.h"
+#include "webrtc/base/gunit.h"
+
+#include "webrtc/base/refcount.h"
+
+namespace rtc {
+
+namespace {
+
+struct LifeTimeCheck;
+
+struct MethodBindTester {
+  void NullaryVoid() { ++call_count; }
+  int NullaryInt() { ++call_count; return 1; }
+  int NullaryConst() const { ++call_count; return 2; }
+  void UnaryVoid(int dummy) { ++call_count; }
+  template <class T> T Identity(T value) { ++call_count; return value; }
+  int UnaryByPointer(int* value) const {
+    ++call_count;
+    return ++(*value);
+  }
+  int UnaryByRef(const int& value) const {
+    ++call_count;
+    return ++const_cast<int&>(value);
+  }
+  int Multiply(int a, int b) const { ++call_count; return a * b; }
+  void RefArgument(const scoped_refptr<LifeTimeCheck>& object) {
+    EXPECT_TRUE(object.get() != nullptr);
+  }
+
+  mutable int call_count;
+};
+
+struct A { int dummy; };
+struct B: public RefCountInterface { int dummy; };
+struct C: public A, B {};
+struct D {
+  int AddRef();
+};
+struct E: public D {
+  int Release();
+};
+struct F {
+  void AddRef();
+  void Release();
+};
+
+struct LifeTimeCheck {
+  LifeTimeCheck() : ref_count_(0) {}
+  void AddRef() { ++ref_count_; }
+  void Release() { --ref_count_; }
+  void NullaryVoid() {}
+  int ref_count_;
+};
+
+int Return42() { return 42; }
+int Negate(int a) { return -a; }
+int Multiply(int a, int b) { return a * b; }
+
+}  // namespace
+
+// Try to catch any problem with scoped_refptr type deduction in rtc::Bind at
+// compile time.
+#define EXPECT_IS_CAPTURED_AS_PTR(T)                              \
+  static_assert(is_same<detail::PointerType<T>::type, T*>::value, \
+                "PointerType")
+#define EXPECT_IS_CAPTURED_AS_SCOPED_REFPTR(T)                        \
+  static_assert(                                                      \
+      is_same<detail::PointerType<T>::type, scoped_refptr<T>>::value, \
+      "PointerType")
+
+EXPECT_IS_CAPTURED_AS_PTR(void);
+EXPECT_IS_CAPTURED_AS_PTR(int);
+EXPECT_IS_CAPTURED_AS_PTR(double);
+EXPECT_IS_CAPTURED_AS_PTR(A);
+EXPECT_IS_CAPTURED_AS_PTR(D);
+EXPECT_IS_CAPTURED_AS_PTR(RefCountInterface*);
+EXPECT_IS_CAPTURED_AS_PTR(
+    decltype(Unretained<RefCountedObject<RefCountInterface>>));
+
+EXPECT_IS_CAPTURED_AS_SCOPED_REFPTR(RefCountInterface);
+EXPECT_IS_CAPTURED_AS_SCOPED_REFPTR(B);
+EXPECT_IS_CAPTURED_AS_SCOPED_REFPTR(C);
+EXPECT_IS_CAPTURED_AS_SCOPED_REFPTR(E);
+EXPECT_IS_CAPTURED_AS_SCOPED_REFPTR(F);
+EXPECT_IS_CAPTURED_AS_SCOPED_REFPTR(RefCountedObject<RefCountInterface>);
+EXPECT_IS_CAPTURED_AS_SCOPED_REFPTR(RefCountedObject<B>);
+EXPECT_IS_CAPTURED_AS_SCOPED_REFPTR(RefCountedObject<C>);
+EXPECT_IS_CAPTURED_AS_SCOPED_REFPTR(const RefCountedObject<RefCountInterface>);
+
+TEST(BindTest, BindToMethod) {
+  MethodBindTester object = {0};
+  EXPECT_EQ(0, object.call_count);
+  Bind(&MethodBindTester::NullaryVoid, &object)();
+  EXPECT_EQ(1, object.call_count);
+  EXPECT_EQ(1, Bind(&MethodBindTester::NullaryInt, &object)());
+  EXPECT_EQ(2, object.call_count);
+  EXPECT_EQ(2, Bind(&MethodBindTester::NullaryConst,
+                    static_cast<const MethodBindTester*>(&object))());
+  EXPECT_EQ(3, object.call_count);
+  Bind(&MethodBindTester::UnaryVoid, &object, 5)();
+  EXPECT_EQ(4, object.call_count);
+  EXPECT_EQ(100, Bind(&MethodBindTester::Identity<int>, &object, 100)());
+  EXPECT_EQ(5, object.call_count);
+  const std::string string_value("test string");
+  EXPECT_EQ(string_value, Bind(&MethodBindTester::Identity<std::string>,
+                               &object, string_value)());
+  EXPECT_EQ(6, object.call_count);
+  int value = 11;
+  // Bind binds by value, even if the method signature is by reference, so
+  // "reference" binds require pointers.
+  EXPECT_EQ(12, Bind(&MethodBindTester::UnaryByPointer, &object, &value)());
+  EXPECT_EQ(12, value);
+  EXPECT_EQ(7, object.call_count);
+  // It's possible to bind to a function that takes a const reference, though
+  // the capture will be a copy. See UnaryByRef hackery above where it removes
+  // the const to make sure the underlying storage is, in fact, a copy.
+  EXPECT_EQ(13, Bind(&MethodBindTester::UnaryByRef, &object, value)());
+  // But the original value is unmodified.
+  EXPECT_EQ(12, value);
+  EXPECT_EQ(8, object.call_count);
+  EXPECT_EQ(56, Bind(&MethodBindTester::Multiply, &object, 7, 8)());
+  EXPECT_EQ(9, object.call_count);
+}
+
+TEST(BindTest, BindToFunction) {
+  EXPECT_EQ(42, Bind(&Return42)());
+  EXPECT_EQ(3, Bind(&Negate, -3)());
+  EXPECT_EQ(56, Bind(&Multiply, 8, 7)());
+}
+
+// Test Bind where method object implements RefCountInterface and is passed as a
+// pointer.
+TEST(BindTest, CapturePointerAsScopedRefPtr) {
+  LifeTimeCheck object;
+  EXPECT_EQ(object.ref_count_, 0);
+  scoped_refptr<LifeTimeCheck> scoped_object(&object);
+  EXPECT_EQ(object.ref_count_, 1);
+  {
+    auto functor = Bind(&LifeTimeCheck::NullaryVoid, &object);
+    EXPECT_EQ(object.ref_count_, 2);
+    scoped_object = nullptr;
+    EXPECT_EQ(object.ref_count_, 1);
+  }
+  EXPECT_EQ(object.ref_count_, 0);
+}
+
+// Test Bind where method object implements RefCountInterface and is passed as a
+// scoped_refptr<>.
+TEST(BindTest, CaptureScopedRefPtrAsScopedRefPtr) {
+  LifeTimeCheck object;
+  EXPECT_EQ(object.ref_count_, 0);
+  scoped_refptr<LifeTimeCheck> scoped_object(&object);
+  EXPECT_EQ(object.ref_count_, 1);
+  {
+    auto functor = Bind(&LifeTimeCheck::NullaryVoid, scoped_object);
+    EXPECT_EQ(object.ref_count_, 2);
+    scoped_object = nullptr;
+    EXPECT_EQ(object.ref_count_, 1);
+  }
+  EXPECT_EQ(object.ref_count_, 0);
+}
+
+// Test Bind where method object is captured as scoped_refptr<> and the functor
+// dies while there are references left.
+TEST(BindTest, FunctorReleasesObjectOnDestruction) {
+  LifeTimeCheck object;
+  EXPECT_EQ(object.ref_count_, 0);
+  scoped_refptr<LifeTimeCheck> scoped_object(&object);
+  EXPECT_EQ(object.ref_count_, 1);
+  Bind(&LifeTimeCheck::NullaryVoid, &object)();
+  EXPECT_EQ(object.ref_count_, 1);
+  scoped_object = nullptr;
+  EXPECT_EQ(object.ref_count_, 0);
+}
+
+// Test Bind with scoped_refptr<> argument.
+TEST(BindTest, ScopedRefPointerArgument) {
+  LifeTimeCheck object;
+  EXPECT_EQ(object.ref_count_, 0);
+  scoped_refptr<LifeTimeCheck> scoped_object(&object);
+  EXPECT_EQ(object.ref_count_, 1);
+  {
+    MethodBindTester bind_tester;
+    auto functor =
+        Bind(&MethodBindTester::RefArgument, &bind_tester, scoped_object);
+    EXPECT_EQ(object.ref_count_, 2);
+  }
+  EXPECT_EQ(object.ref_count_, 1);
+  scoped_object = nullptr;
+  EXPECT_EQ(object.ref_count_, 0);
+}
+
+namespace {
+
+const int* Ref(const int& a) { return &a; }
+
+}  // anonymous namespace
+
+// Test Bind with non-scoped_refptr<> reference argument, which should be
+// modified to a non-reference capture.
+TEST(BindTest, RefArgument) {
+  const int x = 42;
+  EXPECT_EQ(&x, Ref(x));
+  // Bind() should make a copy of |x|, i.e. the pointers should be different.
+  auto functor = Bind(&Ref, x);
+  EXPECT_NE(&x, functor());
+}
+
+}  // namespace rtc

webrtc/rtc_base/bitbuffer.cc

@@ -0,0 +1,310 @@
+/*
+ *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/bitbuffer.h"
+
+#include <algorithm>
+#include <limits>
+
+#include "webrtc/base/checks.h"
+
+namespace {
+
+// Returns the lowest (right-most) |bit_count| bits in |byte|.
+uint8_t LowestBits(uint8_t byte, size_t bit_count) {
+  RTC_DCHECK_LE(bit_count, 8);
+  return byte & ((1 << bit_count) - 1);
+}
+
+// Returns the highest (left-most) |bit_count| bits in |byte|, shifted to the
+// lowest bits (to the right).
+uint8_t HighestBits(uint8_t byte, size_t bit_count) {
+  RTC_DCHECK_LE(bit_count, 8);
+  uint8_t shift = 8 - static_cast<uint8_t>(bit_count);
+  uint8_t mask = 0xFF << shift;
+  return (byte & mask) >> shift;
+}
+
+// Returns the highest byte of |val| in a uint8_t.
+uint8_t HighestByte(uint64_t val) {
+  return static_cast<uint8_t>(val >> 56);
+}
+
+// Returns the result of writing partial data from |source|, of
+// |source_bit_count| size in the highest bits, to |target| at
+// |target_bit_offset| from the highest bit.
+uint8_t WritePartialByte(uint8_t source,
+                         size_t source_bit_count,
+                         uint8_t target,
+                         size_t target_bit_offset) {
+  RTC_DCHECK(target_bit_offset < 8);
+  RTC_DCHECK(source_bit_count < 9);
+  RTC_DCHECK(source_bit_count <= (8 - target_bit_offset));
+  // Generate a mask for just the bits we're going to overwrite, so:
+  uint8_t mask =
+      // The number of bits we want, in the most significant bits...
+      static_cast<uint8_t>(0xFF << (8 - source_bit_count))
+      // ...shifted over to the target offset from the most signficant bit.
+      >> target_bit_offset;
+
+  // We want the target, with the bits we'll overwrite masked off, or'ed with
+  // the bits from the source we want.
+  return (target & ~mask) | (source >> target_bit_offset);
+}
+
+// Counts the number of bits used in the binary representation of val.
+size_t CountBits(uint64_t val) {
+  size_t bit_count = 0;
+  while (val != 0) {
+    bit_count++;
+    val >>= 1;
+  }
+  return bit_count;
+}
+
+}  // namespace
+
+namespace rtc {
+
+BitBuffer::BitBuffer(const uint8_t* bytes, size_t byte_count)
+    : bytes_(bytes), byte_count_(byte_count), byte_offset_(), bit_offset_() {
+  RTC_DCHECK(static_cast<uint64_t>(byte_count_) <=
+             std::numeric_limits<uint32_t>::max());
+}
+
+uint64_t BitBuffer::RemainingBitCount() const {
+  return (static_cast<uint64_t>(byte_count_) - byte_offset_) * 8 - bit_offset_;
+}
+
+bool BitBuffer::ReadUInt8(uint8_t* val) {
+  uint32_t bit_val;
+  if (!ReadBits(&bit_val, sizeof(uint8_t) * 8)) {
+    return false;
+  }
+  RTC_DCHECK(bit_val <= std::numeric_limits<uint8_t>::max());
+  *val = static_cast<uint8_t>(bit_val);
+  return true;
+}
+
+bool BitBuffer::ReadUInt16(uint16_t* val) {
+  uint32_t bit_val;
+  if (!ReadBits(&bit_val, sizeof(uint16_t) * 8)) {
+    return false;
+  }
+  RTC_DCHECK(bit_val <= std::numeric_limits<uint16_t>::max());
+  *val = static_cast<uint16_t>(bit_val);
+  return true;
+}
+
+bool BitBuffer::ReadUInt32(uint32_t* val) {
+  return ReadBits(val, sizeof(uint32_t) * 8);
+}
+
+bool BitBuffer::PeekBits(uint32_t* val, size_t bit_count) {
+  if (!val || bit_count > RemainingBitCount() || bit_count > 32) {
+    return false;
+  }
+  const uint8_t* bytes = bytes_ + byte_offset_;
+  size_t remaining_bits_in_current_byte = 8 - bit_offset_;
+  uint32_t bits = LowestBits(*bytes++, remaining_bits_in_current_byte);
+  // If we're reading fewer bits than what's left in the current byte, just
+  // return the portion of this byte that we need.
+  if (bit_count < remaining_bits_in_current_byte) {
+    *val = HighestBits(bits, bit_offset_ + bit_count);
+    return true;
+  }
+  // Otherwise, subtract what we've read from the bit count and read as many
+  // full bytes as we can into bits.
+  bit_count -= remaining_bits_in_current_byte;
+  while (bit_count >= 8) {
+    bits = (bits << 8) | *bytes++;
+    bit_count -= 8;
+  }
+  // Whatever we have left is smaller than a byte, so grab just the bits we need
+  // and shift them into the lowest bits.
+  if (bit_count > 0) {
+    bits <<= bit_count;
+    bits |= HighestBits(*bytes, bit_count);
+  }
+  *val = bits;
+  return true;
+}
+
+bool BitBuffer::ReadBits(uint32_t* val, size_t bit_count) {
+  return PeekBits(val, bit_count) && ConsumeBits(bit_count);
+}
+
+bool BitBuffer::ConsumeBytes(size_t byte_count) {
+  return ConsumeBits(byte_count * 8);
+}
+
+bool BitBuffer::ConsumeBits(size_t bit_count) {
+  if (bit_count > RemainingBitCount()) {
+    return false;
+  }
+
+  byte_offset_ += (bit_offset_ + bit_count) / 8;
+  bit_offset_ = (bit_offset_ + bit_count) % 8;
+  return true;
+}
+
+bool BitBuffer::ReadExponentialGolomb(uint32_t* val) {
+  if (!val) {
+    return false;
+  }
+  // Store off the current byte/bit offset, in case we want to restore them due
+  // to a failed parse.
+  size_t original_byte_offset = byte_offset_;
+  size_t original_bit_offset = bit_offset_;
+
+  // Count the number of leading 0 bits by peeking/consuming them one at a time.
+  size_t zero_bit_count = 0;
+  uint32_t peeked_bit;
+  while (PeekBits(&peeked_bit, 1) && peeked_bit == 0) {
+    zero_bit_count++;
+    ConsumeBits(1);
+  }
+
+  // We should either be at the end of the stream, or the next bit should be 1.
+  RTC_DCHECK(!PeekBits(&peeked_bit, 1) || peeked_bit == 1);
+
+  // The bit count of the value is the number of zeros + 1. Make sure that many
+  // bits fits in a uint32_t and that we have enough bits left for it, and then
+  // read the value.
+  size_t value_bit_count = zero_bit_count + 1;
+  if (value_bit_count > 32 || !ReadBits(val, value_bit_count)) {
+    RTC_CHECK(Seek(original_byte_offset, original_bit_offset));
+    return false;
+  }
+  *val -= 1;
+  return true;
+}
+
+bool BitBuffer::ReadSignedExponentialGolomb(int32_t* val) {
+  uint32_t unsigned_val;
+  if (!ReadExponentialGolomb(&unsigned_val)) {
+    return false;
+  }
+  if ((unsigned_val & 1) == 0) {
+    *val = -static_cast<int32_t>(unsigned_val / 2);
+  } else {
+    *val = (unsigned_val + 1) / 2;
+  }
+  return true;
+}
+
+void BitBuffer::GetCurrentOffset(
+    size_t* out_byte_offset, size_t* out_bit_offset) {
+  RTC_CHECK(out_byte_offset != nullptr);
+  RTC_CHECK(out_bit_offset != nullptr);
+  *out_byte_offset = byte_offset_;
+  *out_bit_offset = bit_offset_;
+}
+
+bool BitBuffer::Seek(size_t byte_offset, size_t bit_offset) {
+  if (byte_offset > byte_count_ || bit_offset > 7 ||
+      (byte_offset == byte_count_ && bit_offset > 0)) {
+    return false;
+  }
+  byte_offset_ = byte_offset;
+  bit_offset_ = bit_offset;
+  return true;
+}
+
+BitBufferWriter::BitBufferWriter(uint8_t* bytes, size_t byte_count)
+    : BitBuffer(bytes, byte_count), writable_bytes_(bytes) {
+}
+
+bool BitBufferWriter::WriteUInt8(uint8_t val) {
+  return WriteBits(val, sizeof(uint8_t) * 8);
+}
+
+bool BitBufferWriter::WriteUInt16(uint16_t val) {
+  return WriteBits(val, sizeof(uint16_t) * 8);
+}
+
+bool BitBufferWriter::WriteUInt32(uint32_t val) {
+  return WriteBits(val, sizeof(uint32_t) * 8);
+}
+
+bool BitBufferWriter::WriteBits(uint64_t val, size_t bit_count) {
+  if (bit_count > RemainingBitCount()) {
+    return false;
+  }
+  size_t total_bits = bit_count;
+
+  // For simplicity, push the bits we want to read from val to the highest bits.
+  val <<= (sizeof(uint64_t) * 8 - bit_count);
+
+  uint8_t* bytes = writable_bytes_ + byte_offset_;
+
+  // The first byte is relatively special; the bit offset to write to may put us
+  // in the middle of the byte, and the total bit count to write may require we
+  // save the bits at the end of the byte.
+  size_t remaining_bits_in_current_byte = 8 - bit_offset_;
+  size_t bits_in_first_byte =
+      std::min(bit_count, remaining_bits_in_current_byte);
+  *bytes = WritePartialByte(
+      HighestByte(val), bits_in_first_byte, *bytes, bit_offset_);
+  if (bit_count <= remaining_bits_in_current_byte) {
+    // Nothing left to write, so quit early.
+    return ConsumeBits(total_bits);
+  }
+
+  // Subtract what we've written from the bit count, shift it off the value, and
+  // write the remaining full bytes.
+  val <<= bits_in_first_byte;
+  bytes++;
+  bit_count -= bits_in_first_byte;
+  while (bit_count >= 8) {
+    *bytes++ = HighestByte(val);
+    val <<= 8;
+    bit_count -= 8;
+  }
+
+  // Last byte may also be partial, so write the remaining bits from the top of
+  // val.
+  if (bit_count > 0) {
+    *bytes = WritePartialByte(HighestByte(val), bit_count, *bytes, 0);
+  }
+
+  // All done! Consume the bits we've written.
+  return ConsumeBits(total_bits);
+}
+
+bool BitBufferWriter::WriteExponentialGolomb(uint32_t val) {
+  // We don't support reading UINT32_MAX, because it doesn't fit in a uint32_t
+  // when encoded, so don't support writing it either.
+  if (val == std::numeric_limits<uint32_t>::max()) {
+    return false;
+  }
+  uint64_t val_to_encode = static_cast<uint64_t>(val) + 1;
+
+  // We need to write CountBits(val+1) 0s and then val+1. Since val (as a
+  // uint64_t) has leading zeros, we can just write the total golomb encoded
+  // size worth of bits, knowing the value will appear last.
+  return WriteBits(val_to_encode, CountBits(val_to_encode) * 2 - 1);
+}
+
+bool BitBufferWriter::WriteSignedExponentialGolomb(int32_t val) {
+  if (val == 0) {
+    return WriteExponentialGolomb(0);
+  } else if (val > 0) {
+    uint32_t signed_val = val;
+    return WriteExponentialGolomb((signed_val * 2) - 1);
+  } else {
+    if (val == std::numeric_limits<int32_t>::min())
+      return false;  // Not supported, would cause overflow.
+    uint32_t signed_val = -val;
+    return WriteExponentialGolomb(signed_val * 2);
+  }
+}
+
+}  // namespace rtc

webrtc/rtc_base/bitbuffer.h

@@ -0,0 +1,126 @@
+/*
+ *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_BITBUFFER_H_
+#define WEBRTC_RTC_BASE_BITBUFFER_H_
+
+#include <stdint.h>  // For integer types.
+#include <stddef.h>  // For size_t.
+
+#include "webrtc/base/constructormagic.h"
+
+namespace rtc {
+
+// A class, similar to ByteBuffer, that can parse bit-sized data out of a set of
+// bytes. Has a similar API to ByteBuffer, plus methods for reading bit-sized
+// and exponential golomb encoded data. For a writable version, use
+// BitBufferWriter. Unlike ByteBuffer, this class doesn't make a copy of the
+// source bytes, so it can be used on read-only data.
+// Sizes/counts specify bits/bytes, for clarity.
+// Byte order is assumed big-endian/network.
+class BitBuffer {
+ public:
+  BitBuffer(const uint8_t* bytes, size_t byte_count);
+
+  // Gets the current offset, in bytes/bits, from the start of the buffer. The
+  // bit offset is the offset into the current byte, in the range [0,7].
+  void GetCurrentOffset(size_t* out_byte_offset, size_t* out_bit_offset);
+
+  // The remaining bits in the byte buffer.
+  uint64_t RemainingBitCount() const;
+
+  // Reads byte-sized values from the buffer. Returns false if there isn't
+  // enough data left for the specified type.
+  bool ReadUInt8(uint8_t* val);
+  bool ReadUInt16(uint16_t* val);
+  bool ReadUInt32(uint32_t* val);
+
+  // Reads bit-sized values from the buffer. Returns false if there isn't enough
+  // data left for the specified bit count..
+  bool ReadBits(uint32_t* val, size_t bit_count);
+
+  // Peeks bit-sized values from the buffer. Returns false if there isn't enough
+  // data left for the specified number of bits. Doesn't move the current
+  // offset.
+  bool PeekBits(uint32_t* val, size_t bit_count);
+
+  // Reads the exponential golomb encoded value at the current offset.
+  // Exponential golomb values are encoded as:
+  // 1) x = source val + 1
+  // 2) In binary, write [countbits(x) - 1] 0s, then x
+  // To decode, we count the number of leading 0 bits, read that many + 1 bits,
+  // and increment the result by 1.
+  // Returns false if there isn't enough data left for the specified type, or if
+  // the value wouldn't fit in a uint32_t.
+  bool ReadExponentialGolomb(uint32_t* val);
+  // Reads signed exponential golomb values at the current offset. Signed
+  // exponential golomb values are just the unsigned values mapped to the
+  // sequence 0, 1, -1, 2, -2, etc. in order.
+  bool ReadSignedExponentialGolomb(int32_t* val);
+
+  // Moves current position |byte_count| bytes forward. Returns false if
+  // there aren't enough bytes left in the buffer.
+  bool ConsumeBytes(size_t byte_count);
+  // Moves current position |bit_count| bits forward. Returns false if
+  // there aren't enough bits left in the buffer.
+  bool ConsumeBits(size_t bit_count);
+
+  // Sets the current offset to the provied byte/bit offsets. The bit
+  // offset is from the given byte, in the range [0,7].
+  bool Seek(size_t byte_offset, size_t bit_offset);
+
+ protected:
+  const uint8_t* const bytes_;
+  // The total size of |bytes_|.
+  size_t byte_count_;
+  // The current offset, in bytes, from the start of |bytes_|.
+  size_t byte_offset_;
+  // The current offset, in bits, into the current byte.
+  size_t bit_offset_;
+
+  RTC_DISALLOW_COPY_AND_ASSIGN(BitBuffer);
+};
+
+// A BitBuffer API for write operations. Supports symmetric write APIs to the
+// reading APIs of BitBuffer. Note that the read/write offset is shared with the
+// BitBuffer API, so both reading and writing will consume bytes/bits.
+class BitBufferWriter : public BitBuffer {
+ public:
+  // Constructs a bit buffer for the writable buffer of |bytes|.
+  BitBufferWriter(uint8_t* bytes, size_t byte_count);
+
+  // Writes byte-sized values from the buffer. Returns false if there isn't
+  // enough data left for the specified type.
+  bool WriteUInt8(uint8_t val);
+  bool WriteUInt16(uint16_t val);
+  bool WriteUInt32(uint32_t val);
+
+  // Writes bit-sized values to the buffer. Returns false if there isn't enough
+  // room left for the specified number of bits.
+  bool WriteBits(uint64_t val, size_t bit_count);
+
+  // Writes the exponential golomb encoded version of the supplied value.
+  // Returns false if there isn't enough room left for the value.
+  bool WriteExponentialGolomb(uint32_t val);
+  // Writes the signed exponential golomb version of the supplied value.
+  // Signed exponential golomb values are just the unsigned values mapped to the
+  // sequence 0, 1, -1, 2, -2, etc. in order.
+  bool WriteSignedExponentialGolomb(int32_t val);
+
+ private:
+  // The buffer, as a writable array.
+  uint8_t* const writable_bytes_;
+
+  RTC_DISALLOW_COPY_AND_ASSIGN(BitBufferWriter);
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_BITBUFFER_H_

webrtc/rtc_base/bitbuffer_unittest.cc

@@ -0,0 +1,329 @@
+/*
+ *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/arraysize.h"
+#include "webrtc/base/bitbuffer.h"
+#include "webrtc/base/bytebuffer.h"
+#include "webrtc/base/gunit.h"
+
+namespace rtc {
+
+TEST(BitBufferTest, ConsumeBits) {
+  const uint8_t bytes[64] = {0};
+  BitBuffer buffer(bytes, 32);
+  uint64_t total_bits = 32 * 8;
+  EXPECT_EQ(total_bits, buffer.RemainingBitCount());
+  EXPECT_TRUE(buffer.ConsumeBits(3));
+  total_bits -= 3;
+  EXPECT_EQ(total_bits, buffer.RemainingBitCount());
+  EXPECT_TRUE(buffer.ConsumeBits(3));
+  total_bits -= 3;
+  EXPECT_EQ(total_bits, buffer.RemainingBitCount());
+  EXPECT_TRUE(buffer.ConsumeBits(15));
+  total_bits -= 15;
+  EXPECT_EQ(total_bits, buffer.RemainingBitCount());
+  EXPECT_TRUE(buffer.ConsumeBits(37));
+  total_bits -= 37;
+  EXPECT_EQ(total_bits, buffer.RemainingBitCount());
+
+  EXPECT_FALSE(buffer.ConsumeBits(32 * 8));
+  EXPECT_EQ(total_bits, buffer.RemainingBitCount());
+}
+
+TEST(BitBufferTest, ReadBytesAligned) {
+  const uint8_t bytes[] = {0x0A, 0xBC, 0xDE, 0xF1, 0x23, 0x45, 0x67, 0x89};
+  uint8_t val8;
+  uint16_t val16;
+  uint32_t val32;
+  BitBuffer buffer(bytes, 8);
+  EXPECT_TRUE(buffer.ReadUInt8(&val8));
+  EXPECT_EQ(0x0Au, val8);
+  EXPECT_TRUE(buffer.ReadUInt8(&val8));
+  EXPECT_EQ(0xBCu, val8);
+  EXPECT_TRUE(buffer.ReadUInt16(&val16));
+  EXPECT_EQ(0xDEF1u, val16);
+  EXPECT_TRUE(buffer.ReadUInt32(&val32));
+  EXPECT_EQ(0x23456789u, val32);
+}
+
+TEST(BitBufferTest, ReadBytesOffset4) {
+  const uint8_t bytes[] = {0x0A, 0xBC, 0xDE, 0xF1, 0x23,
+                           0x45, 0x67, 0x89, 0x0A};
+  uint8_t val8;
+  uint16_t val16;
+  uint32_t val32;
+  BitBuffer buffer(bytes, 9);
+  EXPECT_TRUE(buffer.ConsumeBits(4));
+
+  EXPECT_TRUE(buffer.ReadUInt8(&val8));
+  EXPECT_EQ(0xABu, val8);
+  EXPECT_TRUE(buffer.ReadUInt8(&val8));
+  EXPECT_EQ(0xCDu, val8);
+  EXPECT_TRUE(buffer.ReadUInt16(&val16));
+  EXPECT_EQ(0xEF12u, val16);
+  EXPECT_TRUE(buffer.ReadUInt32(&val32));
+  EXPECT_EQ(0x34567890u, val32);
+}
+
+TEST(BitBufferTest, ReadBytesOffset3) {
+  // The pattern we'll check against is counting down from 0b1111. It looks
+  // weird here because it's all offset by 3.
+  // Byte pattern is:
+  //    56701234
+  //  0b00011111,
+  //  0b11011011,
+  //  0b10010111,
+  //  0b01010011,
+  //  0b00001110,
+  //  0b11001010,
+  //  0b10000110,
+  //  0b01000010
+  //       xxxxx <-- last 5 bits unused.
+
+  // The bytes. It almost looks like counting down by two at a time, except the
+  // jump at 5->3->0, since that's when the high bit is turned off.
+  const uint8_t bytes[] = {0x1F, 0xDB, 0x97, 0x53, 0x0E, 0xCA, 0x86, 0x42};
+
+  uint8_t val8;
+  uint16_t val16;
+  uint32_t val32;
+  BitBuffer buffer(bytes, 8);
+  EXPECT_TRUE(buffer.ConsumeBits(3));
+  EXPECT_TRUE(buffer.ReadUInt8(&val8));
+  EXPECT_EQ(0xFEu, val8);
+  EXPECT_TRUE(buffer.ReadUInt16(&val16));
+  EXPECT_EQ(0xDCBAu, val16);
+  EXPECT_TRUE(buffer.ReadUInt32(&val32));
+  EXPECT_EQ(0x98765432u, val32);
+  // 5 bits left unread. Not enough to read a uint8_t.
+  EXPECT_EQ(5u, buffer.RemainingBitCount());
+  EXPECT_FALSE(buffer.ReadUInt8(&val8));
+}
+
+TEST(BitBufferTest, ReadBits) {
+  // Bit values are:
+  //  0b01001101,
+  //  0b00110010
+  const uint8_t bytes[] = {0x4D, 0x32};
+  uint32_t val;
+  BitBuffer buffer(bytes, 2);
+  EXPECT_TRUE(buffer.ReadBits(&val, 3));
+  // 0b010
+  EXPECT_EQ(0x2u, val);
+  EXPECT_TRUE(buffer.ReadBits(&val, 2));
+  // 0b01
+  EXPECT_EQ(0x1u, val);
+  EXPECT_TRUE(buffer.ReadBits(&val, 7));
+  // 0b1010011
+  EXPECT_EQ(0x53u, val);
+  EXPECT_TRUE(buffer.ReadBits(&val, 2));
+  // 0b00
+  EXPECT_EQ(0x0u, val);
+  EXPECT_TRUE(buffer.ReadBits(&val, 1));
+  // 0b1
+  EXPECT_EQ(0x1u, val);
+  EXPECT_TRUE(buffer.ReadBits(&val, 1));
+  // 0b0
+  EXPECT_EQ(0x0u, val);
+
+  EXPECT_FALSE(buffer.ReadBits(&val, 1));
+}
+
+TEST(BitBufferTest, SetOffsetValues) {
+  uint8_t bytes[4] = {0};
+  BitBufferWriter buffer(bytes, 4);
+
+  size_t byte_offset, bit_offset;
+  // Bit offsets are [0,7].
+  EXPECT_TRUE(buffer.Seek(0, 0));
+  EXPECT_TRUE(buffer.Seek(0, 7));
+  buffer.GetCurrentOffset(&byte_offset, &bit_offset);
+  EXPECT_EQ(0u, byte_offset);
+  EXPECT_EQ(7u, bit_offset);
+  EXPECT_FALSE(buffer.Seek(0, 8));
+  buffer.GetCurrentOffset(&byte_offset, &bit_offset);
+  EXPECT_EQ(0u, byte_offset);
+  EXPECT_EQ(7u, bit_offset);
+  // Byte offsets are [0,length]. At byte offset length, the bit offset must be
+  // 0.
+  EXPECT_TRUE(buffer.Seek(0, 0));
+  EXPECT_TRUE(buffer.Seek(2, 4));
+  buffer.GetCurrentOffset(&byte_offset, &bit_offset);
+  EXPECT_EQ(2u, byte_offset);
+  EXPECT_EQ(4u, bit_offset);
+  EXPECT_TRUE(buffer.Seek(4, 0));
+  EXPECT_FALSE(buffer.Seek(5, 0));
+  buffer.GetCurrentOffset(&byte_offset, &bit_offset);
+  EXPECT_EQ(4u, byte_offset);
+  EXPECT_EQ(0u, bit_offset);
+  EXPECT_FALSE(buffer.Seek(4, 1));
+
+  // Disable death test on Android because it relies on fork() and doesn't play
+  // nicely.
+#if GTEST_HAS_DEATH_TEST
+#if !defined(WEBRTC_ANDROID)
+  // Passing a null out parameter is death.
+  EXPECT_DEATH(buffer.GetCurrentOffset(&byte_offset, nullptr), "");
+#endif
+#endif
+}
+
+uint64_t GolombEncoded(uint32_t val) {
+  val++;
+  uint32_t bit_counter = val;
+  uint64_t bit_count = 0;
+  while (bit_counter > 0) {
+    bit_count++;
+    bit_counter >>= 1;
+  }
+  return static_cast<uint64_t>(val) << (64 - (bit_count * 2 - 1));
+}
+
+TEST(BitBufferTest, GolombUint32Values) {
+  ByteBufferWriter byteBuffer;
+  byteBuffer.Resize(16);
+  BitBuffer buffer(reinterpret_cast<const uint8_t*>(byteBuffer.Data()),
+                   byteBuffer.Capacity());
+  // Test over the uint32_t range with a large enough step that the test doesn't
+  // take forever. Around 20,000 iterations should do.
+  const int kStep = std::numeric_limits<uint32_t>::max() / 20000;
+  for (uint32_t i = 0; i < std::numeric_limits<uint32_t>::max() - kStep;
+       i += kStep) {
+    uint64_t encoded_val = GolombEncoded(i);
+    byteBuffer.Clear();
+    byteBuffer.WriteUInt64(encoded_val);
+    uint32_t decoded_val;
+    EXPECT_TRUE(buffer.Seek(0, 0));
+    EXPECT_TRUE(buffer.ReadExponentialGolomb(&decoded_val));
+    EXPECT_EQ(i, decoded_val);
+  }
+}
+
+TEST(BitBufferTest, SignedGolombValues) {
+  uint8_t golomb_bits[] = {
+      0x80,  // 1
+      0x40,  // 010
+      0x60,  // 011
+      0x20,  // 00100
+      0x38,  // 00111
+  };
+  int32_t expected[] = {0, 1, -1, 2, -3};
+  for (size_t i = 0; i < sizeof(golomb_bits); ++i) {
+    BitBuffer buffer(&golomb_bits[i], 1);
+    int32_t decoded_val;
+    ASSERT_TRUE(buffer.ReadSignedExponentialGolomb(&decoded_val));
+    EXPECT_EQ(expected[i], decoded_val)
+        << "Mismatch in expected/decoded value for golomb_bits[" << i
+        << "]: " << static_cast<int>(golomb_bits[i]);
+  }
+}
+
+TEST(BitBufferTest, NoGolombOverread) {
+  const uint8_t bytes[] = {0x00, 0xFF, 0xFF};
+  // Make sure the bit buffer correctly enforces byte length on golomb reads.
+  // If it didn't, the above buffer would be valid at 3 bytes.
+  BitBuffer buffer(bytes, 1);
+  uint32_t decoded_val;
+  EXPECT_FALSE(buffer.ReadExponentialGolomb(&decoded_val));
+
+  BitBuffer longer_buffer(bytes, 2);
+  EXPECT_FALSE(longer_buffer.ReadExponentialGolomb(&decoded_val));
+
+  BitBuffer longest_buffer(bytes, 3);
+  EXPECT_TRUE(longest_buffer.ReadExponentialGolomb(&decoded_val));
+  // Golomb should have read 9 bits, so 0x01FF, and since it is golomb, the
+  // result is 0x01FF - 1 = 0x01FE.
+  EXPECT_EQ(0x01FEu, decoded_val);
+}
+
+TEST(BitBufferWriterTest, SymmetricReadWrite) {
+  uint8_t bytes[16] = {0};
+  BitBufferWriter buffer(bytes, 4);
+
+  // Write some bit data at various sizes.
+  EXPECT_TRUE(buffer.WriteBits(0x2u, 3));
+  EXPECT_TRUE(buffer.WriteBits(0x1u, 2));
+  EXPECT_TRUE(buffer.WriteBits(0x53u, 7));
+  EXPECT_TRUE(buffer.WriteBits(0x0u, 2));
+  EXPECT_TRUE(buffer.WriteBits(0x1u, 1));
+  EXPECT_TRUE(buffer.WriteBits(0x1ABCDu, 17));
+  // That should be all that fits in the buffer.
+  EXPECT_FALSE(buffer.WriteBits(1, 1));
+
+  EXPECT_TRUE(buffer.Seek(0, 0));
+  uint32_t val;
+  EXPECT_TRUE(buffer.ReadBits(&val, 3));
+  EXPECT_EQ(0x2u, val);
+  EXPECT_TRUE(buffer.ReadBits(&val, 2));
+  EXPECT_EQ(0x1u, val);
+  EXPECT_TRUE(buffer.ReadBits(&val, 7));
+  EXPECT_EQ(0x53u, val);
+  EXPECT_TRUE(buffer.ReadBits(&val, 2));
+  EXPECT_EQ(0x0u, val);
+  EXPECT_TRUE(buffer.ReadBits(&val, 1));
+  EXPECT_EQ(0x1u, val);
+  EXPECT_TRUE(buffer.ReadBits(&val, 17));
+  EXPECT_EQ(0x1ABCDu, val);
+  // And there should be nothing left.
+  EXPECT_FALSE(buffer.ReadBits(&val, 1));
+}
+
+TEST(BitBufferWriterTest, SymmetricBytesMisaligned) {
+  uint8_t bytes[16] = {0};
+  BitBufferWriter buffer(bytes, 16);
+
+  // Offset 3, to get things misaligned.
+  EXPECT_TRUE(buffer.ConsumeBits(3));
+  EXPECT_TRUE(buffer.WriteUInt8(0x12u));
+  EXPECT_TRUE(buffer.WriteUInt16(0x3456u));
+  EXPECT_TRUE(buffer.WriteUInt32(0x789ABCDEu));
+
+  buffer.Seek(0, 3);
+  uint8_t val8;
+  uint16_t val16;
+  uint32_t val32;
+  EXPECT_TRUE(buffer.ReadUInt8(&val8));
+  EXPECT_EQ(0x12u, val8);
+  EXPECT_TRUE(buffer.ReadUInt16(&val16));
+  EXPECT_EQ(0x3456u, val16);
+  EXPECT_TRUE(buffer.ReadUInt32(&val32));
+  EXPECT_EQ(0x789ABCDEu, val32);
+}
+
+TEST(BitBufferWriterTest, SymmetricGolomb) {
+  char test_string[] = "my precious";
+  uint8_t bytes[64] = {0};
+  BitBufferWriter buffer(bytes, 64);
+  for (size_t i = 0; i < arraysize(test_string); ++i) {
+    EXPECT_TRUE(buffer.WriteExponentialGolomb(test_string[i]));
+  }
+  buffer.Seek(0, 0);
+  for (size_t i = 0; i < arraysize(test_string); ++i) {
+    uint32_t val;
+    EXPECT_TRUE(buffer.ReadExponentialGolomb(&val));
+    EXPECT_LE(val, std::numeric_limits<uint8_t>::max());
+    EXPECT_EQ(test_string[i], static_cast<char>(val));
+  }
+}
+
+TEST(BitBufferWriterTest, WriteClearsBits) {
+  uint8_t bytes[] = {0xFF, 0xFF};
+  BitBufferWriter buffer(bytes, 2);
+  EXPECT_TRUE(buffer.ConsumeBits(3));
+  EXPECT_TRUE(buffer.WriteBits(0, 1));
+  EXPECT_EQ(0xEFu, bytes[0]);
+  EXPECT_TRUE(buffer.WriteBits(0, 3));
+  EXPECT_EQ(0xE1u, bytes[0]);
+  EXPECT_TRUE(buffer.WriteBits(0, 2));
+  EXPECT_EQ(0xE0u, bytes[0]);
+  EXPECT_EQ(0x7F, bytes[1]);
+}
+
+}  // namespace rtc

webrtc/rtc_base/buffer.h

@@ -0,0 +1,383 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_BUFFER_H_
+#define WEBRTC_RTC_BASE_BUFFER_H_
+
+#include <algorithm>
+#include <cstring>
+#include <memory>
+#include <type_traits>
+#include <utility>
+
+#include "webrtc/base/array_view.h"
+#include "webrtc/base/checks.h"
+#include "webrtc/base/type_traits.h"
+
+namespace rtc {
+
+namespace internal {
+
+// (Internal; please don't use outside this file.) Determines if elements of
+// type U are compatible with a BufferT<T>. For most types, we just ignore
+// top-level const and forbid top-level volatile and require T and U to be
+// otherwise equal, but all byte-sized integers (notably char, int8_t, and
+// uint8_t) are compatible with each other. (Note: We aim to get rid of this
+// behavior, and treat all types the same.)
+template <typename T, typename U>
+struct BufferCompat {
+  static constexpr bool value =
+      !std::is_volatile<U>::value &&
+      ((std::is_integral<T>::value && sizeof(T) == 1)
+           ? (std::is_integral<U>::value && sizeof(U) == 1)
+           : (std::is_same<T, typename std::remove_const<U>::type>::value));
+};
+
+}  // namespace internal
+
+// Basic buffer class, can be grown and shrunk dynamically.
+// Unlike std::string/vector, does not initialize data when increasing size.
+template <typename T>
+class BufferT {
+  // We want T's destructor and default constructor to be trivial, i.e. perform
+  // no action, so that we don't have to touch the memory we allocate and
+  // deallocate. And we want T to be trivially copyable, so that we can copy T
+  // instances with std::memcpy. This is precisely the definition of a trivial
+  // type.
+  static_assert(std::is_trivial<T>::value, "T must be a trivial type.");
+
+  // This class relies heavily on being able to mutate its data.
+  static_assert(!std::is_const<T>::value, "T may not be const");
+
+ public:
+  using value_type = T;
+
+  // An empty BufferT.
+  BufferT() : size_(0), capacity_(0), data_(nullptr) {
+    RTC_DCHECK(IsConsistent());
+  }
+
+  // Disable copy construction and copy assignment, since copying a buffer is
+  // expensive enough that we want to force the user to be explicit about it.
+  BufferT(const BufferT&) = delete;
+  BufferT& operator=(const BufferT&) = delete;
+
+  BufferT(BufferT&& buf)
+      : size_(buf.size()),
+        capacity_(buf.capacity()),
+        data_(std::move(buf.data_)) {
+    RTC_DCHECK(IsConsistent());
+    buf.OnMovedFrom();
+  }
+
+  // Construct a buffer with the specified number of uninitialized elements.
+  explicit BufferT(size_t size) : BufferT(size, size) {}
+
+  BufferT(size_t size, size_t capacity)
+      : size_(size),
+        capacity_(std::max(size, capacity)),
+        data_(new T[capacity_]) {
+    RTC_DCHECK(IsConsistent());
+  }
+
+  // Construct a buffer and copy the specified number of elements into it.
+  template <typename U,
+            typename std::enable_if<
+                internal::BufferCompat<T, U>::value>::type* = nullptr>
+  BufferT(const U* data, size_t size) : BufferT(data, size, size) {}
+
+  template <typename U,
+            typename std::enable_if<
+                internal::BufferCompat<T, U>::value>::type* = nullptr>
+  BufferT(U* data, size_t size, size_t capacity) : BufferT(size, capacity) {
+    static_assert(sizeof(T) == sizeof(U), "");
+    std::memcpy(data_.get(), data, size * sizeof(U));
+  }
+
+  // Construct a buffer from the contents of an array.
+  template <typename U,
+            size_t N,
+            typename std::enable_if<
+                internal::BufferCompat<T, U>::value>::type* = nullptr>
+  BufferT(U (&array)[N]) : BufferT(array, N) {}
+
+  // Get a pointer to the data. Just .data() will give you a (const) T*, but if
+  // T is a byte-sized integer, you may also use .data<U>() for any other
+  // byte-sized integer U.
+  template <typename U = T,
+            typename std::enable_if<
+                internal::BufferCompat<T, U>::value>::type* = nullptr>
+  const U* data() const {
+    RTC_DCHECK(IsConsistent());
+    return reinterpret_cast<U*>(data_.get());
+  }
+
+  template <typename U = T,
+            typename std::enable_if<
+                internal::BufferCompat<T, U>::value>::type* = nullptr>
+  U* data() {
+    RTC_DCHECK(IsConsistent());
+    return reinterpret_cast<U*>(data_.get());
+  }
+
+  bool empty() const {
+    RTC_DCHECK(IsConsistent());
+    return size_ == 0;
+  }
+
+  size_t size() const {
+    RTC_DCHECK(IsConsistent());
+    return size_;
+  }
+
+  size_t capacity() const {
+    RTC_DCHECK(IsConsistent());
+    return capacity_;
+  }
+
+  BufferT& operator=(BufferT&& buf) {
+    RTC_DCHECK(IsConsistent());
+    RTC_DCHECK(buf.IsConsistent());
+    size_ = buf.size_;
+    capacity_ = buf.capacity_;
+    data_ = std::move(buf.data_);
+    buf.OnMovedFrom();
+    return *this;
+  }
+
+  bool operator==(const BufferT& buf) const {
+    RTC_DCHECK(IsConsistent());
+    if (size_ != buf.size_) {
+      return false;
+    }
+    if (std::is_integral<T>::value) {
+      // Optimization.
+      return std::memcmp(data_.get(), buf.data_.get(), size_ * sizeof(T)) == 0;
+    }
+    for (size_t i = 0; i < size_; ++i) {
+      if (data_[i] != buf.data_[i]) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  bool operator!=(const BufferT& buf) const { return !(*this == buf); }
+
+  T& operator[](size_t index) {
+    RTC_DCHECK_LT(index, size_);
+    return data()[index];
+  }
+
+  T operator[](size_t index) const {
+    RTC_DCHECK_LT(index, size_);
+    return data()[index];
+  }
+
+  T* begin() { return data(); }
+  T* end() { return data() + size(); }
+  const T* begin() const { return data(); }
+  const T* end() const { return data() + size(); }
+  const T* cbegin() const { return data(); }
+  const T* cend() const { return data() + size(); }
+
+  // The SetData functions replace the contents of the buffer. They accept the
+  // same input types as the constructors.
+  template <typename U,
+            typename std::enable_if<
+                internal::BufferCompat<T, U>::value>::type* = nullptr>
+  void SetData(const U* data, size_t size) {
+    RTC_DCHECK(IsConsistent());
+    size_ = 0;
+    AppendData(data, size);
+  }
+
+  template <typename U,
+            size_t N,
+            typename std::enable_if<
+                internal::BufferCompat<T, U>::value>::type* = nullptr>
+  void SetData(const U (&array)[N]) {
+    SetData(array, N);
+  }
+
+  template <typename W,
+            typename std::enable_if<
+                HasDataAndSize<const W, const T>::value>::type* = nullptr>
+  void SetData(const W& w) {
+    SetData(w.data(), w.size());
+  }
+
+  // Replace the data in the buffer with at most |max_elements| of data, using
+  // the function |setter|, which should have the following signature:
+  //   size_t setter(ArrayView<U> view)
+  // |setter| is given an appropriately typed ArrayView of the area in which to
+  // write the data (i.e. starting at the beginning of the buffer) and should
+  // return the number of elements actually written. This number must be <=
+  // |max_elements|.
+  template <typename U = T,
+            typename F,
+            typename std::enable_if<
+                internal::BufferCompat<T, U>::value>::type* = nullptr>
+  size_t SetData(size_t max_elements, F&& setter) {
+    RTC_DCHECK(IsConsistent());
+    size_ = 0;
+    return AppendData<U>(max_elements, std::forward<F>(setter));
+  }
+
+  // The AppendData functions add data to the end of the buffer. They accept
+  // the same input types as the constructors.
+  template <typename U,
+            typename std::enable_if<
+                internal::BufferCompat<T, U>::value>::type* = nullptr>
+  void AppendData(const U* data, size_t size) {
+    RTC_DCHECK(IsConsistent());
+    const size_t new_size = size_ + size;
+    EnsureCapacityWithHeadroom(new_size, true);
+    static_assert(sizeof(T) == sizeof(U), "");
+    std::memcpy(data_.get() + size_, data, size * sizeof(U));
+    size_ = new_size;
+    RTC_DCHECK(IsConsistent());
+  }
+
+  template <typename U,
+            size_t N,
+            typename std::enable_if<
+                internal::BufferCompat<T, U>::value>::type* = nullptr>
+  void AppendData(const U (&array)[N]) {
+    AppendData(array, N);
+  }
+
+  template <typename W,
+            typename std::enable_if<
+                HasDataAndSize<const W, const T>::value>::type* = nullptr>
+  void AppendData(const W& w) {
+    AppendData(w.data(), w.size());
+  }
+
+  template <typename U,
+            typename std::enable_if<
+                internal::BufferCompat<T, U>::value>::type* = nullptr>
+  void AppendData(const U& item) {
+    AppendData(&item, 1);
+  }
+
+  // Append at most |max_elements| to the end of the buffer, using the function
+  // |setter|, which should have the following signature:
+  //   size_t setter(ArrayView<U> view)
+  // |setter| is given an appropriately typed ArrayView of the area in which to
+  // write the data (i.e. starting at the former end of the buffer) and should
+  // return the number of elements actually written. This number must be <=
+  // |max_elements|.
+  template <typename U = T,
+            typename F,
+            typename std::enable_if<
+                internal::BufferCompat<T, U>::value>::type* = nullptr>
+  size_t AppendData(size_t max_elements, F&& setter) {
+    RTC_DCHECK(IsConsistent());
+    const size_t old_size = size_;
+    SetSize(old_size + max_elements);
+    U* base_ptr = data<U>() + old_size;
+    size_t written_elements = setter(rtc::ArrayView<U>(base_ptr, max_elements));
+
+    RTC_CHECK_LE(written_elements, max_elements);
+    size_ = old_size + written_elements;
+    RTC_DCHECK(IsConsistent());
+    return written_elements;
+  }
+
+  // Sets the size of the buffer. If the new size is smaller than the old, the
+  // buffer contents will be kept but truncated; if the new size is greater,
+  // the existing contents will be kept and the new space will be
+  // uninitialized.
+  void SetSize(size_t size) {
+    EnsureCapacityWithHeadroom(size, true);
+    size_ = size;
+  }
+
+  // Ensure that the buffer size can be increased to at least capacity without
+  // further reallocation. (Of course, this operation might need to reallocate
+  // the buffer.)
+  void EnsureCapacity(size_t capacity) {
+    // Don't allocate extra headroom, since the user is asking for a specific
+    // capacity.
+    EnsureCapacityWithHeadroom(capacity, false);
+  }
+
+  // Resets the buffer to zero size without altering capacity. Works even if the
+  // buffer has been moved from.
+  void Clear() {
+    size_ = 0;
+    RTC_DCHECK(IsConsistent());
+  }
+
+  // Swaps two buffers. Also works for buffers that have been moved from.
+  friend void swap(BufferT& a, BufferT& b) {
+    using std::swap;
+    swap(a.size_, b.size_);
+    swap(a.capacity_, b.capacity_);
+    swap(a.data_, b.data_);
+  }
+
+ private:
+  void EnsureCapacityWithHeadroom(size_t capacity, bool extra_headroom) {
+    RTC_DCHECK(IsConsistent());
+    if (capacity <= capacity_)
+      return;
+
+    // If the caller asks for extra headroom, ensure that the new capacity is
+    // >= 1.5 times the old capacity. Any constant > 1 is sufficient to prevent
+    // quadratic behavior; as to why we pick 1.5 in particular, see
+    // https://github.com/facebook/folly/blob/master/folly/docs/FBVector.md and
+    // http://www.gahcep.com/cpp-internals-stl-vector-part-1/.
+    const size_t new_capacity =
+        extra_headroom ? std::max(capacity, capacity_ + capacity_ / 2)
+                       : capacity;
+
+    std::unique_ptr<T[]> new_data(new T[new_capacity]);
+    std::memcpy(new_data.get(), data_.get(), size_ * sizeof(T));
+    data_ = std::move(new_data);
+    capacity_ = new_capacity;
+    RTC_DCHECK(IsConsistent());
+  }
+
+  // Precondition for all methods except Clear and the destructor.
+  // Postcondition for all methods except move construction and move
+  // assignment, which leave the moved-from object in a possibly inconsistent
+  // state.
+  bool IsConsistent() const {
+    return (data_ || capacity_ == 0) && capacity_ >= size_;
+  }
+
+  // Called when *this has been moved from. Conceptually it's a no-op, but we
+  // can mutate the state slightly to help subsequent sanity checks catch bugs.
+  void OnMovedFrom() {
+#if RTC_DCHECK_IS_ON
+    // Make *this consistent and empty. Shouldn't be necessary, but better safe
+    // than sorry.
+    size_ = 0;
+    capacity_ = 0;
+#else
+    // Ensure that *this is always inconsistent, to provoke bugs.
+    size_ = 1;
+    capacity_ = 0;
+#endif
+  }
+
+  size_t size_;
+  size_t capacity_;
+  std::unique_ptr<T[]> data_;
+};
+
+// By far the most common sort of buffer.
+using Buffer = BufferT<uint8_t>;
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_BUFFER_H_

webrtc/rtc_base/buffer_unittest.cc

@@ -0,0 +1,437 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/buffer.h"
+
+#include "webrtc/base/array_view.h"
+#include "webrtc/base/gunit.h"
+
+#include <type_traits>
+#include <utility>
+
+namespace rtc {
+
+namespace {
+
+// clang-format off
+const uint8_t kTestData[] = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
+                             0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf};
+// clang-format on
+
+void TestBuf(const Buffer& b1, size_t size, size_t capacity) {
+  EXPECT_EQ(b1.size(), size);
+  EXPECT_EQ(b1.capacity(), capacity);
+}
+
+}  // namespace
+
+TEST(BufferTest, TestConstructEmpty) {
+  TestBuf(Buffer(), 0, 0);
+  TestBuf(Buffer(Buffer()), 0, 0);
+  TestBuf(Buffer(0), 0, 0);
+
+  // We can't use a literal 0 for the first argument, because C++ will allow
+  // that to be considered a null pointer, which makes the call ambiguous.
+  TestBuf(Buffer(0 + 0, 10), 0, 10);
+
+  TestBuf(Buffer(kTestData, 0), 0, 0);
+  TestBuf(Buffer(kTestData, 0, 20), 0, 20);
+}
+
+TEST(BufferTest, TestConstructData) {
+  Buffer buf(kTestData, 7);
+  EXPECT_EQ(buf.size(), 7u);
+  EXPECT_EQ(buf.capacity(), 7u);
+  EXPECT_FALSE(buf.empty());
+  EXPECT_EQ(0, memcmp(buf.data(), kTestData, 7));
+}
+
+TEST(BufferTest, TestConstructDataWithCapacity) {
+  Buffer buf(kTestData, 7, 14);
+  EXPECT_EQ(buf.size(), 7u);
+  EXPECT_EQ(buf.capacity(), 14u);
+  EXPECT_FALSE(buf.empty());
+  EXPECT_EQ(0, memcmp(buf.data(), kTestData, 7));
+}
+
+TEST(BufferTest, TestConstructArray) {
+  Buffer buf(kTestData);
+  EXPECT_EQ(buf.size(), 16u);
+  EXPECT_EQ(buf.capacity(), 16u);
+  EXPECT_FALSE(buf.empty());
+  EXPECT_EQ(0, memcmp(buf.data(), kTestData, 16));
+}
+
+TEST(BufferTest, TestSetData) {
+  Buffer buf(kTestData + 4, 7);
+  buf.SetData(kTestData, 9);
+  EXPECT_EQ(buf.size(), 9u);
+  EXPECT_EQ(buf.capacity(), 7u * 3 / 2);
+  EXPECT_FALSE(buf.empty());
+  EXPECT_EQ(0, memcmp(buf.data(), kTestData, 9));
+  Buffer buf2;
+  buf2.SetData(buf);
+  EXPECT_EQ(buf.size(), 9u);
+  EXPECT_EQ(buf.capacity(), 7u * 3 / 2);
+  EXPECT_EQ(0, memcmp(buf.data(), kTestData, 9));
+}
+
+TEST(BufferTest, TestAppendData) {
+  Buffer buf(kTestData + 4, 3);
+  buf.AppendData(kTestData + 10, 2);
+  const int8_t exp[] = {0x4, 0x5, 0x6, 0xa, 0xb};
+  EXPECT_EQ(buf, Buffer(exp));
+  Buffer buf2;
+  buf2.AppendData(buf);
+  buf2.AppendData(rtc::ArrayView<uint8_t>(buf));
+  const int8_t exp2[] = {0x4, 0x5, 0x6, 0xa, 0xb, 0x4, 0x5, 0x6, 0xa, 0xb};
+  EXPECT_EQ(buf2, Buffer(exp2));
+}
+
+TEST(BufferTest, TestSetAndAppendWithUnknownArg) {
+  struct TestDataContainer {
+    size_t size() const { return 3; }
+    const uint8_t* data() const { return kTestData; }
+  };
+  Buffer buf;
+  buf.SetData(TestDataContainer());
+  EXPECT_EQ(3u, buf.size());
+  EXPECT_EQ(Buffer(kTestData, 3), buf);
+  buf.AppendData(TestDataContainer());
+  EXPECT_EQ(6u, buf.size());
+  EXPECT_EQ(0, memcmp(buf.data(), kTestData, 3));
+  EXPECT_EQ(0, memcmp(buf.data() + 3, kTestData, 3));
+}
+
+TEST(BufferTest, TestSetSizeSmaller) {
+  Buffer buf;
+  buf.SetData(kTestData, 15);
+  buf.SetSize(10);
+  EXPECT_EQ(buf.size(), 10u);
+  EXPECT_EQ(buf.capacity(), 15u);  // Hasn't shrunk.
+  EXPECT_FALSE(buf.empty());
+  EXPECT_EQ(buf, Buffer(kTestData, 10));
+}
+
+TEST(BufferTest, TestSetSizeLarger) {
+  Buffer buf;
+  buf.SetData(kTestData, 15);
+  EXPECT_EQ(buf.size(), 15u);
+  EXPECT_EQ(buf.capacity(), 15u);
+  EXPECT_FALSE(buf.empty());
+  buf.SetSize(20);
+  EXPECT_EQ(buf.size(), 20u);
+  EXPECT_EQ(buf.capacity(), 15u * 3 / 2);  // Has grown.
+  EXPECT_FALSE(buf.empty());
+  EXPECT_EQ(0, memcmp(buf.data(), kTestData, 15));
+}
+
+TEST(BufferTest, TestEnsureCapacitySmaller) {
+  Buffer buf(kTestData);
+  const char* data = buf.data<char>();
+  buf.EnsureCapacity(4);
+  EXPECT_EQ(buf.capacity(), 16u);     // Hasn't shrunk.
+  EXPECT_EQ(buf.data<char>(), data);  // No reallocation.
+  EXPECT_FALSE(buf.empty());
+  EXPECT_EQ(buf, Buffer(kTestData));
+}
+
+TEST(BufferTest, TestEnsureCapacityLarger) {
+  Buffer buf(kTestData, 5);
+  buf.EnsureCapacity(10);
+  const int8_t* data = buf.data<int8_t>();
+  EXPECT_EQ(buf.capacity(), 10u);
+  buf.AppendData(kTestData + 5, 5);
+  EXPECT_EQ(buf.data<int8_t>(), data);  // No reallocation.
+  EXPECT_FALSE(buf.empty());
+  EXPECT_EQ(buf, Buffer(kTestData, 10));
+}
+
+TEST(BufferTest, TestMoveConstruct) {
+  Buffer buf1(kTestData, 3, 40);
+  const uint8_t* data = buf1.data();
+  Buffer buf2(std::move(buf1));
+  EXPECT_EQ(buf2.size(), 3u);
+  EXPECT_EQ(buf2.capacity(), 40u);
+  EXPECT_EQ(buf2.data(), data);
+  EXPECT_FALSE(buf2.empty());
+  buf1.Clear();
+  EXPECT_EQ(buf1.size(), 0u);
+  EXPECT_EQ(buf1.capacity(), 0u);
+  EXPECT_EQ(buf1.data(), nullptr);
+  EXPECT_TRUE(buf1.empty());
+}
+
+TEST(BufferTest, TestMoveAssign) {
+  Buffer buf1(kTestData, 3, 40);
+  const uint8_t* data = buf1.data();
+  Buffer buf2(kTestData);
+  buf2 = std::move(buf1);
+  EXPECT_EQ(buf2.size(), 3u);
+  EXPECT_EQ(buf2.capacity(), 40u);
+  EXPECT_EQ(buf2.data(), data);
+  EXPECT_FALSE(buf2.empty());
+  buf1.Clear();
+  EXPECT_EQ(buf1.size(), 0u);
+  EXPECT_EQ(buf1.capacity(), 0u);
+  EXPECT_EQ(buf1.data(), nullptr);
+  EXPECT_TRUE(buf1.empty());
+}
+
+TEST(BufferTest, TestSwap) {
+  Buffer buf1(kTestData, 3);
+  Buffer buf2(kTestData, 6, 40);
+  uint8_t* data1 = buf1.data();
+  uint8_t* data2 = buf2.data();
+  using std::swap;
+  swap(buf1, buf2);
+  EXPECT_EQ(buf1.size(), 6u);
+  EXPECT_EQ(buf1.capacity(), 40u);
+  EXPECT_EQ(buf1.data(), data2);
+  EXPECT_FALSE(buf1.empty());
+  EXPECT_EQ(buf2.size(), 3u);
+  EXPECT_EQ(buf2.capacity(), 3u);
+  EXPECT_EQ(buf2.data(), data1);
+  EXPECT_FALSE(buf2.empty());
+}
+
+TEST(BufferTest, TestClear) {
+  Buffer buf;
+  buf.SetData(kTestData, 15);
+  EXPECT_EQ(buf.size(), 15u);
+  EXPECT_EQ(buf.capacity(), 15u);
+  EXPECT_FALSE(buf.empty());
+  const char *data = buf.data<char>();
+  buf.Clear();
+  EXPECT_EQ(buf.size(), 0u);
+  EXPECT_EQ(buf.capacity(), 15u);  // Hasn't shrunk.
+  EXPECT_EQ(buf.data<char>(), data); // No reallocation.
+  EXPECT_TRUE(buf.empty());
+}
+
+TEST(BufferTest, TestLambdaSetAppend) {
+  auto setter = [] (rtc::ArrayView<uint8_t> av) {
+    for (int i = 0; i != 15; ++i)
+      av[i] = kTestData[i];
+    return 15;
+  };
+
+  Buffer buf1;
+  buf1.SetData(kTestData, 15);
+  buf1.AppendData(kTestData, 15);
+
+  Buffer buf2;
+  EXPECT_EQ(buf2.SetData(15, setter), 15u);
+  EXPECT_EQ(buf2.AppendData(15, setter), 15u);
+  EXPECT_EQ(buf1, buf2);
+  EXPECT_EQ(buf1.capacity(), buf2.capacity());
+  EXPECT_FALSE(buf1.empty());
+  EXPECT_FALSE(buf2.empty());
+}
+
+TEST(BufferTest, TestLambdaSetAppendSigned) {
+  auto setter = [] (rtc::ArrayView<int8_t> av) {
+    for (int i = 0; i != 15; ++i)
+      av[i] = kTestData[i];
+    return 15;
+  };
+
+  Buffer buf1;
+  buf1.SetData(kTestData, 15);
+  buf1.AppendData(kTestData, 15);
+
+  Buffer buf2;
+  EXPECT_EQ(buf2.SetData<int8_t>(15, setter), 15u);
+  EXPECT_EQ(buf2.AppendData<int8_t>(15, setter), 15u);
+  EXPECT_EQ(buf1, buf2);
+  EXPECT_EQ(buf1.capacity(), buf2.capacity());
+  EXPECT_FALSE(buf1.empty());
+  EXPECT_FALSE(buf2.empty());
+}
+
+TEST(BufferTest, TestLambdaAppendEmpty) {
+  auto setter = [] (rtc::ArrayView<uint8_t> av) {
+    for (int i = 0; i != 15; ++i)
+      av[i] = kTestData[i];
+    return 15;
+  };
+
+  Buffer buf1;
+  buf1.SetData(kTestData, 15);
+
+  Buffer buf2;
+  EXPECT_EQ(buf2.AppendData(15, setter), 15u);
+  EXPECT_EQ(buf1, buf2);
+  EXPECT_EQ(buf1.capacity(), buf2.capacity());
+  EXPECT_FALSE(buf1.empty());
+  EXPECT_FALSE(buf2.empty());
+}
+
+TEST(BufferTest, TestLambdaAppendPartial) {
+  auto setter = [] (rtc::ArrayView<uint8_t> av) {
+    for (int i = 0; i != 7; ++i)
+      av[i] = kTestData[i];
+    return 7;
+  };
+
+  Buffer buf;
+  EXPECT_EQ(buf.AppendData(15, setter), 7u);
+  EXPECT_EQ(buf.size(), 7u);            // Size is exactly what we wrote.
+  EXPECT_GE(buf.capacity(), 7u);        // Capacity is valid.
+  EXPECT_NE(buf.data<char>(), nullptr); // Data is actually stored.
+  EXPECT_FALSE(buf.empty());
+}
+
+TEST(BufferTest, TestMutableLambdaSetAppend) {
+  uint8_t magic_number = 17;
+  auto setter = [magic_number] (rtc::ArrayView<uint8_t> av) mutable {
+    for (int i = 0; i != 15; ++i) {
+      av[i] = magic_number;
+      ++magic_number;
+    }
+    return 15;
+  };
+
+  EXPECT_EQ(magic_number, 17);
+
+  Buffer buf;
+  EXPECT_EQ(buf.SetData(15, setter), 15u);
+  EXPECT_EQ(buf.AppendData(15, setter), 15u);
+  EXPECT_EQ(buf.size(), 30u);           // Size is exactly what we wrote.
+  EXPECT_GE(buf.capacity(), 30u);       // Capacity is valid.
+  EXPECT_NE(buf.data<char>(), nullptr); // Data is actually stored.
+  EXPECT_FALSE(buf.empty());
+
+  for (uint8_t i = 0; i != buf.size(); ++i) {
+    EXPECT_EQ(buf.data()[i], magic_number + i);
+  }
+}
+
+TEST(BufferTest, TestBracketRead) {
+  Buffer buf(kTestData, 7);
+  EXPECT_EQ(buf.size(), 7u);
+  EXPECT_EQ(buf.capacity(), 7u);
+  EXPECT_NE(buf.data(), nullptr);
+  EXPECT_FALSE(buf.empty());
+
+  for (size_t i = 0; i != 7u; ++i) {
+    EXPECT_EQ(buf[i], kTestData[i]);
+  }
+}
+
+TEST(BufferTest, TestBracketReadConst) {
+  Buffer buf(kTestData, 7);
+  EXPECT_EQ(buf.size(), 7u);
+  EXPECT_EQ(buf.capacity(), 7u);
+  EXPECT_NE(buf.data(), nullptr);
+  EXPECT_FALSE(buf.empty());
+
+  const Buffer& cbuf = buf;
+
+  for (size_t i = 0; i != 7u; ++i) {
+    EXPECT_EQ(cbuf[i], kTestData[i]);
+  }
+}
+
+TEST(BufferTest, TestBracketWrite) {
+  Buffer buf(7);
+  EXPECT_EQ(buf.size(), 7u);
+  EXPECT_EQ(buf.capacity(), 7u);
+  EXPECT_NE(buf.data(), nullptr);
+  EXPECT_FALSE(buf.empty());
+
+  for (size_t i = 0; i != 7u; ++i) {
+    buf[i] = kTestData[i];
+  }
+
+  for (size_t i = 0; i != 7u; ++i) {
+    EXPECT_EQ(buf[i], kTestData[i]);
+  }
+}
+
+TEST(BufferTest, TestBeginEnd) {
+  const Buffer cbuf(kTestData);
+  Buffer buf(kTestData);
+  auto b1 = cbuf.begin();
+  for (auto& x : buf) {
+    EXPECT_EQ(*b1, x);
+    ++b1;
+    ++x;
+  }
+  EXPECT_EQ(cbuf.end(), b1);
+  auto b2 = buf.begin();
+  for (auto& y : cbuf) {
+    EXPECT_EQ(*b2, y + 1);
+    ++b2;
+  }
+  EXPECT_EQ(buf.end(), b2);
+}
+
+TEST(BufferTest, TestInt16) {
+  static constexpr int16_t test_data[] = {14, 15, 16, 17, 18};
+  BufferT<int16_t> buf(test_data);
+  EXPECT_EQ(buf.size(), 5u);
+  EXPECT_EQ(buf.capacity(), 5u);
+  EXPECT_NE(buf.data(), nullptr);
+  EXPECT_FALSE(buf.empty());
+  for (size_t i = 0; i != buf.size(); ++i) {
+    EXPECT_EQ(test_data[i], buf[i]);
+  }
+  BufferT<int16_t> buf2(test_data);
+  EXPECT_EQ(buf, buf2);
+  buf2[0] = 9;
+  EXPECT_NE(buf, buf2);
+}
+
+TEST(BufferTest, TestFloat) {
+  static constexpr float test_data[] = {14, 15, 16, 17, 18};
+  BufferT<float> buf;
+  EXPECT_EQ(buf.size(), 0u);
+  EXPECT_EQ(buf.capacity(), 0u);
+  EXPECT_EQ(buf.data(), nullptr);
+  EXPECT_TRUE(buf.empty());
+  buf.SetData(test_data);
+  EXPECT_EQ(buf.size(), 5u);
+  EXPECT_EQ(buf.capacity(), 5u);
+  EXPECT_NE(buf.data(), nullptr);
+  EXPECT_FALSE(buf.empty());
+  float* p1 = buf.data();
+  while (buf.data() == p1) {
+    buf.AppendData(test_data);
+  }
+  EXPECT_EQ(buf.size(), buf.capacity());
+  EXPECT_GT(buf.size(), 5u);
+  EXPECT_EQ(buf.size() % 5, 0u);
+  EXPECT_NE(buf.data(), nullptr);
+  for (size_t i = 0; i != buf.size(); ++i) {
+    EXPECT_EQ(test_data[i % 5], buf[i]);
+  }
+}
+
+TEST(BufferTest, TestStruct) {
+  struct BloodStone {
+    bool blood;
+    const char* stone;
+  };
+  BufferT<BloodStone> buf(4);
+  EXPECT_EQ(buf.size(), 4u);
+  EXPECT_EQ(buf.capacity(), 4u);
+  EXPECT_NE(buf.data(), nullptr);
+  EXPECT_FALSE(buf.empty());
+  BufferT<BloodStone*> buf2(4);
+  for (size_t i = 0; i < buf2.size(); ++i) {
+    buf2[i] = &buf[i];
+  }
+  static const char kObsidian[] = "obsidian";
+  buf2[2]->stone = kObsidian;
+  EXPECT_EQ(kObsidian, buf[2].stone);
+}
+
+}  // namespace rtc

webrtc/rtc_base/bufferqueue.cc

@@ -0,0 +1,94 @@
+/*
+ *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/bufferqueue.h"
+
+#include <algorithm>
+
+namespace rtc {
+
+BufferQueue::BufferQueue(size_t capacity, size_t default_size)
+    : capacity_(capacity), default_size_(default_size) {
+}
+
+BufferQueue::~BufferQueue() {
+  CritScope cs(&crit_);
+
+  for (Buffer* buffer : queue_) {
+    delete buffer;
+  }
+  for (Buffer* buffer : free_list_) {
+    delete buffer;
+  }
+}
+
+size_t BufferQueue::size() const {
+  CritScope cs(&crit_);
+  return queue_.size();
+}
+
+void BufferQueue::Clear() {
+  CritScope cs(&crit_);
+  while (!queue_.empty()) {
+    free_list_.push_back(queue_.front());
+    queue_.pop_front();
+  }
+}
+
+bool BufferQueue::ReadFront(void* buffer, size_t bytes, size_t* bytes_read) {
+  CritScope cs(&crit_);
+  if (queue_.empty()) {
+    return false;
+  }
+
+  bool was_writable = queue_.size() < capacity_;
+  Buffer* packet = queue_.front();
+  queue_.pop_front();
+
+  bytes = std::min(bytes, packet->size());
+  memcpy(buffer, packet->data(), bytes);
+  if (bytes_read) {
+    *bytes_read = bytes;
+  }
+  free_list_.push_back(packet);
+  if (!was_writable) {
+    NotifyWritableForTest();
+  }
+  return true;
+}
+
+bool BufferQueue::WriteBack(const void* buffer, size_t bytes,
+                            size_t* bytes_written) {
+  CritScope cs(&crit_);
+  if (queue_.size() == capacity_) {
+    return false;
+  }
+
+  bool was_readable = !queue_.empty();
+  Buffer* packet;
+  if (!free_list_.empty()) {
+    packet = free_list_.back();
+    free_list_.pop_back();
+  } else {
+    packet = new Buffer(bytes, default_size_);
+  }
+
+  packet->SetData(static_cast<const uint8_t*>(buffer), bytes);
+  if (bytes_written) {
+    *bytes_written = bytes;
+  }
+  queue_.push_back(packet);
+  if (!was_readable) {
+    NotifyReadableForTest();
+  }
+  return true;
+}
+
+}  // namespace rtc

webrtc/rtc_base/bufferqueue.h

@@ -0,0 +1,61 @@
+/*
+ *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_BUFFERQUEUE_H_
+#define WEBRTC_RTC_BASE_BUFFERQUEUE_H_
+
+#include <deque>
+#include <vector>
+
+#include "webrtc/base/buffer.h"
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/base/criticalsection.h"
+
+namespace rtc {
+
+class BufferQueue {
+ public:
+  // Creates a buffer queue with a given capacity and default buffer size.
+  BufferQueue(size_t capacity, size_t default_size);
+  virtual ~BufferQueue();
+
+  // Return number of queued buffers.
+  size_t size() const;
+
+  // Clear the BufferQueue by moving all Buffers from |queue_| to |free_list_|.
+  void Clear();
+
+  // ReadFront will only read one buffer at a time and will truncate buffers
+  // that don't fit in the passed memory.
+  // Returns true unless no data could be returned.
+  bool ReadFront(void* data, size_t bytes, size_t* bytes_read);
+
+  // WriteBack always writes either the complete memory or nothing.
+  // Returns true unless no data could be written.
+  bool WriteBack(const void* data, size_t bytes, size_t* bytes_written);
+
+ protected:
+  // These methods are called when the state of the queue changes.
+  virtual void NotifyReadableForTest() {}
+  virtual void NotifyWritableForTest() {}
+
+ private:
+  size_t capacity_;
+  size_t default_size_;
+  CriticalSection crit_;
+  std::deque<Buffer*> queue_ GUARDED_BY(crit_);
+  std::vector<Buffer*> free_list_ GUARDED_BY(crit_);
+
+  RTC_DISALLOW_COPY_AND_ASSIGN(BufferQueue);
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_BUFFERQUEUE_H_

webrtc/rtc_base/bufferqueue_unittest.cc

@@ -0,0 +1,86 @@
+/*
+ *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/bufferqueue.h"
+#include "webrtc/base/gunit.h"
+
+namespace rtc {
+
+TEST(BufferQueueTest, TestAll) {
+  const size_t kSize = 16;
+  const char in[kSize * 2 + 1] = "0123456789ABCDEFGHIJKLMNOPQRSTUV";
+  char out[kSize * 2];
+  size_t bytes;
+  BufferQueue queue1(1, kSize);
+  BufferQueue queue2(2, kSize);
+
+  // The queue is initially empty.
+  EXPECT_EQ(0u, queue1.size());
+  EXPECT_FALSE(queue1.ReadFront(out, kSize, &bytes));
+
+  // A write should succeed.
+  EXPECT_TRUE(queue1.WriteBack(in, kSize, &bytes));
+  EXPECT_EQ(kSize, bytes);
+  EXPECT_EQ(1u, queue1.size());
+
+  // The queue is full now (only one buffer allowed).
+  EXPECT_FALSE(queue1.WriteBack(in, kSize, &bytes));
+  EXPECT_EQ(1u, queue1.size());
+
+  // Reading previously written buffer.
+  EXPECT_TRUE(queue1.ReadFront(out, kSize, &bytes));
+  EXPECT_EQ(kSize, bytes);
+  EXPECT_EQ(0, memcmp(in, out, kSize));
+
+  // The queue is empty again now.
+  EXPECT_FALSE(queue1.ReadFront(out, kSize, &bytes));
+  EXPECT_EQ(0u, queue1.size());
+
+  // Reading only returns available data.
+  EXPECT_TRUE(queue1.WriteBack(in, kSize, &bytes));
+  EXPECT_EQ(kSize, bytes);
+  EXPECT_EQ(1u, queue1.size());
+  EXPECT_TRUE(queue1.ReadFront(out, kSize * 2, &bytes));
+  EXPECT_EQ(kSize, bytes);
+  EXPECT_EQ(0, memcmp(in, out, kSize));
+  EXPECT_EQ(0u, queue1.size());
+
+  // Reading maintains buffer boundaries.
+  EXPECT_TRUE(queue2.WriteBack(in, kSize / 2, &bytes));
+  EXPECT_EQ(1u, queue2.size());
+  EXPECT_TRUE(queue2.WriteBack(in + kSize / 2, kSize / 2, &bytes));
+  EXPECT_EQ(2u, queue2.size());
+  EXPECT_TRUE(queue2.ReadFront(out, kSize, &bytes));
+  EXPECT_EQ(kSize / 2, bytes);
+  EXPECT_EQ(0, memcmp(in, out, kSize / 2));
+  EXPECT_EQ(1u, queue2.size());
+  EXPECT_TRUE(queue2.ReadFront(out, kSize, &bytes));
+  EXPECT_EQ(kSize / 2, bytes);
+  EXPECT_EQ(0, memcmp(in + kSize / 2, out, kSize / 2));
+  EXPECT_EQ(0u, queue2.size());
+
+  // Reading truncates buffers.
+  EXPECT_TRUE(queue2.WriteBack(in, kSize / 2, &bytes));
+  EXPECT_EQ(1u, queue2.size());
+  EXPECT_TRUE(queue2.WriteBack(in + kSize / 2, kSize / 2, &bytes));
+  EXPECT_EQ(2u, queue2.size());
+  // Read first packet partially in too-small buffer.
+  EXPECT_TRUE(queue2.ReadFront(out, kSize / 4, &bytes));
+  EXPECT_EQ(kSize / 4, bytes);
+  EXPECT_EQ(0, memcmp(in, out, kSize / 4));
+  EXPECT_EQ(1u, queue2.size());
+  // Remainder of first packet is truncated, reading starts with next packet.
+  EXPECT_TRUE(queue2.ReadFront(out, kSize, &bytes));
+  EXPECT_EQ(kSize / 2, bytes);
+  EXPECT_EQ(0, memcmp(in + kSize / 2, out, kSize / 2));
+  EXPECT_EQ(0u, queue2.size());
+}
+
+}  // namespace rtc

webrtc/rtc_base/bytebuffer.cc

@@ -0,0 +1,283 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/bytebuffer.h"
+
+#include <string.h>
+
+#include <algorithm>
+
+#include "webrtc/base/basictypes.h"
+#include "webrtc/base/byteorder.h"
+
+namespace rtc {
+
+static const int DEFAULT_SIZE = 4096;
+
+ByteBufferWriter::ByteBufferWriter()
+    : ByteBuffer(ORDER_NETWORK) {
+  Construct(nullptr, DEFAULT_SIZE);
+}
+
+ByteBufferWriter::ByteBufferWriter(ByteOrder byte_order)
+    : ByteBuffer(byte_order) {
+  Construct(nullptr, DEFAULT_SIZE);
+}
+
+ByteBufferWriter::ByteBufferWriter(const char* bytes, size_t len)
+    : ByteBuffer(ORDER_NETWORK) {
+  Construct(bytes, len);
+}
+
+ByteBufferWriter::ByteBufferWriter(const char* bytes, size_t len,
+                                   ByteOrder byte_order)
+    : ByteBuffer(byte_order) {
+  Construct(bytes, len);
+}
+
+void ByteBufferWriter::Construct(const char* bytes, size_t len) {
+  size_ = len;
+  bytes_ = new char[size_];
+
+  if (bytes) {
+    end_ = len;
+    memcpy(bytes_, bytes, end_);
+  } else {
+    end_ = 0;
+  }
+}
+
+ByteBufferWriter::~ByteBufferWriter() {
+  delete[] bytes_;
+}
+
+void ByteBufferWriter::WriteUInt8(uint8_t val) {
+  WriteBytes(reinterpret_cast<const char*>(&val), 1);
+}
+
+void ByteBufferWriter::WriteUInt16(uint16_t val) {
+  uint16_t v = (Order() == ORDER_NETWORK) ? HostToNetwork16(val) : val;
+  WriteBytes(reinterpret_cast<const char*>(&v), 2);
+}
+
+void ByteBufferWriter::WriteUInt24(uint32_t val) {
+  uint32_t v = (Order() == ORDER_NETWORK) ? HostToNetwork32(val) : val;
+  char* start = reinterpret_cast<char*>(&v);
+  if (Order() == ORDER_NETWORK || IsHostBigEndian()) {
+    ++start;
+  }
+  WriteBytes(start, 3);
+}
+
+void ByteBufferWriter::WriteUInt32(uint32_t val) {
+  uint32_t v = (Order() == ORDER_NETWORK) ? HostToNetwork32(val) : val;
+  WriteBytes(reinterpret_cast<const char*>(&v), 4);
+}
+
+void ByteBufferWriter::WriteUInt64(uint64_t val) {
+  uint64_t v = (Order() == ORDER_NETWORK) ? HostToNetwork64(val) : val;
+  WriteBytes(reinterpret_cast<const char*>(&v), 8);
+}
+
+// Serializes an unsigned varint in the format described by
+// https://developers.google.com/protocol-buffers/docs/encoding#varints
+// with the caveat that integers are 64-bit, not 128-bit.
+void ByteBufferWriter::WriteUVarint(uint64_t val) {
+  while (val >= 0x80) {
+    // Write 7 bits at a time, then set the msb to a continuation byte (msb=1).
+    char byte = static_cast<char>(val) | 0x80;
+    WriteBytes(&byte, 1);
+    val >>= 7;
+  }
+  char last_byte = static_cast<char>(val);
+  WriteBytes(&last_byte, 1);
+}
+
+void ByteBufferWriter::WriteString(const std::string& val) {
+  WriteBytes(val.c_str(), val.size());
+}
+
+void ByteBufferWriter::WriteBytes(const char* val, size_t len) {
+  memcpy(ReserveWriteBuffer(len), val, len);
+}
+
+char* ByteBufferWriter::ReserveWriteBuffer(size_t len) {
+  if (Length() + len > Capacity())
+    Resize(Length() + len);
+
+  char* start = bytes_ + end_;
+  end_ += len;
+  return start;
+}
+
+void ByteBufferWriter::Resize(size_t size) {
+  size_t len = std::min(end_, size);
+  if (size > size_) {
+    // Reallocate a larger buffer.
+    size_ = std::max(size, 3 * size_ / 2);
+    char* new_bytes = new char[size_];
+    memcpy(new_bytes, bytes_, len);
+    delete [] bytes_;
+    bytes_ = new_bytes;
+  }
+  end_ = len;
+}
+
+void ByteBufferWriter::Clear() {
+  memset(bytes_, 0, size_);
+  end_ = 0;
+}
+
+
+ByteBufferReader::ByteBufferReader(const char* bytes, size_t len)
+    : ByteBuffer(ORDER_NETWORK) {
+  Construct(bytes, len);
+}
+
+ByteBufferReader::ByteBufferReader(const char* bytes, size_t len,
+                                   ByteOrder byte_order)
+    : ByteBuffer(byte_order) {
+  Construct(bytes, len);
+}
+
+ByteBufferReader::ByteBufferReader(const char* bytes)
+    : ByteBuffer(ORDER_NETWORK) {
+  Construct(bytes, strlen(bytes));
+}
+
+ByteBufferReader::ByteBufferReader(const Buffer& buf)
+    : ByteBuffer(ORDER_NETWORK) {
+  Construct(buf.data<char>(), buf.size());
+}
+
+ByteBufferReader::ByteBufferReader(const ByteBufferWriter& buf)
+    : ByteBuffer(buf.Order()) {
+  Construct(buf.Data(), buf.Length());
+}
+
+void ByteBufferReader::Construct(const char* bytes, size_t len) {
+  bytes_ = bytes;
+  size_ = len;
+  start_ = 0;
+  end_ = len;
+}
+
+bool ByteBufferReader::ReadUInt8(uint8_t* val) {
+  if (!val) return false;
+
+  return ReadBytes(reinterpret_cast<char*>(val), 1);
+}
+
+bool ByteBufferReader::ReadUInt16(uint16_t* val) {
+  if (!val) return false;
+
+  uint16_t v;
+  if (!ReadBytes(reinterpret_cast<char*>(&v), 2)) {
+    return false;
+  } else {
+    *val = (Order() == ORDER_NETWORK) ? NetworkToHost16(v) : v;
+    return true;
+  }
+}
+
+bool ByteBufferReader::ReadUInt24(uint32_t* val) {
+  if (!val) return false;
+
+  uint32_t v = 0;
+  char* read_into = reinterpret_cast<char*>(&v);
+  if (Order() == ORDER_NETWORK || IsHostBigEndian()) {
+    ++read_into;
+  }
+
+  if (!ReadBytes(read_into, 3)) {
+    return false;
+  } else {
+    *val = (Order() == ORDER_NETWORK) ? NetworkToHost32(v) : v;
+    return true;
+  }
+}
+
+bool ByteBufferReader::ReadUInt32(uint32_t* val) {
+  if (!val) return false;
+
+  uint32_t v;
+  if (!ReadBytes(reinterpret_cast<char*>(&v), 4)) {
+    return false;
+  } else {
+    *val = (Order() == ORDER_NETWORK) ? NetworkToHost32(v) : v;
+    return true;
+  }
+}
+
+bool ByteBufferReader::ReadUInt64(uint64_t* val) {
+  if (!val) return false;
+
+  uint64_t v;
+  if (!ReadBytes(reinterpret_cast<char*>(&v), 8)) {
+    return false;
+  } else {
+    *val = (Order() == ORDER_NETWORK) ? NetworkToHost64(v) : v;
+    return true;
+  }
+}
+
+bool ByteBufferReader::ReadUVarint(uint64_t* val) {
+  if (!val) {
+    return false;
+  }
+  // Integers are deserialized 7 bits at a time, with each byte having a
+  // continuation byte (msb=1) if there are more bytes to be read.
+  uint64_t v = 0;
+  for (int i = 0; i < 64; i += 7) {
+    char byte;
+    if (!ReadBytes(&byte, 1)) {
+      return false;
+    }
+    // Read the first 7 bits of the byte, then offset by bits read so far.
+    v |= (static_cast<uint64_t>(byte) & 0x7F) << i;
+    // True if the msb is not a continuation byte.
+    if (static_cast<uint64_t>(byte) < 0x80) {
+      *val = v;
+      return true;
+    }
+  }
+  return false;
+}
+
+bool ByteBufferReader::ReadString(std::string* val, size_t len) {
+  if (!val) return false;
+
+  if (len > Length()) {
+    return false;
+  } else {
+    val->append(bytes_ + start_, len);
+    start_ += len;
+    return true;
+  }
+}
+
+bool ByteBufferReader::ReadBytes(char* val, size_t len) {
+  if (len > Length()) {
+    return false;
+  } else {
+    memcpy(val, bytes_ + start_, len);
+    start_ += len;
+    return true;
+  }
+}
+
+bool ByteBufferReader::Consume(size_t size) {
+  if (size > Length())
+    return false;
+  start_ += size;
+  return true;
+}
+
+}  // namespace rtc

webrtc/rtc_base/bytebuffer.h

@@ -0,0 +1,139 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_BYTEBUFFER_H_
+#define WEBRTC_RTC_BASE_BYTEBUFFER_H_
+
+#include <string>
+
+#include "webrtc/base/basictypes.h"
+#include "webrtc/base/buffer.h"
+#include "webrtc/base/constructormagic.h"
+
+namespace rtc {
+
+class ByteBuffer {
+ public:
+  enum ByteOrder {
+    ORDER_NETWORK = 0,  // Default, use network byte order (big endian).
+    ORDER_HOST,         // Use the native order of the host.
+  };
+
+  explicit ByteBuffer(ByteOrder byte_order) : byte_order_(byte_order) {}
+
+  ByteOrder Order() const { return byte_order_; }
+
+ private:
+  ByteOrder byte_order_;
+
+  RTC_DISALLOW_COPY_AND_ASSIGN(ByteBuffer);
+};
+
+class ByteBufferWriter : public ByteBuffer {
+ public:
+  // |byte_order| defines order of bytes in the buffer.
+  ByteBufferWriter();
+  explicit ByteBufferWriter(ByteOrder byte_order);
+  ByteBufferWriter(const char* bytes, size_t len);
+  ByteBufferWriter(const char* bytes, size_t len, ByteOrder byte_order);
+
+  ~ByteBufferWriter();
+
+  const char* Data() const { return bytes_; }
+  size_t Length() const { return end_; }
+  size_t Capacity() const { return size_; }
+
+  // Write value to the buffer. Resizes the buffer when it is
+  // neccessary.
+  void WriteUInt8(uint8_t val);
+  void WriteUInt16(uint16_t val);
+  void WriteUInt24(uint32_t val);
+  void WriteUInt32(uint32_t val);
+  void WriteUInt64(uint64_t val);
+  void WriteUVarint(uint64_t val);
+  void WriteString(const std::string& val);
+  void WriteBytes(const char* val, size_t len);
+
+  // Reserves the given number of bytes and returns a char* that can be written
+  // into. Useful for functions that require a char* buffer and not a
+  // ByteBufferWriter.
+  char* ReserveWriteBuffer(size_t len);
+
+  // Resize the buffer to the specified |size|.
+  void Resize(size_t size);
+
+  // Clears the contents of the buffer. After this, Length() will be 0.
+  void Clear();
+
+ private:
+  void Construct(const char* bytes, size_t size);
+
+  char* bytes_;
+  size_t size_;
+  size_t end_;
+
+  // There are sensible ways to define these, but they aren't needed in our code
+  // base.
+  RTC_DISALLOW_COPY_AND_ASSIGN(ByteBufferWriter);
+};
+
+// The ByteBufferReader references the passed data, i.e. the pointer must be
+// valid during the lifetime of the reader.
+class ByteBufferReader : public ByteBuffer {
+ public:
+  ByteBufferReader(const char* bytes, size_t len);
+  ByteBufferReader(const char* bytes, size_t len, ByteOrder byte_order);
+
+  // Initializes buffer from a zero-terminated string.
+  explicit ByteBufferReader(const char* bytes);
+
+  explicit ByteBufferReader(const Buffer& buf);
+
+  explicit ByteBufferReader(const ByteBufferWriter& buf);
+
+  // Returns start of unprocessed data.
+  const char* Data() const { return bytes_ + start_; }
+  // Returns number of unprocessed bytes.
+  size_t Length() const { return end_ - start_; }
+
+  // Read a next value from the buffer. Return false if there isn't
+  // enough data left for the specified type.
+  bool ReadUInt8(uint8_t* val);
+  bool ReadUInt16(uint16_t* val);
+  bool ReadUInt24(uint32_t* val);
+  bool ReadUInt32(uint32_t* val);
+  bool ReadUInt64(uint64_t* val);
+  bool ReadUVarint(uint64_t* val);
+  bool ReadBytes(char* val, size_t len);
+
+  // Appends next |len| bytes from the buffer to |val|. Returns false
+  // if there is less than |len| bytes left.
+  bool ReadString(std::string* val, size_t len);
+
+  // Moves current position |size| bytes forward. Returns false if
+  // there is less than |size| bytes left in the buffer. Consume doesn't
+  // permanently remove data, so remembered read positions are still valid
+  // after this call.
+  bool Consume(size_t size);
+
+ private:
+  void Construct(const char* bytes, size_t size);
+
+  const char* bytes_;
+  size_t size_;
+  size_t start_;
+  size_t end_;
+
+  RTC_DISALLOW_COPY_AND_ASSIGN(ByteBufferReader);
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_BYTEBUFFER_H_

webrtc/rtc_base/bytebuffer_unittest.cc

@@ -0,0 +1,258 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/arraysize.h"
+#include "webrtc/base/bytebuffer.h"
+#include "webrtc/base/byteorder.h"
+#include "webrtc/base/gunit.h"
+
+namespace rtc {
+
+TEST(ByteBufferTest, TestByteOrder) {
+  uint16_t n16 = 1;
+  uint32_t n32 = 1;
+  uint64_t n64 = 1;
+
+  EXPECT_EQ(n16, NetworkToHost16(HostToNetwork16(n16)));
+  EXPECT_EQ(n32, NetworkToHost32(HostToNetwork32(n32)));
+  EXPECT_EQ(n64, NetworkToHost64(HostToNetwork64(n64)));
+
+  if (IsHostBigEndian()) {
+    // The host is the network (big) endian.
+    EXPECT_EQ(n16, HostToNetwork16(n16));
+    EXPECT_EQ(n32, HostToNetwork32(n32));
+    EXPECT_EQ(n64, HostToNetwork64(n64));
+
+    // GetBE converts big endian to little endian here.
+    EXPECT_EQ(n16 >> 8, GetBE16(&n16));
+    EXPECT_EQ(n32 >> 24, GetBE32(&n32));
+    EXPECT_EQ(n64 >> 56, GetBE64(&n64));
+  } else {
+    // The host is little endian.
+    EXPECT_NE(n16, HostToNetwork16(n16));
+    EXPECT_NE(n32, HostToNetwork32(n32));
+    EXPECT_NE(n64, HostToNetwork64(n64));
+
+    // GetBE converts little endian to big endian here.
+    EXPECT_EQ(GetBE16(&n16), HostToNetwork16(n16));
+    EXPECT_EQ(GetBE32(&n32), HostToNetwork32(n32));
+    EXPECT_EQ(GetBE64(&n64), HostToNetwork64(n64));
+
+    // GetBE converts little endian to big endian here.
+    EXPECT_EQ(n16 << 8, GetBE16(&n16));
+    EXPECT_EQ(n32 << 24, GetBE32(&n32));
+    EXPECT_EQ(n64 << 56, GetBE64(&n64));
+  }
+}
+
+TEST(ByteBufferTest, TestBufferLength) {
+  ByteBufferWriter buffer;
+  size_t size = 0;
+  EXPECT_EQ(size, buffer.Length());
+
+  buffer.WriteUInt8(1);
+  ++size;
+  EXPECT_EQ(size, buffer.Length());
+
+  buffer.WriteUInt16(1);
+  size += 2;
+  EXPECT_EQ(size, buffer.Length());
+
+  buffer.WriteUInt24(1);
+  size += 3;
+  EXPECT_EQ(size, buffer.Length());
+
+  buffer.WriteUInt32(1);
+  size += 4;
+  EXPECT_EQ(size, buffer.Length());
+
+  buffer.WriteUInt64(1);
+  size += 8;
+  EXPECT_EQ(size, buffer.Length());
+}
+
+TEST(ByteBufferTest, TestReadWriteBuffer) {
+  ByteBufferWriter::ByteOrder orders[2] = { ByteBufferWriter::ORDER_HOST,
+                                            ByteBufferWriter::ORDER_NETWORK };
+  for (size_t i = 0; i < arraysize(orders); i++) {
+    ByteBufferWriter buffer(orders[i]);
+    EXPECT_EQ(orders[i], buffer.Order());
+    ByteBufferReader read_buf(nullptr, 0, orders[i]);
+    EXPECT_EQ(orders[i], read_buf.Order());
+    uint8_t ru8;
+    EXPECT_FALSE(read_buf.ReadUInt8(&ru8));
+
+    // Write and read uint8_t.
+    uint8_t wu8 = 1;
+    buffer.WriteUInt8(wu8);
+    ByteBufferReader read_buf1(buffer.Data(), buffer.Length(), orders[i]);
+    EXPECT_TRUE(read_buf1.ReadUInt8(&ru8));
+    EXPECT_EQ(wu8, ru8);
+    EXPECT_EQ(0U, read_buf1.Length());
+    buffer.Clear();
+
+    // Write and read uint16_t.
+    uint16_t wu16 = (1 << 8) + 1;
+    buffer.WriteUInt16(wu16);
+    ByteBufferReader read_buf2(buffer.Data(), buffer.Length(), orders[i]);
+    uint16_t ru16;
+    EXPECT_TRUE(read_buf2.ReadUInt16(&ru16));
+    EXPECT_EQ(wu16, ru16);
+    EXPECT_EQ(0U, read_buf2.Length());
+    buffer.Clear();
+
+    // Write and read uint24.
+    uint32_t wu24 = (3 << 16) + (2 << 8) + 1;
+    buffer.WriteUInt24(wu24);
+    ByteBufferReader read_buf3(buffer.Data(), buffer.Length(), orders[i]);
+    uint32_t ru24;
+    EXPECT_TRUE(read_buf3.ReadUInt24(&ru24));
+    EXPECT_EQ(wu24, ru24);
+    EXPECT_EQ(0U, read_buf3.Length());
+    buffer.Clear();
+
+    // Write and read uint32_t.
+    uint32_t wu32 = (4 << 24) + (3 << 16) + (2 << 8) + 1;
+    buffer.WriteUInt32(wu32);
+    ByteBufferReader read_buf4(buffer.Data(), buffer.Length(), orders[i]);
+    uint32_t ru32;
+    EXPECT_TRUE(read_buf4.ReadUInt32(&ru32));
+    EXPECT_EQ(wu32, ru32);
+    EXPECT_EQ(0U, read_buf3.Length());
+    buffer.Clear();
+
+    // Write and read uint64_t.
+    uint32_t another32 = (8 << 24) + (7 << 16) + (6 << 8) + 5;
+    uint64_t wu64 = (static_cast<uint64_t>(another32) << 32) + wu32;
+    buffer.WriteUInt64(wu64);
+    ByteBufferReader read_buf5(buffer.Data(), buffer.Length(), orders[i]);
+    uint64_t ru64;
+    EXPECT_TRUE(read_buf5.ReadUInt64(&ru64));
+    EXPECT_EQ(wu64, ru64);
+    EXPECT_EQ(0U, read_buf5.Length());
+    buffer.Clear();
+
+    // Write and read string.
+    std::string write_string("hello");
+    buffer.WriteString(write_string);
+    ByteBufferReader read_buf6(buffer.Data(), buffer.Length(), orders[i]);
+    std::string read_string;
+    EXPECT_TRUE(read_buf6.ReadString(&read_string, write_string.size()));
+    EXPECT_EQ(write_string, read_string);
+    EXPECT_EQ(0U, read_buf6.Length());
+    buffer.Clear();
+
+    // Write and read bytes
+    char write_bytes[] = "foo";
+    buffer.WriteBytes(write_bytes, 3);
+    ByteBufferReader read_buf7(buffer.Data(), buffer.Length(), orders[i]);
+    char read_bytes[3];
+    EXPECT_TRUE(read_buf7.ReadBytes(read_bytes, 3));
+    for (int i = 0; i < 3; ++i) {
+      EXPECT_EQ(write_bytes[i], read_bytes[i]);
+    }
+    EXPECT_EQ(0U, read_buf7.Length());
+    buffer.Clear();
+
+    // Write and read reserved buffer space
+    char* write_dst = buffer.ReserveWriteBuffer(3);
+    memcpy(write_dst, write_bytes, 3);
+    ByteBufferReader read_buf8(buffer.Data(), buffer.Length(), orders[i]);
+    memset(read_bytes, 0, 3);
+    EXPECT_TRUE(read_buf8.ReadBytes(read_bytes, 3));
+    for (int i = 0; i < 3; ++i) {
+      EXPECT_EQ(write_bytes[i], read_bytes[i]);
+    }
+    EXPECT_EQ(0U, read_buf8.Length());
+    buffer.Clear();
+
+    // Write and read in order.
+    buffer.WriteUInt8(wu8);
+    buffer.WriteUInt16(wu16);
+    buffer.WriteUInt24(wu24);
+    buffer.WriteUInt32(wu32);
+    buffer.WriteUInt64(wu64);
+    ByteBufferReader read_buf9(buffer.Data(), buffer.Length(), orders[i]);
+    EXPECT_TRUE(read_buf9.ReadUInt8(&ru8));
+    EXPECT_EQ(wu8, ru8);
+    EXPECT_TRUE(read_buf9.ReadUInt16(&ru16));
+    EXPECT_EQ(wu16, ru16);
+    EXPECT_TRUE(read_buf9.ReadUInt24(&ru24));
+    EXPECT_EQ(wu24, ru24);
+    EXPECT_TRUE(read_buf9.ReadUInt32(&ru32));
+    EXPECT_EQ(wu32, ru32);
+    EXPECT_TRUE(read_buf9.ReadUInt64(&ru64));
+    EXPECT_EQ(wu64, ru64);
+    EXPECT_EQ(0U, read_buf9.Length());
+    buffer.Clear();
+  }
+}
+
+TEST(ByteBufferTest, TestReadWriteUVarint) {
+  ByteBufferWriter::ByteOrder orders[2] = {ByteBufferWriter::ORDER_HOST,
+                                           ByteBufferWriter::ORDER_NETWORK};
+  for (ByteBufferWriter::ByteOrder& order : orders) {
+    ByteBufferWriter write_buffer(order);
+    size_t size = 0;
+    EXPECT_EQ(size, write_buffer.Length());
+
+    write_buffer.WriteUVarint(1u);
+    ++size;
+    EXPECT_EQ(size, write_buffer.Length());
+
+    write_buffer.WriteUVarint(2u);
+    ++size;
+    EXPECT_EQ(size, write_buffer.Length());
+
+    write_buffer.WriteUVarint(27u);
+    ++size;
+    EXPECT_EQ(size, write_buffer.Length());
+
+    write_buffer.WriteUVarint(149u);
+    size += 2;
+    EXPECT_EQ(size, write_buffer.Length());
+
+    write_buffer.WriteUVarint(68719476736u);
+    size += 6;
+    EXPECT_EQ(size, write_buffer.Length());
+
+    ByteBufferReader read_buffer(write_buffer.Data(), write_buffer.Length(),
+                                 order);
+    EXPECT_EQ(size, read_buffer.Length());
+    uint64_t val1, val2, val3, val4, val5;
+
+    ASSERT_TRUE(read_buffer.ReadUVarint(&val1));
+    EXPECT_EQ(1u, val1);
+    --size;
+    EXPECT_EQ(size, read_buffer.Length());
+
+    ASSERT_TRUE(read_buffer.ReadUVarint(&val2));
+    EXPECT_EQ(2u, val2);
+    --size;
+    EXPECT_EQ(size, read_buffer.Length());
+
+    ASSERT_TRUE(read_buffer.ReadUVarint(&val3));
+    EXPECT_EQ(27u, val3);
+    --size;
+    EXPECT_EQ(size, read_buffer.Length());
+
+    ASSERT_TRUE(read_buffer.ReadUVarint(&val4));
+    EXPECT_EQ(149u, val4);
+    size -= 2;
+    EXPECT_EQ(size, read_buffer.Length());
+
+    ASSERT_TRUE(read_buffer.ReadUVarint(&val5));
+    EXPECT_EQ(68719476736u, val5);
+    size -= 6;
+    EXPECT_EQ(size, read_buffer.Length());
+  }
+}
+
+}  // namespace rtc

webrtc/rtc_base/byteorder.h

@@ -0,0 +1,178 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_BYTEORDER_H_
+#define WEBRTC_RTC_BASE_BYTEORDER_H_
+
+#if defined(WEBRTC_POSIX) && !defined(__native_client__)
+#include <arpa/inet.h>
+#endif
+
+#include "webrtc/base/basictypes.h"
+
+#if defined(WEBRTC_MAC)
+#include <libkern/OSByteOrder.h>
+
+#define htobe16(v) OSSwapHostToBigInt16(v)
+#define htobe32(v) OSSwapHostToBigInt32(v)
+#define htobe64(v) OSSwapHostToBigInt64(v)
+#define be16toh(v) OSSwapBigToHostInt16(v)
+#define be32toh(v) OSSwapBigToHostInt32(v)
+#define be64toh(v) OSSwapBigToHostInt64(v)
+
+#define htole16(v) OSSwapHostToLittleInt16(v)
+#define htole32(v) OSSwapHostToLittleInt32(v)
+#define htole64(v) OSSwapHostToLittleInt64(v)
+#define le16toh(v) OSSwapLittleToHostInt16(v)
+#define le32toh(v) OSSwapLittleToHostInt32(v)
+#define le64toh(v) OSSwapLittleToHostInt64(v)
+#elif defined(WEBRTC_WIN) || defined(__native_client__)
+
+#if defined(WEBRTC_WIN)
+#include <stdlib.h>
+#include <winsock2.h>
+#else
+#include <netinet/in.h>
+#endif
+
+#define htobe16(v) htons(v)
+#define htobe32(v) htonl(v)
+#define be16toh(v) ntohs(v)
+#define be32toh(v) ntohl(v)
+#if defined(WEBRTC_WIN)
+#define htobe64(v) htonll(v)
+#define be64toh(v) ntohll(v)
+#endif
+
+#if defined(RTC_ARCH_CPU_LITTLE_ENDIAN)
+#define htole16(v) (v)
+#define htole32(v) (v)
+#define htole64(v) (v)
+#define le16toh(v) (v)
+#define le32toh(v) (v)
+#define le64toh(v) (v)
+#if defined(__native_client__)
+#define htobe64(v) __builtin_bswap64(v)
+#define be64toh(v) __builtin_bswap64(v)
+#endif
+#elif defined(RTC_ARCH_CPU_BIG_ENDIAN)
+#define htole16(v) __builtin_bswap16(v)
+#define htole32(v) __builtin_bswap32(v)
+#define htole64(v) __builtin_bswap64(v)
+#define le16toh(v) __builtin_bswap16(v)
+#define le32toh(v) __builtin_bswap32(v)
+#define le64toh(v) __builtin_bswap64(v)
+#if defined(__native_client__)
+#define htobe64(v) (v)
+#define be64toh(v) (v)
+#endif
+#else
+#error RTC_ARCH_CPU_BIG_ENDIAN or RTC_ARCH_CPU_LITTLE_ENDIAN must be defined.
+#endif  // defined(RTC_ARCH_CPU_LITTLE_ENDIAN)
+#elif defined(WEBRTC_POSIX)
+#include <endian.h>
+#endif
+
+namespace rtc {
+
+// Reading and writing of little and big-endian numbers from memory
+
+inline void Set8(void* memory, size_t offset, uint8_t v) {
+  static_cast<uint8_t*>(memory)[offset] = v;
+}
+
+inline uint8_t Get8(const void* memory, size_t offset) {
+  return static_cast<const uint8_t*>(memory)[offset];
+}
+
+inline void SetBE16(void* memory, uint16_t v) {
+  *static_cast<uint16_t*>(memory) = htobe16(v);
+}
+
+inline void SetBE32(void* memory, uint32_t v) {
+  *static_cast<uint32_t*>(memory) = htobe32(v);
+}
+
+inline void SetBE64(void* memory, uint64_t v) {
+  *static_cast<uint64_t*>(memory) = htobe64(v);
+}
+
+inline uint16_t GetBE16(const void* memory) {
+  return be16toh(*static_cast<const uint16_t*>(memory));
+}
+
+inline uint32_t GetBE32(const void* memory) {
+  return be32toh(*static_cast<const uint32_t*>(memory));
+}
+
+inline uint64_t GetBE64(const void* memory) {
+  return be64toh(*static_cast<const uint64_t*>(memory));
+}
+
+inline void SetLE16(void* memory, uint16_t v) {
+  *static_cast<uint16_t*>(memory) = htole16(v);
+}
+
+inline void SetLE32(void* memory, uint32_t v) {
+  *static_cast<uint32_t*>(memory) = htole32(v);
+}
+
+inline void SetLE64(void* memory, uint64_t v) {
+  *static_cast<uint64_t*>(memory) = htole64(v);
+}
+
+inline uint16_t GetLE16(const void* memory) {
+  return le16toh(*static_cast<const uint16_t*>(memory));
+}
+
+inline uint32_t GetLE32(const void* memory) {
+  return le32toh(*static_cast<const uint32_t*>(memory));
+}
+
+inline uint64_t GetLE64(const void* memory) {
+  return le64toh(*static_cast<const uint64_t*>(memory));
+}
+
+// Check if the current host is big endian.
+inline bool IsHostBigEndian() {
+#if defined(RTC_ARCH_CPU_BIG_ENDIAN)
+  return true;
+#else
+  return false;
+#endif
+}
+
+inline uint16_t HostToNetwork16(uint16_t n) {
+  return htobe16(n);
+}
+
+inline uint32_t HostToNetwork32(uint32_t n) {
+  return htobe32(n);
+}
+
+inline uint64_t HostToNetwork64(uint64_t n) {
+  return htobe64(n);
+}
+
+inline uint16_t NetworkToHost16(uint16_t n) {
+  return be16toh(n);
+}
+
+inline uint32_t NetworkToHost32(uint32_t n) {
+  return be32toh(n);
+}
+
+inline uint64_t NetworkToHost64(uint64_t n) {
+  return be64toh(n);
+}
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_BYTEORDER_H_

webrtc/rtc_base/byteorder_unittest.cc

@@ -0,0 +1,83 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <stdint.h>
+
+#include "webrtc/base/byteorder.h"
+#include "webrtc/base/gunit.h"
+
+namespace rtc {
+
+// Test memory set functions put values into memory in expected order.
+TEST(ByteOrderTest, TestSet) {
+  uint8_t buf[8] = {0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u};
+  Set8(buf, 0, 0xfb);
+  Set8(buf, 1, 0x12);
+  EXPECT_EQ(0xfb, buf[0]);
+  EXPECT_EQ(0x12, buf[1]);
+  SetBE16(buf, 0x1234);
+  EXPECT_EQ(0x12, buf[0]);
+  EXPECT_EQ(0x34, buf[1]);
+  SetLE16(buf, 0x1234);
+  EXPECT_EQ(0x34, buf[0]);
+  EXPECT_EQ(0x12, buf[1]);
+  SetBE32(buf, 0x12345678);
+  EXPECT_EQ(0x12, buf[0]);
+  EXPECT_EQ(0x34, buf[1]);
+  EXPECT_EQ(0x56, buf[2]);
+  EXPECT_EQ(0x78, buf[3]);
+  SetLE32(buf, 0x12345678);
+  EXPECT_EQ(0x78, buf[0]);
+  EXPECT_EQ(0x56, buf[1]);
+  EXPECT_EQ(0x34, buf[2]);
+  EXPECT_EQ(0x12, buf[3]);
+  SetBE64(buf, UINT64_C(0x0123456789abcdef));
+  EXPECT_EQ(0x01, buf[0]);
+  EXPECT_EQ(0x23, buf[1]);
+  EXPECT_EQ(0x45, buf[2]);
+  EXPECT_EQ(0x67, buf[3]);
+  EXPECT_EQ(0x89, buf[4]);
+  EXPECT_EQ(0xab, buf[5]);
+  EXPECT_EQ(0xcd, buf[6]);
+  EXPECT_EQ(0xef, buf[7]);
+  SetLE64(buf, UINT64_C(0x0123456789abcdef));
+  EXPECT_EQ(0xef, buf[0]);
+  EXPECT_EQ(0xcd, buf[1]);
+  EXPECT_EQ(0xab, buf[2]);
+  EXPECT_EQ(0x89, buf[3]);
+  EXPECT_EQ(0x67, buf[4]);
+  EXPECT_EQ(0x45, buf[5]);
+  EXPECT_EQ(0x23, buf[6]);
+  EXPECT_EQ(0x01, buf[7]);
+}
+
+// Test memory get functions get values from memory in expected order.
+TEST(ByteOrderTest, TestGet) {
+  uint8_t buf[8];
+  buf[0] = 0x01u;
+  buf[1] = 0x23u;
+  buf[2] = 0x45u;
+  buf[3] = 0x67u;
+  buf[4] = 0x89u;
+  buf[5] = 0xabu;
+  buf[6] = 0xcdu;
+  buf[7] = 0xefu;
+  EXPECT_EQ(0x01u, Get8(buf, 0));
+  EXPECT_EQ(0x23u, Get8(buf, 1));
+  EXPECT_EQ(0x0123u, GetBE16(buf));
+  EXPECT_EQ(0x2301u, GetLE16(buf));
+  EXPECT_EQ(0x01234567u, GetBE32(buf));
+  EXPECT_EQ(0x67452301u, GetLE32(buf));
+  EXPECT_EQ(UINT64_C(0x0123456789abcdef), GetBE64(buf));
+  EXPECT_EQ(UINT64_C(0xefcdab8967452301), GetLE64(buf));
+}
+
+}  // namespace rtc
+

webrtc/rtc_base/callback.h

@@ -0,0 +1,260 @@
+// This file was GENERATED by command:
+//     pump.py callback.h.pump
+// DO NOT EDIT BY HAND!!!
+
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+// To generate callback.h from callback.h.pump, execute:
+// /home/build/google3/third_party/gtest/scripts/pump.py callback.h.pump
+
+// Callbacks are callable object containers. They can hold a function pointer
+// or a function object and behave like a value type. Internally, data is
+// reference-counted, making copies and pass-by-value inexpensive.
+//
+// Callbacks are typed using template arguments.  The format is:
+//   CallbackN<ReturnType, ParamType1, ..., ParamTypeN>
+// where N is the number of arguments supplied to the callable object.
+// Callbacks are invoked using operator(), just like a function or a function
+// object. Default-constructed callbacks are "empty," and executing an empty
+// callback does nothing. A callback can be made empty by assigning it from
+// a default-constructed callback.
+//
+// Callbacks are similar in purpose to std::function (which isn't available on
+// all platforms we support) and a lightweight alternative to sigslots. Since
+// they effectively hide the type of the object they call, they're useful in
+// breaking dependencies between objects that need to interact with one another.
+// Notably, they can hold the results of Bind(), std::bind*, etc, without
+// needing
+// to know the resulting object type of those calls.
+//
+// Sigslots, on the other hand, provide a fuller feature set, such as multiple
+// subscriptions to a signal, optional thread-safety, and lifetime tracking of
+// slots. When these features are needed, choose sigslots.
+//
+// Example:
+//   int sqr(int x) { return x * x; }
+//   struct AddK {
+//     int k;
+//     int operator()(int x) const { return x + k; }
+//   } add_k = {5};
+//
+//   Callback1<int, int> my_callback;
+//   cout << my_callback.empty() << endl;  // true
+//
+//   my_callback = Callback1<int, int>(&sqr);
+//   cout << my_callback.empty() << endl;  // false
+//   cout << my_callback(3) << endl;  // 9
+//
+//   my_callback = Callback1<int, int>(add_k);
+//   cout << my_callback(10) << endl;  // 15
+//
+//   my_callback = Callback1<int, int>();
+//   cout << my_callback.empty() << endl;  // true
+
+#ifndef WEBRTC_RTC_BASE_CALLBACK_H_
+#define WEBRTC_RTC_BASE_CALLBACK_H_
+
+#include "webrtc/base/refcount.h"
+#include "webrtc/base/scoped_ref_ptr.h"
+
+namespace rtc {
+
+template <class R>
+class Callback0 {
+ public:
+  // Default copy operations are appropriate for this class.
+  Callback0() {}
+  template <class T> Callback0(const T& functor)
+      : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {}
+  R operator()() {
+    if (empty())
+      return R();
+    return helper_->Run();
+  }
+  bool empty() const { return !helper_; }
+
+ private:
+  struct Helper : RefCountInterface {
+    virtual ~Helper() {}
+    virtual R Run() = 0;
+  };
+  template <class T> struct HelperImpl : Helper {
+    explicit HelperImpl(const T& functor) : functor_(functor) {}
+    virtual R Run() {
+      return functor_();
+    }
+    T functor_;
+  };
+  scoped_refptr<Helper> helper_;
+};
+
+template <class R,
+          class P1>
+class Callback1 {
+ public:
+  // Default copy operations are appropriate for this class.
+  Callback1() {}
+  template <class T> Callback1(const T& functor)
+      : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {}
+  R operator()(P1 p1) {
+    if (empty())
+      return R();
+    return helper_->Run(p1);
+  }
+  bool empty() const { return !helper_; }
+
+ private:
+  struct Helper : RefCountInterface {
+    virtual ~Helper() {}
+    virtual R Run(P1 p1) = 0;
+  };
+  template <class T> struct HelperImpl : Helper {
+    explicit HelperImpl(const T& functor) : functor_(functor) {}
+    virtual R Run(P1 p1) {
+      return functor_(p1);
+    }
+    T functor_;
+  };
+  scoped_refptr<Helper> helper_;
+};
+
+template <class R,
+          class P1,
+          class P2>
+class Callback2 {
+ public:
+  // Default copy operations are appropriate for this class.
+  Callback2() {}
+  template <class T> Callback2(const T& functor)
+      : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {}
+  R operator()(P1 p1, P2 p2) {
+    if (empty())
+      return R();
+    return helper_->Run(p1, p2);
+  }
+  bool empty() const { return !helper_; }
+
+ private:
+  struct Helper : RefCountInterface {
+    virtual ~Helper() {}
+    virtual R Run(P1 p1, P2 p2) = 0;
+  };
+  template <class T> struct HelperImpl : Helper {
+    explicit HelperImpl(const T& functor) : functor_(functor) {}
+    virtual R Run(P1 p1, P2 p2) {
+      return functor_(p1, p2);
+    }
+    T functor_;
+  };
+  scoped_refptr<Helper> helper_;
+};
+
+template <class R,
+          class P1,
+          class P2,
+          class P3>
+class Callback3 {
+ public:
+  // Default copy operations are appropriate for this class.
+  Callback3() {}
+  template <class T> Callback3(const T& functor)
+      : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {}
+  R operator()(P1 p1, P2 p2, P3 p3) {
+    if (empty())
+      return R();
+    return helper_->Run(p1, p2, p3);
+  }
+  bool empty() const { return !helper_; }
+
+ private:
+  struct Helper : RefCountInterface {
+    virtual ~Helper() {}
+    virtual R Run(P1 p1, P2 p2, P3 p3) = 0;
+  };
+  template <class T> struct HelperImpl : Helper {
+    explicit HelperImpl(const T& functor) : functor_(functor) {}
+    virtual R Run(P1 p1, P2 p2, P3 p3) {
+      return functor_(p1, p2, p3);
+    }
+    T functor_;
+  };
+  scoped_refptr<Helper> helper_;
+};
+
+template <class R,
+          class P1,
+          class P2,
+          class P3,
+          class P4>
+class Callback4 {
+ public:
+  // Default copy operations are appropriate for this class.
+  Callback4() {}
+  template <class T> Callback4(const T& functor)
+      : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {}
+  R operator()(P1 p1, P2 p2, P3 p3, P4 p4) {
+    if (empty())
+      return R();
+    return helper_->Run(p1, p2, p3, p4);
+  }
+  bool empty() const { return !helper_; }
+
+ private:
+  struct Helper : RefCountInterface {
+    virtual ~Helper() {}
+    virtual R Run(P1 p1, P2 p2, P3 p3, P4 p4) = 0;
+  };
+  template <class T> struct HelperImpl : Helper {
+    explicit HelperImpl(const T& functor) : functor_(functor) {}
+    virtual R Run(P1 p1, P2 p2, P3 p3, P4 p4) {
+      return functor_(p1, p2, p3, p4);
+    }
+    T functor_;
+  };
+  scoped_refptr<Helper> helper_;
+};
+
+template <class R,
+          class P1,
+          class P2,
+          class P3,
+          class P4,
+          class P5>
+class Callback5 {
+ public:
+  // Default copy operations are appropriate for this class.
+  Callback5() {}
+  template <class T> Callback5(const T& functor)
+      : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {}
+  R operator()(P1 p1, P2 p2, P3 p3, P4 p4, P5 p5) {
+    if (empty())
+      return R();
+    return helper_->Run(p1, p2, p3, p4, p5);
+  }
+  bool empty() const { return !helper_; }
+
+ private:
+  struct Helper : RefCountInterface {
+    virtual ~Helper() {}
+    virtual R Run(P1 p1, P2 p2, P3 p3, P4 p4, P5 p5) = 0;
+  };
+  template <class T> struct HelperImpl : Helper {
+    explicit HelperImpl(const T& functor) : functor_(functor) {}
+    virtual R Run(P1 p1, P2 p2, P3 p3, P4 p4, P5 p5) {
+      return functor_(p1, p2, p3, p4, p5);
+    }
+    T functor_;
+  };
+  scoped_refptr<Helper> helper_;
+};
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_CALLBACK_H_

webrtc/rtc_base/callback.h.pump

@@ -0,0 +1,103 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+// To generate callback.h from callback.h.pump, execute:
+// /home/build/google3/third_party/gtest/scripts/pump.py callback.h.pump
+
+// Callbacks are callable object containers. They can hold a function pointer
+// or a function object and behave like a value type. Internally, data is
+// reference-counted, making copies and pass-by-value inexpensive.
+//
+// Callbacks are typed using template arguments.  The format is:
+//   CallbackN<ReturnType, ParamType1, ..., ParamTypeN>
+// where N is the number of arguments supplied to the callable object.
+// Callbacks are invoked using operator(), just like a function or a function
+// object. Default-constructed callbacks are "empty," and executing an empty
+// callback does nothing. A callback can be made empty by assigning it from
+// a default-constructed callback.
+//
+// Callbacks are similar in purpose to std::function (which isn't available on
+// all platforms we support) and a lightweight alternative to sigslots. Since
+// they effectively hide the type of the object they call, they're useful in
+// breaking dependencies between objects that need to interact with one another.
+// Notably, they can hold the results of Bind(), std::bind*, etc, without needing
+// to know the resulting object type of those calls.
+//
+// Sigslots, on the other hand, provide a fuller feature set, such as multiple
+// subscriptions to a signal, optional thread-safety, and lifetime tracking of
+// slots. When these features are needed, choose sigslots.
+//
+// Example:
+//   int sqr(int x) { return x * x; }
+//   struct AddK {
+//     int k;
+//     int operator()(int x) const { return x + k; }
+//   } add_k = {5};
+//
+//   Callback1<int, int> my_callback;
+//   cout << my_callback.empty() << endl;  // true
+//
+//   my_callback = Callback1<int, int>(&sqr);
+//   cout << my_callback.empty() << endl;  // false
+//   cout << my_callback(3) << endl;  // 9
+//
+//   my_callback = Callback1<int, int>(add_k);
+//   cout << my_callback(10) << endl;  // 15
+//
+//   my_callback = Callback1<int, int>();
+//   cout << my_callback.empty() << endl;  // true
+
+#ifndef WEBRTC_RTC_BASE_CALLBACK_H_
+#define WEBRTC_RTC_BASE_CALLBACK_H_
+
+#include "webrtc/base/refcount.h"
+#include "webrtc/base/scoped_ref_ptr.h"
+
+namespace rtc {
+
+$var n = 5
+$range i 0..n
+$for i [[
+$range j 1..i
+
+template <class R$for j [[,
+          class P$j]]>
+class Callback$i {
+ public:
+  // Default copy operations are appropriate for this class.
+  Callback$i() {}
+  template <class T> Callback$i(const T& functor)
+      : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {}
+  R operator()($for j , [[P$j p$j]]) {
+    if (empty())
+      return R();
+    return helper_->Run($for j , [[p$j]]);
+  }
+  bool empty() const { return !helper_; }
+
+ private:
+  struct Helper : RefCountInterface {
+    virtual ~Helper() {}
+    virtual R Run($for j , [[P$j p$j]]) = 0;
+  };
+  template <class T> struct HelperImpl : Helper {
+    explicit HelperImpl(const T& functor) : functor_(functor) {}
+    virtual R Run($for j , [[P$j p$j]]) {
+      return functor_($for j , [[p$j]]);
+    }
+    T functor_;
+  };
+  scoped_refptr<Helper> helper_;
+};
+
+]]
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_CALLBACK_H_

webrtc/rtc_base/callback_unittest.cc

@@ -0,0 +1,140 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/bind.h"
+#include "webrtc/base/callback.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/keep_ref_until_done.h"
+#include "webrtc/base/refcount.h"
+
+namespace rtc {
+
+namespace {
+
+void f() {}
+int g() { return 42; }
+int h(int x) { return x * x; }
+void i(int& x) { x *= x; }  // NOLINT: Testing refs
+
+struct BindTester {
+  int a() { return 24; }
+  int b(int x) const { return x * x; }
+};
+
+class RefCountedBindTester : public RefCountInterface {
+ public:
+  RefCountedBindTester() : count_(0) {}
+  int AddRef() const override {
+    return ++count_;
+  }
+  int Release() const override {
+    return --count_;
+  }
+  int RefCount() const { return count_; }
+
+ private:
+  mutable int count_;
+};
+
+}  // namespace
+
+TEST(CallbackTest, VoidReturn) {
+  Callback0<void> cb;
+  EXPECT_TRUE(cb.empty());
+  cb();  // Executing an empty callback should not crash.
+  cb = Callback0<void>(&f);
+  EXPECT_FALSE(cb.empty());
+  cb();
+}
+
+TEST(CallbackTest, IntReturn) {
+  Callback0<int> cb;
+  EXPECT_TRUE(cb.empty());
+  cb = Callback0<int>(&g);
+  EXPECT_FALSE(cb.empty());
+  EXPECT_EQ(42, cb());
+  EXPECT_EQ(42, cb());
+}
+
+TEST(CallbackTest, OneParam) {
+  Callback1<int, int> cb1(&h);
+  EXPECT_FALSE(cb1.empty());
+  EXPECT_EQ(9, cb1(-3));
+  EXPECT_EQ(100, cb1(10));
+
+  // Try clearing a callback.
+  cb1 = Callback1<int, int>();
+  EXPECT_TRUE(cb1.empty());
+
+  // Try a callback with a ref parameter.
+  Callback1<void, int&> cb2(&i);
+  int x = 3;
+  cb2(x);
+  EXPECT_EQ(9, x);
+  cb2(x);
+  EXPECT_EQ(81, x);
+}
+
+TEST(CallbackTest, WithBind) {
+  BindTester t;
+  Callback0<int> cb1 = Bind(&BindTester::a, &t);
+  EXPECT_EQ(24, cb1());
+  EXPECT_EQ(24, cb1());
+  cb1 = Bind(&BindTester::b, &t, 10);
+  EXPECT_EQ(100, cb1());
+  EXPECT_EQ(100, cb1());
+  cb1 = Bind(&BindTester::b, &t, 5);
+  EXPECT_EQ(25, cb1());
+  EXPECT_EQ(25, cb1());
+}
+
+TEST(KeepRefUntilDoneTest, simple) {
+  RefCountedBindTester t;
+  EXPECT_EQ(0, t.RefCount());
+  {
+    Callback0<void> cb = KeepRefUntilDone(&t);
+    EXPECT_EQ(1, t.RefCount());
+    cb();
+    EXPECT_EQ(1, t.RefCount());
+    cb();
+    EXPECT_EQ(1, t.RefCount());
+  }
+  EXPECT_EQ(0, t.RefCount());
+}
+
+TEST(KeepRefUntilDoneTest, copy) {
+  RefCountedBindTester t;
+  EXPECT_EQ(0, t.RefCount());
+  Callback0<void> cb2;
+  {
+    Callback0<void> cb = KeepRefUntilDone(&t);
+    EXPECT_EQ(1, t.RefCount());
+    cb2 = cb;
+  }
+  EXPECT_EQ(1, t.RefCount());
+  cb2 = Callback0<void>();
+  EXPECT_EQ(0, t.RefCount());
+}
+
+TEST(KeepRefUntilDoneTest, scopedref) {
+  RefCountedBindTester t;
+  EXPECT_EQ(0, t.RefCount());
+  {
+    scoped_refptr<RefCountedBindTester> t_scoped_ref(&t);
+    Callback0<void> cb = KeepRefUntilDone(t_scoped_ref);
+    t_scoped_ref = nullptr;
+    EXPECT_EQ(1, t.RefCount());
+    cb();
+    EXPECT_EQ(1, t.RefCount());
+  }
+  EXPECT_EQ(0, t.RefCount());
+}
+
+}  // namespace rtc

webrtc/rtc_base/checks.cc

@@ -0,0 +1,141 @@
+/*
+ *  Copyright 2006 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+// Most of this was borrowed (with minor modifications) from V8's and Chromium's
+// src/base/logging.cc.
+
+// Use the C++ version to provide __GLIBCXX__.
+#include <cstdarg>
+#include <cstdio>
+#include <cstdlib>
+
+#if defined(__GLIBCXX__) && !defined(__UCLIBC__)
+#include <cxxabi.h>
+#include <execinfo.h>
+#endif
+
+#if defined(WEBRTC_ANDROID)
+#define RTC_LOG_TAG "rtc"
+#include <android/log.h>  // NOLINT
+#endif
+
+#if defined(WEBRTC_WIN)
+#include <windows.h>
+#endif
+
+#include "webrtc/base/checks.h"
+#include "webrtc/base/logging.h"
+
+#if defined(_MSC_VER)
+// Warning C4722: destructor never returns, potential memory leak.
+// FatalMessage's dtor very intentionally aborts.
+#pragma warning(disable:4722)
+#endif
+
+namespace rtc {
+
+void VPrintError(const char* format, va_list args) {
+#if defined(WEBRTC_ANDROID)
+  __android_log_vprint(ANDROID_LOG_ERROR, RTC_LOG_TAG, format, args);
+#else
+  vfprintf(stderr, format, args);
+#endif
+}
+
+void PrintError(const char* format, ...) {
+  va_list args;
+  va_start(args, format);
+  VPrintError(format, args);
+  va_end(args);
+}
+
+// TODO(ajm): This works on Mac (although the parsing fails) but I don't seem
+// to get usable symbols on Linux. This is copied from V8. Chromium has a more
+// advanced stace trace system; also more difficult to copy.
+void DumpBacktrace() {
+#if defined(__GLIBCXX__) && !defined(__UCLIBC__)
+  void* trace[100];
+  int size = backtrace(trace, sizeof(trace) / sizeof(*trace));
+  char** symbols = backtrace_symbols(trace, size);
+  PrintError("\n==== C stack trace ===============================\n\n");
+  if (size == 0) {
+    PrintError("(empty)\n");
+  } else if (symbols == nullptr) {
+    PrintError("(no symbols)\n");
+  } else {
+    for (int i = 1; i < size; ++i) {
+      char mangled[201];
+      if (sscanf(symbols[i], "%*[^(]%*[(]%200[^)+]", mangled) == 1) {  // NOLINT
+        PrintError("%2d: ", i);
+        int status;
+        size_t length;
+        char* demangled =
+            abi::__cxa_demangle(mangled, nullptr, &length, &status);
+        PrintError("%s\n", demangled != nullptr ? demangled : mangled);
+        free(demangled);
+      } else {
+        // If parsing failed, at least print the unparsed symbol.
+        PrintError("%s\n", symbols[i]);
+      }
+    }
+  }
+  free(symbols);
+#endif
+}
+
+FatalMessage::FatalMessage(const char* file, int line) {
+  Init(file, line);
+}
+
+FatalMessage::FatalMessage(const char* file, int line, std::string* result) {
+  Init(file, line);
+  stream_ << "Check failed: " << *result << std::endl << "# ";
+  delete result;
+}
+
+NO_RETURN FatalMessage::~FatalMessage() {
+  fflush(stdout);
+  fflush(stderr);
+  stream_ << std::endl << "#" << std::endl;
+  PrintError(stream_.str().c_str());
+  DumpBacktrace();
+  fflush(stderr);
+  abort();
+}
+
+void FatalMessage::Init(const char* file, int line) {
+  stream_ << std::endl << std::endl
+          << "#" << std::endl
+          << "# Fatal error in " << file << ", line " << line << std::endl
+          << "# last system error: " << LAST_SYSTEM_ERROR << std::endl
+          << "# ";
+}
+
+// MSVC doesn't like complex extern templates and DLLs.
+#if !defined(COMPILER_MSVC)
+// Explicit instantiations for commonly used comparisons.
+template std::string* MakeCheckOpString<int, int>(
+    const int&, const int&, const char* names);
+template std::string* MakeCheckOpString<unsigned long, unsigned long>(
+    const unsigned long&, const unsigned long&, const char* names);
+template std::string* MakeCheckOpString<unsigned long, unsigned int>(
+    const unsigned long&, const unsigned int&, const char* names);
+template std::string* MakeCheckOpString<unsigned int, unsigned long>(
+    const unsigned int&, const unsigned long&, const char* names);
+template std::string* MakeCheckOpString<std::string, std::string>(
+    const std::string&, const std::string&, const char* name);
+#endif
+
+}  // namespace rtc
+
+// Function to call from the C version of the RTC_CHECK and RTC_DCHECK macros.
+NO_RETURN void rtc_FatalMessage(const char* file, int line, const char* msg) {
+  rtc::FatalMessage(file, line).stream() << msg;
+}

webrtc/rtc_base/checks.h

@@ -0,0 +1,289 @@
+/*
+ *  Copyright 2006 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_CHECKS_H_
+#define WEBRTC_RTC_BASE_CHECKS_H_
+
+#include "webrtc/typedefs.h"
+
+// If you for some reson need to know if DCHECKs are on, test the value of
+// RTC_DCHECK_IS_ON. (Test its value, not if it's defined; it'll always be
+// defined, to either a true or a false value.)
+#if !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)
+#define RTC_DCHECK_IS_ON 1
+#else
+#define RTC_DCHECK_IS_ON 0
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+NO_RETURN void rtc_FatalMessage(const char* file, int line, const char* msg);
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#ifdef __cplusplus
+// C++ version.
+
+#include <sstream>
+#include <string>
+
+#include "webrtc/base/safe_compare.h"
+
+// The macros here print a message to stderr and abort under various
+// conditions. All will accept additional stream messages. For example:
+// RTC_DCHECK_EQ(foo, bar) << "I'm printed when foo != bar.";
+//
+// - RTC_CHECK(x) is an assertion that x is always true, and that if it isn't,
+//   it's better to terminate the process than to continue. During development,
+//   the reason that it's better to terminate might simply be that the error
+//   handling code isn't in place yet; in production, the reason might be that
+//   the author of the code truly believes that x will always be true, but that
+//   she recognizes that if she is wrong, abrupt and unpleasant process
+//   termination is still better than carrying on with the assumption violated.
+//
+//   RTC_CHECK always evaluates its argument, so it's OK for x to have side
+//   effects.
+//
+// - RTC_DCHECK(x) is the same as RTC_CHECK(x)---an assertion that x is always
+//   true---except that x will only be evaluated in debug builds; in production
+//   builds, x is simply assumed to be true. This is useful if evaluating x is
+//   expensive and the expected cost of failing to detect the violated
+//   assumption is acceptable. You should not handle cases where a production
+//   build fails to spot a violated condition, even those that would result in
+//   crashes. If the code needs to cope with the error, make it cope, but don't
+//   call RTC_DCHECK; if the condition really can't occur, but you'd sleep
+//   better at night knowing that the process will suicide instead of carrying
+//   on in case you were wrong, use RTC_CHECK instead of RTC_DCHECK.
+//
+//   RTC_DCHECK only evaluates its argument in debug builds, so if x has visible
+//   side effects, you need to write e.g.
+//     bool w = x; RTC_DCHECK(w);
+//
+// - RTC_CHECK_EQ, _NE, _GT, ..., and RTC_DCHECK_EQ, _NE, _GT, ... are
+//   specialized variants of RTC_CHECK and RTC_DCHECK that print prettier
+//   messages if the condition doesn't hold. Prefer them to raw RTC_CHECK and
+//   RTC_DCHECK.
+//
+// - FATAL() aborts unconditionally.
+//
+// TODO(ajm): Ideally, checks.h would be combined with logging.h, but
+// consolidation with system_wrappers/logging.h should happen first.
+
+namespace rtc {
+
+// Helper macro which avoids evaluating the arguments to a stream if
+// the condition doesn't hold.
+#define RTC_LAZY_STREAM(stream, condition)                                    \
+  !(condition) ? static_cast<void>(0) : rtc::FatalMessageVoidify() & (stream)
+
+// The actual stream used isn't important. We reference |ignored| in the code
+// but don't evaluate it; this is to avoid "unused variable" warnings (we do so
+// in a particularly convoluted way with an extra ?: because that appears to be
+// the simplest construct that keeps Visual Studio from complaining about
+// condition being unused).
+#define RTC_EAT_STREAM_PARAMETERS(ignored) \
+  (true ? true : ((void)(ignored), true))  \
+      ? static_cast<void>(0)               \
+      : rtc::FatalMessageVoidify() & rtc::FatalMessage("", 0).stream()
+
+// Call RTC_EAT_STREAM_PARAMETERS with an argument that fails to compile if
+// values of the same types as |a| and |b| can't be compared with the given
+// operation, and that would evaluate |a| and |b| if evaluated.
+#define RTC_EAT_STREAM_PARAMETERS_OP(op, a, b) \
+  RTC_EAT_STREAM_PARAMETERS(((void)rtc::Safe##op(a, b)))
+
+// RTC_CHECK dies with a fatal error if condition is not true. It is *not*
+// controlled by NDEBUG or anything else, so the check will be executed
+// regardless of compilation mode.
+//
+// We make sure RTC_CHECK et al. always evaluates their arguments, as
+// doing RTC_CHECK(FunctionWithSideEffect()) is a common idiom.
+#define RTC_CHECK(condition)                                      \
+  RTC_LAZY_STREAM(rtc::FatalMessage(__FILE__, __LINE__).stream(), \
+                  !(condition))                                   \
+      << "Check failed: " #condition << std::endl << "# "
+
+// Helper macro for binary operators.
+// Don't use this macro directly in your code, use RTC_CHECK_EQ et al below.
+//
+// TODO(akalin): Rewrite this so that constructs like if (...)
+// RTC_CHECK_EQ(...) else { ... } work properly.
+#define RTC_CHECK_OP(name, op, val1, val2)                                 \
+  if (std::string* _result =                                               \
+          rtc::Check##name##Impl((val1), (val2), #val1 " " #op " " #val2)) \
+    rtc::FatalMessage(__FILE__, __LINE__, _result).stream()
+
+// Build the error message string.  This is separate from the "Impl"
+// function template because it is not performance critical and so can
+// be out of line, while the "Impl" code should be inline.  Caller
+// takes ownership of the returned string.
+template<class t1, class t2>
+std::string* MakeCheckOpString(const t1& v1, const t2& v2, const char* names) {
+  std::ostringstream ss;
+  ss << names << " (" << v1 << " vs. " << v2 << ")";
+  std::string* msg = new std::string(ss.str());
+  return msg;
+}
+
+// MSVC doesn't like complex extern templates and DLLs.
+#if !defined(COMPILER_MSVC)
+// Commonly used instantiations of MakeCheckOpString<>. Explicitly instantiated
+// in logging.cc.
+extern template std::string* MakeCheckOpString<int, int>(
+    const int&, const int&, const char* names);
+extern template
+std::string* MakeCheckOpString<unsigned long, unsigned long>(
+    const unsigned long&, const unsigned long&, const char* names);
+extern template
+std::string* MakeCheckOpString<unsigned long, unsigned int>(
+    const unsigned long&, const unsigned int&, const char* names);
+extern template
+std::string* MakeCheckOpString<unsigned int, unsigned long>(
+    const unsigned int&, const unsigned long&, const char* names);
+extern template
+std::string* MakeCheckOpString<std::string, std::string>(
+    const std::string&, const std::string&, const char* name);
+#endif
+
+// Helper functions for RTC_CHECK_OP macro.
+// The (int, int) specialization works around the issue that the compiler
+// will not instantiate the template version of the function on values of
+// unnamed enum type - see comment below.
+#define DEFINE_RTC_CHECK_OP_IMPL(name)                                       \
+  template <class t1, class t2>                                              \
+  inline std::string* Check##name##Impl(const t1& v1, const t2& v2,          \
+                                        const char* names) {                 \
+    if (rtc::Safe##name(v1, v2))                                             \
+      return nullptr;                                                        \
+    else                                                                     \
+      return rtc::MakeCheckOpString(v1, v2, names);                          \
+  }                                                                          \
+  inline std::string* Check##name##Impl(int v1, int v2, const char* names) { \
+    if (rtc::Safe##name(v1, v2))                                             \
+      return nullptr;                                                        \
+    else                                                                     \
+      return rtc::MakeCheckOpString(v1, v2, names);                          \
+  }
+DEFINE_RTC_CHECK_OP_IMPL(Eq)
+DEFINE_RTC_CHECK_OP_IMPL(Ne)
+DEFINE_RTC_CHECK_OP_IMPL(Le)
+DEFINE_RTC_CHECK_OP_IMPL(Lt)
+DEFINE_RTC_CHECK_OP_IMPL(Ge)
+DEFINE_RTC_CHECK_OP_IMPL(Gt)
+#undef DEFINE_RTC_CHECK_OP_IMPL
+
+#define RTC_CHECK_EQ(val1, val2) RTC_CHECK_OP(Eq, ==, val1, val2)
+#define RTC_CHECK_NE(val1, val2) RTC_CHECK_OP(Ne, !=, val1, val2)
+#define RTC_CHECK_LE(val1, val2) RTC_CHECK_OP(Le, <=, val1, val2)
+#define RTC_CHECK_LT(val1, val2) RTC_CHECK_OP(Lt, <, val1, val2)
+#define RTC_CHECK_GE(val1, val2) RTC_CHECK_OP(Ge, >=, val1, val2)
+#define RTC_CHECK_GT(val1, val2) RTC_CHECK_OP(Gt, >, val1, val2)
+
+// The RTC_DCHECK macro is equivalent to RTC_CHECK except that it only generates
+// code in debug builds. It does reference the condition parameter in all cases,
+// though, so callers won't risk getting warnings about unused variables.
+#if RTC_DCHECK_IS_ON
+#define RTC_DCHECK(condition) RTC_CHECK(condition)
+#define RTC_DCHECK_EQ(v1, v2) RTC_CHECK_EQ(v1, v2)
+#define RTC_DCHECK_NE(v1, v2) RTC_CHECK_NE(v1, v2)
+#define RTC_DCHECK_LE(v1, v2) RTC_CHECK_LE(v1, v2)
+#define RTC_DCHECK_LT(v1, v2) RTC_CHECK_LT(v1, v2)
+#define RTC_DCHECK_GE(v1, v2) RTC_CHECK_GE(v1, v2)
+#define RTC_DCHECK_GT(v1, v2) RTC_CHECK_GT(v1, v2)
+#else
+#define RTC_DCHECK(condition) RTC_EAT_STREAM_PARAMETERS(condition)
+#define RTC_DCHECK_EQ(v1, v2) RTC_EAT_STREAM_PARAMETERS_OP(Eq, v1, v2)
+#define RTC_DCHECK_NE(v1, v2) RTC_EAT_STREAM_PARAMETERS_OP(Ne, v1, v2)
+#define RTC_DCHECK_LE(v1, v2) RTC_EAT_STREAM_PARAMETERS_OP(Le, v1, v2)
+#define RTC_DCHECK_LT(v1, v2) RTC_EAT_STREAM_PARAMETERS_OP(Lt, v1, v2)
+#define RTC_DCHECK_GE(v1, v2) RTC_EAT_STREAM_PARAMETERS_OP(Ge, v1, v2)
+#define RTC_DCHECK_GT(v1, v2) RTC_EAT_STREAM_PARAMETERS_OP(Gt, v1, v2)
+#endif
+
+// This is identical to LogMessageVoidify but in name.
+class FatalMessageVoidify {
+ public:
+  FatalMessageVoidify() { }
+  // This has to be an operator with a precedence lower than << but
+  // higher than ?:
+  void operator&(std::ostream&) { }
+};
+
+#define RTC_UNREACHABLE_CODE_HIT false
+#define RTC_NOTREACHED() RTC_DCHECK(RTC_UNREACHABLE_CODE_HIT)
+
+#define FATAL() rtc::FatalMessage(__FILE__, __LINE__).stream()
+// TODO(ajm): Consider adding RTC_NOTIMPLEMENTED macro when
+// base/logging.h and system_wrappers/logging.h are consolidated such that we
+// can match the Chromium behavior.
+
+// Like a stripped-down LogMessage from logging.h, except that it aborts.
+class FatalMessage {
+ public:
+  FatalMessage(const char* file, int line);
+  // Used for RTC_CHECK_EQ(), etc. Takes ownership of the given string.
+  FatalMessage(const char* file, int line, std::string* result);
+  NO_RETURN ~FatalMessage();
+
+  std::ostream& stream() { return stream_; }
+
+ private:
+  void Init(const char* file, int line);
+
+  std::ostringstream stream_;
+};
+
+// Performs the integer division a/b and returns the result. CHECKs that the
+// remainder is zero.
+template <typename T>
+inline T CheckedDivExact(T a, T b) {
+  RTC_CHECK_EQ(a % b, 0) << a << " is not evenly divisible by " << b;
+  return a / b;
+}
+
+}  // namespace rtc
+
+#else  // __cplusplus not defined
+// C version. Lacks many features compared to the C++ version, but usage
+// guidelines are the same.
+
+#define RTC_CHECK(condition)                                             \
+  do {                                                                   \
+    if (!(condition)) {                                                  \
+      rtc_FatalMessage(__FILE__, __LINE__, "CHECK failed: " #condition); \
+    }                                                                    \
+  } while (0)
+
+#define RTC_CHECK_EQ(a, b) RTC_CHECK((a) == (b))
+#define RTC_CHECK_NE(a, b) RTC_CHECK((a) != (b))
+#define RTC_CHECK_LE(a, b) RTC_CHECK((a) <= (b))
+#define RTC_CHECK_LT(a, b) RTC_CHECK((a) < (b))
+#define RTC_CHECK_GE(a, b) RTC_CHECK((a) >= (b))
+#define RTC_CHECK_GT(a, b) RTC_CHECK((a) > (b))
+
+#define RTC_DCHECK(condition)                                             \
+  do {                                                                    \
+    if (RTC_DCHECK_IS_ON && !(condition)) {                               \
+      rtc_FatalMessage(__FILE__, __LINE__, "DCHECK failed: " #condition); \
+    }                                                                     \
+  } while (0)
+
+#define RTC_DCHECK_EQ(a, b) RTC_DCHECK((a) == (b))
+#define RTC_DCHECK_NE(a, b) RTC_DCHECK((a) != (b))
+#define RTC_DCHECK_LE(a, b) RTC_DCHECK((a) <= (b))
+#define RTC_DCHECK_LT(a, b) RTC_DCHECK((a) < (b))
+#define RTC_DCHECK_GE(a, b) RTC_DCHECK((a) >= (b))
+#define RTC_DCHECK_GT(a, b) RTC_DCHECK((a) > (b))
+
+#endif  // __cplusplus
+
+#endif  // WEBRTC_RTC_BASE_CHECKS_H_

webrtc/rtc_base/compile_assert_c.h

@@ -0,0 +1,21 @@
+/*
+ *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_COMPILE_ASSERT_C_H_
+#define WEBRTC_RTC_BASE_COMPILE_ASSERT_C_H_
+
+// Use this macro to verify at compile time that certain restrictions are met.
+// The argument is the boolean expression to evaluate.
+// Example:
+//   RTC_COMPILE_ASSERT(sizeof(foo) < 128);
+// Note: In C++, use static_assert instead!
+#define RTC_COMPILE_ASSERT(expression) switch (0) {case 0: case expression:;}
+
+#endif  // WEBRTC_RTC_BASE_COMPILE_ASSERT_C_H_

webrtc/rtc_base/constructormagic.h

@@ -0,0 +1,34 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_CONSTRUCTORMAGIC_H_
+#define WEBRTC_RTC_BASE_CONSTRUCTORMAGIC_H_
+
+// Put this in the declarations for a class to be unassignable.
+#define RTC_DISALLOW_ASSIGN(TypeName) \
+  void operator=(const TypeName&) = delete
+
+// A macro to disallow the copy constructor and operator= functions. This should
+// be used in the declarations for a class.
+#define RTC_DISALLOW_COPY_AND_ASSIGN(TypeName) \
+  TypeName(const TypeName&) = delete;          \
+  RTC_DISALLOW_ASSIGN(TypeName)
+
+// A macro to disallow all the implicit constructors, namely the default
+// constructor, copy constructor and operator= functions.
+//
+// This should be used in the declarations for a class that wants to prevent
+// anyone from instantiating it. This is especially useful for classes
+// containing only static methods.
+#define RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(TypeName) \
+  TypeName() = delete;                               \
+  RTC_DISALLOW_COPY_AND_ASSIGN(TypeName)
+
+#endif  // WEBRTC_RTC_BASE_CONSTRUCTORMAGIC_H_

webrtc/rtc_base/copyonwritebuffer.cc

@@ -0,0 +1,112 @@
+/*
+ *  Copyright 2016 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/copyonwritebuffer.h"
+
+namespace rtc {
+
+CopyOnWriteBuffer::CopyOnWriteBuffer() {
+  RTC_DCHECK(IsConsistent());
+}
+
+CopyOnWriteBuffer::CopyOnWriteBuffer(const CopyOnWriteBuffer& buf)
+    : buffer_(buf.buffer_) {
+}
+
+CopyOnWriteBuffer::CopyOnWriteBuffer(CopyOnWriteBuffer&& buf)
+    : buffer_(std::move(buf.buffer_)) {
+}
+
+CopyOnWriteBuffer::CopyOnWriteBuffer(size_t size)
+    : buffer_(size > 0 ? new RefCountedObject<Buffer>(size) : nullptr) {
+  RTC_DCHECK(IsConsistent());
+}
+
+CopyOnWriteBuffer::CopyOnWriteBuffer(size_t size, size_t capacity)
+    : buffer_(size > 0 || capacity > 0
+          ? new RefCountedObject<Buffer>(size, capacity)
+          : nullptr) {
+  RTC_DCHECK(IsConsistent());
+}
+
+CopyOnWriteBuffer::~CopyOnWriteBuffer() = default;
+
+bool CopyOnWriteBuffer::operator==(const CopyOnWriteBuffer& buf) const {
+  // Must either use the same buffer internally or have the same contents.
+  RTC_DCHECK(IsConsistent());
+  RTC_DCHECK(buf.IsConsistent());
+  return buffer_.get() == buf.buffer_.get() ||
+      (buffer_.get() && buf.buffer_.get() &&
+      *buffer_.get() == *buf.buffer_.get());
+}
+
+void CopyOnWriteBuffer::SetSize(size_t size) {
+  RTC_DCHECK(IsConsistent());
+  if (!buffer_) {
+    if (size > 0) {
+      buffer_ = new RefCountedObject<Buffer>(size);
+    }
+    RTC_DCHECK(IsConsistent());
+    return;
+  }
+
+  // Clone data if referenced.
+  if (!buffer_->HasOneRef()) {
+    buffer_ = new RefCountedObject<Buffer>(
+        buffer_->data(),
+        std::min(buffer_->size(), size),
+        std::max(buffer_->capacity(), size));
+  }
+  buffer_->SetSize(size);
+  RTC_DCHECK(IsConsistent());
+}
+
+void CopyOnWriteBuffer::EnsureCapacity(size_t capacity) {
+  RTC_DCHECK(IsConsistent());
+  if (!buffer_) {
+    if (capacity > 0) {
+      buffer_ = new RefCountedObject<Buffer>(0, capacity);
+    }
+    RTC_DCHECK(IsConsistent());
+    return;
+  } else if (capacity <= buffer_->capacity()) {
+    return;
+  }
+
+  CloneDataIfReferenced(std::max(buffer_->capacity(), capacity));
+  buffer_->EnsureCapacity(capacity);
+  RTC_DCHECK(IsConsistent());
+}
+
+void CopyOnWriteBuffer::Clear() {
+  if (!buffer_)
+    return;
+
+  if (buffer_->HasOneRef()) {
+    buffer_->Clear();
+  } else {
+    buffer_ = new RefCountedObject<Buffer>(0, buffer_->capacity());
+  }
+  RTC_DCHECK(IsConsistent());
+}
+
+void CopyOnWriteBuffer::CloneDataIfReferenced(size_t new_capacity) {
+  if (buffer_->HasOneRef()) {
+    return;
+  }
+
+  buffer_ = new RefCountedObject<Buffer>(buffer_->data(), buffer_->size(),
+      new_capacity);
+  RTC_DCHECK(IsConsistent());
+}
+
+
+
+}  // namespace rtc

webrtc/rtc_base/copyonwritebuffer.h

@@ -0,0 +1,241 @@
+/*
+ *  Copyright 2016 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_COPYONWRITEBUFFER_H_
+#define WEBRTC_RTC_BASE_COPYONWRITEBUFFER_H_
+
+#include <algorithm>
+#include <utility>
+
+#include "webrtc/base/buffer.h"
+#include "webrtc/base/checks.h"
+#include "webrtc/base/refcount.h"
+#include "webrtc/base/scoped_ref_ptr.h"
+
+namespace rtc {
+
+class CopyOnWriteBuffer {
+ public:
+  // An empty buffer.
+  CopyOnWriteBuffer();
+  // Copy size and contents of an existing buffer.
+  CopyOnWriteBuffer(const CopyOnWriteBuffer& buf);
+  // Move contents from an existing buffer.
+  CopyOnWriteBuffer(CopyOnWriteBuffer&& buf);
+
+  // Construct a buffer with the specified number of uninitialized bytes.
+  explicit CopyOnWriteBuffer(size_t size);
+  CopyOnWriteBuffer(size_t size, size_t capacity);
+
+  // Construct a buffer and copy the specified number of bytes into it. The
+  // source array may be (const) uint8_t*, int8_t*, or char*.
+  template <typename T,
+            typename std::enable_if<
+                internal::BufferCompat<uint8_t, T>::value>::type* = nullptr>
+  CopyOnWriteBuffer(const T* data, size_t size)
+      : CopyOnWriteBuffer(data, size, size) {}
+  template <typename T,
+            typename std::enable_if<
+                internal::BufferCompat<uint8_t, T>::value>::type* = nullptr>
+  CopyOnWriteBuffer(const T* data, size_t size, size_t capacity)
+      : CopyOnWriteBuffer(size, capacity) {
+    if (buffer_) {
+      std::memcpy(buffer_->data(), data, size);
+    }
+  }
+
+  // Construct a buffer from the contents of an array.
+  template <typename T,
+            size_t N,
+            typename std::enable_if<
+                internal::BufferCompat<uint8_t, T>::value>::type* = nullptr>
+  CopyOnWriteBuffer(const T (&array)[N])  // NOLINT: runtime/explicit
+      : CopyOnWriteBuffer(array, N) {}
+
+  ~CopyOnWriteBuffer();
+
+  // Get a pointer to the data. Just .data() will give you a (const) uint8_t*,
+  // but you may also use .data<int8_t>() and .data<char>().
+  template <typename T = uint8_t,
+            typename std::enable_if<
+                internal::BufferCompat<uint8_t, T>::value>::type* = nullptr>
+  const T* data() const {
+    return cdata<T>();
+  }
+
+  // Get writable pointer to the data. This will create a copy of the underlying
+  // data if it is shared with other buffers.
+  template <typename T = uint8_t,
+            typename std::enable_if<
+                internal::BufferCompat<uint8_t, T>::value>::type* = nullptr>
+  T* data() {
+    RTC_DCHECK(IsConsistent());
+    if (!buffer_) {
+      return nullptr;
+    }
+    CloneDataIfReferenced(buffer_->capacity());
+    return buffer_->data<T>();
+  }
+
+  // Get const pointer to the data. This will not create a copy of the
+  // underlying data if it is shared with other buffers.
+  template <typename T = uint8_t,
+            typename std::enable_if<
+                internal::BufferCompat<uint8_t, T>::value>::type* = nullptr>
+  const T* cdata() const {
+    RTC_DCHECK(IsConsistent());
+    if (!buffer_) {
+      return nullptr;
+    }
+    return buffer_->data<T>();
+  }
+
+  size_t size() const {
+    RTC_DCHECK(IsConsistent());
+    return buffer_ ? buffer_->size() : 0;
+  }
+
+  size_t capacity() const {
+    RTC_DCHECK(IsConsistent());
+    return buffer_ ? buffer_->capacity() : 0;
+  }
+
+  CopyOnWriteBuffer& operator=(const CopyOnWriteBuffer& buf) {
+    RTC_DCHECK(IsConsistent());
+    RTC_DCHECK(buf.IsConsistent());
+    if (&buf != this) {
+      buffer_ = buf.buffer_;
+    }
+    return *this;
+  }
+
+  CopyOnWriteBuffer& operator=(CopyOnWriteBuffer&& buf) {
+    RTC_DCHECK(IsConsistent());
+    RTC_DCHECK(buf.IsConsistent());
+    buffer_ = std::move(buf.buffer_);
+    return *this;
+  }
+
+  bool operator==(const CopyOnWriteBuffer& buf) const;
+
+  bool operator!=(const CopyOnWriteBuffer& buf) const {
+    return !(*this == buf);
+  }
+
+  uint8_t& operator[](size_t index) {
+    RTC_DCHECK_LT(index, size());
+    return data()[index];
+  }
+
+  uint8_t operator[](size_t index) const {
+    RTC_DCHECK_LT(index, size());
+    return cdata()[index];
+  }
+
+  // Replace the contents of the buffer. Accepts the same types as the
+  // constructors.
+  template <typename T,
+            typename std::enable_if<
+                internal::BufferCompat<uint8_t, T>::value>::type* = nullptr>
+  void SetData(const T* data, size_t size) {
+    RTC_DCHECK(IsConsistent());
+    if (!buffer_) {
+      buffer_ = size > 0 ? new RefCountedObject<Buffer>(data, size) : nullptr;
+    } else if (!buffer_->HasOneRef()) {
+      buffer_ = new RefCountedObject<Buffer>(data, size, buffer_->capacity());
+    } else {
+      buffer_->SetData(data, size);
+    }
+    RTC_DCHECK(IsConsistent());
+  }
+
+  template <typename T,
+            size_t N,
+            typename std::enable_if<
+                internal::BufferCompat<uint8_t, T>::value>::type* = nullptr>
+  void SetData(const T (&array)[N]) {
+    SetData(array, N);
+  }
+
+  void SetData(const CopyOnWriteBuffer& buf) {
+    RTC_DCHECK(IsConsistent());
+    RTC_DCHECK(buf.IsConsistent());
+    if (&buf != this) {
+      buffer_ = buf.buffer_;
+    }
+  }
+
+  // Append data to the buffer. Accepts the same types as the constructors.
+  template <typename T,
+            typename std::enable_if<
+                internal::BufferCompat<uint8_t, T>::value>::type* = nullptr>
+  void AppendData(const T* data, size_t size) {
+    RTC_DCHECK(IsConsistent());
+    if (!buffer_) {
+      buffer_ = new RefCountedObject<Buffer>(data, size);
+      RTC_DCHECK(IsConsistent());
+      return;
+    }
+
+    CloneDataIfReferenced(std::max(buffer_->capacity(),
+        buffer_->size() + size));
+    buffer_->AppendData(data, size);
+    RTC_DCHECK(IsConsistent());
+  }
+
+  template <typename T,
+            size_t N,
+            typename std::enable_if<
+                internal::BufferCompat<uint8_t, T>::value>::type* = nullptr>
+  void AppendData(const T (&array)[N]) {
+    AppendData(array, N);
+  }
+
+  void AppendData(const CopyOnWriteBuffer& buf) {
+    AppendData(buf.data(), buf.size());
+  }
+
+  // Sets the size of the buffer. If the new size is smaller than the old, the
+  // buffer contents will be kept but truncated; if the new size is greater,
+  // the existing contents will be kept and the new space will be
+  // uninitialized.
+  void SetSize(size_t size);
+
+  // Ensure that the buffer size can be increased to at least capacity without
+  // further reallocation. (Of course, this operation might need to reallocate
+  // the buffer.)
+  void EnsureCapacity(size_t capacity);
+
+  // Resets the buffer to zero size without altering capacity. Works even if the
+  // buffer has been moved from.
+  void Clear();
+
+  // Swaps two buffers.
+  friend void swap(CopyOnWriteBuffer& a, CopyOnWriteBuffer& b) {
+    std::swap(a.buffer_, b.buffer_);
+  }
+
+ private:
+  // Create a copy of the underlying data if it is referenced from other Buffer
+  // objects.
+  void CloneDataIfReferenced(size_t new_capacity);
+
+  // Pre- and postcondition of all methods.
+  bool IsConsistent() const {
+    return (!buffer_ || buffer_->capacity() > 0);
+  }
+
+  // buffer_ is either null, or points to an rtc::Buffer with capacity > 0.
+  scoped_refptr<RefCountedObject<Buffer>> buffer_;
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_COPYONWRITEBUFFER_H_

webrtc/rtc_base/copyonwritebuffer_unittest.cc

@@ -0,0 +1,319 @@
+/*
+ *  Copyright 2016 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/copyonwritebuffer.h"
+#include "webrtc/base/gunit.h"
+
+namespace rtc {
+
+namespace {
+
+// clang-format off
+const uint8_t kTestData[] = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
+                             0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf};
+// clang-format on
+
+}  // namespace
+
+void EnsureBuffersShareData(const CopyOnWriteBuffer& buf1,
+                            const CopyOnWriteBuffer& buf2) {
+  // Data is shared between buffers.
+  EXPECT_EQ(buf1.size(), buf2.size());
+  EXPECT_EQ(buf1.capacity(), buf2.capacity());
+  const uint8_t* data1 = buf1.data();
+  const uint8_t* data2 = buf2.data();
+  EXPECT_EQ(data1, data2);
+  EXPECT_EQ(buf1, buf2);
+}
+
+void EnsureBuffersDontShareData(const CopyOnWriteBuffer& buf1,
+                                const CopyOnWriteBuffer& buf2) {
+  // Data is not shared between buffers.
+  const uint8_t* data1 = buf1.cdata();
+  const uint8_t* data2 = buf2.cdata();
+  EXPECT_NE(data1, data2);
+}
+
+TEST(CopyOnWriteBufferTest, TestCreateEmptyData) {
+  CopyOnWriteBuffer buf(static_cast<const uint8_t*>(nullptr), 0);
+  EXPECT_EQ(buf.size(), 0u);
+  EXPECT_EQ(buf.capacity(), 0u);
+  EXPECT_EQ(buf.data(), nullptr);
+}
+
+TEST(CopyOnWriteBufferTest, TestMoveConstruct) {
+  CopyOnWriteBuffer buf1(kTestData, 3, 10);
+  size_t buf1_size = buf1.size();
+  size_t buf1_capacity = buf1.capacity();
+  const uint8_t* buf1_data = buf1.cdata();
+
+  CopyOnWriteBuffer buf2(std::move(buf1));
+  EXPECT_EQ(buf1.size(), 0u);
+  EXPECT_EQ(buf1.capacity(), 0u);
+  EXPECT_EQ(buf1.data(), nullptr);
+  EXPECT_EQ(buf2.size(), buf1_size);
+  EXPECT_EQ(buf2.capacity(), buf1_capacity);
+  EXPECT_EQ(buf2.data(), buf1_data);
+}
+
+TEST(CopyOnWriteBufferTest, TestMoveAssign) {
+  CopyOnWriteBuffer buf1(kTestData, 3, 10);
+  size_t buf1_size = buf1.size();
+  size_t buf1_capacity = buf1.capacity();
+  const uint8_t* buf1_data = buf1.cdata();
+
+  CopyOnWriteBuffer buf2;
+  buf2 = std::move(buf1);
+  EXPECT_EQ(buf1.size(), 0u);
+  EXPECT_EQ(buf1.capacity(), 0u);
+  EXPECT_EQ(buf1.data(), nullptr);
+  EXPECT_EQ(buf2.size(), buf1_size);
+  EXPECT_EQ(buf2.capacity(), buf1_capacity);
+  EXPECT_EQ(buf2.data(), buf1_data);
+}
+
+TEST(CopyOnWriteBufferTest, TestSwap) {
+  CopyOnWriteBuffer buf1(kTestData, 3, 10);
+  size_t buf1_size = buf1.size();
+  size_t buf1_capacity = buf1.capacity();
+  const uint8_t* buf1_data = buf1.cdata();
+
+  CopyOnWriteBuffer buf2(kTestData, 6, 20);
+  size_t buf2_size = buf2.size();
+  size_t buf2_capacity = buf2.capacity();
+  const uint8_t* buf2_data = buf2.cdata();
+
+  std::swap(buf1, buf2);
+  EXPECT_EQ(buf1.size(), buf2_size);
+  EXPECT_EQ(buf1.capacity(), buf2_capacity);
+  EXPECT_EQ(buf1.data(), buf2_data);
+  EXPECT_EQ(buf2.size(), buf1_size);
+  EXPECT_EQ(buf2.capacity(), buf1_capacity);
+  EXPECT_EQ(buf2.data(), buf1_data);
+}
+
+TEST(CopyOnWriteBufferTest, TestAppendData) {
+  CopyOnWriteBuffer buf1(kTestData, 3, 10);
+  CopyOnWriteBuffer buf2(buf1);
+
+  EnsureBuffersShareData(buf1, buf2);
+
+  // AppendData copies the underlying buffer.
+  buf2.AppendData("foo");
+  EXPECT_EQ(buf2.size(), buf1.size() + 4);  // "foo" + trailing 0x00
+  EXPECT_EQ(buf2.capacity(), buf1.capacity());
+  EXPECT_NE(buf2.data(), buf1.data());
+
+  EXPECT_EQ(buf1, CopyOnWriteBuffer(kTestData, 3));
+  const int8_t exp[] = {0x0, 0x1, 0x2, 'f', 'o', 'o', 0x0};
+  EXPECT_EQ(buf2, CopyOnWriteBuffer(exp));
+}
+
+TEST(CopyOnWriteBufferTest, SetEmptyData) {
+  CopyOnWriteBuffer buf(10);
+
+  buf.SetData<uint8_t>(nullptr, 0);
+
+  EXPECT_EQ(0u, buf.size());
+}
+
+TEST(CopyOnWriteBufferTest, SetDataNoMoreThanCapacityDoesntCauseReallocation) {
+  CopyOnWriteBuffer buf1(3, 10);
+  const uint8_t* const original_allocation = buf1.cdata();
+
+  buf1.SetData(kTestData, 10);
+
+  EXPECT_EQ(original_allocation, buf1.cdata());
+  EXPECT_EQ(buf1, CopyOnWriteBuffer(kTestData, 10));
+}
+
+TEST(CopyOnWriteBufferTest, SetDataMakeReferenceCopy) {
+  CopyOnWriteBuffer buf1(kTestData, 3, 10);
+  CopyOnWriteBuffer buf2;
+
+  buf2.SetData(buf1);
+
+  EnsureBuffersShareData(buf1, buf2);
+}
+
+TEST(CopyOnWriteBufferTest, SetDataOnSharedKeepsOriginal) {
+  const uint8_t data[] = "foo";
+  CopyOnWriteBuffer buf1(kTestData, 3, 10);
+  const uint8_t* const original_allocation = buf1.cdata();
+  CopyOnWriteBuffer buf2(buf1);
+
+  buf2.SetData(data);
+
+  EnsureBuffersDontShareData(buf1, buf2);
+  EXPECT_EQ(original_allocation, buf1.cdata());
+  EXPECT_EQ(buf1, CopyOnWriteBuffer(kTestData, 3));
+  EXPECT_EQ(buf2, CopyOnWriteBuffer(data));
+}
+
+TEST(CopyOnWriteBufferTest, SetDataOnSharedKeepsCapacity) {
+  CopyOnWriteBuffer buf1(kTestData, 3, 10);
+  CopyOnWriteBuffer buf2(buf1);
+  EnsureBuffersShareData(buf1, buf2);
+
+  buf2.SetData(kTestData, 2);
+
+  EnsureBuffersDontShareData(buf1, buf2);
+  EXPECT_EQ(2u, buf2.size());
+  EXPECT_EQ(10u, buf2.capacity());
+}
+
+TEST(CopyOnWriteBufferTest, TestEnsureCapacity) {
+  CopyOnWriteBuffer buf1(kTestData, 3, 10);
+  CopyOnWriteBuffer buf2(buf1);
+
+  // Smaller than existing capacity -> no change and still same contents.
+  buf2.EnsureCapacity(8);
+  EnsureBuffersShareData(buf1, buf2);
+  EXPECT_EQ(buf1.size(), 3u);
+  EXPECT_EQ(buf1.capacity(), 10u);
+  EXPECT_EQ(buf2.size(), 3u);
+  EXPECT_EQ(buf2.capacity(), 10u);
+
+  // Lager than existing capacity -> data is cloned.
+  buf2.EnsureCapacity(16);
+  EnsureBuffersDontShareData(buf1, buf2);
+  EXPECT_EQ(buf1.size(), 3u);
+  EXPECT_EQ(buf1.capacity(), 10u);
+  EXPECT_EQ(buf2.size(), 3u);
+  EXPECT_EQ(buf2.capacity(), 16u);
+  // The size and contents are still the same.
+  EXPECT_EQ(buf1, buf2);
+}
+
+TEST(CopyOnWriteBufferTest, SetSizeDoesntChangeOriginal) {
+  CopyOnWriteBuffer buf1(kTestData, 3, 10);
+  const uint8_t* const original_allocation = buf1.cdata();
+  CopyOnWriteBuffer buf2(buf1);
+
+  buf2.SetSize(16);
+
+  EnsureBuffersDontShareData(buf1, buf2);
+  EXPECT_EQ(original_allocation, buf1.cdata());
+  EXPECT_EQ(3u, buf1.size());
+  EXPECT_EQ(10u, buf1.capacity());
+}
+
+TEST(CopyOnWriteBufferTest, SetSizeCloneContent) {
+  CopyOnWriteBuffer buf1(kTestData, 3, 10);
+  CopyOnWriteBuffer buf2(buf1);
+
+  buf2.SetSize(16);
+
+  EXPECT_EQ(buf2.size(), 16u);
+  EXPECT_EQ(0, memcmp(buf2.data(), kTestData, 3));
+}
+
+TEST(CopyOnWriteBufferTest, SetSizeMayIncreaseCapacity) {
+  CopyOnWriteBuffer buf(kTestData, 3, 10);
+
+  buf.SetSize(16);
+
+  EXPECT_EQ(16u, buf.size());
+  EXPECT_EQ(16u, buf.capacity());
+}
+
+TEST(CopyOnWriteBufferTest, SetSizeDoesntDecreaseCapacity) {
+  CopyOnWriteBuffer buf1(kTestData, 5, 10);
+  CopyOnWriteBuffer buf2(buf1);
+
+  buf2.SetSize(2);
+
+  EXPECT_EQ(2u, buf2.size());
+  EXPECT_EQ(10u, buf2.capacity());
+}
+
+TEST(CopyOnWriteBufferTest, ClearDoesntChangeOriginal) {
+  CopyOnWriteBuffer buf1(kTestData, 3, 10);
+  const uint8_t* const original_allocation = buf1.cdata();
+  CopyOnWriteBuffer buf2(buf1);
+
+  buf2.Clear();
+
+  EnsureBuffersDontShareData(buf1, buf2);
+  EXPECT_EQ(3u, buf1.size());
+  EXPECT_EQ(10u, buf1.capacity());
+  EXPECT_EQ(original_allocation, buf1.cdata());
+  EXPECT_EQ(0u, buf2.size());
+}
+
+TEST(CopyOnWriteBufferTest, ClearDoesntChangeCapacity) {
+  CopyOnWriteBuffer buf1(kTestData, 3, 10);
+  CopyOnWriteBuffer buf2(buf1);
+
+  buf2.Clear();
+
+  EXPECT_EQ(0u, buf2.size());
+  EXPECT_EQ(10u, buf2.capacity());
+}
+
+TEST(CopyOnWriteBufferTest, TestConstDataAccessor) {
+  CopyOnWriteBuffer buf1(kTestData, 3, 10);
+  CopyOnWriteBuffer buf2(buf1);
+
+  // .cdata() doesn't clone data.
+  const uint8_t* cdata1 = buf1.cdata();
+  const uint8_t* cdata2 = buf2.cdata();
+  EXPECT_EQ(cdata1, cdata2);
+
+  // Non-const .data() clones data if shared.
+  const uint8_t* data1 = buf1.data();
+  const uint8_t* data2 = buf2.data();
+  EXPECT_NE(data1, data2);
+  // buf1 was cloned above.
+  EXPECT_NE(data1, cdata1);
+  // Therefore buf2 was no longer sharing data and was not cloned.
+  EXPECT_EQ(data2, cdata1);
+}
+
+TEST(CopyOnWriteBufferTest, TestBacketRead) {
+  CopyOnWriteBuffer buf1(kTestData, 3, 10);
+  CopyOnWriteBuffer buf2(buf1);
+
+  EnsureBuffersShareData(buf1, buf2);
+  // Non-const reads clone the data if shared.
+  for (size_t i = 0; i != 3u; ++i) {
+    EXPECT_EQ(buf1[i], kTestData[i]);
+  }
+  EnsureBuffersDontShareData(buf1, buf2);
+}
+
+TEST(CopyOnWriteBufferTest, TestBacketReadConst) {
+  CopyOnWriteBuffer buf1(kTestData, 3, 10);
+  CopyOnWriteBuffer buf2(buf1);
+
+  EnsureBuffersShareData(buf1, buf2);
+  const CopyOnWriteBuffer& cbuf1 = buf1;
+  for (size_t i = 0; i != 3u; ++i) {
+    EXPECT_EQ(cbuf1[i], kTestData[i]);
+  }
+  EnsureBuffersShareData(buf1, buf2);
+}
+
+TEST(CopyOnWriteBufferTest, TestBacketWrite) {
+  CopyOnWriteBuffer buf1(kTestData, 3, 10);
+  CopyOnWriteBuffer buf2(buf1);
+
+  EnsureBuffersShareData(buf1, buf2);
+  for (size_t i = 0; i != 3u; ++i) {
+    buf1[i] = kTestData[i] + 1;
+  }
+  EXPECT_EQ(buf1.size(), 3u);
+  EXPECT_EQ(buf1.capacity(), 10u);
+  EXPECT_EQ(buf2.size(), 3u);
+  EXPECT_EQ(buf2.capacity(), 10u);
+  EXPECT_EQ(0, memcmp(buf2.cdata(), kTestData, 3));
+}
+
+}  // namespace rtc

webrtc/rtc_base/cpu_time.cc

@@ -0,0 +1,114 @@
+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/cpu_time.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/timeutils.h"
+
+#if defined(WEBRTC_LINUX)
+#include <time.h>
+#elif defined(WEBRTC_MAC)
+#include <sys/resource.h>
+#include <sys/types.h>
+#include <sys/times.h>
+#include <mach/thread_info.h>
+#include <mach/thread_act.h>
+#include <mach/mach_init.h>
+#include <unistd.h>
+#elif defined(WEBRTC_WIN)
+#include <windows.h>
+#endif
+
+#if defined(WEBRTC_WIN)
+namespace {
+// FILETIME resolution is 100 nanosecs.
+const int64_t kNanosecsPerFiletime = 100;
+}  // namespace
+#endif
+
+namespace rtc {
+
+int64_t GetProcessCpuTimeNanos() {
+#if defined(WEBRTC_LINUX)
+  struct timespec ts;
+  if (clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &ts) == 0) {
+    return ts.tv_sec * kNumNanosecsPerSec + ts.tv_nsec;
+  } else {
+    LOG_ERR(LS_ERROR) << "clock_gettime() failed.";
+  }
+#elif defined(WEBRTC_MAC)
+  struct rusage rusage;
+  if (getrusage(RUSAGE_SELF, &rusage) == 0) {
+    return rusage.ru_utime.tv_sec * kNumNanosecsPerSec +
+           rusage.ru_utime.tv_usec * kNumNanosecsPerMicrosec;
+  } else {
+    LOG_ERR(LS_ERROR) << "getrusage() failed.";
+  }
+#elif defined(WEBRTC_WIN)
+  FILETIME createTime;
+  FILETIME exitTime;
+  FILETIME kernelTime;
+  FILETIME userTime;
+  if (GetProcessTimes(GetCurrentProcess(), &createTime, &exitTime, &kernelTime,
+                      &userTime) != 0) {
+    return ((static_cast<uint64_t>(userTime.dwHighDateTime) << 32) +
+            userTime.dwLowDateTime) *
+           kNanosecsPerFiletime;
+  } else {
+    LOG_ERR(LS_ERROR) << "GetProcessTimes() failed.";
+  }
+#else
+  // Not implemented yet.
+  static_assert(
+      false, "GetProcessCpuTimeNanos() platform support not yet implemented.");
+#endif
+  return -1;
+}
+
+int64_t GetThreadCpuTimeNanos() {
+#if defined(WEBRTC_LINUX)
+  struct timespec ts;
+  if (clock_gettime(CLOCK_THREAD_CPUTIME_ID, &ts) == 0) {
+    return ts.tv_sec * kNumNanosecsPerSec + ts.tv_nsec;
+  } else {
+    LOG_ERR(LS_ERROR) << "clock_gettime() failed.";
+  }
+#elif defined(WEBRTC_MAC)
+  thread_basic_info_data_t info;
+  mach_msg_type_number_t count = THREAD_BASIC_INFO_COUNT;
+  if (thread_info(mach_thread_self(), THREAD_BASIC_INFO, (thread_info_t)&info,
+                  &count) == KERN_SUCCESS) {
+    return info.user_time.seconds * kNumNanosecsPerSec +
+           info.user_time.microseconds * kNumNanosecsPerMicrosec;
+  } else {
+    LOG_ERR(LS_ERROR) << "thread_info() failed.";
+  }
+#elif defined(WEBRTC_WIN)
+  FILETIME createTime;
+  FILETIME exitTime;
+  FILETIME kernelTime;
+  FILETIME userTime;
+  if (GetThreadTimes(GetCurrentThread(), &createTime, &exitTime, &kernelTime,
+                     &userTime) != 0) {
+    return ((static_cast<uint64_t>(userTime.dwHighDateTime) << 32) +
+            userTime.dwLowDateTime) *
+           kNanosecsPerFiletime;
+  } else {
+    LOG_ERR(LS_ERROR) << "GetThreadTimes() failed.";
+  }
+#else
+  // Not implemented yet.
+  static_assert(
+      false, "GetProcessCpuTimeNanos() platform support not yet implemented.");
+#endif
+  return -1;
+}
+
+}  // namespace rtc

webrtc/rtc_base/cpu_time.h

@@ -0,0 +1,28 @@
+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_CPU_TIME_H_
+#define WEBRTC_RTC_BASE_CPU_TIME_H_
+
+#include <stdint.h>
+
+namespace rtc {
+
+// Returns total CPU time of a current process in nanoseconds.
+// Time base is unknown, therefore use only to calculate deltas.
+int64_t GetProcessCpuTimeNanos();
+
+// Returns total CPU time of a current thread in nanoseconds.
+// Time base is unknown, therefore use only to calculate deltas.
+int64_t GetThreadCpuTimeNanos();
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_CPU_TIME_H_

webrtc/rtc_base/cpu_time_unittest.cc

@@ -0,0 +1,106 @@
+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <memory>
+#include <algorithm>
+#include "webrtc/base/cpu_time.h"
+#include "webrtc/base/platform_thread.h"
+#include "webrtc/base/timeutils.h"
+#include "webrtc/test/gtest.h"
+#include "webrtc/system_wrappers/include/cpu_info.h"
+#include "webrtc/system_wrappers/include/sleep.h"
+
+// Only run these tests on non-instrumented builds, because timing on
+// instrumented builds is unreliable, causing the test to be flaky.
+#if defined(THREAD_SANITIZER) || defined(MEMORY_SANITIZER) || \
+    defined(ADDRESS_SANITIZER)
+#define MAYBE_TEST(test_name) DISABLED_##test_name
+#else
+#define MAYBE_TEST(test_name) test_name
+#endif
+
+namespace {
+const int kAllowedErrorMillisecs = 30;
+const int kProcessingTimeMillisecs = 300;
+const int kWorkingThreads = 2;
+
+// Consumes approximately kProcessingTimeMillisecs of CPU time in single thread.
+bool WorkingFunction(void* counter_pointer) {
+  int64_t* counter = reinterpret_cast<int64_t*>(counter_pointer);
+  *counter = 0;
+  int64_t stop_cpu_time =
+      rtc::GetThreadCpuTimeNanos() +
+      kProcessingTimeMillisecs * rtc::kNumNanosecsPerMillisec;
+  while (rtc::GetThreadCpuTimeNanos() < stop_cpu_time) {
+    (*counter)++;
+  }
+  return false;
+}
+}  // namespace
+
+namespace rtc {
+
+// A minimal test which can be run on instrumented builds, so that they're at
+// least exercising the code to check for memory leaks/etc.
+TEST(CpuTimeTest, BasicTest) {
+  int64_t process_start_time_nanos = GetProcessCpuTimeNanos();
+  int64_t thread_start_time_nanos = GetThreadCpuTimeNanos();
+  int64_t process_duration_nanos =
+      GetProcessCpuTimeNanos() - process_start_time_nanos;
+  int64_t thread_duration_nanos =
+      GetThreadCpuTimeNanos() - thread_start_time_nanos;
+  EXPECT_GE(process_duration_nanos, 0);
+  EXPECT_GE(thread_duration_nanos, 0);
+}
+
+TEST(CpuTimeTest, MAYBE_TEST(TwoThreads)) {
+  int64_t process_start_time_nanos = GetProcessCpuTimeNanos();
+  int64_t thread_start_time_nanos = GetThreadCpuTimeNanos();
+  int64_t counter1;
+  int64_t counter2;
+  PlatformThread thread1(WorkingFunction, reinterpret_cast<void*>(&counter1),
+                         "Thread1");
+  PlatformThread thread2(WorkingFunction, reinterpret_cast<void*>(&counter2),
+                         "Thread2");
+  thread1.Start();
+  thread2.Start();
+  thread1.Stop();
+  thread2.Stop();
+
+  EXPECT_GE(counter1, 0);
+  EXPECT_GE(counter2, 0);
+  int64_t process_duration_nanos =
+      GetProcessCpuTimeNanos() - process_start_time_nanos;
+  int64_t thread_duration_nanos =
+      GetThreadCpuTimeNanos() - thread_start_time_nanos;
+  // This thread did almost nothing.
+  // Therefore GetThreadCpuTime is not a wall clock.
+  EXPECT_LE(thread_duration_nanos,
+            kAllowedErrorMillisecs * kNumNanosecsPerMillisec);
+  // Total process time is at least twice working threads' CPU time.
+  // Therefore process and thread times are correctly related.
+  EXPECT_GE(
+      process_duration_nanos,
+      kWorkingThreads * (kProcessingTimeMillisecs - kAllowedErrorMillisecs)
+      * kNumNanosecsPerMillisec);
+}
+
+TEST(CpuTimeTest, MAYBE_TEST(Sleeping)) {
+  int64_t process_start_time_nanos = GetProcessCpuTimeNanos();
+  webrtc::SleepMs(kProcessingTimeMillisecs);
+  int64_t process_duration_nanos =
+      GetProcessCpuTimeNanos() - process_start_time_nanos;
+  // Sleeping should not introduce any additional CPU time.
+  // Therefore GetProcessCpuTime is not a wall clock.
+  EXPECT_LE(process_duration_nanos,
+            kWorkingThreads * kAllowedErrorMillisecs * kNumNanosecsPerMillisec);
+}
+
+}  // namespace rtc

webrtc/rtc_base/crc32.cc

@@ -0,0 +1,52 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/crc32.h"
+
+#include "webrtc/base/arraysize.h"
+
+namespace rtc {
+
+// This implementation is based on the sample implementation in RFC 1952.
+
+// CRC32 polynomial, in reversed form.
+// See RFC 1952, or http://en.wikipedia.org/wiki/Cyclic_redundancy_check
+static const uint32_t kCrc32Polynomial = 0xEDB88320;
+static uint32_t kCrc32Table[256] = {0};
+
+static void EnsureCrc32TableInited() {
+  if (kCrc32Table[arraysize(kCrc32Table) - 1])
+    return;  // already inited
+  for (uint32_t i = 0; i < arraysize(kCrc32Table); ++i) {
+    uint32_t c = i;
+    for (size_t j = 0; j < 8; ++j) {
+      if (c & 1) {
+        c = kCrc32Polynomial ^ (c >> 1);
+      } else {
+        c >>= 1;
+      }
+    }
+    kCrc32Table[i] = c;
+  }
+}
+
+uint32_t UpdateCrc32(uint32_t start, const void* buf, size_t len) {
+  EnsureCrc32TableInited();
+
+  uint32_t c = start ^ 0xFFFFFFFF;
+  const uint8_t* u = static_cast<const uint8_t*>(buf);
+  for (size_t i = 0; i < len; ++i) {
+    c = kCrc32Table[(c ^ u[i]) & 0xFF] ^ (c >> 8);
+  }
+  return c ^ 0xFFFFFFFF;
+}
+
+}  // namespace rtc
+

webrtc/rtc_base/crc32.h

@@ -0,0 +1,34 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_CRC32_H_
+#define WEBRTC_RTC_BASE_CRC32_H_
+
+#include <string>
+
+#include "webrtc/base/basictypes.h"
+
+namespace rtc {
+
+// Updates a CRC32 checksum with |len| bytes from |buf|. |initial| holds the
+// checksum result from the previous update; for the first call, it should be 0.
+uint32_t UpdateCrc32(uint32_t initial, const void* buf, size_t len);
+
+// Computes a CRC32 checksum using |len| bytes from |buf|.
+inline uint32_t ComputeCrc32(const void* buf, size_t len) {
+  return UpdateCrc32(0, buf, len);
+}
+inline uint32_t ComputeCrc32(const std::string& str) {
+  return ComputeCrc32(str.c_str(), str.size());
+}
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_CRC32_H_

webrtc/rtc_base/crc32_unittest.cc

@@ -0,0 +1,35 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/crc32.h"
+#include "webrtc/base/gunit.h"
+
+#include <string>
+
+namespace rtc {
+
+TEST(Crc32Test, TestBasic) {
+  EXPECT_EQ(0U, ComputeCrc32(""));
+  EXPECT_EQ(0x352441C2U, ComputeCrc32("abc"));
+  EXPECT_EQ(0x171A3F5FU,
+      ComputeCrc32("abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"));
+}
+
+TEST(Crc32Test, TestMultipleUpdates) {
+  std::string input =
+      "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq";
+  uint32_t c = 0;
+  for (size_t i = 0; i < input.size(); ++i) {
+    c = UpdateCrc32(c, &input[i], 1);
+  }
+  EXPECT_EQ(0x171A3F5FU, c);
+}
+
+}  // namespace rtc

webrtc/rtc_base/criticalsection.cc

@@ -0,0 +1,252 @@
+/*
+ *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/criticalsection.h"
+
+#include "webrtc/base/checks.h"
+#include "webrtc/base/platform_thread.h"
+
+// TODO(tommi): Split this file up to per-platform implementation files.
+
+namespace rtc {
+
+CriticalSection::CriticalSection() {
+#if defined(WEBRTC_WIN)
+  InitializeCriticalSection(&crit_);
+#elif defined(WEBRTC_POSIX)
+# if defined(WEBRTC_MAC) && !USE_NATIVE_MUTEX_ON_MAC
+  lock_queue_ = 0;
+  owning_thread_ = 0;
+  recursion_ = 0;
+  semaphore_ = dispatch_semaphore_create(0);
+# else
+  pthread_mutexattr_t mutex_attribute;
+  pthread_mutexattr_init(&mutex_attribute);
+  pthread_mutexattr_settype(&mutex_attribute, PTHREAD_MUTEX_RECURSIVE);
+  pthread_mutex_init(&mutex_, &mutex_attribute);
+  pthread_mutexattr_destroy(&mutex_attribute);
+# endif
+  CS_DEBUG_CODE(thread_ = 0);
+  CS_DEBUG_CODE(recursion_count_ = 0);
+  RTC_UNUSED(thread_);
+  RTC_UNUSED(recursion_count_);
+#else
+# error Unsupported platform.
+#endif
+}
+
+CriticalSection::~CriticalSection() {
+#if defined(WEBRTC_WIN)
+  DeleteCriticalSection(&crit_);
+#elif defined(WEBRTC_POSIX)
+# if defined(WEBRTC_MAC) && !USE_NATIVE_MUTEX_ON_MAC
+  dispatch_release(semaphore_);
+# else
+  pthread_mutex_destroy(&mutex_);
+# endif
+#else
+# error Unsupported platform.
+#endif
+}
+
+void CriticalSection::Enter() const EXCLUSIVE_LOCK_FUNCTION() {
+#if defined(WEBRTC_WIN)
+  EnterCriticalSection(&crit_);
+#elif defined(WEBRTC_POSIX)
+# if defined(WEBRTC_MAC) && !USE_NATIVE_MUTEX_ON_MAC
+  int spin = 3000;
+  PlatformThreadRef self = CurrentThreadRef();
+  bool have_lock = false;
+  do {
+    // Instead of calling TryEnter() in this loop, we do two interlocked
+    // operations, first a read-only one in order to avoid affecting the lock
+    // cache-line while spinning, in case another thread is using the lock.
+    if (!IsThreadRefEqual(owning_thread_, self)) {
+      if (AtomicOps::AcquireLoad(&lock_queue_) == 0) {
+        if (AtomicOps::CompareAndSwap(&lock_queue_, 0, 1) == 0) {
+          have_lock = true;
+          break;
+        }
+      }
+    } else {
+      AtomicOps::Increment(&lock_queue_);
+      have_lock = true;
+      break;
+    }
+
+    sched_yield();
+  } while (--spin);
+
+  if (!have_lock && AtomicOps::Increment(&lock_queue_) > 1) {
+    // Owning thread cannot be the current thread since TryEnter() would
+    // have succeeded.
+    RTC_DCHECK(!IsThreadRefEqual(owning_thread_, self));
+    // Wait for the lock to become available.
+    dispatch_semaphore_wait(semaphore_, DISPATCH_TIME_FOREVER);
+    RTC_DCHECK(owning_thread_ == 0);
+    RTC_DCHECK(!recursion_);
+  }
+
+  owning_thread_ = self;
+  ++recursion_;
+
+# else
+  pthread_mutex_lock(&mutex_);
+# endif
+
+# if CS_DEBUG_CHECKS
+  if (!recursion_count_) {
+    RTC_DCHECK(!thread_);
+    thread_ = CurrentThreadRef();
+  } else {
+    RTC_DCHECK(CurrentThreadIsOwner());
+  }
+  ++recursion_count_;
+# endif
+#else
+# error Unsupported platform.
+#endif
+}
+
+bool CriticalSection::TryEnter() const EXCLUSIVE_TRYLOCK_FUNCTION(true) {
+#if defined(WEBRTC_WIN)
+  return TryEnterCriticalSection(&crit_) != FALSE;
+#elif defined(WEBRTC_POSIX)
+# if defined(WEBRTC_MAC) && !USE_NATIVE_MUTEX_ON_MAC
+  if (!IsThreadRefEqual(owning_thread_, CurrentThreadRef())) {
+    if (AtomicOps::CompareAndSwap(&lock_queue_, 0, 1) != 0)
+      return false;
+    owning_thread_ = CurrentThreadRef();
+    RTC_DCHECK(!recursion_);
+  } else {
+    AtomicOps::Increment(&lock_queue_);
+  }
+  ++recursion_;
+# else
+  if (pthread_mutex_trylock(&mutex_) != 0)
+    return false;
+# endif
+# if CS_DEBUG_CHECKS
+  if (!recursion_count_) {
+    RTC_DCHECK(!thread_);
+    thread_ = CurrentThreadRef();
+  } else {
+    RTC_DCHECK(CurrentThreadIsOwner());
+  }
+  ++recursion_count_;
+# endif
+  return true;
+#else
+# error Unsupported platform.
+#endif
+}
+
+void CriticalSection::Leave() const UNLOCK_FUNCTION() {
+  RTC_DCHECK(CurrentThreadIsOwner());
+#if defined(WEBRTC_WIN)
+  LeaveCriticalSection(&crit_);
+#elif defined(WEBRTC_POSIX)
+# if CS_DEBUG_CHECKS
+  --recursion_count_;
+  RTC_DCHECK(recursion_count_ >= 0);
+  if (!recursion_count_)
+    thread_ = 0;
+# endif
+# if defined(WEBRTC_MAC) && !USE_NATIVE_MUTEX_ON_MAC
+  RTC_DCHECK(IsThreadRefEqual(owning_thread_, CurrentThreadRef()));
+  RTC_DCHECK_GE(recursion_, 0);
+  --recursion_;
+  if (!recursion_)
+    owning_thread_ = 0;
+
+  if (AtomicOps::Decrement(&lock_queue_) > 0 && !recursion_)
+    dispatch_semaphore_signal(semaphore_);
+# else
+  pthread_mutex_unlock(&mutex_);
+# endif
+#else
+# error Unsupported platform.
+#endif
+}
+
+bool CriticalSection::CurrentThreadIsOwner() const {
+#if defined(WEBRTC_WIN)
+  // OwningThread has type HANDLE but actually contains the Thread ID:
+  // http://stackoverflow.com/questions/12675301/why-is-the-owningthread-member-of-critical-section-of-type-handle-when-it-is-de
+  // Converting through size_t avoids the VS 2015 warning C4312: conversion from
+  // 'type1' to 'type2' of greater size
+  return crit_.OwningThread ==
+         reinterpret_cast<HANDLE>(static_cast<size_t>(GetCurrentThreadId()));
+#elif defined(WEBRTC_POSIX)
+# if CS_DEBUG_CHECKS
+  return IsThreadRefEqual(thread_, CurrentThreadRef());
+# else
+  return true;
+# endif  // CS_DEBUG_CHECKS
+#else
+# error Unsupported platform.
+#endif
+}
+
+CritScope::CritScope(const CriticalSection* cs) : cs_(cs) { cs_->Enter(); }
+CritScope::~CritScope() { cs_->Leave(); }
+
+TryCritScope::TryCritScope(const CriticalSection* cs)
+    : cs_(cs), locked_(cs->TryEnter()) {
+  CS_DEBUG_CODE(lock_was_called_ = false);
+  RTC_UNUSED(lock_was_called_);
+}
+
+TryCritScope::~TryCritScope() {
+  CS_DEBUG_CODE(RTC_DCHECK(lock_was_called_));
+  if (locked_)
+    cs_->Leave();
+}
+
+bool TryCritScope::locked() const {
+  CS_DEBUG_CODE(lock_was_called_ = true);
+  return locked_;
+}
+
+void GlobalLockPod::Lock() {
+#if !defined(WEBRTC_WIN) && (!defined(WEBRTC_MAC) || USE_NATIVE_MUTEX_ON_MAC)
+  const struct timespec ts_null = {0};
+#endif
+
+  while (AtomicOps::CompareAndSwap(&lock_acquired, 0, 1)) {
+#if defined(WEBRTC_WIN)
+    ::Sleep(0);
+#elif defined(WEBRTC_MAC) && !USE_NATIVE_MUTEX_ON_MAC
+    sched_yield();
+#else
+    nanosleep(&ts_null, nullptr);
+#endif
+  }
+}
+
+void GlobalLockPod::Unlock() {
+  int old_value = AtomicOps::CompareAndSwap(&lock_acquired, 1, 0);
+  RTC_DCHECK_EQ(1, old_value) << "Unlock called without calling Lock first";
+}
+
+GlobalLock::GlobalLock() {
+  lock_acquired = 0;
+}
+
+GlobalLockScope::GlobalLockScope(GlobalLockPod* lock)
+    : lock_(lock) {
+  lock_->Lock();
+}
+
+GlobalLockScope::~GlobalLockScope() {
+  lock_->Unlock();
+}
+
+}  // namespace rtc

webrtc/rtc_base/criticalsection.h

@@ -0,0 +1,156 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_CRITICALSECTION_H_
+#define WEBRTC_RTC_BASE_CRITICALSECTION_H_
+
+#include "webrtc/base/atomicops.h"
+#include "webrtc/base/checks.h"
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/base/platform_thread_types.h"
+#include "webrtc/base/thread_annotations.h"
+#include "webrtc/typedefs.h"
+
+#if defined(WEBRTC_WIN)
+// Include winsock2.h before including <windows.h> to maintain consistency with
+// win32.h.  We can't include win32.h directly here since it pulls in
+// headers such as basictypes.h which causes problems in Chromium where webrtc
+// exists as two separate projects, webrtc and libjingle.
+#include <winsock2.h>
+#include <windows.h>
+#include <sal.h>  // must come after windows headers.
+#endif  // defined(WEBRTC_WIN)
+
+#if defined(WEBRTC_POSIX)
+#include <pthread.h>
+#endif
+
+// See notes in the 'Performance' unit test for the effects of this flag.
+#define USE_NATIVE_MUTEX_ON_MAC 0
+
+#if defined(WEBRTC_MAC) && !USE_NATIVE_MUTEX_ON_MAC
+#include <dispatch/dispatch.h>
+#endif
+
+#define CS_DEBUG_CHECKS RTC_DCHECK_IS_ON
+
+#if CS_DEBUG_CHECKS
+#define CS_DEBUG_CODE(x) x
+#else  // !CS_DEBUG_CHECKS
+#define CS_DEBUG_CODE(x)
+#endif  // !CS_DEBUG_CHECKS
+
+namespace rtc {
+
+// Locking methods (Enter, TryEnter, Leave)are const to permit protecting
+// members inside a const context without requiring mutable CriticalSections
+// everywhere.
+class LOCKABLE CriticalSection {
+ public:
+  CriticalSection();
+  ~CriticalSection();
+
+  void Enter() const EXCLUSIVE_LOCK_FUNCTION();
+  bool TryEnter() const EXCLUSIVE_TRYLOCK_FUNCTION(true);
+  void Leave() const UNLOCK_FUNCTION();
+
+ private:
+  // Use only for RTC_DCHECKing.
+  bool CurrentThreadIsOwner() const;
+
+#if defined(WEBRTC_WIN)
+  mutable CRITICAL_SECTION crit_;
+#elif defined(WEBRTC_POSIX)
+# if defined(WEBRTC_MAC) && !USE_NATIVE_MUTEX_ON_MAC
+  // Number of times the lock has been locked + number of threads waiting.
+  // TODO(tommi): We could use this number and subtract the recursion count
+  // to find places where we have multiple threads contending on the same lock.
+  mutable volatile int lock_queue_;
+  // |recursion_| represents the recursion count + 1 for the thread that owns
+  // the lock. Only modified by the thread that owns the lock.
+  mutable int recursion_;
+  // Used to signal a single waiting thread when the lock becomes available.
+  mutable dispatch_semaphore_t semaphore_;
+  // The thread that currently holds the lock. Required to handle recursion.
+  mutable PlatformThreadRef owning_thread_;
+# else
+  mutable pthread_mutex_t mutex_;
+# endif
+  mutable PlatformThreadRef thread_;  // Only used by RTC_DCHECKs.
+  mutable int recursion_count_;       // Only used by RTC_DCHECKs.
+#else  // !defined(WEBRTC_WIN) && !defined(WEBRTC_POSIX)
+# error Unsupported platform.
+#endif
+};
+
+// CritScope, for serializing execution through a scope.
+class SCOPED_LOCKABLE CritScope {
+ public:
+  explicit CritScope(const CriticalSection* cs) EXCLUSIVE_LOCK_FUNCTION(cs);
+  ~CritScope() UNLOCK_FUNCTION();
+ private:
+  const CriticalSection* const cs_;
+  RTC_DISALLOW_COPY_AND_ASSIGN(CritScope);
+};
+
+// Tries to lock a critical section on construction via
+// CriticalSection::TryEnter, and unlocks on destruction if the
+// lock was taken. Never blocks.
+//
+// IMPORTANT: Unlike CritScope, the lock may not be owned by this thread in
+// subsequent code. Users *must* check locked() to determine if the
+// lock was taken. If you're not calling locked(), you're doing it wrong!
+class TryCritScope {
+ public:
+  explicit TryCritScope(const CriticalSection* cs);
+  ~TryCritScope();
+#if defined(WEBRTC_WIN)
+  _Check_return_ bool locked() const;
+#elif defined(WEBRTC_POSIX)
+  bool locked() const __attribute__ ((__warn_unused_result__));
+#else  // !defined(WEBRTC_WIN) && !defined(WEBRTC_POSIX)
+# error Unsupported platform.
+#endif
+ private:
+  const CriticalSection* const cs_;
+  const bool locked_;
+  mutable bool lock_was_called_;  // Only used by RTC_DCHECKs.
+  RTC_DISALLOW_COPY_AND_ASSIGN(TryCritScope);
+};
+
+// A POD lock used to protect global variables. Do NOT use for other purposes.
+// No custom constructor or private data member should be added.
+class LOCKABLE GlobalLockPod {
+ public:
+  void Lock() EXCLUSIVE_LOCK_FUNCTION();
+
+  void Unlock() UNLOCK_FUNCTION();
+
+  volatile int lock_acquired;
+};
+
+class GlobalLock : public GlobalLockPod {
+ public:
+  GlobalLock();
+};
+
+// GlobalLockScope, for serializing execution through a scope.
+class SCOPED_LOCKABLE GlobalLockScope {
+ public:
+  explicit GlobalLockScope(GlobalLockPod* lock) EXCLUSIVE_LOCK_FUNCTION(lock);
+  ~GlobalLockScope() UNLOCK_FUNCTION();
+ private:
+  GlobalLockPod* const lock_;
+  RTC_DISALLOW_COPY_AND_ASSIGN(GlobalLockScope);
+};
+
+} // namespace rtc
+
+#endif // WEBRTC_RTC_BASE_CRITICALSECTION_H_

webrtc/rtc_base/criticalsection_unittest.cc

@@ -0,0 +1,413 @@
+/*
+ *  Copyright 2014 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <memory>
+#include <set>
+#include <vector>
+
+#include "webrtc/base/arraysize.h"
+#include "webrtc/base/checks.h"
+#include "webrtc/base/criticalsection.h"
+#include "webrtc/base/event.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/platform_thread.h"
+#include "webrtc/base/thread.h"
+
+namespace rtc {
+
+namespace {
+
+const int kLongTime = 10000;  // 10 seconds
+const int kNumThreads = 16;
+const int kOperationsToRun = 1000;
+
+class UniqueValueVerifier {
+ public:
+  void Verify(const std::vector<int>& values) {
+    for (size_t i = 0; i < values.size(); ++i) {
+      std::pair<std::set<int>::iterator, bool> result =
+          all_values_.insert(values[i]);
+      // Each value should only be taken by one thread, so if this value
+      // has already been added, something went wrong.
+      EXPECT_TRUE(result.second)
+          << " Thread=" << Thread::Current() << " value=" << values[i];
+    }
+  }
+
+  void Finalize() {}
+
+ private:
+  std::set<int> all_values_;
+};
+
+class CompareAndSwapVerifier {
+ public:
+  CompareAndSwapVerifier() : zero_count_(0) {}
+
+  void Verify(const std::vector<int>& values) {
+    for (auto v : values) {
+      if (v == 0) {
+        EXPECT_EQ(0, zero_count_) << "Thread=" << Thread::Current();
+        ++zero_count_;
+      } else {
+        EXPECT_EQ(1, v) << " Thread=" << Thread::Current();
+      }
+    }
+  }
+
+  void Finalize() {
+    EXPECT_EQ(1, zero_count_);
+  }
+ private:
+  int zero_count_;
+};
+
+class RunnerBase : public MessageHandler {
+ public:
+  explicit RunnerBase(int value)
+      : threads_active_(0),
+        start_event_(true, false),
+        done_event_(true, false),
+        shared_value_(value) {}
+
+  bool Run() {
+    // Signal all threads to start.
+    start_event_.Set();
+
+    // Wait for all threads to finish.
+    return done_event_.Wait(kLongTime);
+  }
+
+  void SetExpectedThreadCount(int count) {
+    threads_active_ = count;
+  }
+
+  int shared_value() const { return shared_value_; }
+
+ protected:
+  // Derived classes must override OnMessage, and call BeforeStart and AfterEnd
+  // at the beginning and the end of OnMessage respectively.
+  void BeforeStart() {
+    ASSERT_TRUE(start_event_.Wait(kLongTime));
+  }
+
+  // Returns true if all threads have finished.
+  bool AfterEnd() {
+    if (AtomicOps::Decrement(&threads_active_) == 0) {
+      done_event_.Set();
+      return true;
+    }
+    return false;
+  }
+
+  int threads_active_;
+  Event start_event_;
+  Event done_event_;
+  int shared_value_;
+};
+
+class LOCKABLE CriticalSectionLock {
+ public:
+  void Lock() EXCLUSIVE_LOCK_FUNCTION() {
+    cs_.Enter();
+  }
+  void Unlock() UNLOCK_FUNCTION() {
+    cs_.Leave();
+  }
+
+ private:
+  CriticalSection cs_;
+};
+
+template <class Lock>
+class LockRunner : public RunnerBase {
+ public:
+  LockRunner() : RunnerBase(0) {}
+
+  void OnMessage(Message* msg) override {
+    BeforeStart();
+
+    lock_.Lock();
+
+    EXPECT_EQ(0, shared_value_);
+    int old = shared_value_;
+
+    // Use a loop to increase the chance of race.
+    for (int i = 0; i < kOperationsToRun; ++i) {
+      ++shared_value_;
+    }
+    EXPECT_EQ(old + kOperationsToRun, shared_value_);
+    shared_value_ = 0;
+
+    lock_.Unlock();
+
+    AfterEnd();
+  }
+
+ private:
+  Lock lock_;
+};
+
+template <class Op, class Verifier>
+class AtomicOpRunner : public RunnerBase {
+ public:
+  explicit AtomicOpRunner(int initial_value) : RunnerBase(initial_value) {}
+
+  void OnMessage(Message* msg) override {
+    BeforeStart();
+
+    std::vector<int> values;
+    values.reserve(kOperationsToRun);
+
+    // Generate a bunch of values by updating shared_value_ atomically.
+    for (int i = 0; i < kOperationsToRun; ++i) {
+      values.push_back(Op::AtomicOp(&shared_value_));
+    }
+
+    { // Add them all to the set.
+      CritScope cs(&all_values_crit_);
+      verifier_.Verify(values);
+    }
+
+    if (AfterEnd()) {
+      verifier_.Finalize();
+    }
+  }
+
+ private:
+  CriticalSection all_values_crit_;
+  Verifier verifier_;
+};
+
+struct IncrementOp {
+  static int AtomicOp(int* i) { return AtomicOps::Increment(i); }
+};
+
+struct DecrementOp {
+  static int AtomicOp(int* i) { return AtomicOps::Decrement(i); }
+};
+
+struct CompareAndSwapOp {
+  static int AtomicOp(int* i) { return AtomicOps::CompareAndSwap(i, 0, 1); }
+};
+
+void StartThreads(std::vector<std::unique_ptr<Thread>>* threads,
+                  MessageHandler* handler) {
+  for (int i = 0; i < kNumThreads; ++i) {
+    std::unique_ptr<Thread> thread(new Thread());
+    thread->Start();
+    thread->Post(RTC_FROM_HERE, handler);
+    threads->push_back(std::move(thread));
+  }
+}
+
+}  // namespace
+
+TEST(AtomicOpsTest, Simple) {
+  int value = 0;
+  EXPECT_EQ(1, AtomicOps::Increment(&value));
+  EXPECT_EQ(1, value);
+  EXPECT_EQ(2, AtomicOps::Increment(&value));
+  EXPECT_EQ(2, value);
+  EXPECT_EQ(1, AtomicOps::Decrement(&value));
+  EXPECT_EQ(1, value);
+  EXPECT_EQ(0, AtomicOps::Decrement(&value));
+  EXPECT_EQ(0, value);
+}
+
+TEST(AtomicOpsTest, SimplePtr) {
+  class Foo {};
+  Foo* volatile foo = nullptr;
+  std::unique_ptr<Foo> a(new Foo());
+  std::unique_ptr<Foo> b(new Foo());
+  // Reading the initial value should work as expected.
+  EXPECT_TRUE(rtc::AtomicOps::AcquireLoadPtr(&foo) == nullptr);
+  // Setting using compare and swap should work.
+  EXPECT_TRUE(rtc::AtomicOps::CompareAndSwapPtr(
+                  &foo, static_cast<Foo*>(nullptr), a.get()) == nullptr);
+  EXPECT_TRUE(rtc::AtomicOps::AcquireLoadPtr(&foo) == a.get());
+  // Setting another value but with the wrong previous pointer should fail
+  // (remain a).
+  EXPECT_TRUE(rtc::AtomicOps::CompareAndSwapPtr(
+                  &foo, static_cast<Foo*>(nullptr), b.get()) == a.get());
+  EXPECT_TRUE(rtc::AtomicOps::AcquireLoadPtr(&foo) == a.get());
+  // Replacing a with b should work.
+  EXPECT_TRUE(rtc::AtomicOps::CompareAndSwapPtr(&foo, a.get(), b.get()) ==
+              a.get());
+  EXPECT_TRUE(rtc::AtomicOps::AcquireLoadPtr(&foo) == b.get());
+}
+
+TEST(AtomicOpsTest, Increment) {
+  // Create and start lots of threads.
+  AtomicOpRunner<IncrementOp, UniqueValueVerifier> runner(0);
+  std::vector<std::unique_ptr<Thread>> threads;
+  StartThreads(&threads, &runner);
+  runner.SetExpectedThreadCount(kNumThreads);
+
+  // Release the hounds!
+  EXPECT_TRUE(runner.Run());
+  EXPECT_EQ(kOperationsToRun * kNumThreads, runner.shared_value());
+}
+
+TEST(AtomicOpsTest, Decrement) {
+  // Create and start lots of threads.
+  AtomicOpRunner<DecrementOp, UniqueValueVerifier> runner(
+      kOperationsToRun * kNumThreads);
+  std::vector<std::unique_ptr<Thread>> threads;
+  StartThreads(&threads, &runner);
+  runner.SetExpectedThreadCount(kNumThreads);
+
+  // Release the hounds!
+  EXPECT_TRUE(runner.Run());
+  EXPECT_EQ(0, runner.shared_value());
+}
+
+TEST(AtomicOpsTest, CompareAndSwap) {
+  // Create and start lots of threads.
+  AtomicOpRunner<CompareAndSwapOp, CompareAndSwapVerifier> runner(0);
+  std::vector<std::unique_ptr<Thread>> threads;
+  StartThreads(&threads, &runner);
+  runner.SetExpectedThreadCount(kNumThreads);
+
+  // Release the hounds!
+  EXPECT_TRUE(runner.Run());
+  EXPECT_EQ(1, runner.shared_value());
+}
+
+TEST(GlobalLockTest, Basic) {
+  // Create and start lots of threads.
+  LockRunner<GlobalLock> runner;
+  std::vector<std::unique_ptr<Thread>> threads;
+  StartThreads(&threads, &runner);
+  runner.SetExpectedThreadCount(kNumThreads);
+
+  // Release the hounds!
+  EXPECT_TRUE(runner.Run());
+  EXPECT_EQ(0, runner.shared_value());
+}
+
+TEST(CriticalSectionTest, Basic) {
+  // Create and start lots of threads.
+  LockRunner<CriticalSectionLock> runner;
+  std::vector<std::unique_ptr<Thread>> threads;
+  StartThreads(&threads, &runner);
+  runner.SetExpectedThreadCount(kNumThreads);
+
+  // Release the hounds!
+  EXPECT_TRUE(runner.Run());
+  EXPECT_EQ(0, runner.shared_value());
+}
+
+class PerfTestData {
+ public:
+  PerfTestData(int expected_count, Event* event)
+      : cache_line_barrier_1_(), cache_line_barrier_2_(),
+        expected_count_(expected_count), event_(event) {
+    cache_line_barrier_1_[0]++;  // Avoid 'is not used'.
+    cache_line_barrier_2_[0]++;  // Avoid 'is not used'.
+  }
+  ~PerfTestData() {}
+
+  void AddToCounter(int add) {
+    rtc::CritScope cs(&lock_);
+    my_counter_ += add;
+    if (my_counter_ == expected_count_)
+      event_->Set();
+  }
+
+  int64_t total() const {
+    // Assume that only one thread is running now.
+    return my_counter_;
+  }
+
+ private:
+  uint8_t cache_line_barrier_1_[64];
+  CriticalSection lock_;
+  uint8_t cache_line_barrier_2_[64];
+  int64_t my_counter_ = 0;
+  const int expected_count_;
+  Event* const event_;
+};
+
+class PerfTestThread {
+ public:
+  PerfTestThread() : thread_(&ThreadFunc, this, "CsPerf") {}
+
+  void Start(PerfTestData* data, int repeats, int id) {
+    RTC_DCHECK(!thread_.IsRunning());
+    RTC_DCHECK(!data_);
+    data_ = data;
+    repeats_ = repeats;
+    my_id_ = id;
+    thread_.Start();
+  }
+
+  void Stop() {
+    RTC_DCHECK(thread_.IsRunning());
+    RTC_DCHECK(data_);
+    thread_.Stop();
+    repeats_ = 0;
+    data_ = nullptr;
+    my_id_ = 0;
+  }
+
+ private:
+  static bool ThreadFunc(void* param) {
+    PerfTestThread* me = static_cast<PerfTestThread*>(param);
+    for (int i = 0; i < me->repeats_; ++i)
+      me->data_->AddToCounter(me->my_id_);
+    return false;
+  }
+
+  PlatformThread thread_;
+  PerfTestData* data_ = nullptr;
+  int repeats_ = 0;
+  int my_id_ = 0;
+};
+
+// Comparison of output of this test as tested on a MacBook Pro Retina, 15-inch,
+// Mid 2014, 2,8 GHz Intel Core i7, 16 GB 1600 MHz DDR3,
+// running OS X El Capitan, 10.11.2.
+//
+// Native mutex implementation:
+// Approximate CPU usage:
+//   System: ~16%
+//   User mode: ~1.3%
+//   Idle: ~82%
+// Unit test output:
+// [       OK ] CriticalSectionTest.Performance (234545 ms)
+//
+// Special partially spin lock based implementation:
+// Approximate CPU usage:
+//   System: ~75%
+//   User mode: ~16%
+//   Idle: ~8%
+// Unit test output:
+// [       OK ] CriticalSectionTest.Performance (2107 ms)
+//
+// The test is disabled by default to avoid unecessarily loading the bots.
+TEST(CriticalSectionTest, DISABLED_Performance) {
+  PerfTestThread threads[8];
+  Event event(false, false);
+
+  static const int kThreadRepeats = 10000000;
+  static const int kExpectedCount = kThreadRepeats * arraysize(threads);
+  PerfTestData test_data(kExpectedCount, &event);
+
+  for (auto& t : threads)
+    t.Start(&test_data, kThreadRepeats, 1);
+
+  event.Wait(Event::kForever);
+
+  for (auto& t : threads)
+    t.Stop();
+}
+
+}  // namespace rtc

webrtc/rtc_base/cryptstring.cc

@@ -0,0 +1,75 @@
+/*
+ *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/cryptstring.h"
+
+namespace rtc {
+
+size_t EmptyCryptStringImpl::GetLength() const {
+  return 0;
+}
+
+void EmptyCryptStringImpl::CopyTo(char* dest, bool nullterminate) const {
+  if (nullterminate) {
+    *dest = '\0';
+  }
+}
+
+std::string EmptyCryptStringImpl::UrlEncode() const {
+  return "";
+}
+
+CryptStringImpl* EmptyCryptStringImpl::Copy() const {
+  return new EmptyCryptStringImpl();
+}
+
+void EmptyCryptStringImpl::CopyRawTo(std::vector<unsigned char>* dest) const {
+  dest->clear();
+}
+
+CryptString::CryptString() : impl_(new EmptyCryptStringImpl()) {
+}
+
+CryptString::CryptString(const CryptString& other)
+    : impl_(other.impl_->Copy()) {
+}
+
+CryptString::CryptString(const CryptStringImpl& impl) : impl_(impl.Copy()) {
+}
+
+CryptString::~CryptString() = default;
+
+size_t InsecureCryptStringImpl::GetLength() const {
+  return password_.size();
+}
+
+void InsecureCryptStringImpl::CopyTo(char* dest, bool nullterminate) const {
+  memcpy(dest, password_.data(), password_.size());
+  if (nullterminate)
+    dest[password_.size()] = 0;
+}
+
+std::string InsecureCryptStringImpl::UrlEncode() const {
+  return password_;
+}
+
+CryptStringImpl* InsecureCryptStringImpl::Copy() const {
+  InsecureCryptStringImpl* copy = new InsecureCryptStringImpl;
+  copy->password() = password_;
+  return copy;
+}
+
+void InsecureCryptStringImpl::CopyRawTo(
+    std::vector<unsigned char>* dest) const {
+  dest->resize(password_.size());
+  memcpy(&dest->front(), password_.data(), password_.size());
+}
+
+};  // namespace rtc

webrtc/rtc_base/cryptstring.h

@@ -0,0 +1,167 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_CRYPTSTRING_H_
+#define WEBRTC_RTC_BASE_CRYPTSTRING_H_
+
+#include <string.h>
+
+#include <memory>
+#include <string>
+#include <vector>
+
+namespace rtc {
+
+class CryptStringImpl {
+public:
+  virtual ~CryptStringImpl() {}
+  virtual size_t GetLength() const = 0;
+  virtual void CopyTo(char * dest, bool nullterminate) const = 0;
+  virtual std::string UrlEncode() const = 0;
+  virtual CryptStringImpl * Copy() const = 0;
+  virtual void CopyRawTo(std::vector<unsigned char> * dest) const = 0;
+};
+
+class EmptyCryptStringImpl : public CryptStringImpl {
+public:
+  ~EmptyCryptStringImpl() override {}
+  size_t GetLength() const override;
+  void CopyTo(char* dest, bool nullterminate) const override;
+  std::string UrlEncode() const override;
+  CryptStringImpl* Copy() const override;
+  void CopyRawTo(std::vector<unsigned char>* dest) const override;
+};
+
+class CryptString {
+ public:
+  CryptString();
+  size_t GetLength() const { return impl_->GetLength(); }
+  void CopyTo(char * dest, bool nullterminate) const { impl_->CopyTo(dest, nullterminate); }
+  CryptString(const CryptString& other);
+  explicit CryptString(const CryptStringImpl& impl);
+  ~CryptString();
+  CryptString & operator=(const CryptString & other) {
+    if (this != &other) {
+      impl_.reset(other.impl_->Copy());
+    }
+    return *this;
+  }
+  void Clear() { impl_.reset(new EmptyCryptStringImpl()); }
+  std::string UrlEncode() const { return impl_->UrlEncode(); }
+  void CopyRawTo(std::vector<unsigned char> * dest) const {
+    return impl_->CopyRawTo(dest);
+  }
+
+ private:
+  std::unique_ptr<const CryptStringImpl> impl_;
+};
+
+
+// Used for constructing strings where a password is involved and we
+// need to ensure that we zero memory afterwards
+class FormatCryptString {
+public:
+  FormatCryptString() {
+    storage_ = new char[32];
+    capacity_ = 32;
+    length_ = 0;
+    storage_[0] = 0;
+  }
+
+  void Append(const std::string & text) {
+    Append(text.data(), text.length());
+  }
+
+  void Append(const char * data, size_t length) {
+    EnsureStorage(length_ + length + 1);
+    memcpy(storage_ + length_, data, length);
+    length_ += length;
+    storage_[length_] = '\0';
+  }
+
+  void Append(const CryptString * password) {
+    size_t len = password->GetLength();
+    EnsureStorage(length_ + len + 1);
+    password->CopyTo(storage_ + length_, true);
+    length_ += len;
+  }
+
+  size_t GetLength() {
+    return length_;
+  }
+
+  const char * GetData() {
+    return storage_;
+  }
+
+
+  // Ensures storage of at least n bytes
+  void EnsureStorage(size_t n) {
+    if (capacity_ >= n) {
+      return;
+    }
+
+    size_t old_capacity = capacity_;
+    char * old_storage = storage_;
+
+    for (;;) {
+      capacity_ *= 2;
+      if (capacity_ >= n)
+        break;
+    }
+
+    storage_ = new char[capacity_];
+
+    if (old_capacity) {
+      memcpy(storage_, old_storage, length_);
+
+      // zero memory in a way that an optimizer won't optimize it out
+      old_storage[0] = 0;
+      for (size_t i = 1; i < old_capacity; i++) {
+        old_storage[i] = old_storage[i - 1];
+      }
+      delete[] old_storage;
+    }
+  }
+
+  ~FormatCryptString() {
+    if (capacity_) {
+      storage_[0] = 0;
+      for (size_t i = 1; i < capacity_; i++) {
+        storage_[i] = storage_[i - 1];
+      }
+    }
+    delete[] storage_;
+  }
+private:
+  char * storage_;
+  size_t capacity_;
+  size_t length_;
+};
+
+class InsecureCryptStringImpl : public CryptStringImpl {
+ public:
+  std::string& password() { return password_; }
+  const std::string& password() const { return password_; }
+
+  ~InsecureCryptStringImpl() override = default;
+  size_t GetLength() const override;
+  void CopyTo(char* dest, bool nullterminate) const override;
+  std::string UrlEncode() const override;
+  CryptStringImpl* Copy() const override;
+  void CopyRawTo(std::vector<unsigned char>* dest) const override;
+
+ private:
+  std::string password_;
+};
+
+}
+
+#endif  // WEBRTC_RTC_BASE_CRYPTSTRING_H_

webrtc/rtc_base/deprecation.h

@@ -0,0 +1,45 @@
+/*
+ *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_DEPRECATION_H_
+#define WEBRTC_RTC_BASE_DEPRECATION_H_
+
+// Annotate the declarations of deprecated functions with this to cause a
+// compiler warning when they're used. Like so:
+//
+//   RTC_DEPRECATED std::pony PonyPlz(const std::pony_spec& ps);
+//
+// NOTE 1: The annotation goes on the declaration in the .h file, not the
+// definition in the .cc file!
+//
+// NOTE 2: In order to keep unit testing the deprecated function without
+// getting warnings, do something like this:
+//
+//   std::pony DEPRECATED_PonyPlz(const std::pony_spec& ps);
+//   RTC_DEPRECATED inline std::pony PonyPlz(const std::pony_spec& ps) {
+//     return DEPRECATED_PonyPlz(ps);
+//   }
+//
+// In other words, rename the existing function, and provide an inline wrapper
+// using the original name that calls it. That way, callers who are willing to
+// call it using the DEPRECATED_-prefixed name don't get the warning.
+//
+// TODO(kwiberg): Remove this when we can use [[deprecated]] from C++14.
+#if defined(_MSC_VER)
+// Note: Deprecation warnings seem to fail to trigger on Windows
+// (https://bugs.chromium.org/p/webrtc/issues/detail?id=5368).
+#define RTC_DEPRECATED __declspec(deprecated)
+#elif defined(__GNUC__)
+#define RTC_DEPRECATED __attribute__ ((__deprecated__))
+#else
+#define RTC_DEPRECATED
+#endif
+
+#endif  // WEBRTC_RTC_BASE_DEPRECATION_H_

webrtc/rtc_base/dscp.h

@@ -0,0 +1,45 @@
+/*
+ *  Copyright 2013 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_DSCP_H_
+#define WEBRTC_RTC_BASE_DSCP_H_
+
+namespace rtc {
+// Differentiated Services Code Point.
+// See http://tools.ietf.org/html/rfc2474 for details.
+enum DiffServCodePoint {
+  DSCP_NO_CHANGE = -1,
+  DSCP_DEFAULT = 0,  // Same as DSCP_CS0
+  DSCP_CS0  = 0,   // The default
+  DSCP_CS1  = 8,   // Bulk/background traffic
+  DSCP_AF11 = 10,
+  DSCP_AF12 = 12,
+  DSCP_AF13 = 14,
+  DSCP_CS2  = 16,
+  DSCP_AF21 = 18,
+  DSCP_AF22 = 20,
+  DSCP_AF23 = 22,
+  DSCP_CS3  = 24,
+  DSCP_AF31 = 26,
+  DSCP_AF32 = 28,
+  DSCP_AF33 = 30,
+  DSCP_CS4  = 32,
+  DSCP_AF41 = 34,  // Video
+  DSCP_AF42 = 36,  // Video
+  DSCP_AF43 = 38,  // Video
+  DSCP_CS5  = 40,  // Video
+  DSCP_EF   = 46,  // Voice
+  DSCP_CS6  = 48,  // Voice
+  DSCP_CS7  = 56,  // Control messages
+};
+
+}  // namespace rtc
+
+ #endif  // WEBRTC_RTC_BASE_DSCP_H_

webrtc/rtc_base/event.cc

@@ -0,0 +1,136 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/event.h"
+
+#if defined(WEBRTC_WIN)
+#include <windows.h>
+#elif defined(WEBRTC_POSIX)
+#include <pthread.h>
+#include <sys/time.h>
+#include <time.h>
+#else
+#error "Must define either WEBRTC_WIN or WEBRTC_POSIX."
+#endif
+
+#include "webrtc/base/checks.h"
+
+namespace rtc {
+
+#if defined(WEBRTC_WIN)
+
+Event::Event(bool manual_reset, bool initially_signaled) {
+  event_handle_ = ::CreateEvent(nullptr,  // Security attributes.
+                                manual_reset, initially_signaled,
+                                nullptr);  // Name.
+  RTC_CHECK(event_handle_);
+}
+
+Event::~Event() {
+  CloseHandle(event_handle_);
+}
+
+void Event::Set() {
+  SetEvent(event_handle_);
+}
+
+void Event::Reset() {
+  ResetEvent(event_handle_);
+}
+
+bool Event::Wait(int milliseconds) {
+  DWORD ms = (milliseconds == kForever) ? INFINITE : milliseconds;
+  return (WaitForSingleObject(event_handle_, ms) == WAIT_OBJECT_0);
+}
+
+#elif defined(WEBRTC_POSIX)
+
+Event::Event(bool manual_reset, bool initially_signaled)
+    : is_manual_reset_(manual_reset),
+      event_status_(initially_signaled) {
+  RTC_CHECK(pthread_mutex_init(&event_mutex_, nullptr) == 0);
+  RTC_CHECK(pthread_cond_init(&event_cond_, nullptr) == 0);
+}
+
+Event::~Event() {
+  pthread_mutex_destroy(&event_mutex_);
+  pthread_cond_destroy(&event_cond_);
+}
+
+void Event::Set() {
+  pthread_mutex_lock(&event_mutex_);
+  event_status_ = true;
+  pthread_cond_broadcast(&event_cond_);
+  pthread_mutex_unlock(&event_mutex_);
+}
+
+void Event::Reset() {
+  pthread_mutex_lock(&event_mutex_);
+  event_status_ = false;
+  pthread_mutex_unlock(&event_mutex_);
+}
+
+bool Event::Wait(int milliseconds) {
+  int error = 0;
+
+  struct timespec ts;
+  if (milliseconds != kForever) {
+    // Converting from seconds and microseconds (1e-6) plus
+    // milliseconds (1e-3) to seconds and nanoseconds (1e-9).
+
+#ifdef HAVE_PTHREAD_COND_TIMEDWAIT_RELATIVE
+    // Use relative time version, which tends to be more efficient for
+    // pthread implementations where provided (like on Android).
+    ts.tv_sec = milliseconds / 1000;
+    ts.tv_nsec = (milliseconds % 1000) * 1000000;
+#else
+    struct timeval tv;
+    gettimeofday(&tv, nullptr);
+
+    ts.tv_sec = tv.tv_sec + (milliseconds / 1000);
+    ts.tv_nsec = tv.tv_usec * 1000 + (milliseconds % 1000) * 1000000;
+
+    // Handle overflow.
+    if (ts.tv_nsec >= 1000000000) {
+      ts.tv_sec++;
+      ts.tv_nsec -= 1000000000;
+    }
+#endif
+  }
+
+  pthread_mutex_lock(&event_mutex_);
+  if (milliseconds != kForever) {
+    while (!event_status_ && error == 0) {
+#ifdef HAVE_PTHREAD_COND_TIMEDWAIT_RELATIVE
+      error = pthread_cond_timedwait_relative_np(
+          &event_cond_, &event_mutex_, &ts);
+#else
+      error = pthread_cond_timedwait(&event_cond_, &event_mutex_, &ts);
+#endif
+    }
+  } else {
+    while (!event_status_ && error == 0)
+      error = pthread_cond_wait(&event_cond_, &event_mutex_);
+  }
+
+  // NOTE(liulk): Exactly one thread will auto-reset this event. All
+  // the other threads will think it's unsignaled.  This seems to be
+  // consistent with auto-reset events in WEBRTC_WIN
+  if (error == 0 && !is_manual_reset_)
+    event_status_ = false;
+
+  pthread_mutex_unlock(&event_mutex_);
+
+  return (error == 0);
+}
+
+#endif
+
+}  // namespace rtc

webrtc/rtc_base/event.h

@@ -0,0 +1,54 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_EVENT_H_
+#define WEBRTC_RTC_BASE_EVENT_H_
+
+#include "webrtc/base/constructormagic.h"
+#if defined(WEBRTC_WIN)
+#include "webrtc/base/win32.h"  // NOLINT: consider this a system header.
+#elif defined(WEBRTC_POSIX)
+#include <pthread.h>
+#else
+#error "Must define either WEBRTC_WIN or WEBRTC_POSIX."
+#endif
+
+namespace rtc {
+
+class Event {
+ public:
+  static const int kForever = -1;
+
+  Event(bool manual_reset, bool initially_signaled);
+  ~Event();
+
+  void Set();
+  void Reset();
+
+  // Wait for the event to become signaled, for the specified number of
+  // |milliseconds|.  To wait indefinetly, pass kForever.
+  bool Wait(int milliseconds);
+
+ private:
+#if defined(WEBRTC_WIN)
+  HANDLE event_handle_;
+#elif defined(WEBRTC_POSIX)
+  pthread_mutex_t event_mutex_;
+  pthread_cond_t event_cond_;
+  const bool is_manual_reset_;
+  bool event_status_;
+#endif
+
+  RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(Event);
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_EVENT_H_

webrtc/rtc_base/event_tracer.cc

@@ -0,0 +1,407 @@
+/*
+ *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#include "webrtc/base/event_tracer.h"
+
+#include <inttypes.h>
+
+#include <string>
+#include <vector>
+
+#include "webrtc/base/checks.h"
+#include "webrtc/base/criticalsection.h"
+#include "webrtc/base/event.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/platform_thread.h"
+#include "webrtc/base/stringutils.h"
+#include "webrtc/base/timeutils.h"
+#include "webrtc/base/trace_event.h"
+
+// This is a guesstimate that should be enough in most cases.
+static const size_t kEventLoggerArgsStrBufferInitialSize = 256;
+static const size_t kTraceArgBufferLength = 32;
+
+namespace webrtc {
+
+namespace {
+
+GetCategoryEnabledPtr g_get_category_enabled_ptr = nullptr;
+AddTraceEventPtr g_add_trace_event_ptr = nullptr;
+
+}  // namespace
+
+void SetupEventTracer(GetCategoryEnabledPtr get_category_enabled_ptr,
+                      AddTraceEventPtr add_trace_event_ptr) {
+  g_get_category_enabled_ptr = get_category_enabled_ptr;
+  g_add_trace_event_ptr = add_trace_event_ptr;
+}
+
+const unsigned char* EventTracer::GetCategoryEnabled(const char* name) {
+  if (g_get_category_enabled_ptr)
+    return g_get_category_enabled_ptr(name);
+
+  // A string with null terminator means category is disabled.
+  return reinterpret_cast<const unsigned char*>("\0");
+}
+
+// Arguments to this function (phase, etc.) are as defined in
+// webrtc/base/trace_event.h.
+void EventTracer::AddTraceEvent(char phase,
+                                const unsigned char* category_enabled,
+                                const char* name,
+                                unsigned long long id,
+                                int num_args,
+                                const char** arg_names,
+                                const unsigned char* arg_types,
+                                const unsigned long long* arg_values,
+                                unsigned char flags) {
+  if (g_add_trace_event_ptr) {
+    g_add_trace_event_ptr(phase,
+                          category_enabled,
+                          name,
+                          id,
+                          num_args,
+                          arg_names,
+                          arg_types,
+                          arg_values,
+                          flags);
+  }
+}
+
+}  // namespace webrtc
+
+namespace rtc {
+namespace tracing {
+namespace {
+
+static void EventTracingThreadFunc(void* params);
+
+// Atomic-int fast path for avoiding logging when disabled.
+static volatile int g_event_logging_active = 0;
+
+// TODO(pbos): Log metadata for all threads, etc.
+class EventLogger final {
+ public:
+  EventLogger()
+      : logging_thread_(EventTracingThreadFunc,
+                        this,
+                        "EventTracingThread",
+                        kLowPriority),
+        shutdown_event_(false, false) {}
+  ~EventLogger() { RTC_DCHECK(thread_checker_.CalledOnValidThread()); }
+
+  void AddTraceEvent(const char* name,
+                     const unsigned char* category_enabled,
+                     char phase,
+                     int num_args,
+                     const char** arg_names,
+                     const unsigned char* arg_types,
+                     const unsigned long long* arg_values,
+                     uint64_t timestamp,
+                     int pid,
+                     rtc::PlatformThreadId thread_id) {
+    std::vector<TraceArg> args(num_args);
+    for (int i = 0; i < num_args; ++i) {
+      TraceArg& arg = args[i];
+      arg.name = arg_names[i];
+      arg.type = arg_types[i];
+      arg.value.as_uint = arg_values[i];
+
+      // Value is a pointer to a temporary string, so we have to make a copy.
+      if (arg.type == TRACE_VALUE_TYPE_COPY_STRING) {
+        // Space for the string and for the terminating null character.
+        size_t str_length = strlen(arg.value.as_string) + 1;
+        char* str_copy = new char[str_length];
+        memcpy(str_copy, arg.value.as_string, str_length);
+        arg.value.as_string = str_copy;
+      }
+    }
+    rtc::CritScope lock(&crit_);
+    trace_events_.push_back(
+        {name, category_enabled, phase, args, timestamp, 1, thread_id});
+  }
+
+// The TraceEvent format is documented here:
+// https://docs.google.com/document/d/1CvAClvFfyA5R-PhYUmn5OOQtYMH4h6I0nSsKchNAySU/preview
+  void Log() {
+    RTC_DCHECK(output_file_);
+    static const int kLoggingIntervalMs = 100;
+    fprintf(output_file_, "{ \"traceEvents\": [\n");
+    bool has_logged_event = false;
+    while (true) {
+      bool shutting_down = shutdown_event_.Wait(kLoggingIntervalMs);
+      std::vector<TraceEvent> events;
+      {
+        rtc::CritScope lock(&crit_);
+        trace_events_.swap(events);
+      }
+      std::string args_str;
+      args_str.reserve(kEventLoggerArgsStrBufferInitialSize);
+      for (TraceEvent& e : events) {
+        args_str.clear();
+        if (!e.args.empty()) {
+          args_str += ", \"args\": {";
+          bool is_first_argument = true;
+          for (TraceArg& arg : e.args) {
+            if (!is_first_argument)
+              args_str += ",";
+            is_first_argument = false;
+            args_str += " \"";
+            args_str += arg.name;
+            args_str += "\": ";
+            args_str += TraceArgValueAsString(arg);
+
+            // Delete our copy of the string.
+            if (arg.type == TRACE_VALUE_TYPE_COPY_STRING) {
+              delete[] arg.value.as_string;
+              arg.value.as_string = nullptr;
+            }
+          }
+          args_str += " }";
+        }
+        fprintf(output_file_,
+                "%s{ \"name\": \"%s\""
+                ", \"cat\": \"%s\""
+                ", \"ph\": \"%c\""
+                ", \"ts\": %" PRIu64
+                ", \"pid\": %d"
+#if defined(WEBRTC_WIN)
+                ", \"tid\": %lu"
+#else
+                ", \"tid\": %d"
+#endif  // defined(WEBRTC_WIN)
+                "%s"
+                "}\n",
+                has_logged_event ? "," : " ", e.name, e.category_enabled,
+                e.phase, e.timestamp, e.pid, e.tid, args_str.c_str());
+        has_logged_event = true;
+      }
+      if (shutting_down)
+        break;
+    }
+    fprintf(output_file_, "]}\n");
+    if (output_file_owned_)
+      fclose(output_file_);
+    output_file_ = nullptr;
+  }
+
+  void Start(FILE* file, bool owned) {
+    RTC_DCHECK(thread_checker_.CalledOnValidThread());
+    RTC_DCHECK(file);
+    RTC_DCHECK(!output_file_);
+    output_file_ = file;
+    output_file_owned_ = owned;
+    {
+      rtc::CritScope lock(&crit_);
+      // Since the atomic fast-path for adding events to the queue can be
+      // bypassed while the logging thread is shutting down there may be some
+      // stale events in the queue, hence the vector needs to be cleared to not
+      // log events from a previous logging session (which may be days old).
+      trace_events_.clear();
+    }
+    // Enable event logging (fast-path). This should be disabled since starting
+    // shouldn't be done twice.
+    RTC_CHECK_EQ(0,
+                 rtc::AtomicOps::CompareAndSwap(&g_event_logging_active, 0, 1));
+
+    // Finally start, everything should be set up now.
+    logging_thread_.Start();
+    TRACE_EVENT_INSTANT0("webrtc", "EventLogger::Start");
+  }
+
+  void Stop() {
+    RTC_DCHECK(thread_checker_.CalledOnValidThread());
+    TRACE_EVENT_INSTANT0("webrtc", "EventLogger::Stop");
+    // Try to stop. Abort if we're not currently logging.
+    if (rtc::AtomicOps::CompareAndSwap(&g_event_logging_active, 1, 0) == 0)
+      return;
+
+    // Wake up logging thread to finish writing.
+    shutdown_event_.Set();
+    // Join the logging thread.
+    logging_thread_.Stop();
+  }
+
+ private:
+  struct TraceArg {
+    const char* name;
+    unsigned char type;
+    // Copied from webrtc/base/trace_event.h TraceValueUnion.
+    union TraceArgValue {
+      bool as_bool;
+      unsigned long long as_uint;
+      long long as_int;
+      double as_double;
+      const void* as_pointer;
+      const char* as_string;
+    } value;
+
+    // Assert that the size of the union is equal to the size of the as_uint
+    // field since we are assigning to arbitrary types using it.
+    static_assert(sizeof(TraceArgValue) == sizeof(unsigned long long),
+                  "Size of TraceArg value union is not equal to the size of "
+                  "the uint field of that union.");
+  };
+
+  struct TraceEvent {
+    const char* name;
+    const unsigned char* category_enabled;
+    char phase;
+    std::vector<TraceArg> args;
+    uint64_t timestamp;
+    int pid;
+    rtc::PlatformThreadId tid;
+  };
+
+  static std::string TraceArgValueAsString(TraceArg arg) {
+    std::string output;
+
+    if (arg.type == TRACE_VALUE_TYPE_STRING ||
+        arg.type == TRACE_VALUE_TYPE_COPY_STRING) {
+      // Space for every character to be an espaced character + two for
+      // quatation marks.
+      output.reserve(strlen(arg.value.as_string) * 2 + 2);
+      output += '\"';
+      const char* c = arg.value.as_string;
+      do {
+        if (*c == '"' || *c == '\\') {
+          output += '\\';
+          output += *c;
+        } else {
+          output += *c;
+        }
+      } while (*++c);
+      output += '\"';
+    } else {
+      output.resize(kTraceArgBufferLength);
+      size_t print_length = 0;
+      switch (arg.type) {
+        case TRACE_VALUE_TYPE_BOOL:
+          if (arg.value.as_bool) {
+            strcpy(&output[0], "true");
+            print_length = 4;
+          } else {
+            strcpy(&output[0], "false");
+            print_length = 5;
+          }
+          break;
+        case TRACE_VALUE_TYPE_UINT:
+          print_length = sprintfn(&output[0], kTraceArgBufferLength, "%llu",
+                                  arg.value.as_uint);
+          break;
+        case TRACE_VALUE_TYPE_INT:
+          print_length = sprintfn(&output[0], kTraceArgBufferLength, "%lld",
+                                  arg.value.as_int);
+          break;
+        case TRACE_VALUE_TYPE_DOUBLE:
+          print_length = sprintfn(&output[0], kTraceArgBufferLength, "%f",
+                                  arg.value.as_double);
+          break;
+        case TRACE_VALUE_TYPE_POINTER:
+          print_length = sprintfn(&output[0], kTraceArgBufferLength, "\"%p\"",
+                                  arg.value.as_pointer);
+          break;
+      }
+      size_t output_length = print_length < kTraceArgBufferLength
+                                 ? print_length
+                                 : kTraceArgBufferLength - 1;
+      // This will hopefully be very close to nop. On most implementations, it
+      // just writes null byte and sets the length field of the string.
+      output.resize(output_length);
+    }
+
+    return output;
+  }
+
+  rtc::CriticalSection crit_;
+  std::vector<TraceEvent> trace_events_ GUARDED_BY(crit_);
+  rtc::PlatformThread logging_thread_;
+  rtc::Event shutdown_event_;
+  rtc::ThreadChecker thread_checker_;
+  FILE* output_file_ = nullptr;
+  bool output_file_owned_ = false;
+};
+
+static void EventTracingThreadFunc(void* params) {
+  static_cast<EventLogger*>(params)->Log();
+}
+
+static EventLogger* volatile g_event_logger = nullptr;
+static const char* const kDisabledTracePrefix = TRACE_DISABLED_BY_DEFAULT("");
+const unsigned char* InternalGetCategoryEnabled(const char* name) {
+  const char* prefix_ptr = &kDisabledTracePrefix[0];
+  const char* name_ptr = name;
+  // Check whether name contains the default-disabled prefix.
+  while (*prefix_ptr == *name_ptr && *prefix_ptr != '\0') {
+    ++prefix_ptr;
+    ++name_ptr;
+  }
+  return reinterpret_cast<const unsigned char*>(*prefix_ptr == '\0' ? ""
+                                                                    : name);
+}
+
+void InternalAddTraceEvent(char phase,
+                           const unsigned char* category_enabled,
+                           const char* name,
+                           unsigned long long id,
+                           int num_args,
+                           const char** arg_names,
+                           const unsigned char* arg_types,
+                           const unsigned long long* arg_values,
+                           unsigned char flags) {
+  // Fast path for when event tracing is inactive.
+  if (rtc::AtomicOps::AcquireLoad(&g_event_logging_active) == 0)
+    return;
+
+  g_event_logger->AddTraceEvent(name, category_enabled, phase, num_args,
+                                arg_names, arg_types, arg_values,
+                                rtc::TimeMicros(), 1, rtc::CurrentThreadId());
+}
+
+}  // namespace
+
+void SetupInternalTracer() {
+  RTC_CHECK(rtc::AtomicOps::CompareAndSwapPtr(
+                &g_event_logger, static_cast<EventLogger*>(nullptr),
+                new EventLogger()) == nullptr);
+  webrtc::SetupEventTracer(InternalGetCategoryEnabled, InternalAddTraceEvent);
+}
+
+void StartInternalCaptureToFile(FILE* file) {
+  g_event_logger->Start(file, false);
+}
+
+bool StartInternalCapture(const char* filename) {
+  FILE* file = fopen(filename, "w");
+  if (!file) {
+    LOG(LS_ERROR) << "Failed to open trace file '" << filename
+                  << "' for writing.";
+    return false;
+  }
+  g_event_logger->Start(file, true);
+  return true;
+}
+
+void StopInternalCapture() {
+  g_event_logger->Stop();
+}
+
+void ShutdownInternalTracer() {
+  StopInternalCapture();
+  EventLogger* old_logger = rtc::AtomicOps::AcquireLoadPtr(&g_event_logger);
+  RTC_DCHECK(old_logger);
+  RTC_CHECK(rtc::AtomicOps::CompareAndSwapPtr(
+                &g_event_logger, old_logger,
+                static_cast<EventLogger*>(nullptr)) == old_logger);
+  delete old_logger;
+  webrtc::SetupEventTracer(nullptr, nullptr);
+}
+
+}  // namespace tracing
+}  // namespace rtc

webrtc/rtc_base/event_tracer.h

@@ -0,0 +1,85 @@
+/*
+ *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+// This file defines the interface for event tracing in WebRTC.
+//
+// Event log handlers are set through SetupEventTracer(). User of this API will
+// provide two function pointers to handle event tracing calls.
+//
+// * GetCategoryEnabledPtr
+//   Event tracing system calls this function to determine if a particular
+//   event category is enabled.
+//
+// * AddTraceEventPtr
+//   Adds a tracing event. It is the user's responsibility to log the data
+//   provided.
+//
+// Parameters for the above two functions are described in trace_event.h.
+
+#ifndef WEBRTC_RTC_BASE_EVENT_TRACER_H_
+#define WEBRTC_RTC_BASE_EVENT_TRACER_H_
+
+#include <stdio.h>
+
+namespace webrtc {
+
+typedef const unsigned char* (*GetCategoryEnabledPtr)(const char* name);
+typedef void (*AddTraceEventPtr)(char phase,
+                                 const unsigned char* category_enabled,
+                                 const char* name,
+                                 unsigned long long id,
+                                 int num_args,
+                                 const char** arg_names,
+                                 const unsigned char* arg_types,
+                                 const unsigned long long* arg_values,
+                                 unsigned char flags);
+
+// User of WebRTC can call this method to setup event tracing.
+//
+// This method must be called before any WebRTC methods. Functions
+// provided should be thread-safe.
+void SetupEventTracer(
+    GetCategoryEnabledPtr get_category_enabled_ptr,
+    AddTraceEventPtr add_trace_event_ptr);
+
+// This class defines interface for the event tracing system to call
+// internally. Do not call these methods directly.
+class EventTracer {
+ public:
+  static const unsigned char* GetCategoryEnabled(
+      const char* name);
+
+  static void AddTraceEvent(
+      char phase,
+      const unsigned char* category_enabled,
+      const char* name,
+      unsigned long long id,
+      int num_args,
+      const char** arg_names,
+      const unsigned char* arg_types,
+      const unsigned long long* arg_values,
+      unsigned char flags);
+};
+
+}  // namespace webrtc
+
+namespace rtc {
+namespace tracing {
+// Set up internal event tracer.
+void SetupInternalTracer();
+bool StartInternalCapture(const char* filename);
+void StartInternalCaptureToFile(FILE* file);
+void StopInternalCapture();
+// Make sure we run this, this will tear down the internal tracing.
+void ShutdownInternalTracer();
+}  // namespace tracing
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_EVENT_TRACER_H_

webrtc/rtc_base/event_tracer_unittest.cc

@@ -0,0 +1,82 @@
+/*
+ *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/event_tracer.h"
+
+#include "webrtc/base/trace_event.h"
+#include "webrtc/system_wrappers/include/static_instance.h"
+#include "webrtc/test/gtest.h"
+
+namespace {
+
+class TestStatistics {
+ public:
+  TestStatistics() : events_logged_(0) {
+  }
+
+  void Reset() {
+    events_logged_ = 0;
+  }
+
+  void Increment() {
+    ++events_logged_;
+  }
+
+  int Count() const { return events_logged_; }
+
+  static TestStatistics* Get() {
+    static TestStatistics* test_stats = nullptr;
+    if (!test_stats)
+      test_stats = new TestStatistics();
+    return test_stats;
+  }
+
+ private:
+  int events_logged_;
+};
+
+static const unsigned char* GetCategoryEnabledHandler(const char* name) {
+  return reinterpret_cast<const unsigned char*>("test");
+}
+
+static void AddTraceEventHandler(char phase,
+                                 const unsigned char* category_enabled,
+                                 const char* name,
+                                 unsigned long long id,
+                                 int num_args,
+                                 const char** arg_names,
+                                 const unsigned char* arg_types,
+                                 const unsigned long long* arg_values,
+                                 unsigned char flags) {
+  TestStatistics::Get()->Increment();
+}
+
+}  // namespace
+
+namespace webrtc {
+
+TEST(EventTracerTest, EventTracerDisabled) {
+  {
+    TRACE_EVENT0("test", "EventTracerDisabled");
+  }
+  EXPECT_FALSE(TestStatistics::Get()->Count());
+  TestStatistics::Get()->Reset();
+}
+
+TEST(EventTracerTest, ScopedTraceEvent) {
+  SetupEventTracer(&GetCategoryEnabledHandler, &AddTraceEventHandler);
+  {
+    TRACE_EVENT0("test", "ScopedTraceEvent");
+  }
+  EXPECT_EQ(2, TestStatistics::Get()->Count());
+  TestStatistics::Get()->Reset();
+}
+
+}  // namespace webrtc

webrtc/rtc_base/event_unittest.cc

@@ -0,0 +1,42 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/event.h"
+#include "webrtc/base/gunit.h"
+
+namespace rtc {
+
+TEST(EventTest, InitiallySignaled) {
+  Event event(false, true);
+  ASSERT_TRUE(event.Wait(0));
+}
+
+TEST(EventTest, ManualReset) {
+  Event event(true, false);
+  ASSERT_FALSE(event.Wait(0));
+
+  event.Set();
+  ASSERT_TRUE(event.Wait(0));
+  ASSERT_TRUE(event.Wait(0));
+
+  event.Reset();
+  ASSERT_FALSE(event.Wait(0));
+}
+
+TEST(EventTest, AutoReset) {
+  Event event(false, false);
+  ASSERT_FALSE(event.Wait(0));
+
+  event.Set();
+  ASSERT_TRUE(event.Wait(0));
+  ASSERT_FALSE(event.Wait(0));
+}
+
+}  // namespace rtc

webrtc/rtc_base/fakeclock.cc

@@ -0,0 +1,50 @@
+/*
+ *  Copyright 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/fakeclock.h"
+
+#include "webrtc/base/checks.h"
+#include "webrtc/base/messagequeue.h"
+
+namespace rtc {
+
+int64_t FakeClock::TimeNanos() const {
+  CritScope cs(&lock_);
+  return time_;
+}
+
+void FakeClock::SetTimeNanos(int64_t nanos) {
+  {
+    CritScope cs(&lock_);
+    RTC_DCHECK(nanos >= time_);
+    time_ = nanos;
+  }
+  // If message queues are waiting in a socket select() with a timeout provided
+  // by the OS, they should wake up and dispatch all messages that are ready.
+  MessageQueueManager::ProcessAllMessageQueues();
+}
+
+void FakeClock::AdvanceTime(TimeDelta delta) {
+  {
+    CritScope cs(&lock_);
+    time_ += delta.ToNanoseconds();
+  }
+  MessageQueueManager::ProcessAllMessageQueues();
+}
+
+ScopedFakeClock::ScopedFakeClock() {
+  prev_clock_ = SetClockForTesting(this);
+}
+
+ScopedFakeClock::~ScopedFakeClock() {
+  SetClockForTesting(prev_clock_);
+}
+
+}  // namespace rtc

webrtc/rtc_base/fakeclock.h

@@ -0,0 +1,71 @@
+/*
+ *  Copyright 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_FAKECLOCK_H_
+#define WEBRTC_RTC_BASE_FAKECLOCK_H_
+
+#include "webrtc/base/criticalsection.h"
+#include "webrtc/base/timedelta.h"
+#include "webrtc/base/timeutils.h"
+
+namespace rtc {
+
+// Fake clock for use with unit tests, which does not tick on its own.
+// Starts at time 0.
+//
+// TODO(deadbeef): Unify with webrtc::SimulatedClock.
+class FakeClock : public ClockInterface {
+ public:
+  ~FakeClock() override {}
+
+  // ClockInterface implementation.
+  int64_t TimeNanos() const override;
+
+  // Methods that can be used by the test to control the time.
+
+  // Should only be used to set a time in the future.
+  void SetTimeNanos(int64_t nanos);
+  void SetTimeMicros(int64_t micros) {
+    SetTimeNanos(kNumNanosecsPerMicrosec * micros);
+  }
+
+  void AdvanceTime(TimeDelta delta);
+  void AdvanceTimeMicros(int64_t micros) {
+    AdvanceTime(rtc::TimeDelta::FromMicroseconds(micros));
+  }
+ private:
+  CriticalSection lock_;
+  int64_t time_ GUARDED_BY(lock_) = 0;
+};
+
+// Helper class that sets itself as the global clock in its constructor and
+// unsets it in its destructor.
+class ScopedFakeClock : public FakeClock {
+ public:
+  ScopedFakeClock();
+  ~ScopedFakeClock() override;
+
+ private:
+  ClockInterface* prev_clock_;
+};
+
+// Helper class to "undo" the fake clock temporarily.
+class ScopedRealClock {
+ public:
+  ScopedRealClock();
+  ~ScopedRealClock();
+
+ private:
+  ClockInterface* prev_clock_;
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_FAKECLOCK_H_

webrtc/rtc_base/fakenetwork.h

@@ -0,0 +1,129 @@
+/*
+ *  Copyright 2009 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_FAKENETWORK_H_
+#define WEBRTC_RTC_BASE_FAKENETWORK_H_
+
+#include <memory>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "webrtc/base/network.h"
+#include "webrtc/base/messagehandler.h"
+#include "webrtc/base/socketaddress.h"
+#include "webrtc/base/stringencode.h"
+#include "webrtc/base/thread.h"
+
+namespace rtc {
+
+const int kFakeIPv4NetworkPrefixLength = 24;
+const int kFakeIPv6NetworkPrefixLength = 64;
+
+// Fake network manager that allows us to manually specify the IPs to use.
+class FakeNetworkManager : public NetworkManagerBase,
+                           public MessageHandler {
+ public:
+  FakeNetworkManager() {}
+
+  typedef std::vector<std::pair<SocketAddress, AdapterType>> IfaceList;
+
+  void AddInterface(const SocketAddress& iface) {
+    // Ensure a unique name for the interface if its name is not given.
+    AddInterface(iface, "test" + rtc::ToString(next_index_++));
+  }
+
+  void AddInterface(const SocketAddress& iface, const std::string& if_name) {
+    AddInterface(iface, if_name, ADAPTER_TYPE_UNKNOWN);
+  }
+
+  void AddInterface(const SocketAddress& iface,
+                    const std::string& if_name,
+                    AdapterType type) {
+    SocketAddress address(if_name, 0);
+    address.SetResolvedIP(iface.ipaddr());
+    ifaces_.push_back(std::make_pair(address, type));
+    DoUpdateNetworks();
+  }
+
+  void RemoveInterface(const SocketAddress& iface) {
+    for (IfaceList::iterator it = ifaces_.begin();
+         it != ifaces_.end(); ++it) {
+      if (it->first.EqualIPs(iface)) {
+        ifaces_.erase(it);
+        break;
+      }
+    }
+    DoUpdateNetworks();
+  }
+
+  virtual void StartUpdating() {
+    ++start_count_;
+    if (start_count_ == 1) {
+      sent_first_update_ = false;
+      rtc::Thread::Current()->Post(RTC_FROM_HERE, this);
+    } else {
+      if (sent_first_update_) {
+        SignalNetworksChanged();
+      }
+    }
+  }
+
+  virtual void StopUpdating() { --start_count_; }
+
+  // MessageHandler interface.
+  virtual void OnMessage(Message* msg) {
+    DoUpdateNetworks();
+  }
+
+  using NetworkManagerBase::set_enumeration_permission;
+  using NetworkManagerBase::set_default_local_addresses;
+
+ private:
+  void DoUpdateNetworks() {
+    if (start_count_ == 0)
+      return;
+    std::vector<Network*> networks;
+    for (IfaceList::iterator it = ifaces_.begin();
+         it != ifaces_.end(); ++it) {
+      int prefix_length = 0;
+      if (it->first.ipaddr().family() == AF_INET) {
+        prefix_length = kFakeIPv4NetworkPrefixLength;
+      } else if (it->first.ipaddr().family() == AF_INET6) {
+        prefix_length = kFakeIPv6NetworkPrefixLength;
+      }
+      IPAddress prefix = TruncateIP(it->first.ipaddr(), prefix_length);
+      std::unique_ptr<Network> net(new Network(it->first.hostname(),
+                                               it->first.hostname(), prefix,
+                                               prefix_length, it->second));
+      net->set_default_local_address_provider(this);
+      net->AddIP(it->first.ipaddr());
+      networks.push_back(net.release());
+    }
+    bool changed;
+    MergeNetworkList(networks, &changed);
+    if (changed || !sent_first_update_) {
+      SignalNetworksChanged();
+      sent_first_update_ = true;
+    }
+  }
+
+  IfaceList ifaces_;
+  int next_index_ = 0;
+  int start_count_ = 0;
+  bool sent_first_update_ = false;
+
+  IPAddress default_local_ipv4_address_;
+  IPAddress default_local_ipv6_address_;
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_FAKENETWORK_H_

webrtc/rtc_base/fakesslidentity.h

@@ -0,0 +1,120 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_FAKESSLIDENTITY_H_
+#define WEBRTC_RTC_BASE_FAKESSLIDENTITY_H_
+
+#include <algorithm>
+#include <memory>
+#include <vector>
+
+#include "webrtc/base/checks.h"
+#include "webrtc/base/messagedigest.h"
+#include "webrtc/base/sslidentity.h"
+
+namespace rtc {
+
+class FakeSSLCertificate : public rtc::SSLCertificate {
+ public:
+  // SHA-1 is the default digest algorithm because it is available in all build
+  // configurations used for unit testing.
+  explicit FakeSSLCertificate(const std::string& data)
+      : data_(data), digest_algorithm_(DIGEST_SHA_1), expiration_time_(-1) {}
+  explicit FakeSSLCertificate(const std::vector<std::string>& certs)
+      : data_(certs.front()),
+        digest_algorithm_(DIGEST_SHA_1),
+        expiration_time_(-1) {
+    std::vector<std::string>::const_iterator it;
+    // Skip certs[0].
+    for (it = certs.begin() + 1; it != certs.end(); ++it) {
+      certs_.push_back(FakeSSLCertificate(*it));
+    }
+  }
+  FakeSSLCertificate* GetReference() const override {
+    return new FakeSSLCertificate(*this);
+  }
+  std::string ToPEMString() const override {
+    return data_;
+  }
+  void ToDER(Buffer* der_buffer) const override {
+    std::string der_string;
+    RTC_CHECK(SSLIdentity::PemToDer(kPemTypeCertificate, data_, &der_string));
+    der_buffer->SetData(der_string.c_str(), der_string.size());
+  }
+  int64_t CertificateExpirationTime() const override {
+    return expiration_time_;
+  }
+  void SetCertificateExpirationTime(int64_t expiration_time) {
+    expiration_time_ = expiration_time;
+  }
+  void set_digest_algorithm(const std::string& algorithm) {
+    digest_algorithm_ = algorithm;
+  }
+  bool GetSignatureDigestAlgorithm(std::string* algorithm) const override {
+    *algorithm = digest_algorithm_;
+    return true;
+  }
+  bool ComputeDigest(const std::string& algorithm,
+                     unsigned char* digest,
+                     size_t size,
+                     size_t* length) const override {
+    *length = rtc::ComputeDigest(algorithm, data_.c_str(), data_.size(),
+                                       digest, size);
+    return (*length != 0);
+  }
+  std::unique_ptr<SSLCertChain> GetChain() const override {
+    if (certs_.empty())
+      return nullptr;
+    std::vector<SSLCertificate*> new_certs(certs_.size());
+    std::transform(certs_.begin(), certs_.end(), new_certs.begin(), DupCert);
+    std::unique_ptr<SSLCertChain> chain(new SSLCertChain(new_certs));
+    std::for_each(new_certs.begin(), new_certs.end(), DeleteCert);
+    return chain;
+  }
+
+ private:
+  static FakeSSLCertificate* DupCert(FakeSSLCertificate cert) {
+    return cert.GetReference();
+  }
+  static void DeleteCert(SSLCertificate* cert) { delete cert; }
+  std::string data_;
+  std::vector<FakeSSLCertificate> certs_;
+  std::string digest_algorithm_;
+  // Expiration time in seconds relative to epoch, 1970-01-01T00:00:00Z (UTC).
+  int64_t expiration_time_;
+};
+
+class FakeSSLIdentity : public rtc::SSLIdentity {
+ public:
+  explicit FakeSSLIdentity(const std::string& data) : cert_(data) {}
+  explicit FakeSSLIdentity(const FakeSSLCertificate& cert) : cert_(cert) {}
+  virtual FakeSSLIdentity* GetReference() const {
+    return new FakeSSLIdentity(*this);
+  }
+  virtual const FakeSSLCertificate& certificate() const { return cert_; }
+  virtual std::string PrivateKeyToPEMString() const {
+    RTC_NOTREACHED();  // Not implemented.
+    return "";
+  }
+  virtual std::string PublicKeyToPEMString() const {
+    RTC_NOTREACHED();  // Not implemented.
+    return "";
+  }
+  virtual bool operator==(const SSLIdentity& other) const {
+    RTC_NOTREACHED();  // Not implemented.
+    return false;
+  }
+ private:
+  FakeSSLCertificate cert_;
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_FAKESSLIDENTITY_H_

webrtc/rtc_base/file.cc

@@ -0,0 +1,94 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/file.h"
+
+#include <utility>
+
+namespace rtc {
+
+namespace {
+
+std::string NormalizePathname(Pathname&& path) {
+  path.Normalize();
+  return path.pathname();
+}
+
+}  // namespace
+
+File::File(PlatformFile file) : file_(file) {}
+
+File::File() : file_(kInvalidPlatformFileValue) {}
+
+File::~File() {
+  Close();
+}
+
+// static
+File File::Open(const std::string& path) {
+  return File(OpenPlatformFile(path));
+}
+
+// static
+File File::Open(Pathname&& path) {
+  return Open(NormalizePathname(std::move(path)));
+}
+
+// static
+File File::Open(const Pathname& path) {
+  return Open(Pathname(path));
+}
+
+// static
+File File::Create(const std::string& path) {
+  return File(CreatePlatformFile(path));
+}
+
+// static
+File File::Create(Pathname&& path) {
+  return Create(NormalizePathname(std::move(path)));
+}
+
+// static
+File File::Create(const Pathname& path) {
+  return Create(Pathname(path));
+}
+
+// static
+bool File::Remove(const std::string& path) {
+  return RemoveFile(path);
+}
+
+// static
+bool File::Remove(Pathname&& path) {
+  return Remove(NormalizePathname(std::move(path)));
+}
+
+// static
+bool File::Remove(const Pathname& path) {
+  return Remove(Pathname(path));
+}
+
+File::File(File&& other) : file_(other.file_) {
+  other.file_ = kInvalidPlatformFileValue;
+}
+
+File& File::operator=(File&& other) {
+  Close();
+  file_ = other.file_;
+  other.file_ = kInvalidPlatformFileValue;
+  return *this;
+}
+
+bool File::IsOpen() {
+  return file_ != kInvalidPlatformFileValue;
+}
+
+}  // namespace rtc

webrtc/rtc_base/file.h

@@ -0,0 +1,82 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_FILE_H_
+#define WEBRTC_RTC_BASE_FILE_H_
+
+#include <stdint.h>
+
+#include <string>
+
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/base/pathutils.h"
+#include "webrtc/base/platform_file.h"
+
+namespace rtc {
+
+// This class wraps the platform specific APIs for simple file interactions.
+//
+// The various read and write methods are best effort, i.e. if an underlying
+// call does not manage to read/write all the data more calls will be performed,
+// until an error is detected or all data is read/written.
+class File {
+ public:
+  // Wraps the given PlatformFile. This class is then responsible for closing
+  // the file, which will be done in the destructor if Close is never called.
+  explicit File(PlatformFile);
+  // The default constructor produces a closed file.
+  File();
+  ~File();
+
+  File(File&& other);
+  File& operator=(File&& other);
+
+  // Open and Create give files with both reading and writing enabled.
+  static File Open(const std::string& path);
+  static File Open(Pathname&& path);
+  static File Open(const Pathname& path);
+  // If the file already exists it will be overwritten.
+  static File Create(const std::string& path);
+  static File Create(Pathname&& path);
+  static File Create(const Pathname& path);
+
+  // Remove a file in the file system.
+  static bool Remove(const std::string& path);
+  static bool Remove(Pathname&& path);
+  static bool Remove(const Pathname& path);
+
+  size_t Write(const uint8_t* data, size_t length);
+  size_t Read(uint8_t* buffer, size_t length);
+
+  // The current position in the file after a call to these methods is platform
+  // dependent (MSVC gives position offset+length, most other
+  // compilers/platforms do not alter the position), i.e. do not depend on it,
+  // do a Seek before any subsequent Read/Write.
+  size_t WriteAt(const uint8_t* data, size_t length, size_t offset);
+  size_t ReadAt(uint8_t* buffer, size_t length, size_t offset);
+
+  // Attempt to position the file at the given offset from the start.
+  // Returns true if successful, false otherwise.
+  bool Seek(size_t offset);
+
+  // Attempt to close the file. Returns true if successful, false otherwise,
+  // most notably when the file is already closed.
+  bool Close();
+
+  bool IsOpen();
+
+ private:
+  PlatformFile file_;
+  RTC_DISALLOW_COPY_AND_ASSIGN(File);
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_FILE_H_

webrtc/rtc_base/file_posix.cc

@@ -0,0 +1,96 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/file.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <limits>
+
+#include "webrtc/base/checks.h"
+
+namespace rtc {
+
+size_t File::Write(const uint8_t* data, size_t length) {
+  size_t total_written = 0;
+  do {
+    ssize_t written;
+    do {
+      written = ::write(file_, data + total_written, length - total_written);
+    } while (written == -1 && errno == EINTR);
+    if (written == -1)
+      break;
+    total_written += written;
+  } while (total_written < length);
+  return total_written;
+}
+
+size_t File::Read(uint8_t* buffer, size_t length) {
+  size_t total_read = 0;
+  do {
+    ssize_t read;
+    do {
+      read = ::read(file_, buffer + total_read, length - total_read);
+    } while (read == -1 && errno == EINTR);
+    if (read == -1)
+      break;
+    total_read += read;
+  } while (total_read < length);
+  return total_read;
+}
+
+size_t File::WriteAt(const uint8_t* data, size_t length, size_t offset) {
+  size_t total_written = 0;
+  do {
+    ssize_t written;
+    do {
+      written = ::pwrite(file_, data + total_written, length - total_written,
+                         offset + total_written);
+    } while (written == -1 && errno == EINTR);
+    if (written == -1)
+      break;
+    total_written += written;
+  } while (total_written < length);
+  return total_written;
+}
+
+size_t File::ReadAt(uint8_t* buffer, size_t length, size_t offset) {
+  size_t total_read = 0;
+  do {
+    ssize_t read;
+    do {
+      read = ::pread(file_, buffer + total_read, length - total_read,
+                     offset + total_read);
+    } while (read == -1 && errno == EINTR);
+    if (read == -1)
+      break;
+    total_read += read;
+  } while (total_read < length);
+  return total_read;
+}
+
+bool File::Seek(size_t offset) {
+  RTC_DCHECK_LE(offset, std::numeric_limits<off_t>::max());
+  return lseek(file_, static_cast<off_t>(offset), SEEK_SET) != -1;
+}
+
+bool File::Close() {
+  if (file_ == rtc::kInvalidPlatformFileValue)
+    return false;
+  bool ret = close(file_) == 0;
+  file_ = rtc::kInvalidPlatformFileValue;
+  return ret;
+}
+
+}  // namespace rtc

webrtc/rtc_base/file_unittest.cc

@@ -0,0 +1,201 @@
+/*
+ *  Copyright 2016 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <limits>
+#include <memory>
+#include <string>
+
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/file.h"
+#include "webrtc/test/testsupport/fileutils.h"
+
+#if defined(WEBRTC_WIN)
+
+#include "webrtc/base/win32.h"
+
+#else  // if defined(WEBRTC_WIN)
+
+#include <errno.h>
+
+#endif
+
+namespace rtc {
+
+int LastError() {
+#if defined(WEBRTC_WIN)
+  return ::GetLastError();
+#else
+  return errno;
+#endif
+}
+
+bool VerifyBuffer(uint8_t* buffer, size_t length, uint8_t start_value) {
+  for (size_t i = 0; i < length; ++i) {
+    uint8_t val = start_value++;
+    EXPECT_EQ(val, buffer[i]);
+    if (buffer[i] != val)
+      return false;
+  }
+  // Prevent the same buffer from being verified multiple times simply
+  // because some operation that should have written to it failed
+  memset(buffer, 0, length);
+  return true;
+}
+
+class FileTest : public ::testing::Test {
+ protected:
+  std::string path_;
+  void SetUp() override {
+    path_ = webrtc::test::TempFilename(webrtc::test::OutputPath(), "test_file");
+    ASSERT_FALSE(path_.empty());
+  }
+  void TearDown() override { RemoveFile(path_); }
+};
+
+TEST_F(FileTest, DefaultConstructor) {
+  File file;
+  uint8_t buffer[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+
+  EXPECT_FALSE(file.IsOpen());
+  EXPECT_EQ(0u, file.Write(buffer, 10));
+  EXPECT_FALSE(file.Seek(0));
+  EXPECT_EQ(0u, file.Read(buffer, 10));
+  EXPECT_EQ(0u, file.WriteAt(buffer, 10, 0));
+  EXPECT_EQ(0u, file.ReadAt(buffer, 10, 0));
+  EXPECT_FALSE(file.Close());
+}
+
+TEST_F(FileTest, DoubleClose) {
+  File file = File::Open(path_);
+  ASSERT_TRUE(file.IsOpen()) << "Error: " << LastError();
+
+  EXPECT_TRUE(file.Close());
+  EXPECT_FALSE(file.Close());
+}
+
+TEST_F(FileTest, SimpleReadWrite) {
+  File file = File::Open(path_);
+  ASSERT_TRUE(file.IsOpen()) << "Error: " << LastError();
+
+  uint8_t data[100] = {0};
+  uint8_t out[100] = {0};
+  for (int i = 0; i < 100; ++i) {
+    data[i] = i;
+  }
+
+  EXPECT_EQ(10u, file.Write(data, 10));
+
+  EXPECT_TRUE(file.Seek(0));
+  EXPECT_EQ(10u, file.Read(out, 10));
+  EXPECT_TRUE(VerifyBuffer(out, 10, 0));
+
+  EXPECT_TRUE(file.Seek(0));
+  EXPECT_EQ(100u, file.Write(data, 100));
+
+  EXPECT_TRUE(file.Seek(0));
+  EXPECT_EQ(100u, file.Read(out, 100));
+  EXPECT_TRUE(VerifyBuffer(out, 100, 0));
+
+  EXPECT_TRUE(file.Seek(1));
+  EXPECT_EQ(50u, file.Write(data, 50));
+  EXPECT_EQ(50u, file.Write(data + 50, 50));
+
+  EXPECT_TRUE(file.Seek(1));
+  EXPECT_EQ(100u, file.Read(out, 100));
+  EXPECT_TRUE(VerifyBuffer(out, 100, 0));
+}
+
+TEST_F(FileTest, ReadWriteClose) {
+  File file = File::Open(path_);
+  ASSERT_TRUE(file.IsOpen()) << "Error: " << LastError();
+
+  uint8_t data[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+  uint8_t out[10] = {0};
+  EXPECT_EQ(10u, file.Write(data, 10));
+  EXPECT_TRUE(file.Close());
+
+  File file2 = File::Open(path_);
+  ASSERT_TRUE(file2.IsOpen()) << "Error: " << LastError();
+  EXPECT_EQ(10u, file2.Read(out, 10));
+  EXPECT_TRUE(VerifyBuffer(out, 10, 0));
+}
+
+TEST_F(FileTest, RandomAccessRead) {
+  File file = File::Open(path_);
+  ASSERT_TRUE(file.IsOpen()) << "Error: " << LastError();
+
+  uint8_t data[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+  uint8_t out[10] = {0};
+  EXPECT_EQ(10u, file.Write(data, 10));
+
+  EXPECT_EQ(4u, file.ReadAt(out, 4, 0));
+  EXPECT_TRUE(VerifyBuffer(out, 4, 0));
+
+  EXPECT_EQ(4u, file.ReadAt(out, 4, 4));
+  EXPECT_TRUE(VerifyBuffer(out, 4, 4));
+
+  EXPECT_EQ(5u, file.ReadAt(out, 5, 5));
+  EXPECT_TRUE(VerifyBuffer(out, 5, 5));
+}
+
+TEST_F(FileTest, RandomAccessReadWrite) {
+  File file = File::Open(path_);
+  ASSERT_TRUE(file.IsOpen()) << "Error: " << LastError();
+
+  uint8_t data[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+  uint8_t out[10] = {0};
+  EXPECT_EQ(10u, file.Write(data, 10));
+  EXPECT_TRUE(file.Seek(4));
+
+  EXPECT_EQ(4u, file.WriteAt(data, 4, 4));
+  EXPECT_EQ(4u, file.ReadAt(out, 4, 4));
+  EXPECT_TRUE(VerifyBuffer(out, 4, 0));
+
+  EXPECT_EQ(2u, file.WriteAt(data, 2, 8));
+  EXPECT_EQ(2u, file.ReadAt(out, 2, 8));
+  EXPECT_TRUE(VerifyBuffer(out, 2, 0));
+}
+
+TEST_F(FileTest, OpenFromPathname) {
+  {
+    File file = File::Open(Pathname(path_));
+    ASSERT_TRUE(file.IsOpen()) << "Error: " << LastError();
+  }
+
+  {
+    Pathname path(path_);
+    File file = File::Open(path);
+    ASSERT_TRUE(file.IsOpen()) << "Error: " << LastError();
+  }
+}
+
+TEST_F(FileTest, CreateFromPathname) {
+  {
+    File file = File::Create(Pathname(path_));
+    ASSERT_TRUE(file.IsOpen()) << "Error: " << LastError();
+  }
+
+  {
+    Pathname path(path_);
+    File file = File::Create(path);
+    ASSERT_TRUE(file.IsOpen()) << "Error: " << LastError();
+  }
+}
+
+TEST_F(FileTest, ShouldBeAbleToRemoveFile) {
+  {
+    File file = File::Open(Pathname(path_));
+    ASSERT_TRUE(file.IsOpen()) << "Error: " << LastError();
+  }
+
+  ASSERT_TRUE(File::Remove(Pathname(path_))) << "Error: " << LastError();
+}
+
+}  // namespace rtc

webrtc/rtc_base/file_win.cc

@@ -0,0 +1,113 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/file.h"
+
+#include <io.h>
+#include "webrtc/base/win32.h"
+
+#include <limits>  // NOLINT: win32.h should be considered a system header
+
+#include "webrtc/base/checks.h"
+
+namespace rtc {
+
+size_t File::Write(const uint8_t* data, size_t length) {
+  RTC_DCHECK_LT(length, std::numeric_limits<DWORD>::max());
+  size_t total_written = 0;
+  do {
+    DWORD written;
+    if (!::WriteFile(file_, data + total_written,
+                     static_cast<DWORD>(length - total_written), &written,
+                     nullptr)) {
+      break;
+    }
+    total_written += written;
+  } while (total_written < length);
+  return total_written;
+}
+
+size_t File::Read(uint8_t* buffer, size_t length) {
+  RTC_DCHECK_LT(length, std::numeric_limits<DWORD>::max());
+  size_t total_read = 0;
+  do {
+    DWORD read;
+    if (!::ReadFile(file_, buffer + total_read,
+                    static_cast<DWORD>(length - total_read), &read, nullptr)) {
+      break;
+    }
+    total_read += read;
+  } while (total_read < length);
+  return total_read;
+}
+
+size_t File::WriteAt(const uint8_t* data, size_t length, size_t offset) {
+  RTC_DCHECK_LT(length, std::numeric_limits<DWORD>::max());
+  size_t total_written = 0;
+  do {
+    DWORD written;
+
+    LARGE_INTEGER offset_li;
+    offset_li.QuadPart = offset + total_written;
+
+    OVERLAPPED overlapped = {0};
+    overlapped.Offset = offset_li.LowPart;
+    overlapped.OffsetHigh = offset_li.HighPart;
+
+    if (!::WriteFile(file_, data + total_written,
+                     static_cast<DWORD>(length - total_written), &written,
+                     &overlapped)) {
+      break;
+    }
+
+    total_written += written;
+  } while (total_written < length);
+  return total_written;
+}
+
+size_t File::ReadAt(uint8_t* buffer, size_t length, size_t offset) {
+  RTC_DCHECK_LT(length, std::numeric_limits<DWORD>::max());
+  size_t total_read = 0;
+  do {
+    DWORD read;
+
+    LARGE_INTEGER offset_li;
+    offset_li.QuadPart = offset + total_read;
+
+    OVERLAPPED overlapped = {0};
+    overlapped.Offset = offset_li.LowPart;
+    overlapped.OffsetHigh = offset_li.HighPart;
+
+    if (!::ReadFile(file_, buffer + total_read,
+                    static_cast<DWORD>(length - total_read), &read,
+                    &overlapped)) {
+      break;
+    }
+
+    total_read += read;
+  } while (total_read < length);
+  return total_read;
+}
+
+bool File::Seek(size_t offset) {
+  LARGE_INTEGER distance;
+  distance.QuadPart = offset;
+  return SetFilePointerEx(file_, distance, nullptr, FILE_BEGIN) != 0;
+}
+
+bool File::Close() {
+  if (file_ == kInvalidPlatformFileValue)
+    return false;
+  bool ret = CloseHandle(file_) != 0;
+  file_ = kInvalidPlatformFileValue;
+  return ret;
+}
+
+}  // namespace rtc

webrtc/rtc_base/filerotatingstream.cc

@@ -0,0 +1,400 @@
+/*
+ *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/filerotatingstream.h"
+
+#include <algorithm>
+#include <iostream>
+#include <string>
+
+#include "webrtc/base/checks.h"
+#include "webrtc/base/fileutils.h"
+#include "webrtc/base/pathutils.h"
+
+// Note: We use std::cerr for logging in the write paths of this stream to avoid
+// infinite loops when logging.
+
+namespace rtc {
+
+FileRotatingStream::FileRotatingStream(const std::string& dir_path,
+                                       const std::string& file_prefix)
+    : FileRotatingStream(dir_path, file_prefix, 0, 0, kRead) {
+}
+
+FileRotatingStream::FileRotatingStream(const std::string& dir_path,
+                                       const std::string& file_prefix,
+                                       size_t max_file_size,
+                                       size_t num_files)
+    : FileRotatingStream(dir_path,
+                         file_prefix,
+                         max_file_size,
+                         num_files,
+                         kWrite) {
+  RTC_DCHECK_GT(max_file_size, 0);
+  RTC_DCHECK_GT(num_files, 1);
+}
+
+FileRotatingStream::FileRotatingStream(const std::string& dir_path,
+                                       const std::string& file_prefix,
+                                       size_t max_file_size,
+                                       size_t num_files,
+                                       Mode mode)
+    : dir_path_(dir_path),
+      file_prefix_(file_prefix),
+      mode_(mode),
+      file_stream_(nullptr),
+      max_file_size_(max_file_size),
+      current_file_index_(0),
+      rotation_index_(0),
+      current_bytes_written_(0),
+      disable_buffering_(false) {
+  RTC_DCHECK(Filesystem::IsFolder(dir_path));
+  switch (mode) {
+    case kWrite: {
+      file_names_.clear();
+      for (size_t i = 0; i < num_files; ++i) {
+        file_names_.push_back(GetFilePath(i, num_files));
+      }
+      rotation_index_ = num_files - 1;
+      break;
+    }
+    case kRead: {
+      file_names_ = GetFilesWithPrefix();
+      std::sort(file_names_.begin(), file_names_.end());
+      if (file_names_.size() > 0) {
+        // |file_names_| is sorted newest first, so read from the end.
+        current_file_index_ = file_names_.size() - 1;
+      }
+      break;
+    }
+  }
+}
+
+FileRotatingStream::~FileRotatingStream() {
+}
+
+StreamState FileRotatingStream::GetState() const {
+  if (mode_ == kRead && current_file_index_ < file_names_.size()) {
+    return SS_OPEN;
+  }
+  if (!file_stream_) {
+    return SS_CLOSED;
+  }
+  return file_stream_->GetState();
+}
+
+StreamResult FileRotatingStream::Read(void* buffer,
+                                      size_t buffer_len,
+                                      size_t* read,
+                                      int* error) {
+  RTC_DCHECK(buffer);
+  if (mode_ != kRead) {
+    return SR_EOS;
+  }
+  if (current_file_index_ >= file_names_.size()) {
+    return SR_EOS;
+  }
+  // We will have no file stream initially, and when we are finished with the
+  // previous file.
+  if (!file_stream_) {
+    if (!OpenCurrentFile()) {
+      return SR_ERROR;
+    }
+  }
+  int local_error = 0;
+  if (!error) {
+    error = &local_error;
+  }
+  StreamResult result = file_stream_->Read(buffer, buffer_len, read, error);
+  if (result == SR_EOS || result == SR_ERROR) {
+    if (result == SR_ERROR) {
+      LOG(LS_ERROR) << "Failed to read from: "
+                    << file_names_[current_file_index_] << "Error: " << error;
+    }
+    // Reached the end of the file, read next file. If there is an error return
+    // the error status but allow for a next read by reading next file.
+    CloseCurrentFile();
+    if (current_file_index_ == 0) {
+      // Just finished reading the last file, signal EOS by setting index.
+      current_file_index_ = file_names_.size();
+    } else {
+      --current_file_index_;
+    }
+    if (read) {
+      *read = 0;
+    }
+    return result == SR_EOS ? SR_SUCCESS : result;
+  } else if (result == SR_SUCCESS) {
+    // Succeeded, continue reading from this file.
+    return SR_SUCCESS;
+  } else {
+    RTC_NOTREACHED();
+  }
+  return result;
+}
+
+StreamResult FileRotatingStream::Write(const void* data,
+                                       size_t data_len,
+                                       size_t* written,
+                                       int* error) {
+  if (mode_ != kWrite) {
+    return SR_EOS;
+  }
+  if (!file_stream_) {
+    std::cerr << "Open() must be called before Write." << std::endl;
+    return SR_ERROR;
+  }
+  // Write as much as will fit in to the current file.
+  RTC_DCHECK_LT(current_bytes_written_, max_file_size_);
+  size_t remaining_bytes = max_file_size_ - current_bytes_written_;
+  size_t write_length = std::min(data_len, remaining_bytes);
+  size_t local_written = 0;
+  if (!written) {
+    written = &local_written;
+  }
+  StreamResult result = file_stream_->Write(data, write_length, written, error);
+  current_bytes_written_ += *written;
+
+  // If we're done with this file, rotate it out.
+  if (current_bytes_written_ >= max_file_size_) {
+    RTC_DCHECK_EQ(current_bytes_written_, max_file_size_);
+    RotateFiles();
+  }
+  return result;
+}
+
+bool FileRotatingStream::Flush() {
+  if (!file_stream_) {
+    return false;
+  }
+  return file_stream_->Flush();
+}
+
+bool FileRotatingStream::GetSize(size_t* size) const {
+  if (mode_ != kRead) {
+    // Not possible to get accurate size on disk when writing because of
+    // potential buffering.
+    return false;
+  }
+  RTC_DCHECK(size);
+  *size = 0;
+  size_t total_size = 0;
+  for (auto file_name : file_names_) {
+    Pathname pathname(file_name);
+    size_t file_size = 0;
+    if (Filesystem::GetFileSize(file_name, &file_size)) {
+      total_size += file_size;
+    }
+  }
+  *size = total_size;
+  return true;
+}
+
+void FileRotatingStream::Close() {
+  CloseCurrentFile();
+}
+
+bool FileRotatingStream::Open() {
+  switch (mode_) {
+    case kRead:
+      // Defer opening to when we first read since we want to return read error
+      // if we fail to open next file.
+      return true;
+    case kWrite: {
+      // Delete existing files when opening for write.
+      std::vector<std::string> matching_files = GetFilesWithPrefix();
+      for (auto matching_file : matching_files) {
+        if (!Filesystem::DeleteFile(matching_file)) {
+          std::cerr << "Failed to delete: " << matching_file << std::endl;
+        }
+      }
+      return OpenCurrentFile();
+    }
+  }
+  return false;
+}
+
+bool FileRotatingStream::DisableBuffering() {
+  disable_buffering_ = true;
+  if (!file_stream_) {
+    std::cerr << "Open() must be called before DisableBuffering()."
+              << std::endl;
+    return false;
+  }
+  return file_stream_->DisableBuffering();
+}
+
+std::string FileRotatingStream::GetFilePath(size_t index) const {
+  RTC_DCHECK_LT(index, file_names_.size());
+  return file_names_[index];
+}
+
+bool FileRotatingStream::OpenCurrentFile() {
+  CloseCurrentFile();
+
+  // Opens the appropriate file in the appropriate mode.
+  RTC_DCHECK_LT(current_file_index_, file_names_.size());
+  std::string file_path = file_names_[current_file_index_];
+  file_stream_.reset(new FileStream());
+  const char* mode = nullptr;
+  switch (mode_) {
+    case kWrite:
+      mode = "w+";
+      // We should always we writing to the zero-th file.
+      RTC_DCHECK_EQ(current_file_index_, 0);
+      break;
+    case kRead:
+      mode = "r";
+      break;
+  }
+  int error = 0;
+  if (!file_stream_->Open(file_path, mode, &error)) {
+    std::cerr << "Failed to open: " << file_path << "Error: " << error
+              << std::endl;
+    file_stream_.reset();
+    return false;
+  }
+  if (disable_buffering_) {
+    file_stream_->DisableBuffering();
+  }
+  return true;
+}
+
+void FileRotatingStream::CloseCurrentFile() {
+  if (!file_stream_) {
+    return;
+  }
+  current_bytes_written_ = 0;
+  file_stream_.reset();
+}
+
+void FileRotatingStream::RotateFiles() {
+  RTC_DCHECK_EQ(mode_, kWrite);
+  CloseCurrentFile();
+  // Rotates the files by deleting the file at |rotation_index_|, which is the
+  // oldest file and then renaming the newer files to have an incremented index.
+  // See header file comments for example.
+  RTC_DCHECK_LT(rotation_index_, file_names_.size());
+  std::string file_to_delete = file_names_[rotation_index_];
+  if (Filesystem::IsFile(file_to_delete)) {
+    if (!Filesystem::DeleteFile(file_to_delete)) {
+      std::cerr << "Failed to delete: " << file_to_delete << std::endl;
+    }
+  }
+  for (auto i = rotation_index_; i > 0; --i) {
+    std::string rotated_name = file_names_[i];
+    std::string unrotated_name = file_names_[i - 1];
+    if (Filesystem::IsFile(unrotated_name)) {
+      if (!Filesystem::MoveFile(unrotated_name, rotated_name)) {
+        std::cerr << "Failed to move: " << unrotated_name << " to "
+                  << rotated_name << std::endl;
+      }
+    }
+  }
+  // Create a new file for 0th index.
+  OpenCurrentFile();
+  OnRotation();
+}
+
+std::vector<std::string> FileRotatingStream::GetFilesWithPrefix() const {
+  std::vector<std::string> files;
+  // Iterate over the files in the directory.
+  DirectoryIterator it;
+  Pathname dir_path;
+  dir_path.SetFolder(dir_path_);
+  if (!it.Iterate(dir_path)) {
+    return files;
+  }
+  do {
+    std::string current_name = it.Name();
+    if (current_name.size() && !it.IsDirectory() &&
+        current_name.compare(0, file_prefix_.size(), file_prefix_) == 0) {
+      Pathname path(dir_path_, current_name);
+      files.push_back(path.pathname());
+    }
+  } while (it.Next());
+  return files;
+}
+
+std::string FileRotatingStream::GetFilePath(size_t index,
+                                            size_t num_files) const {
+  RTC_DCHECK_LT(index, num_files);
+  std::ostringstream file_name;
+  // The format will be "_%<num_digits>zu". We want to zero pad the index so
+  // that it will sort nicely.
+  size_t max_digits = ((num_files - 1) / 10) + 1;
+  size_t num_digits = (index / 10) + 1;
+  RTC_DCHECK_LE(num_digits, max_digits);
+  size_t padding = max_digits - num_digits;
+
+  file_name << file_prefix_ << "_";
+  for (size_t i = 0; i < padding; ++i) {
+    file_name << "0";
+  }
+  file_name << index;
+
+  Pathname file_path(dir_path_, file_name.str());
+  return file_path.pathname();
+}
+
+CallSessionFileRotatingStream::CallSessionFileRotatingStream(
+    const std::string& dir_path)
+    : FileRotatingStream(dir_path, kLogPrefix),
+      max_total_log_size_(0),
+      num_rotations_(0) {
+}
+
+CallSessionFileRotatingStream::CallSessionFileRotatingStream(
+    const std::string& dir_path,
+    size_t max_total_log_size)
+    : FileRotatingStream(dir_path,
+                         kLogPrefix,
+                         max_total_log_size / 2,
+                         GetNumRotatingLogFiles(max_total_log_size) + 1),
+      max_total_log_size_(max_total_log_size),
+      num_rotations_(0) {
+  RTC_DCHECK_GE(max_total_log_size, 4);
+}
+
+const char* CallSessionFileRotatingStream::kLogPrefix = "webrtc_log";
+const size_t CallSessionFileRotatingStream::kRotatingLogFileDefaultSize =
+    1024 * 1024;
+
+void CallSessionFileRotatingStream::OnRotation() {
+  ++num_rotations_;
+  if (num_rotations_ == 1) {
+    // On the first rotation adjust the max file size so subsequent files after
+    // the first are smaller.
+    SetMaxFileSize(GetRotatingLogSize(max_total_log_size_));
+  } else if (num_rotations_ == (GetNumFiles() - 1)) {
+    // On the next rotation the very first file is going to be deleted. Change
+    // the rotation index so this doesn't happen.
+    SetRotationIndex(GetRotationIndex() - 1);
+  }
+}
+
+size_t CallSessionFileRotatingStream::GetRotatingLogSize(
+    size_t max_total_log_size) {
+  size_t num_rotating_log_files = GetNumRotatingLogFiles(max_total_log_size);
+  size_t rotating_log_size = num_rotating_log_files > 2
+                                 ? kRotatingLogFileDefaultSize
+                                 : max_total_log_size / 4;
+  return rotating_log_size;
+}
+
+size_t CallSessionFileRotatingStream::GetNumRotatingLogFiles(
+    size_t max_total_log_size) {
+  // At minimum have two rotating files. Otherwise split the available log size
+  // evenly across 1MB files.
+  return std::max((size_t)2,
+                  (max_total_log_size / 2) / kRotatingLogFileDefaultSize);
+}
+
+}  // namespace rtc

webrtc/rtc_base/filerotatingstream.h

@@ -0,0 +1,173 @@
+/*
+ *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_FILEROTATINGSTREAM_H_
+#define WEBRTC_RTC_BASE_FILEROTATINGSTREAM_H_
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/base/stream.h"
+
+namespace rtc {
+
+// FileRotatingStream writes to a file in the directory specified in the
+// constructor. It rotates the files once the current file is full. The
+// individual file size and the number of files used is configurable in the
+// constructor. Open() must be called before using this stream.
+class FileRotatingStream : public StreamInterface {
+ public:
+  // Use this constructor for reading a directory previously written to with
+  // this stream.
+  FileRotatingStream(const std::string& dir_path,
+                     const std::string& file_prefix);
+
+  // Use this constructor for writing to a directory. Files in the directory
+  // matching the prefix will be deleted on open.
+  FileRotatingStream(const std::string& dir_path,
+                     const std::string& file_prefix,
+                     size_t max_file_size,
+                     size_t num_files);
+
+  ~FileRotatingStream() override;
+
+  // StreamInterface methods.
+  StreamState GetState() const override;
+  StreamResult Read(void* buffer,
+                    size_t buffer_len,
+                    size_t* read,
+                    int* error) override;
+  StreamResult Write(const void* data,
+                     size_t data_len,
+                     size_t* written,
+                     int* error) override;
+  bool Flush() override;
+  // Returns the total file size currently used on disk.
+  bool GetSize(size_t* size) const override;
+  void Close() override;
+
+  // Opens the appropriate file(s). Call this before using the stream.
+  bool Open();
+
+  // Disabling buffering causes writes to block until disk is updated. This is
+  // enabled by default for performance.
+  bool DisableBuffering();
+
+  // Returns the path used for the i-th newest file, where the 0th file is the
+  // newest file. The file may or may not exist, this is just used for
+  // formatting. Index must be less than GetNumFiles().
+  std::string GetFilePath(size_t index) const;
+
+  // Returns the number of files that will used by this stream.
+  size_t GetNumFiles() const { return file_names_.size(); }
+
+ protected:
+  size_t GetMaxFileSize() const { return max_file_size_; }
+
+  void SetMaxFileSize(size_t size) { max_file_size_ = size; }
+
+  size_t GetRotationIndex() const { return rotation_index_; }
+
+  void SetRotationIndex(size_t index) { rotation_index_ = index; }
+
+  virtual void OnRotation() {}
+
+ private:
+  enum Mode { kRead, kWrite };
+
+  FileRotatingStream(const std::string& dir_path,
+                     const std::string& file_prefix,
+                     size_t max_file_size,
+                     size_t num_files,
+                     Mode mode);
+
+  bool OpenCurrentFile();
+  void CloseCurrentFile();
+
+  // Rotates the files by creating a new current file, renaming the
+  // existing files, and deleting the oldest one. e.g.
+  // file_0 -> file_1
+  // file_1 -> file_2
+  // file_2 -> delete
+  // create new file_0
+  void RotateFiles();
+
+  // Returns a list of file names in the directory beginning with the prefix.
+  std::vector<std::string> GetFilesWithPrefix() const;
+  // Private version of GetFilePath.
+  std::string GetFilePath(size_t index, size_t num_files) const;
+
+  const std::string dir_path_;
+  const std::string file_prefix_;
+  const Mode mode_;
+
+  // FileStream is used to write to the current file.
+  std::unique_ptr<FileStream> file_stream_;
+  // Convenience storage for file names so we don't generate them over and over.
+  std::vector<std::string> file_names_;
+  size_t max_file_size_;
+  size_t current_file_index_;
+  // The rotation index indicates the index of the file that will be
+  // deleted first on rotation. Indices lower than this index will be rotated.
+  size_t rotation_index_;
+  // Number of bytes written to current file. We need this because with
+  // buffering the file size read from disk might not be accurate.
+  size_t current_bytes_written_;
+  bool disable_buffering_;
+
+  RTC_DISALLOW_COPY_AND_ASSIGN(FileRotatingStream);
+};
+
+// CallSessionFileRotatingStream is meant to be used in situations where we will
+// have limited disk space. Its purpose is to read and write logs up to a
+// maximum size. Once the maximum size is exceeded, logs from the middle are
+// deleted whereas logs from the beginning and end are preserved. The reason for
+// this is because we anticipate that in WebRTC the beginning and end of the
+// logs are most useful for call diagnostics.
+//
+// This implementation simply writes to a single file until
+// |max_total_log_size| / 2 bytes are written to it, and subsequently writes to
+// a set of rotating files. We do this by inheriting FileRotatingStream and
+// setting the appropriate internal variables so that we don't delete the last
+// (earliest) file on rotate, and that that file's size is bigger.
+//
+// Open() must be called before using this stream.
+class CallSessionFileRotatingStream : public FileRotatingStream {
+ public:
+  // Use this constructor for reading a directory previously written to with
+  // this stream.
+  explicit CallSessionFileRotatingStream(const std::string& dir_path);
+  // Use this constructor for writing to a directory. Files in the directory
+  // matching what's used by the stream will be deleted. |max_total_log_size|
+  // must be at least 4.
+  CallSessionFileRotatingStream(const std::string& dir_path,
+                                size_t max_total_log_size);
+  ~CallSessionFileRotatingStream() override {}
+
+ protected:
+  void OnRotation() override;
+
+ private:
+  static size_t GetRotatingLogSize(size_t max_total_log_size);
+  static size_t GetNumRotatingLogFiles(size_t max_total_log_size);
+  static const char* kLogPrefix;
+  static const size_t kRotatingLogFileDefaultSize;
+
+  const size_t max_total_log_size_;
+  size_t num_rotations_;
+
+  RTC_DISALLOW_COPY_AND_ASSIGN(CallSessionFileRotatingStream);
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_FILEROTATINGSTREAM_H_

webrtc/rtc_base/filerotatingstream_unittest.cc

@@ -0,0 +1,345 @@
+/*
+ *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <memory>
+
+#include "webrtc/base/arraysize.h"
+#include "webrtc/base/checks.h"
+#include "webrtc/base/filerotatingstream.h"
+#include "webrtc/base/fileutils.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/pathutils.h"
+#include "webrtc/test/testsupport/fileutils.h"
+
+namespace rtc {
+
+namespace {
+
+void CleanupLogDirectory(const FileRotatingStream& stream) {
+  for (size_t i = 0; i < stream.GetNumFiles(); ++i) {
+    // Ignore return value, not all files are expected to exist.
+    webrtc::test::RemoveFile(stream.GetFilePath(i));
+  }
+}
+
+}  // namespace
+
+#if defined (WEBRTC_ANDROID)
+// Fails on Android: https://bugs.chromium.org/p/webrtc/issues/detail?id=4364.
+#define MAYBE_FileRotatingStreamTest DISABLED_FileRotatingStreamTest
+#else
+#define MAYBE_FileRotatingStreamTest FileRotatingStreamTest
+#endif
+
+class MAYBE_FileRotatingStreamTest : public ::testing::Test {
+ protected:
+  static const char* kFilePrefix;
+  static const size_t kMaxFileSize;
+
+  void Init(const std::string& dir_name,
+            const std::string& file_prefix,
+            size_t max_file_size,
+            size_t num_log_files) {
+    dir_path_ = webrtc::test::OutputPath();
+
+    // Append per-test output path in order to run within gtest parallel.
+    dir_path_.append(dir_name);
+    dir_path_.push_back(Pathname::DefaultFolderDelimiter());
+    ASSERT_TRUE(webrtc::test::CreateDir(dir_path_));
+    stream_.reset(new FileRotatingStream(dir_path_, file_prefix, max_file_size,
+                                         num_log_files));
+  }
+
+  void TearDown() override {
+    // On windows, open files can't be removed.
+    stream_->Close();
+    CleanupLogDirectory(*stream_);
+    EXPECT_TRUE(webrtc::test::RemoveDir(dir_path_));
+
+    stream_.reset();
+  }
+
+  // Writes the data to the stream and flushes it.
+  void WriteAndFlush(const void* data, const size_t data_len) {
+    EXPECT_EQ(SR_SUCCESS, stream_->WriteAll(data, data_len, nullptr, nullptr));
+    EXPECT_TRUE(stream_->Flush());
+  }
+
+  // Checks that the stream reads in the expected contents and then returns an
+  // end of stream result.
+  void VerifyStreamRead(const char* expected_contents,
+                        const size_t expected_length,
+                        const std::string& dir_path,
+                        const char* file_prefix) {
+    std::unique_ptr<FileRotatingStream> stream;
+    stream.reset(new FileRotatingStream(dir_path, file_prefix));
+    ASSERT_TRUE(stream->Open());
+    size_t read = 0;
+    size_t stream_size = 0;
+    EXPECT_TRUE(stream->GetSize(&stream_size));
+    std::unique_ptr<uint8_t[]> buffer(new uint8_t[expected_length]);
+    EXPECT_EQ(SR_SUCCESS,
+              stream->ReadAll(buffer.get(), expected_length, &read, nullptr));
+    EXPECT_EQ(0, memcmp(expected_contents, buffer.get(), expected_length));
+    EXPECT_EQ(SR_EOS, stream->ReadAll(buffer.get(), 1, nullptr, nullptr));
+    EXPECT_EQ(stream_size, read);
+  }
+
+  void VerifyFileContents(const char* expected_contents,
+                          const size_t expected_length,
+                          const std::string& file_path) {
+    std::unique_ptr<uint8_t[]> buffer(new uint8_t[expected_length]);
+    FileStream stream;
+    ASSERT_TRUE(stream.Open(file_path, "r", nullptr));
+    EXPECT_EQ(rtc::SR_SUCCESS,
+              stream.ReadAll(buffer.get(), expected_length, nullptr, nullptr));
+    EXPECT_EQ(0, memcmp(expected_contents, buffer.get(), expected_length));
+    size_t file_size = 0;
+    EXPECT_TRUE(stream.GetSize(&file_size));
+    EXPECT_EQ(file_size, expected_length);
+  }
+
+  std::unique_ptr<FileRotatingStream> stream_;
+  std::string dir_path_;
+};
+
+const char* MAYBE_FileRotatingStreamTest::kFilePrefix =
+    "FileRotatingStreamTest";
+const size_t MAYBE_FileRotatingStreamTest::kMaxFileSize = 2;
+
+// Tests that stream state is correct before and after Open / Close.
+TEST_F(MAYBE_FileRotatingStreamTest, State) {
+  Init("FileRotatingStreamTestState", kFilePrefix, kMaxFileSize, 3);
+
+  EXPECT_EQ(SS_CLOSED, stream_->GetState());
+  ASSERT_TRUE(stream_->Open());
+  EXPECT_EQ(SS_OPEN, stream_->GetState());
+  stream_->Close();
+  EXPECT_EQ(SS_CLOSED, stream_->GetState());
+}
+
+// Tests that nothing is written to file when data of length zero is written.
+TEST_F(MAYBE_FileRotatingStreamTest, EmptyWrite) {
+  Init("FileRotatingStreamTestEmptyWrite", kFilePrefix, kMaxFileSize, 3);
+
+  ASSERT_TRUE(stream_->Open());
+  WriteAndFlush("a", 0);
+
+  std::string logfile_path = stream_->GetFilePath(0);
+  FileStream stream;
+  ASSERT_TRUE(stream.Open(logfile_path, "r", nullptr));
+  size_t file_size = 0;
+  EXPECT_TRUE(stream.GetSize(&file_size));
+  EXPECT_EQ(0u, file_size);
+}
+
+// Tests that a write operation followed by a read returns the expected data
+// and writes to the expected files.
+TEST_F(MAYBE_FileRotatingStreamTest, WriteAndRead) {
+  Init("FileRotatingStreamTestWriteAndRead", kFilePrefix, kMaxFileSize, 3);
+
+  ASSERT_TRUE(stream_->Open());
+  // The test is set up to create three log files of length 2. Write and check
+  // contents.
+  std::string messages[3] = {"aa", "bb", "cc"};
+  for (size_t i = 0; i < arraysize(messages); ++i) {
+    const std::string& message = messages[i];
+    WriteAndFlush(message.c_str(), message.size());
+    // Since the max log size is 2, we will be causing rotation. Read from the
+    // next file.
+    VerifyFileContents(message.c_str(), message.size(),
+                       stream_->GetFilePath(1));
+  }
+  // Check that exactly three files exist.
+  for (size_t i = 0; i < arraysize(messages); ++i) {
+    EXPECT_TRUE(Filesystem::IsFile(stream_->GetFilePath(i)));
+  }
+  std::string message("d");
+  WriteAndFlush(message.c_str(), message.size());
+  for (size_t i = 0; i < arraysize(messages); ++i) {
+    EXPECT_TRUE(Filesystem::IsFile(stream_->GetFilePath(i)));
+  }
+  // TODO(tkchin): Maybe check all the files in the dir.
+
+  // Reopen for read.
+  std::string expected_contents("bbccd");
+  VerifyStreamRead(expected_contents.c_str(), expected_contents.size(),
+                   dir_path_, kFilePrefix);
+}
+
+// Tests that writing data greater than the total capacity of the files
+// overwrites the files correctly and is read correctly after.
+TEST_F(MAYBE_FileRotatingStreamTest, WriteOverflowAndRead) {
+  Init("FileRotatingStreamTestWriteOverflowAndRead", kFilePrefix, kMaxFileSize,
+       3);
+  ASSERT_TRUE(stream_->Open());
+  // This should cause overflow across all three files, such that the first file
+  // we wrote to also gets overwritten.
+  std::string message("foobarbaz");
+  WriteAndFlush(message.c_str(), message.size());
+  std::string expected_file_contents("z");
+  VerifyFileContents(expected_file_contents.c_str(),
+                     expected_file_contents.size(), stream_->GetFilePath(0));
+  std::string expected_stream_contents("arbaz");
+  VerifyStreamRead(expected_stream_contents.c_str(),
+                   expected_stream_contents.size(), dir_path_, kFilePrefix);
+}
+
+// Tests that the returned file paths have the right folder and prefix.
+TEST_F(MAYBE_FileRotatingStreamTest, GetFilePath) {
+  Init("FileRotatingStreamTestGetFilePath", kFilePrefix, kMaxFileSize, 20);
+  for (auto i = 0; i < 20; ++i) {
+    Pathname path(stream_->GetFilePath(i));
+    EXPECT_EQ(0, path.folder().compare(dir_path_));
+    EXPECT_EQ(0, path.filename().compare(0, strlen(kFilePrefix), kFilePrefix));
+  }
+}
+
+#if defined (WEBRTC_ANDROID)
+// Fails on Android: https://bugs.chromium.org/p/webrtc/issues/detail?id=4364.
+#define MAYBE_CallSessionFileRotatingStreamTest \
+    DISABLED_CallSessionFileRotatingStreamTest
+#else
+#define MAYBE_CallSessionFileRotatingStreamTest \
+    CallSessionFileRotatingStreamTest
+#endif
+
+class MAYBE_CallSessionFileRotatingStreamTest : public ::testing::Test {
+ protected:
+  void Init(const std::string& dir_name, size_t max_total_log_size) {
+    dir_path_ = webrtc::test::OutputPath();
+
+    // Append per-test output path in order to run within gtest parallel.
+    dir_path_.append(dir_name);
+    dir_path_.push_back(Pathname::DefaultFolderDelimiter());
+    ASSERT_TRUE(webrtc::test::CreateDir(dir_path_));
+    stream_.reset(
+        new CallSessionFileRotatingStream(dir_path_, max_total_log_size));
+  }
+
+  virtual void TearDown() {
+    // On windows, open files can't be removed.
+    stream_->Close();
+    CleanupLogDirectory(*stream_);
+    EXPECT_TRUE(webrtc::test::RemoveDir(dir_path_));
+
+    stream_.reset();
+  }
+
+  // Writes the data to the stream and flushes it.
+  void WriteAndFlush(const void* data, const size_t data_len) {
+    EXPECT_EQ(SR_SUCCESS, stream_->WriteAll(data, data_len, nullptr, nullptr));
+    EXPECT_TRUE(stream_->Flush());
+  }
+
+  // Checks that the stream reads in the expected contents and then returns an
+  // end of stream result.
+  void VerifyStreamRead(const char* expected_contents,
+                        const size_t expected_length,
+                        const std::string& dir_path) {
+    std::unique_ptr<CallSessionFileRotatingStream> stream(
+        new CallSessionFileRotatingStream(dir_path));
+    ASSERT_TRUE(stream->Open());
+    size_t read = 0;
+    size_t stream_size = 0;
+    EXPECT_TRUE(stream->GetSize(&stream_size));
+    std::unique_ptr<uint8_t[]> buffer(new uint8_t[expected_length]);
+    EXPECT_EQ(SR_SUCCESS,
+              stream->ReadAll(buffer.get(), expected_length, &read, nullptr));
+    EXPECT_EQ(0, memcmp(expected_contents, buffer.get(), expected_length));
+    EXPECT_EQ(SR_EOS, stream->ReadAll(buffer.get(), 1, nullptr, nullptr));
+    EXPECT_EQ(stream_size, read);
+  }
+
+  std::unique_ptr<CallSessionFileRotatingStream> stream_;
+  std::string dir_path_;
+};
+
+// Tests that writing and reading to a stream with the smallest possible
+// capacity works.
+TEST_F(MAYBE_CallSessionFileRotatingStreamTest, WriteAndReadSmallest) {
+  Init("CallSessionFileRotatingStreamTestWriteAndReadSmallest", 4);
+
+  ASSERT_TRUE(stream_->Open());
+  std::string message("abcde");
+  WriteAndFlush(message.c_str(), message.size());
+  std::string expected_contents("abe");
+  VerifyStreamRead(expected_contents.c_str(), expected_contents.size(),
+                   dir_path_);
+}
+
+// Tests that writing and reading to a stream with capacity lesser than 4MB
+// behaves correctly.
+TEST_F(MAYBE_CallSessionFileRotatingStreamTest, WriteAndReadSmall) {
+  Init("CallSessionFileRotatingStreamTestWriteAndReadSmall", 8);
+
+  ASSERT_TRUE(stream_->Open());
+  std::string message("123456789");
+  WriteAndFlush(message.c_str(), message.size());
+  std::string expected_contents("1234789");
+  VerifyStreamRead(expected_contents.c_str(), expected_contents.size(),
+                   dir_path_);
+}
+
+// Tests that writing and reading to a stream with capacity greater than 4MB
+// behaves correctly.
+TEST_F(MAYBE_CallSessionFileRotatingStreamTest, WriteAndReadLarge) {
+  Init("CallSessionFileRotatingStreamTestWriteAndReadLarge", 6 * 1024 * 1024);
+
+  ASSERT_TRUE(stream_->Open());
+  const size_t buffer_size = 1024 * 1024;
+  std::unique_ptr<uint8_t[]> buffer(new uint8_t[buffer_size]);
+  for (int i = 0; i < 8; i++) {
+    memset(buffer.get(), i, buffer_size);
+    EXPECT_EQ(SR_SUCCESS,
+              stream_->WriteAll(buffer.get(), buffer_size, nullptr, nullptr));
+  }
+
+  stream_.reset(new CallSessionFileRotatingStream(dir_path_));
+  ASSERT_TRUE(stream_->Open());
+  std::unique_ptr<uint8_t[]> expected_buffer(new uint8_t[buffer_size]);
+  int expected_vals[] = {0, 1, 2, 6, 7};
+  for (size_t i = 0; i < arraysize(expected_vals); ++i) {
+    memset(expected_buffer.get(), expected_vals[i], buffer_size);
+    EXPECT_EQ(SR_SUCCESS,
+              stream_->ReadAll(buffer.get(), buffer_size, nullptr, nullptr));
+    EXPECT_EQ(0, memcmp(buffer.get(), expected_buffer.get(), buffer_size));
+  }
+  EXPECT_EQ(SR_EOS, stream_->ReadAll(buffer.get(), 1, nullptr, nullptr));
+}
+
+// Tests that writing and reading to a stream where only the first file is
+// written to behaves correctly.
+TEST_F(MAYBE_CallSessionFileRotatingStreamTest, WriteAndReadFirstHalf) {
+  Init("CallSessionFileRotatingStreamTestWriteAndReadFirstHalf",
+       6 * 1024 * 1024);
+  ASSERT_TRUE(stream_->Open());
+  const size_t buffer_size = 1024 * 1024;
+  std::unique_ptr<uint8_t[]> buffer(new uint8_t[buffer_size]);
+  for (int i = 0; i < 2; i++) {
+    memset(buffer.get(), i, buffer_size);
+    EXPECT_EQ(SR_SUCCESS,
+              stream_->WriteAll(buffer.get(), buffer_size, nullptr, nullptr));
+  }
+
+  stream_.reset(new CallSessionFileRotatingStream(dir_path_));
+  ASSERT_TRUE(stream_->Open());
+  std::unique_ptr<uint8_t[]> expected_buffer(new uint8_t[buffer_size]);
+  int expected_vals[] = {0, 1};
+  for (size_t i = 0; i < arraysize(expected_vals); ++i) {
+    memset(expected_buffer.get(), expected_vals[i], buffer_size);
+    EXPECT_EQ(SR_SUCCESS,
+              stream_->ReadAll(buffer.get(), buffer_size, nullptr, nullptr));
+    EXPECT_EQ(0, memcmp(buffer.get(), expected_buffer.get(), buffer_size));
+  }
+  EXPECT_EQ(SR_EOS, stream_->ReadAll(buffer.get(), 1, nullptr, nullptr));
+}
+
+}  // namespace rtc

webrtc/rtc_base/fileutils.cc

@@ -0,0 +1,133 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/fileutils.h"
+
+#include "webrtc/base/arraysize.h"
+#include "webrtc/base/checks.h"
+#include "webrtc/base/pathutils.h"
+#include "webrtc/base/stringutils.h"
+
+#if defined(WEBRTC_WIN)
+#include "webrtc/base/win32filesystem.h"
+#else
+#include "webrtc/base/unixfilesystem.h"
+#endif
+
+#if !defined(WEBRTC_WIN)
+#define MAX_PATH 260
+#endif
+
+namespace rtc {
+
+//////////////////////////
+// Directory Iterator   //
+//////////////////////////
+
+// A DirectoryIterator is created with a given directory. It originally points
+// to the first file in the directory, and can be advanecd with Next(). This
+// allows you to get information about each file.
+
+  // Constructor
+DirectoryIterator::DirectoryIterator()
+#ifdef WEBRTC_WIN
+    : handle_(INVALID_HANDLE_VALUE) {
+#else
+    : dir_(nullptr),
+      dirent_(nullptr){
+#endif
+}
+
+  // Destructor
+DirectoryIterator::~DirectoryIterator() {
+#if defined(WEBRTC_WIN)
+  if (handle_ != INVALID_HANDLE_VALUE)
+    ::FindClose(handle_);
+#else
+  if (dir_)
+    closedir(dir_);
+#endif
+}
+
+  // Starts traversing a directory.
+  // dir is the directory to traverse
+  // returns true if the directory exists and is valid
+bool DirectoryIterator::Iterate(const Pathname &dir) {
+  directory_ = dir.pathname();
+#if defined(WEBRTC_WIN)
+  if (handle_ != INVALID_HANDLE_VALUE)
+    ::FindClose(handle_);
+  std::string d = dir.pathname() + '*';
+  handle_ = ::FindFirstFile(ToUtf16(d).c_str(), &data_);
+  if (handle_ == INVALID_HANDLE_VALUE)
+    return false;
+#else
+  if (dir_ != nullptr)
+    closedir(dir_);
+  dir_ = ::opendir(directory_.c_str());
+  if (dir_ == nullptr)
+    return false;
+  dirent_ = readdir(dir_);
+  if (dirent_ == nullptr)
+    return false;
+
+  if (::stat(std::string(directory_ + Name()).c_str(), &stat_) != 0)
+    return false;
+#endif
+  return true;
+}
+
+  // Advances to the next file
+  // returns true if there were more files in the directory.
+bool DirectoryIterator::Next() {
+#if defined(WEBRTC_WIN)
+  return ::FindNextFile(handle_, &data_) == TRUE;
+#else
+  dirent_ = ::readdir(dir_);
+  if (dirent_ == nullptr)
+    return false;
+
+  return ::stat(std::string(directory_ + Name()).c_str(), &stat_) == 0;
+#endif
+}
+
+  // returns true if the file currently pointed to is a directory
+bool DirectoryIterator::IsDirectory() const {
+#if defined(WEBRTC_WIN)
+  return (data_.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != FALSE;
+#else
+  return S_ISDIR(stat_.st_mode);
+#endif
+}
+
+  // returns the name of the file currently pointed to
+std::string DirectoryIterator::Name() const {
+#if defined(WEBRTC_WIN)
+  return ToUtf8(data_.cFileName);
+#else
+  RTC_DCHECK(dirent_);
+  return dirent_->d_name;
+#endif
+}
+
+FilesystemInterface* Filesystem::default_filesystem_ = nullptr;
+
+FilesystemInterface *Filesystem::EnsureDefaultFilesystem() {
+  if (!default_filesystem_) {
+#if defined(WEBRTC_WIN)
+    default_filesystem_ = new Win32Filesystem();
+#else
+    default_filesystem_ = new UnixFilesystem();
+#endif
+  }
+  return default_filesystem_;
+}
+
+}  // namespace rtc

webrtc/rtc_base/fileutils.h

@@ -0,0 +1,182 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_FILEUTILS_H_
+#define WEBRTC_RTC_BASE_FILEUTILS_H_
+
+#include <string>
+
+#if !defined(WEBRTC_WIN)
+#include <dirent.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#endif
+
+#include "webrtc/base/checks.h"
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/base/platform_file.h"
+
+namespace rtc {
+
+class FileStream;
+class Pathname;
+
+//////////////////////////
+// Directory Iterator   //
+//////////////////////////
+
+// A DirectoryIterator is created with a given directory. It originally points
+// to the first file in the directory, and can be advanecd with Next(). This
+// allows you to get information about each file.
+
+class DirectoryIterator {
+  friend class Filesystem;
+ public:
+  // Constructor
+  DirectoryIterator();
+  // Destructor
+  virtual ~DirectoryIterator();
+
+  // Starts traversing a directory
+  // dir is the directory to traverse
+  // returns true if the directory exists and is valid
+  // The iterator will point to the first entry in the directory
+  virtual bool Iterate(const Pathname &path);
+
+  // Advances to the next file
+  // returns true if there were more files in the directory.
+  virtual bool Next();
+
+  // returns true if the file currently pointed to is a directory
+  virtual bool IsDirectory() const;
+
+  // returns the name of the file currently pointed to
+  virtual std::string Name() const;
+
+ private:
+  std::string directory_;
+#if defined(WEBRTC_WIN)
+  WIN32_FIND_DATA data_;
+  HANDLE handle_;
+#else
+  DIR *dir_;
+  struct dirent *dirent_;
+  struct stat stat_;
+#endif
+};
+
+class FilesystemInterface {
+ public:
+  virtual ~FilesystemInterface() {}
+
+  // This will attempt to delete the path located at filename.
+  // It DCHECKs and returns false if the path points to a folder or a
+  // non-existent file.
+  virtual bool DeleteFile(const Pathname &filename) = 0;
+
+  // Creates a directory. This will call itself recursively to create /foo/bar
+  // even if /foo does not exist. Returns true if the function succeeds.
+  virtual bool CreateFolder(const Pathname &pathname) = 0;
+
+  // This moves a file from old_path to new_path, where "old_path" is a
+  // plain file. This DCHECKs and returns false if old_path points to a
+  // directory, and returns true if the function succeeds.
+  virtual bool MoveFile(const Pathname &old_path, const Pathname &new_path) = 0;
+
+  // Returns true if pathname refers to a directory
+  virtual bool IsFolder(const Pathname& pathname) = 0;
+
+  // Returns true if pathname refers to a file
+  virtual bool IsFile(const Pathname& pathname) = 0;
+
+  // Returns true if pathname refers to no filesystem object, every parent
+  // directory either exists, or is also absent.
+  virtual bool IsAbsent(const Pathname& pathname) = 0;
+
+  // A folder appropriate for storing temporary files (Contents are
+  // automatically deleted when the program exits)
+  virtual bool GetTemporaryFolder(Pathname &path, bool create,
+                                  const std::string *append) = 0;
+
+  virtual std::string TempFilename(const Pathname &dir,
+                                   const std::string &prefix) = 0;
+
+  // Determines the size of the file indicated by path.
+  virtual bool GetFileSize(const Pathname& path, size_t* size) = 0;
+};
+
+class Filesystem {
+ public:
+  static FilesystemInterface *default_filesystem() {
+    RTC_DCHECK(default_filesystem_);
+    return default_filesystem_;
+  }
+
+  static void set_default_filesystem(FilesystemInterface *filesystem) {
+    default_filesystem_ = filesystem;
+  }
+
+  static FilesystemInterface *swap_default_filesystem(
+      FilesystemInterface *filesystem) {
+    FilesystemInterface *cur = default_filesystem_;
+    default_filesystem_ = filesystem;
+    return cur;
+  }
+
+  static bool CreateFolder(const Pathname &pathname) {
+    return EnsureDefaultFilesystem()->CreateFolder(pathname);
+  }
+
+  static bool DeleteFile(const Pathname &filename) {
+    return EnsureDefaultFilesystem()->DeleteFile(filename);
+  }
+
+  static bool MoveFile(const Pathname &old_path, const Pathname &new_path) {
+    return EnsureDefaultFilesystem()->MoveFile(old_path, new_path);
+  }
+
+  static bool IsFolder(const Pathname& pathname) {
+    return EnsureDefaultFilesystem()->IsFolder(pathname);
+  }
+
+  static bool IsFile(const Pathname &pathname) {
+    return EnsureDefaultFilesystem()->IsFile(pathname);
+  }
+
+  static bool IsAbsent(const Pathname &pathname) {
+    return EnsureDefaultFilesystem()->IsAbsent(pathname);
+  }
+
+  static bool GetTemporaryFolder(Pathname &path, bool create,
+                                 const std::string *append) {
+    return EnsureDefaultFilesystem()->GetTemporaryFolder(path, create, append);
+  }
+
+  static std::string TempFilename(const Pathname &dir,
+                                  const std::string &prefix) {
+    return EnsureDefaultFilesystem()->TempFilename(dir, prefix);
+  }
+
+  static bool GetFileSize(const Pathname& path, size_t* size) {
+    return EnsureDefaultFilesystem()->GetFileSize(path, size);
+  }
+
+ private:
+  static FilesystemInterface* default_filesystem_;
+
+  static FilesystemInterface *EnsureDefaultFilesystem();
+  RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(Filesystem);
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_FILEUTILS_H_

webrtc/rtc_base/fileutils_unittest.cc

@@ -0,0 +1,33 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <memory>
+
+#include "webrtc/base/fileutils.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/pathutils.h"
+#include "webrtc/base/stream.h"
+
+namespace rtc {
+
+#if defined (WEBRTC_ANDROID)
+// Fails on Android: https://bugs.chromium.org/p/webrtc/issues/detail?id=4364.
+#define MAYBE_FilesystemTest DISABLED_FilesystemTest
+#else
+#define MAYBE_FilesystemTest FilesystemTest
+#endif
+
+// Make sure we can get a temp folder for the later tests.
+TEST(MAYBE_FilesystemTest, GetTemporaryFolder) {
+  Pathname path;
+  EXPECT_TRUE(Filesystem::GetTemporaryFolder(path, true, nullptr));
+}
+
+}  // namespace rtc

webrtc/rtc_base/firewallsocketserver.cc

@@ -0,0 +1,271 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/firewallsocketserver.h"
+
+#include <algorithm>
+
+#include "webrtc/base/asyncsocket.h"
+#include "webrtc/base/checks.h"
+#include "webrtc/base/logging.h"
+
+namespace rtc {
+
+class FirewallSocket : public AsyncSocketAdapter {
+ public:
+  FirewallSocket(FirewallSocketServer* server, AsyncSocket* socket, int type)
+    : AsyncSocketAdapter(socket), server_(server), type_(type) {
+  }
+
+  int Bind(const SocketAddress& addr) override {
+    if (!server_->IsBindableIp(addr.ipaddr())) {
+      SetError(EINVAL);
+      return SOCKET_ERROR;
+    }
+    return AsyncSocketAdapter::Bind(addr);
+  }
+
+  int Connect(const SocketAddress& addr) override {
+    if (type_ == SOCK_STREAM) {
+      if (!server_->Check(FP_TCP, GetLocalAddress(), addr)) {
+        LOG(LS_VERBOSE) << "FirewallSocket outbound TCP connection from "
+                        << GetLocalAddress().ToSensitiveString() << " to "
+                        << addr.ToSensitiveString() << " denied";
+        // TODO: Handle this asynchronously.
+        SetError(EHOSTUNREACH);
+        return SOCKET_ERROR;
+      }
+    }
+    return AsyncSocketAdapter::Connect(addr);
+  }
+  int Send(const void* pv, size_t cb) override {
+    return SendTo(pv, cb, GetRemoteAddress());
+  }
+  int SendTo(const void* pv, size_t cb, const SocketAddress& addr) override {
+    RTC_DCHECK(type_ == SOCK_DGRAM || type_ == SOCK_STREAM);
+    FirewallProtocol protocol = (type_ == SOCK_DGRAM) ? FP_UDP : FP_TCP;
+    if (!server_->Check(protocol, GetLocalAddress(), addr)) {
+      LOG(LS_VERBOSE) << "FirewallSocket outbound packet with type " << type_
+                      << " from " << GetLocalAddress().ToSensitiveString()
+                      << " to " << addr.ToSensitiveString() << " dropped";
+      return static_cast<int>(cb);
+    }
+    return AsyncSocketAdapter::SendTo(pv, cb, addr);
+  }
+  int Recv(void* pv, size_t cb, int64_t* timestamp) override {
+    SocketAddress addr;
+    return RecvFrom(pv, cb, &addr, timestamp);
+  }
+  int RecvFrom(void* pv,
+               size_t cb,
+               SocketAddress* paddr,
+               int64_t* timestamp) override {
+    if (type_ == SOCK_DGRAM) {
+      while (true) {
+        int res = AsyncSocketAdapter::RecvFrom(pv, cb, paddr, timestamp);
+        if (res <= 0)
+          return res;
+        if (server_->Check(FP_UDP, *paddr, GetLocalAddress()))
+          return res;
+        LOG(LS_VERBOSE) << "FirewallSocket inbound UDP packet from "
+                        << paddr->ToSensitiveString() << " to "
+                        << GetLocalAddress().ToSensitiveString() << " dropped";
+      }
+    }
+    return AsyncSocketAdapter::RecvFrom(pv, cb, paddr, timestamp);
+  }
+
+  int Listen(int backlog) override {
+    if (!server_->tcp_listen_enabled()) {
+      LOG(LS_VERBOSE) << "FirewallSocket listen attempt denied";
+      return -1;
+    }
+
+    return AsyncSocketAdapter::Listen(backlog);
+  }
+  AsyncSocket* Accept(SocketAddress* paddr) override {
+    SocketAddress addr;
+    while (AsyncSocket* sock = AsyncSocketAdapter::Accept(&addr)) {
+      if (server_->Check(FP_TCP, addr, GetLocalAddress())) {
+        if (paddr)
+          *paddr = addr;
+        return sock;
+      }
+      sock->Close();
+      delete sock;
+      LOG(LS_VERBOSE) << "FirewallSocket inbound TCP connection from "
+                      << addr.ToSensitiveString() << " to "
+                      << GetLocalAddress().ToSensitiveString() << " denied";
+    }
+    return 0;
+  }
+
+ private:
+  FirewallSocketServer* server_;
+  int type_;
+};
+
+FirewallSocketServer::FirewallSocketServer(SocketServer* server,
+                                           FirewallManager* manager,
+                                           bool should_delete_server)
+    : server_(server), manager_(manager),
+      should_delete_server_(should_delete_server),
+      udp_sockets_enabled_(true), tcp_sockets_enabled_(true),
+      tcp_listen_enabled_(true) {
+  if (manager_)
+    manager_->AddServer(this);
+}
+
+FirewallSocketServer::~FirewallSocketServer() {
+  if (manager_)
+    manager_->RemoveServer(this);
+
+  if (server_ && should_delete_server_) {
+    delete server_;
+    server_ = nullptr;
+  }
+}
+
+void FirewallSocketServer::AddRule(bool allow, FirewallProtocol p,
+                                   FirewallDirection d,
+                                   const SocketAddress& addr) {
+  SocketAddress any;
+  if (d == FD_IN || d == FD_ANY) {
+    AddRule(allow, p, any, addr);
+  }
+  if (d == FD_OUT || d == FD_ANY) {
+    AddRule(allow, p, addr, any);
+  }
+}
+
+
+void FirewallSocketServer::AddRule(bool allow, FirewallProtocol p,
+                                   const SocketAddress& src,
+                                   const SocketAddress& dst) {
+  Rule r;
+  r.allow = allow;
+  r.p = p;
+  r.src = src;
+  r.dst = dst;
+  CritScope scope(&crit_);
+  rules_.push_back(r);
+}
+
+void FirewallSocketServer::ClearRules() {
+  CritScope scope(&crit_);
+  rules_.clear();
+}
+
+bool FirewallSocketServer::Check(FirewallProtocol p,
+                                 const SocketAddress& src,
+                                 const SocketAddress& dst) {
+  CritScope scope(&crit_);
+  for (size_t i = 0; i < rules_.size(); ++i) {
+    const Rule& r = rules_[i];
+    if ((r.p != p) && (r.p != FP_ANY))
+      continue;
+    if ((r.src.ipaddr() != src.ipaddr()) && !r.src.IsNil())
+      continue;
+    if ((r.src.port() != src.port()) && (r.src.port() != 0))
+      continue;
+    if ((r.dst.ipaddr() != dst.ipaddr()) && !r.dst.IsNil())
+      continue;
+    if ((r.dst.port() != dst.port()) && (r.dst.port() != 0))
+      continue;
+    return r.allow;
+  }
+  return true;
+}
+
+void FirewallSocketServer::SetUnbindableIps(
+    const std::vector<rtc::IPAddress>& unbindable_ips) {
+  unbindable_ips_ = unbindable_ips;
+}
+
+bool FirewallSocketServer::IsBindableIp(const rtc::IPAddress& ip) {
+  return std::find(unbindable_ips_.begin(), unbindable_ips_.end(), ip) ==
+         unbindable_ips_.end();
+}
+
+Socket* FirewallSocketServer::CreateSocket(int type) {
+  return CreateSocket(AF_INET, type);
+}
+
+Socket* FirewallSocketServer::CreateSocket(int family, int type) {
+  return WrapSocket(server_->CreateAsyncSocket(family, type), type);
+}
+
+AsyncSocket* FirewallSocketServer::CreateAsyncSocket(int type) {
+  return CreateAsyncSocket(AF_INET, type);
+}
+
+AsyncSocket* FirewallSocketServer::CreateAsyncSocket(int family, int type) {
+  return WrapSocket(server_->CreateAsyncSocket(family, type), type);
+}
+
+void FirewallSocketServer::SetMessageQueue(MessageQueue* queue) {
+  server_->SetMessageQueue(queue);
+}
+
+bool FirewallSocketServer::Wait(int cms, bool process_io) {
+  return server_->Wait(cms, process_io);
+}
+
+void FirewallSocketServer::WakeUp() {
+  return server_->WakeUp();
+}
+
+AsyncSocket* FirewallSocketServer::WrapSocket(AsyncSocket* sock, int type) {
+  if (!sock ||
+      (type == SOCK_STREAM && !tcp_sockets_enabled_) ||
+      (type == SOCK_DGRAM && !udp_sockets_enabled_)) {
+    LOG(LS_VERBOSE) << "FirewallSocketServer socket creation denied";
+    delete sock;
+    return nullptr;
+  }
+  return new FirewallSocket(this, sock, type);
+}
+
+FirewallManager::FirewallManager() {
+}
+
+FirewallManager::~FirewallManager() {
+  RTC_DCHECK(servers_.empty());
+}
+
+void FirewallManager::AddServer(FirewallSocketServer* server) {
+  CritScope scope(&crit_);
+  servers_.push_back(server);
+}
+
+void FirewallManager::RemoveServer(FirewallSocketServer* server) {
+  CritScope scope(&crit_);
+  servers_.erase(std::remove(servers_.begin(), servers_.end(), server),
+                 servers_.end());
+}
+
+void FirewallManager::AddRule(bool allow, FirewallProtocol p,
+                              FirewallDirection d, const SocketAddress& addr) {
+  CritScope scope(&crit_);
+  for (std::vector<FirewallSocketServer*>::const_iterator it =
+      servers_.begin(); it != servers_.end(); ++it) {
+    (*it)->AddRule(allow, p, d, addr);
+  }
+}
+
+void FirewallManager::ClearRules() {
+  CritScope scope(&crit_);
+  for (std::vector<FirewallSocketServer*>::const_iterator it =
+      servers_.begin(); it != servers_.end(); ++it) {
+    (*it)->ClearRules();
+  }
+}
+
+}  // namespace rtc

webrtc/rtc_base/firewallsocketserver.h

@@ -0,0 +1,125 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_FIREWALLSOCKETSERVER_H_
+#define WEBRTC_RTC_BASE_FIREWALLSOCKETSERVER_H_
+
+#include <vector>
+#include "webrtc/base/socketserver.h"
+#include "webrtc/base/criticalsection.h"
+
+namespace rtc {
+
+class FirewallManager;
+
+// This SocketServer shim simulates a rule-based firewall server.
+
+enum FirewallProtocol { FP_UDP, FP_TCP, FP_ANY };
+enum FirewallDirection { FD_IN, FD_OUT, FD_ANY };
+
+class FirewallSocketServer : public SocketServer {
+ public:
+  FirewallSocketServer(SocketServer* server,
+                       FirewallManager* manager = nullptr,
+                       bool should_delete_server = false);
+  ~FirewallSocketServer() override;
+
+  SocketServer* socketserver() const { return server_; }
+  void set_socketserver(SocketServer* server) {
+    if (server_ && should_delete_server_) {
+      delete server_;
+      server_ = nullptr;
+      should_delete_server_ = false;
+    }
+    server_ = server;
+  }
+
+  // Settings to control whether CreateSocket or Socket::Listen succeed.
+  void set_udp_sockets_enabled(bool enabled) { udp_sockets_enabled_ = enabled; }
+  void set_tcp_sockets_enabled(bool enabled) { tcp_sockets_enabled_ = enabled; }
+  bool tcp_listen_enabled() const { return tcp_listen_enabled_; }
+  void set_tcp_listen_enabled(bool enabled) { tcp_listen_enabled_ = enabled; }
+
+  // Rules govern the behavior of Connect/Accept/Send/Recv attempts.
+  void AddRule(bool allow, FirewallProtocol p = FP_ANY,
+               FirewallDirection d = FD_ANY,
+               const SocketAddress& addr = SocketAddress());
+  void AddRule(bool allow, FirewallProtocol p,
+               const SocketAddress& src, const SocketAddress& dst);
+  void ClearRules();
+
+  bool Check(FirewallProtocol p,
+             const SocketAddress& src, const SocketAddress& dst);
+
+  // Set the IP addresses for which Bind will fail. By default this list is
+  // empty. This can be used to simulate a real OS that refuses to bind to
+  // addresses under various circumstances.
+  //
+  // No matter how many addresses are added (including INADDR_ANY), the server
+  // will still allow creating outgoing TCP connections, since they don't
+  // require explicitly binding a socket.
+  void SetUnbindableIps(const std::vector<rtc::IPAddress>& unbindable_ips);
+  bool IsBindableIp(const rtc::IPAddress& ip);
+
+  Socket* CreateSocket(int type) override;
+  Socket* CreateSocket(int family, int type) override;
+
+  AsyncSocket* CreateAsyncSocket(int type) override;
+  AsyncSocket* CreateAsyncSocket(int family, int type) override;
+
+  void SetMessageQueue(MessageQueue* queue) override;
+  bool Wait(int cms, bool process_io) override;
+  void WakeUp() override;
+
+  Socket * WrapSocket(Socket * sock, int type);
+  AsyncSocket * WrapSocket(AsyncSocket * sock, int type);
+
+ private:
+  SocketServer * server_;
+  FirewallManager * manager_;
+  CriticalSection crit_;
+  struct Rule {
+    bool allow;
+    FirewallProtocol p;
+    FirewallDirection d;
+    SocketAddress src;
+    SocketAddress dst;
+  };
+  std::vector<Rule> rules_;
+  std::vector<rtc::IPAddress> unbindable_ips_;
+  bool should_delete_server_;
+  bool udp_sockets_enabled_;
+  bool tcp_sockets_enabled_;
+  bool tcp_listen_enabled_;
+};
+
+// FirewallManager allows you to manage firewalls in multiple threads together
+
+class FirewallManager {
+ public:
+  FirewallManager();
+  ~FirewallManager();
+
+  void AddServer(FirewallSocketServer * server);
+  void RemoveServer(FirewallSocketServer * server);
+
+  void AddRule(bool allow, FirewallProtocol p = FP_ANY,
+               FirewallDirection d = FD_ANY,
+               const SocketAddress& addr = SocketAddress());
+  void ClearRules();
+
+ private:
+  CriticalSection crit_;
+  std::vector<FirewallSocketServer *> servers_;
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_FIREWALLSOCKETSERVER_H_

webrtc/rtc_base/flags.cc

@@ -0,0 +1,299 @@
+/*
+ *  Copyright 2006 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/flags.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "webrtc/base/checks.h"
+
+#if defined(WEBRTC_WIN)
+#include "webrtc/base/win32.h"
+#include <shellapi.h>
+#endif
+
+namespace rtc {
+// -----------------------------------------------------------------------------
+// Implementation of Flag
+
+Flag::Flag(const char* file, const char* name, const char* comment,
+           Type type, void* variable, FlagValue default__)
+    : file_(file),
+      name_(name),
+      comment_(comment),
+      type_(type),
+      variable_(reinterpret_cast<FlagValue*>(variable)),
+      default_(default__) {
+  FlagList::Register(this);
+}
+
+
+void Flag::SetToDefault() {
+  // Note that we cannot simply do '*variable_ = default_;' since
+  // flag variables are not really of type FlagValue and thus may
+  // be smaller! The FlagValue union is simply 'overlayed' on top
+  // of a flag variable for convenient access. Since union members
+  // are guarantee to be aligned at the beginning, this works.
+  switch (type_) {
+    case Flag::BOOL:
+      variable_->b = default_.b;
+      return;
+    case Flag::INT:
+      variable_->i = default_.i;
+      return;
+    case Flag::FLOAT:
+      variable_->f = default_.f;
+      return;
+    case Flag::STRING:
+      variable_->s = default_.s;
+      return;
+  }
+  FATAL() << "unreachable code";
+}
+
+
+static const char* Type2String(Flag::Type type) {
+  switch (type) {
+    case Flag::BOOL: return "bool";
+    case Flag::INT: return "int";
+    case Flag::FLOAT: return "float";
+    case Flag::STRING: return "string";
+  }
+  FATAL() << "unreachable code";
+}
+
+
+static void PrintFlagValue(Flag::Type type, FlagValue* p) {
+  switch (type) {
+    case Flag::BOOL:
+      printf("%s", (p->b ? "true" : "false"));
+      return;
+    case Flag::INT:
+      printf("%d", p->i);
+      return;
+    case Flag::FLOAT:
+      printf("%f", p->f);
+      return;
+    case Flag::STRING:
+      printf("%s", p->s);
+      return;
+  }
+  FATAL() << "unreachable code";
+}
+
+
+void Flag::Print(bool print_current_value) {
+  printf("  --%s (%s)  type: %s  default: ", name_, comment_,
+          Type2String(type_));
+  PrintFlagValue(type_, &default_);
+  if (print_current_value) {
+    printf("  current value: ");
+    PrintFlagValue(type_, variable_);
+  }
+  printf("\n");
+}
+
+
+// -----------------------------------------------------------------------------
+// Implementation of FlagList
+
+Flag* FlagList::list_ = nullptr;
+
+FlagList::FlagList() {
+  list_ = nullptr;
+}
+
+void FlagList::Print(const char* file, bool print_current_value) {
+  // Since flag registration is likely by file (= C++ file),
+  // we don't need to sort by file and still get grouped output.
+  const char* current = nullptr;
+  for (Flag* f = list_; f != nullptr; f = f->next()) {
+    if (file == nullptr || file == f->file()) {
+      if (current != f->file()) {
+        printf("Flags from %s:\n", f->file());
+        current = f->file();
+      }
+      f->Print(print_current_value);
+    }
+  }
+}
+
+
+Flag* FlagList::Lookup(const char* name) {
+  Flag* f = list_;
+  while (f != nullptr && strcmp(name, f->name()) != 0)
+    f = f->next();
+  return f;
+}
+
+
+void FlagList::SplitArgument(const char* arg,
+                             char* buffer, int buffer_size,
+                             const char** name, const char** value,
+                             bool* is_bool) {
+  *name = nullptr;
+  *value = nullptr;
+  *is_bool = false;
+
+  if (*arg == '-') {
+    // find the begin of the flag name
+    arg++;  // remove 1st '-'
+    if (*arg == '-')
+      arg++;  // remove 2nd '-'
+    if (arg[0] == 'n' && arg[1] == 'o') {
+      arg += 2;  // remove "no"
+      *is_bool = true;
+    }
+    *name = arg;
+
+    // find the end of the flag name
+    while (*arg != '\0' && *arg != '=')
+      arg++;
+
+    // get the value if any
+    if (*arg == '=') {
+      // make a copy so we can NUL-terminate flag name
+      int n = static_cast<int>(arg - *name);
+      RTC_CHECK_LT(n, buffer_size);
+      memcpy(buffer, *name, n * sizeof(char));
+      buffer[n] = '\0';
+      *name = buffer;
+      // get the value
+      *value = arg + 1;
+    }
+  }
+}
+
+
+int FlagList::SetFlagsFromCommandLine(int* argc, const char** argv,
+                                      bool remove_flags) {
+  // parse arguments
+  for (int i = 1; i < *argc; /* see below */) {
+    int j = i;  // j > 0
+    const char* arg = argv[i++];
+
+    // split arg into flag components
+    char buffer[1024];
+    const char* name;
+    const char* value;
+    bool is_bool;
+    SplitArgument(arg, buffer, sizeof buffer, &name, &value, &is_bool);
+
+    if (name != nullptr) {
+      // lookup the flag
+      Flag* flag = Lookup(name);
+      if (flag == nullptr) {
+        fprintf(stderr, "Error: unrecognized flag %s\n", arg);
+        return j;
+      }
+
+      // if we still need a flag value, use the next argument if available
+      if (flag->type() != Flag::BOOL && value == nullptr) {
+        if (i < *argc) {
+          value = argv[i++];
+        } else {
+          fprintf(stderr, "Error: missing value for flag %s of type %s\n",
+            arg, Type2String(flag->type()));
+          return j;
+        }
+      }
+
+      // set the flag
+      char empty[] = { '\0' };
+      char* endp = empty;
+      switch (flag->type()) {
+        case Flag::BOOL:
+          *flag->bool_variable() = !is_bool;
+          break;
+        case Flag::INT:
+          *flag->int_variable() = strtol(value, &endp, 10);
+          break;
+        case Flag::FLOAT:
+          *flag->float_variable() = strtod(value, &endp);
+          break;
+        case Flag::STRING:
+          *flag->string_variable() = value;
+          break;
+      }
+
+      // handle errors
+      if ((flag->type() == Flag::BOOL && value != nullptr) ||
+          (flag->type() != Flag::BOOL && is_bool) || *endp != '\0') {
+        fprintf(stderr, "Error: illegal value for flag %s of type %s\n",
+          arg, Type2String(flag->type()));
+        return j;
+      }
+
+      // remove the flag & value from the command
+      if (remove_flags)
+        while (j < i)
+          argv[j++] = nullptr;
+    }
+  }
+
+  // shrink the argument list
+  if (remove_flags) {
+    int j = 1;
+    for (int i = 1; i < *argc; i++) {
+      if (argv[i] != nullptr)
+        argv[j++] = argv[i];
+    }
+    *argc = j;
+  }
+
+  // parsed all flags successfully
+  return 0;
+}
+
+void FlagList::Register(Flag* flag) {
+  RTC_DCHECK(flag);
+  RTC_DCHECK_GT(strlen(flag->name()), 0);
+  // NOTE: Don't call Lookup() within Register because it accesses the name_
+  // of other flags in list_, and if the flags are coming from two different
+  // compilation units, the initialization order between them is undefined, and
+  // this will trigger an asan initialization-order-fiasco error.
+  flag->next_ = list_;
+  list_ = flag;
+}
+
+#if defined(WEBRTC_WIN)
+WindowsCommandLineArguments::WindowsCommandLineArguments() {
+  // start by getting the command line.
+  LPTSTR command_line = ::GetCommandLine();
+   // now, convert it to a list of wide char strings.
+  LPWSTR *wide_argv = ::CommandLineToArgvW(command_line, &argc_);
+  // now allocate an array big enough to hold that many string pointers.
+  argv_ = new char*[argc_];
+
+  // iterate over the returned wide strings;
+  for(int i = 0; i < argc_; ++i) {
+    std::string s = rtc::ToUtf8(wide_argv[i], wcslen(wide_argv[i]));
+    char *buffer = new char[s.length() + 1];
+    rtc::strcpyn(buffer, s.length() + 1, s.c_str());
+
+    // make sure the argv array has the right string at this point.
+    argv_[i] = buffer;
+  }
+  LocalFree(wide_argv);
+}
+
+WindowsCommandLineArguments::~WindowsCommandLineArguments() {
+  // need to free each string in the array, and then the array.
+  for(int i = 0; i < argc_; i++) {
+    delete[] argv_[i];
+  }
+
+  delete[] argv_;
+}
+#endif  // WEBRTC_WIN
+
+}  // namespace rtc

webrtc/rtc_base/flags.h

@@ -0,0 +1,268 @@
+/*
+ *  Copyright 2006 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+
+// Originally comes from shared/commandlineflags/flags.h
+
+// Flags are defined and declared using DEFINE_xxx and DECLARE_xxx macros,
+// where xxx is the flag type. Flags are referred to via FLAG_yyy,
+// where yyy is the flag name. For intialization and iteration of flags,
+// see the FlagList class. For full programmatic access to any
+// flag, see the Flag class.
+//
+// The implementation only relies and basic C++ functionality
+// and needs no special library or STL support.
+
+#ifndef WEBRTC_RTC_BASE_FLAGS_H_
+#define WEBRTC_RTC_BASE_FLAGS_H_
+
+#include "webrtc/base/checks.h"
+#include "webrtc/base/constructormagic.h"
+
+namespace rtc {
+
+// Internal use only.
+union FlagValue {
+  // Note: Because in C++ non-bool values are silently converted into
+  // bool values ('bool b = "false";' results in b == true!), we pass
+  // and int argument to New_BOOL as this appears to be safer - sigh.
+  // In particular, it prevents the (not uncommon!) bug where a bool
+  // flag is defined via: DEFINE_bool(flag, "false", "some comment");.
+  static FlagValue New_BOOL(int b) {
+    FlagValue v;
+    v.b = (b != 0);
+    return v;
+  }
+
+  static FlagValue New_INT(int i) {
+    FlagValue v;
+    v.i = i;
+    return v;
+  }
+
+  static FlagValue New_FLOAT(float f) {
+    FlagValue v;
+    v.f = f;
+    return v;
+  }
+
+  static FlagValue New_STRING(const char* s) {
+    FlagValue v;
+    v.s = s;
+    return v;
+  }
+
+  bool b;
+  int i;
+  double f;
+  const char* s;
+};
+
+
+// Each flag can be accessed programmatically via a Flag object.
+class Flag {
+ public:
+  enum Type { BOOL, INT, FLOAT, STRING };
+
+  // Internal use only.
+  Flag(const char* file, const char* name, const char* comment,
+       Type type, void* variable, FlagValue default_);
+
+  // General flag information
+  const char* file() const  { return file_; }
+  const char* name() const  { return name_; }
+  const char* comment() const  { return comment_; }
+
+  // Flag type
+  Type type() const  { return type_; }
+
+  // Flag variables
+  bool* bool_variable() const {
+    RTC_DCHECK_EQ(BOOL, type_);
+    return &variable_->b;
+  }
+
+  int* int_variable() const {
+    RTC_DCHECK_EQ(INT, type_);
+    return &variable_->i;
+  }
+
+  double* float_variable() const {
+    RTC_DCHECK_EQ(FLOAT, type_);
+    return &variable_->f;
+  }
+
+  const char** string_variable() const {
+    RTC_DCHECK_EQ(STRING, type_);
+    return &variable_->s;
+  }
+
+  // Default values
+  bool bool_default() const {
+    RTC_DCHECK_EQ(BOOL, type_);
+    return default_.b;
+  }
+
+  int int_default() const {
+    RTC_DCHECK_EQ(INT, type_);
+    return default_.i;
+  }
+
+  double float_default() const {
+    RTC_DCHECK_EQ(FLOAT, type_);
+    return default_.f;
+  }
+
+  const char* string_default() const {
+    RTC_DCHECK_EQ(STRING, type_);
+    return default_.s;
+  }
+
+  // Resets a flag to its default value
+  void SetToDefault();
+
+  // Iteration support
+  Flag* next() const  { return next_; }
+
+  // Prints flag information. The current flag value is only printed
+  // if print_current_value is set.
+  void Print(bool print_current_value);
+
+ private:
+  const char* file_;
+  const char* name_;
+  const char* comment_;
+
+  Type type_;
+  FlagValue* variable_;
+  FlagValue default_;
+
+  Flag* next_;
+
+  friend class FlagList;  // accesses next_
+};
+
+
+// Internal use only.
+#define DEFINE_FLAG(type, c_type, name, default, comment) \
+  /* define and initialize the flag */                    \
+  c_type FLAG_##name = (default);                         \
+  /* register the flag */                                 \
+  static rtc::Flag Flag_##name(__FILE__, #name, (comment),      \
+                               rtc::Flag::type, &FLAG_##name,   \
+                               rtc::FlagValue::New_##type(default))
+
+
+// Internal use only.
+#define DECLARE_FLAG(c_type, name)              \
+  /* declare the external flag */               \
+  extern c_type FLAG_##name
+
+
+// Use the following macros to define a new flag:
+#define DEFINE_bool(name, default, comment) \
+  DEFINE_FLAG(BOOL, bool, name, default, comment)
+#define DEFINE_int(name, default, comment) \
+  DEFINE_FLAG(INT, int, name, default, comment)
+#define DEFINE_float(name, default, comment) \
+  DEFINE_FLAG(FLOAT, double, name, default, comment)
+#define DEFINE_string(name, default, comment) \
+  DEFINE_FLAG(STRING, const char*, name, default, comment)
+
+
+// Use the following macros to declare a flag defined elsewhere:
+#define DECLARE_bool(name)  DECLARE_FLAG(bool, name)
+#define DECLARE_int(name)  DECLARE_FLAG(int, name)
+#define DECLARE_float(name)  DECLARE_FLAG(double, name)
+#define DECLARE_string(name)  DECLARE_FLAG(const char*, name)
+
+
+// The global list of all flags.
+class FlagList {
+ public:
+  FlagList();
+
+  // The null-terminated list of all flags. Traverse with Flag::next().
+  static Flag* list()  { return list_; }
+
+  // If file != nullptr, prints information for all flags defined in file;
+  // otherwise prints information for all flags in all files. The current flag
+  // value is only printed if print_current_value is set.
+  static void Print(const char* file, bool print_current_value);
+
+  // Lookup a flag by name. Returns the matching flag or null.
+  static Flag* Lookup(const char* name);
+
+  // Helper function to parse flags: Takes an argument arg and splits it into
+  // a flag name and flag value (or null if they are missing). is_bool is set
+  // if the arg started with "-no" or "--no". The buffer may be used to NUL-
+  // terminate the name, it must be large enough to hold any possible name.
+  static void SplitArgument(const char* arg,
+                            char* buffer, int buffer_size,
+                            const char** name, const char** value,
+                            bool* is_bool);
+
+  // Set the flag values by parsing the command line. If remove_flags
+  // is set, the flags and associated values are removed from (argc,
+  // argv). Returns 0 if no error occurred. Otherwise, returns the
+  // argv index > 0 for the argument where an error occurred. In that
+  // case, (argc, argv) will remain unchanged indepdendent of the
+  // remove_flags value, and no assumptions about flag settings should
+  // be made.
+  //
+  // The following syntax for flags is accepted (both '-' and '--' are ok):
+  //
+  //   --flag        (bool flags only)
+  //   --noflag      (bool flags only)
+  //   --flag=value  (non-bool flags only, no spaces around '=')
+  //   --flag value  (non-bool flags only)
+  static int SetFlagsFromCommandLine(int* argc,
+                                     const char** argv,
+                                     bool remove_flags);
+  static inline int SetFlagsFromCommandLine(int* argc,
+                                            char** argv,
+                                            bool remove_flags) {
+    return SetFlagsFromCommandLine(argc, const_cast<const char**>(argv),
+                                   remove_flags);
+  }
+
+  // Registers a new flag. Called during program initialization. Not
+  // thread-safe.
+  static void Register(Flag* flag);
+
+ private:
+  static Flag* list_;
+};
+
+#if defined(WEBRTC_WIN)
+// A helper class to translate Windows command line arguments into UTF8,
+// which then allows us to just pass them to the flags system.
+// This encapsulates all the work of getting the command line and translating
+// it to an array of 8-bit strings; all you have to do is create one of these,
+// and then call argc() and argv().
+class WindowsCommandLineArguments {
+ public:
+  WindowsCommandLineArguments();
+  ~WindowsCommandLineArguments();
+
+  int argc() { return argc_; }
+  char **argv() { return argv_; }
+ private:
+  int argc_;
+  char **argv_;
+
+ private:
+  RTC_DISALLOW_COPY_AND_ASSIGN(WindowsCommandLineArguments);
+};
+#endif  // WEBRTC_WIN
+
+}  // namespace rtc
+
+#endif  // SHARED_COMMANDLINEFLAGS_FLAGS_H_

webrtc/rtc_base/format_macros.h

@@ -0,0 +1,96 @@
+/*
+ *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_FORMAT_MACROS_H_
+#define WEBRTC_RTC_BASE_FORMAT_MACROS_H_
+
+// This file defines the format macros for some integer types and is derived
+// from Chromium's base/format_macros.h.
+
+// To print a 64-bit value in a portable way:
+//   int64_t value;
+//   printf("xyz:%" PRId64, value);
+// The "d" in the macro corresponds to %d; you can also use PRIu64 etc.
+//
+// To print a size_t value in a portable way:
+//   size_t size;
+//   printf("xyz: %" PRIuS, size);
+// The "u" in the macro corresponds to %u, and S is for "size".
+
+#include "webrtc/typedefs.h"
+
+#if defined(WEBRTC_POSIX)
+
+#if (defined(_INTTYPES_H) || defined(_INTTYPES_H_)) && !defined(PRId64)
+#error "inttypes.h has already been included before this header file, but "
+#error "without __STDC_FORMAT_MACROS defined."
+#endif
+
+#if !defined(__STDC_FORMAT_MACROS)
+#define __STDC_FORMAT_MACROS
+#endif
+
+#include <inttypes.h>
+
+#if !defined(PRIuS)
+#define PRIuS "zu"
+#endif
+
+// The size of NSInteger and NSUInteger varies between 32-bit and 64-bit
+// architectures and Apple does not provides standard format macros and
+// recommends casting. This has many drawbacks, so instead define macros
+// for formatting those types.
+#if defined(WEBRTC_MAC)
+#if defined(WEBRTC_ARCH_64_BITS)
+#if !defined(PRIdNS)
+#define PRIdNS "ld"
+#endif
+#if !defined(PRIuNS)
+#define PRIuNS "lu"
+#endif
+#if !defined(PRIxNS)
+#define PRIxNS "lx"
+#endif
+#else  // defined(WEBRTC_ARCH_64_BITS)
+#if !defined(PRIdNS)
+#define PRIdNS "d"
+#endif
+#if !defined(PRIuNS)
+#define PRIuNS "u"
+#endif
+#if !defined(PRIxNS)
+#define PRIxNS "x"
+#endif
+#endif
+#endif  // defined(WEBRTC_MAC)
+
+#else  // WEBRTC_WIN
+
+#include <inttypes.h>
+
+#if !defined(PRId64)
+#define PRId64 "I64d"
+#endif
+
+#if !defined(PRIu64)
+#define PRIu64 "I64u"
+#endif
+
+#if !defined(PRIx64)
+#define PRIx64 "I64x"
+#endif
+
+#if !defined(PRIuS)
+#define PRIuS "Iu"
+#endif
+
+#endif
+
+#endif  // WEBRTC_RTC_BASE_FORMAT_MACROS_H_

webrtc/rtc_base/function_view.h

@@ -0,0 +1,130 @@
+/*
+ *  Copyright 2016 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_FUNCTION_VIEW_H_
+#define WEBRTC_RTC_BASE_FUNCTION_VIEW_H_
+
+#include <type_traits>
+#include <utility>
+
+#include "webrtc/base/checks.h"
+
+// Just like std::function, FunctionView will wrap any callable and hide its
+// actual type, exposing only its signature. But unlike std::function,
+// FunctionView doesn't own its callable---it just points to it. Thus, it's a
+// good choice mainly as a function argument when the callable argument will
+// not be called again once the function has returned.
+//
+// Its constructors are implicit, so that callers won't have to convert lambdas
+// and other callables to FunctionView<Blah(Blah, Blah)> explicitly. This is
+// safe because FunctionView is only a reference to the real callable.
+//
+// Example use:
+//
+//   void SomeFunction(rtc::FunctionView<int(int)> index_transform);
+//   ...
+//   SomeFunction([](int i) { return 2 * i + 1; });
+//
+// Note: FunctionView is tiny (essentially just two pointers) and trivially
+// copyable, so it's probably cheaper to pass it by value than by const
+// reference.
+
+namespace rtc {
+
+template <typename T>
+class FunctionView;  // Undefined.
+
+template <typename RetT, typename... ArgT>
+class FunctionView<RetT(ArgT...)> final {
+ public:
+  // Constructor for lambdas and other callables; it accepts every type of
+  // argument except those noted in its enable_if call.
+  template <
+      typename F,
+      typename std::enable_if<
+          // Not for function pointers; we have another constructor for that
+          // below.
+          !std::is_function<typename std::remove_pointer<
+              typename std::remove_reference<F>::type>::type>::value &&
+
+          // Not for nullptr; we have another constructor for that below.
+          !std::is_same<std::nullptr_t,
+                        typename std::remove_cv<F>::type>::value &&
+
+          // Not for FunctionView objects; we have another constructor for that
+          // (the implicitly declared copy constructor).
+          !std::is_same<FunctionView,
+                        typename std::remove_cv<typename std::remove_reference<
+                            F>::type>::type>::value>::type* = nullptr>
+  FunctionView(F&& f)
+      : call_(CallVoidPtr<typename std::remove_reference<F>::type>) {
+    f_.void_ptr = &f;
+  }
+
+  // Constructor that accepts function pointers. If the argument is null, the
+  // result is an empty FunctionView.
+  template <
+      typename F,
+      typename std::enable_if<std::is_function<typename std::remove_pointer<
+          typename std::remove_reference<F>::type>::type>::value>::type* =
+          nullptr>
+  FunctionView(F&& f)
+      : call_(f ? CallFunPtr<typename std::remove_pointer<F>::type> : nullptr) {
+    f_.fun_ptr = reinterpret_cast<void (*)()>(f);
+  }
+
+  // Constructor that accepts nullptr. It creates an empty FunctionView.
+  template <typename F,
+            typename std::enable_if<std::is_same<
+                std::nullptr_t,
+                typename std::remove_cv<F>::type>::value>::type* = nullptr>
+  FunctionView(F&& f) : call_(nullptr) {}
+
+  // Default constructor. Creates an empty FunctionView.
+  FunctionView() : call_(nullptr) {}
+
+  RetT operator()(ArgT... args) const {
+    RTC_DCHECK(call_);
+    return call_(f_, std::forward<ArgT>(args)...);
+  }
+
+  // Returns true if we have a function, false if we don't (i.e., we're null).
+  explicit operator bool() const { return !!call_; }
+
+ private:
+  union VoidUnion {
+    void* void_ptr;
+    void (*fun_ptr)();
+  };
+
+  template <typename F>
+  static RetT CallVoidPtr(VoidUnion vu, ArgT... args) {
+    return (*static_cast<F*>(vu.void_ptr))(std::forward<ArgT>(args)...);
+  }
+  template <typename F>
+  static RetT CallFunPtr(VoidUnion vu, ArgT... args) {
+    return (reinterpret_cast<typename std::add_pointer<F>::type>(vu.fun_ptr))(
+        std::forward<ArgT>(args)...);
+  }
+
+  // A pointer to the callable thing, with type information erased. It's a
+  // union because we have to use separate types depending on if the callable
+  // thing is a function pointer or something else.
+  VoidUnion f_;
+
+  // Pointer to a dispatch function that knows the type of the callable thing
+  // that's stored in f_, and how to call it. A FunctionView object is empty
+  // (null) iff call_ is null.
+  RetT (*call_)(VoidUnion, ArgT...);
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_FUNCTION_VIEW_H_

webrtc/rtc_base/function_view_unittest.cc

@@ -0,0 +1,175 @@
+/*
+ *  Copyright 2016 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <memory>
+#include <utility>
+
+#include "webrtc/base/function_view.h"
+#include "webrtc/base/gunit.h"
+
+namespace rtc {
+
+namespace {
+
+int CallWith33(rtc::FunctionView<int(int)> fv) {
+  return fv ? fv(33) : -1;
+}
+
+int Add33(int x) {
+  return x + 33;
+}
+
+}  // namespace
+
+// Test the main use case of FunctionView: implicitly converting a callable
+// argument.
+TEST(FunctionViewTest, ImplicitConversion) {
+  EXPECT_EQ(38, CallWith33([](int x) { return x + 5; }));
+  EXPECT_EQ(66, CallWith33(Add33));
+  EXPECT_EQ(-1, CallWith33(nullptr));
+}
+
+TEST(FunctionViewTest, IntIntLambdaWithoutState) {
+  auto f = [](int x) { return x + 1; };
+  EXPECT_EQ(18, f(17));
+  rtc::FunctionView<int(int)> fv(f);
+  EXPECT_TRUE(fv);
+  EXPECT_EQ(18, fv(17));
+}
+
+TEST(FunctionViewTest, IntVoidLambdaWithState) {
+  int x = 13;
+  auto f = [x]() mutable { return ++x; };
+  rtc::FunctionView<int()> fv(f);
+  EXPECT_TRUE(fv);
+  EXPECT_EQ(14, f());
+  EXPECT_EQ(15, fv());
+  EXPECT_EQ(16, f());
+  EXPECT_EQ(17, fv());
+}
+
+TEST(FunctionViewTest, IntIntFunction) {
+  rtc::FunctionView<int(int)> fv(Add33);
+  EXPECT_TRUE(fv);
+  EXPECT_EQ(50, fv(17));
+}
+
+TEST(FunctionViewTest, IntIntFunctionPointer) {
+  rtc::FunctionView<int(int)> fv(&Add33);
+  EXPECT_TRUE(fv);
+  EXPECT_EQ(50, fv(17));
+}
+
+TEST(FunctionViewTest, Null) {
+  // These two call constructors that statically construct null FunctionViews.
+  EXPECT_FALSE(rtc::FunctionView<int()>());
+  EXPECT_FALSE(rtc::FunctionView<int()>(nullptr));
+
+  // This calls the constructor for function pointers.
+  EXPECT_FALSE(rtc::FunctionView<int()>(reinterpret_cast<int(*)()>(0)));
+}
+
+// Ensure that FunctionView handles move-only arguments and return values.
+TEST(FunctionViewTest, UniquePtrPassthrough) {
+  auto f = [](std::unique_ptr<int> x) { return x; };
+  rtc::FunctionView<std::unique_ptr<int>(std::unique_ptr<int>)> fv(f);
+  std::unique_ptr<int> x(new int);
+  int* x_addr = x.get();
+  auto y = fv(std::move(x));
+  EXPECT_EQ(x_addr, y.get());
+}
+
+TEST(FunctionViewTest, CopyConstructor) {
+  auto f17 = [] { return 17; };
+  rtc::FunctionView<int()> fv1(f17);
+  rtc::FunctionView<int()> fv2(fv1);
+  EXPECT_EQ(17, fv1());
+  EXPECT_EQ(17, fv2());
+}
+
+TEST(FunctionViewTest, MoveConstructorIsCopy) {
+  auto f17 = [] { return 17; };
+  rtc::FunctionView<int()> fv1(f17);
+  rtc::FunctionView<int()> fv2(std::move(fv1));
+  EXPECT_EQ(17, fv1());
+  EXPECT_EQ(17, fv2());
+}
+
+TEST(FunctionViewTest, CopyAssignment) {
+  auto f17 = [] { return 17; };
+  rtc::FunctionView<int()> fv1(f17);
+  auto f23 = [] { return 23; };
+  rtc::FunctionView<int()> fv2(f23);
+  EXPECT_EQ(17, fv1());
+  EXPECT_EQ(23, fv2());
+  fv2 = fv1;
+  EXPECT_EQ(17, fv1());
+  EXPECT_EQ(17, fv2());
+}
+
+TEST(FunctionViewTest, MoveAssignmentIsCopy) {
+  auto f17 = [] { return 17; };
+  rtc::FunctionView<int()> fv1(f17);
+  auto f23 = [] { return 23; };
+  rtc::FunctionView<int()> fv2(f23);
+  EXPECT_EQ(17, fv1());
+  EXPECT_EQ(23, fv2());
+  fv2 = std::move(fv1);
+  EXPECT_EQ(17, fv1());
+  EXPECT_EQ(17, fv2());
+}
+
+TEST(FunctionViewTest, Swap) {
+  auto f17 = [] { return 17; };
+  rtc::FunctionView<int()> fv1(f17);
+  auto f23 = [] { return 23; };
+  rtc::FunctionView<int()> fv2(f23);
+  EXPECT_EQ(17, fv1());
+  EXPECT_EQ(23, fv2());
+  using std::swap;
+  swap(fv1, fv2);
+  EXPECT_EQ(23, fv1());
+  EXPECT_EQ(17, fv2());
+}
+
+// Ensure that when you copy-construct a FunctionView, the new object points to
+// the same function as the old one (as opposed to the new object pointing to
+// the old one).
+TEST(FunctionViewTest, CopyConstructorChaining) {
+  auto f17 = [] { return 17; };
+  rtc::FunctionView<int()> fv1(f17);
+  rtc::FunctionView<int()> fv2(fv1);
+  EXPECT_EQ(17, fv1());
+  EXPECT_EQ(17, fv2());
+  auto f23 = [] { return 23; };
+  fv1 = f23;
+  EXPECT_EQ(23, fv1());
+  EXPECT_EQ(17, fv2());
+}
+
+// Ensure that when you assign one FunctionView to another, we actually make a
+// copy (as opposed to making the second FunctionView point to the first one).
+TEST(FunctionViewTest, CopyAssignmentChaining) {
+  auto f17 = [] { return 17; };
+  rtc::FunctionView<int()> fv1(f17);
+  rtc::FunctionView<int()> fv2;
+  EXPECT_TRUE(fv1);
+  EXPECT_EQ(17, fv1());
+  EXPECT_FALSE(fv2);
+  fv2 = fv1;
+  EXPECT_EQ(17, fv1());
+  EXPECT_EQ(17, fv2());
+  auto f23 = [] { return 23; };
+  fv1 = f23;
+  EXPECT_EQ(23, fv1());
+  EXPECT_EQ(17, fv2());
+}
+
+}  // namespace rtc

webrtc/rtc_base/gtest_prod_util.h

@@ -0,0 +1,38 @@
+/*
+ *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_GTEST_PROD_UTIL_H_
+#define WEBRTC_RTC_BASE_GTEST_PROD_UTIL_H_
+
+// Define our own version of FRIEND_TEST here rather than including
+// gtest_prod.h to avoid depending on any part of GTest in production code.
+#define FRIEND_TEST_WEBRTC(test_case_name, test_name)\
+friend class test_case_name##_##test_name##_Test
+
+// This file is a plain copy of Chromium's base/gtest_prod_util.h.
+//
+// This is a wrapper for gtest's FRIEND_TEST macro that friends
+// test with all possible prefixes. This is very helpful when changing the test
+// prefix, because the friend declarations don't need to be updated.
+//
+// Example usage:
+//
+// class MyClass {
+//  private:
+//   void MyMethod();
+//   FRIEND_TEST_ALL_PREFIXES(MyClassTest, MyMethod);
+// };
+#define FRIEND_TEST_ALL_PREFIXES(test_case_name, test_name) \
+  FRIEND_TEST_WEBRTC(test_case_name, test_name); \
+  FRIEND_TEST_WEBRTC(test_case_name, DISABLED_##test_name); \
+  FRIEND_TEST_WEBRTC(test_case_name, FLAKY_##test_name); \
+  FRIEND_TEST_WEBRTC(test_case_name, FAILS_##test_name)
+
+#endif  // WEBRTC_RTC_BASE_GTEST_PROD_UTIL_H_

webrtc/rtc_base/gunit.h

@@ -0,0 +1,150 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_GUNIT_H_
+#define WEBRTC_RTC_BASE_GUNIT_H_
+
+#include "webrtc/base/fakeclock.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/thread.h"
+#if defined(GTEST_RELATIVE_PATH)
+#include "webrtc/test/gtest.h"
+#else
+#include "testing/base/public/gunit.h"
+#endif
+
+// Wait until "ex" is true, or "timeout" expires.
+#define WAIT(ex, timeout)                                       \
+  for (int64_t start = rtc::SystemTimeMillis();                 \
+       !(ex) && rtc::SystemTimeMillis() < start + (timeout);) { \
+    rtc::Thread::Current()->ProcessMessages(0);                 \
+    rtc::Thread::Current()->SleepMs(1);                         \
+  }
+
+// This returns the result of the test in res, so that we don't re-evaluate
+// the expression in the XXXX_WAIT macros below, since that causes problems
+// when the expression is only true the first time you check it.
+#define WAIT_(ex, timeout, res)                                   \
+  do {                                                            \
+    int64_t start = rtc::SystemTimeMillis();                      \
+    res = (ex);                                                   \
+    while (!res && rtc::SystemTimeMillis() < start + (timeout)) { \
+      rtc::Thread::Current()->ProcessMessages(0);                 \
+      rtc::Thread::Current()->SleepMs(1);                         \
+      res = (ex);                                                 \
+    }                                                             \
+  } while (0)
+
+// The typical EXPECT_XXXX and ASSERT_XXXXs, but done until true or a timeout.
+#define EXPECT_TRUE_WAIT(ex, timeout) \
+  do { \
+    bool res; \
+    WAIT_(ex, timeout, res); \
+    if (!res) EXPECT_TRUE(ex); \
+  } while (0)
+
+#define EXPECT_EQ_WAIT(v1, v2, timeout) \
+  do { \
+    bool res; \
+    WAIT_(v1 == v2, timeout, res); \
+    if (!res) EXPECT_EQ(v1, v2); \
+  } while (0)
+
+#define ASSERT_TRUE_WAIT(ex, timeout) \
+  do { \
+    bool res; \
+    WAIT_(ex, timeout, res); \
+    if (!res) ASSERT_TRUE(ex); \
+  } while (0)
+
+#define ASSERT_EQ_WAIT(v1, v2, timeout) \
+  do { \
+    bool res; \
+    WAIT_(v1 == v2, timeout, res); \
+    if (!res) ASSERT_EQ(v1, v2); \
+  } while (0)
+
+// Version with a "soft" timeout and a margin. This logs if the timeout is
+// exceeded, but it only fails if the expression still isn't true after the
+// margin time passes.
+#define EXPECT_TRUE_WAIT_MARGIN(ex, timeout, margin)                       \
+  do {                                                                     \
+    bool res;                                                              \
+    WAIT_(ex, timeout, res);                                               \
+    if (res) {                                                             \
+      break;                                                               \
+    }                                                                      \
+    LOG(LS_WARNING) << "Expression " << #ex << " still not true after "    \
+                    << (timeout) << "ms; waiting an additional " << margin \
+                    << "ms";                                               \
+    WAIT_(ex, margin, res);                                                \
+    if (!res) {                                                            \
+      EXPECT_TRUE(ex);                                                     \
+    }                                                                      \
+  } while (0)
+
+// Wait until "ex" is true, or "timeout" expires, using fake clock where
+// messages are processed every millisecond.
+// TODO(pthatcher): Allow tests to control how many milliseconds to advance.
+#define SIMULATED_WAIT(ex, timeout, clock)                    \
+  for (int64_t start = rtc::TimeMillis();                     \
+       !(ex) && rtc::TimeMillis() < start + (timeout);) {     \
+    (clock).AdvanceTime(rtc::TimeDelta::FromMilliseconds(1)); \
+  }
+
+// This returns the result of the test in res, so that we don't re-evaluate
+// the expression in the XXXX_WAIT macros below, since that causes problems
+// when the expression is only true the first time you check it.
+#define SIMULATED_WAIT_(ex, timeout, res, clock)                \
+  do {                                                          \
+    int64_t start = rtc::TimeMillis();                          \
+    res = (ex);                                                 \
+    while (!res && rtc::TimeMillis() < start + (timeout)) {     \
+      (clock).AdvanceTime(rtc::TimeDelta::FromMilliseconds(1)); \
+      res = (ex);                                               \
+    }                                                           \
+  } while (0)
+
+// The typical EXPECT_XXXX, but done until true or a timeout with a fake clock.
+#define EXPECT_TRUE_SIMULATED_WAIT(ex, timeout, clock) \
+  do {                                                 \
+    bool res;                                          \
+    SIMULATED_WAIT_(ex, timeout, res, clock);          \
+    if (!res) {                                        \
+      EXPECT_TRUE(ex);                                 \
+    }                                                  \
+  } while (0)
+
+#define EXPECT_EQ_SIMULATED_WAIT(v1, v2, timeout, clock) \
+  do {                                                   \
+    bool res;                                            \
+    SIMULATED_WAIT_(v1 == v2, timeout, res, clock);      \
+    if (!res) {                                          \
+      EXPECT_EQ(v1, v2);                                 \
+    }                                                    \
+  } while (0)
+
+#define ASSERT_TRUE_SIMULATED_WAIT(ex, timeout, clock) \
+  do {                                                 \
+    bool res;                                          \
+    SIMULATED_WAIT_(ex, timeout, res, clock);          \
+    if (!res)                                          \
+      ASSERT_TRUE(ex);                                 \
+  } while (0)
+
+#define ASSERT_EQ_SIMULATED_WAIT(v1, v2, timeout, clock) \
+  do {                                                   \
+    bool res;                                            \
+    SIMULATED_WAIT_(v1 == v2, timeout, res, clock);      \
+    if (!res)                                            \
+      ASSERT_EQ(v1, v2);                                 \
+  } while (0)
+
+#endif  // WEBRTC_RTC_BASE_GUNIT_H_

webrtc/rtc_base/gunit_prod.h

@@ -0,0 +1,24 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_GUNIT_PROD_H_
+#define WEBRTC_RTC_BASE_GUNIT_PROD_H_
+
+#if defined(WEBRTC_ANDROID)
+// Android doesn't use gtest at all, so anything that relies on gtest should
+// check this define first.
+#define NO_GTEST
+#elif defined (GTEST_RELATIVE_PATH)
+#include "gtest/gtest_prod.h"
+#else
+#include "testing/base/gunit_prod.h"
+#endif
+
+#endif  // WEBRTC_RTC_BASE_GUNIT_PROD_H_

webrtc/rtc_base/helpers.cc

@@ -0,0 +1,218 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/helpers.h"
+
+#include <limits>
+#include <memory>
+
+#include <openssl/rand.h>
+
+#include "webrtc/base/base64.h"
+#include "webrtc/base/basictypes.h"
+#include "webrtc/base/checks.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/timeutils.h"
+
+// Protect against max macro inclusion.
+#undef max
+
+namespace rtc {
+
+// Base class for RNG implementations.
+class RandomGenerator {
+ public:
+  virtual ~RandomGenerator() {}
+  virtual bool Init(const void* seed, size_t len) = 0;
+  virtual bool Generate(void* buf, size_t len) = 0;
+};
+
+// The OpenSSL RNG.
+class SecureRandomGenerator : public RandomGenerator {
+ public:
+  SecureRandomGenerator() {}
+  ~SecureRandomGenerator() override {}
+  bool Init(const void* seed, size_t len) override { return true; }
+  bool Generate(void* buf, size_t len) override {
+    return (RAND_bytes(reinterpret_cast<unsigned char*>(buf), len) > 0);
+  }
+};
+
+// A test random generator, for predictable output.
+class TestRandomGenerator : public RandomGenerator {
+ public:
+  TestRandomGenerator() : seed_(7) {
+  }
+  ~TestRandomGenerator() override {
+  }
+  bool Init(const void* seed, size_t len) override { return true; }
+  bool Generate(void* buf, size_t len) override {
+    for (size_t i = 0; i < len; ++i) {
+      static_cast<uint8_t*>(buf)[i] = static_cast<uint8_t>(GetRandom());
+    }
+    return true;
+  }
+
+ private:
+  int GetRandom() {
+    return ((seed_ = seed_ * 214013L + 2531011L) >> 16) & 0x7fff;
+  }
+  int seed_;
+};
+
+namespace {
+
+// TODO: Use Base64::Base64Table instead.
+static const char kBase64[64] = {
+    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
+    'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
+    'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
+    'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
+    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'};
+
+static const char kHex[16] = {'0', '1', '2', '3', '4', '5', '6', '7',
+                              '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
+
+static const char kUuidDigit17[4] = {'8', '9', 'a', 'b'};
+
+// This round about way of creating a global RNG is to safe-guard against
+// indeterminant static initialization order.
+std::unique_ptr<RandomGenerator>& GetGlobalRng() {
+  RTC_DEFINE_STATIC_LOCAL(std::unique_ptr<RandomGenerator>, global_rng,
+                          (new SecureRandomGenerator()));
+  return global_rng;
+}
+
+RandomGenerator& Rng() {
+  return *GetGlobalRng();
+}
+
+}  // namespace
+
+void SetRandomTestMode(bool test) {
+  if (!test) {
+    GetGlobalRng().reset(new SecureRandomGenerator());
+  } else {
+    GetGlobalRng().reset(new TestRandomGenerator());
+  }
+}
+
+bool InitRandom(int seed) {
+  return InitRandom(reinterpret_cast<const char*>(&seed), sizeof(seed));
+}
+
+bool InitRandom(const char* seed, size_t len) {
+  if (!Rng().Init(seed, len)) {
+    LOG(LS_ERROR) << "Failed to init random generator!";
+    return false;
+  }
+  return true;
+}
+
+std::string CreateRandomString(size_t len) {
+  std::string str;
+  RTC_CHECK(CreateRandomString(len, &str));
+  return str;
+}
+
+static bool CreateRandomString(size_t len,
+                        const char* table, int table_size,
+                        std::string* str) {
+  str->clear();
+  // Avoid biased modulo division below.
+  if (256 % table_size) {
+    LOG(LS_ERROR) << "Table size must divide 256 evenly!";
+    return false;
+  }
+  std::unique_ptr<uint8_t[]> bytes(new uint8_t[len]);
+  if (!Rng().Generate(bytes.get(), len)) {
+    LOG(LS_ERROR) << "Failed to generate random string!";
+    return false;
+  }
+  str->reserve(len);
+  for (size_t i = 0; i < len; ++i) {
+    str->push_back(table[bytes[i] % table_size]);
+  }
+  return true;
+}
+
+bool CreateRandomString(size_t len, std::string* str) {
+  return CreateRandomString(len, kBase64, 64, str);
+}
+
+bool CreateRandomString(size_t len, const std::string& table,
+                        std::string* str) {
+  return CreateRandomString(len, table.c_str(),
+                            static_cast<int>(table.size()), str);
+}
+
+bool CreateRandomData(size_t length, std::string* data) {
+  data->resize(length);
+  // std::string is guaranteed to use contiguous memory in c++11 so we can
+  // safely write directly to it.
+  return Rng().Generate(&data->at(0), length);
+}
+
+// Version 4 UUID is of the form:
+// xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
+// Where 'x' is a hex digit, and 'y' is 8, 9, a or b.
+std::string CreateRandomUuid() {
+  std::string str;
+  std::unique_ptr<uint8_t[]> bytes(new uint8_t[31]);
+  RTC_CHECK(Rng().Generate(bytes.get(), 31));
+  str.reserve(36);
+  for (size_t i = 0; i < 8; ++i) {
+    str.push_back(kHex[bytes[i] % 16]);
+  }
+  str.push_back('-');
+  for (size_t i = 8; i < 12; ++i) {
+    str.push_back(kHex[bytes[i] % 16]);
+  }
+  str.push_back('-');
+  str.push_back('4');
+  for (size_t i = 12; i < 15; ++i) {
+    str.push_back(kHex[bytes[i] % 16]);
+  }
+  str.push_back('-');
+  str.push_back(kUuidDigit17[bytes[15] % 4]);
+  for (size_t i = 16; i < 19; ++i) {
+    str.push_back(kHex[bytes[i] % 16]);
+  }
+  str.push_back('-');
+  for (size_t i = 19; i < 31; ++i) {
+    str.push_back(kHex[bytes[i] % 16]);
+  }
+  return str;
+}
+
+uint32_t CreateRandomId() {
+  uint32_t id;
+  RTC_CHECK(Rng().Generate(&id, sizeof(id)));
+  return id;
+}
+
+uint64_t CreateRandomId64() {
+  return static_cast<uint64_t>(CreateRandomId()) << 32 | CreateRandomId();
+}
+
+uint32_t CreateRandomNonZeroId() {
+  uint32_t id;
+  do {
+    id = CreateRandomId();
+  } while (id == 0);
+  return id;
+}
+
+double CreateRandomDouble() {
+  return CreateRandomId() / (std::numeric_limits<uint32_t>::max() +
+                             std::numeric_limits<double>::epsilon());
+}
+
+}  // namespace rtc

webrtc/rtc_base/helpers.h

@@ -0,0 +1,64 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_RTC_BASE_HELPERS_H_
+#define WEBRTC_RTC_BASE_HELPERS_H_
+
+#include <string>
+#include "webrtc/base/basictypes.h"
+
+namespace rtc {
+
+// For testing, we can return predictable data.
+void SetRandomTestMode(bool test);
+
+// Initializes the RNG, and seeds it with the specified entropy.
+bool InitRandom(int seed);
+bool InitRandom(const char* seed, size_t len);
+
+// Generates a (cryptographically) random string of the given length.
+// We generate base64 values so that they will be printable.
+std::string CreateRandomString(size_t length);
+
+// Generates a (cryptographically) random string of the given length.
+// We generate base64 values so that they will be printable.
+// Return false if the random number generator failed.
+bool CreateRandomString(size_t length, std::string* str);
+
+// Generates a (cryptographically) random string of the given length,
+// with characters from the given table. Return false if the random
+// number generator failed.
+// For ease of implementation, the function requires that the table
+// size evenly divide 256; otherwise, it returns false.
+bool CreateRandomString(size_t length, const std::string& table,
+                        std::string* str);
+
+// Generates (cryptographically) random data of the given length.
+// Return false if the random number generator failed.
+bool CreateRandomData(size_t length, std::string* data);
+
+// Generates a (cryptographically) random UUID version 4 string.
+std::string CreateRandomUuid();
+
+// Generates a random id.
+uint32_t CreateRandomId();
+
+// Generates a 64 bit random id.
+uint64_t CreateRandomId64();
+
+// Generates a random id > 0.
+uint32_t CreateRandomNonZeroId();
+
+// Generates a random double between 0.0 (inclusive) and 1.0 (exclusive).
+double CreateRandomDouble();
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_HELPERS_H_