Adds a modified copy of talk/base to webrtc/base. It is the first step in migrating talk/base to webrtc/base.

BUG=N/A
R=andrew@webrtc.org, wu@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/12199004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6107 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/base/transformadapter.cc

@@ -0,0 +1,185 @@
+/*
+ *  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/transformadapter.h"
+
+#include <string.h>
+
+#include "webrtc/base/common.h"
+
+namespace rtc {
+
+///////////////////////////////////////////////////////////////////////////////
+
+TransformAdapter::TransformAdapter(StreamInterface * stream,
+                                   TransformInterface * transform,
+                                   bool direction_read)
+    : StreamAdapterInterface(stream), transform_(transform),
+      direction_read_(direction_read), state_(ST_PROCESSING), len_(0) {
+}
+
+TransformAdapter::~TransformAdapter() {
+  TransformAdapter::Close();
+  delete transform_;
+}
+
+StreamResult
+TransformAdapter::Read(void * buffer, size_t buffer_len,
+                       size_t * read, int * error) {
+  if (!direction_read_)
+    return SR_EOS;
+
+  while (state_ != ST_ERROR) {
+    if (state_ == ST_COMPLETE)
+      return SR_EOS;
+
+    // Buffer more data
+    if ((state_ == ST_PROCESSING) && (len_ < sizeof(buffer_))) {
+      size_t subread;
+      StreamResult result = StreamAdapterInterface::Read(
+                              buffer_ + len_,
+                              sizeof(buffer_) - len_,
+                              &subread,
+                              &error_);
+      if (result == SR_BLOCK) {
+        return SR_BLOCK;
+      } else if (result == SR_ERROR) {
+        state_ = ST_ERROR;
+        break;
+      } else if (result == SR_EOS) {
+        state_ = ST_FLUSHING;
+      } else {
+        len_ += subread;
+      }
+    }
+
+    // Process buffered data
+    size_t in_len = len_;
+    size_t out_len = buffer_len;
+    StreamResult result = transform_->Transform(buffer_, &in_len,
+                                                buffer, &out_len,
+                                                (state_ == ST_FLUSHING));
+    ASSERT(result != SR_BLOCK);
+    if (result == SR_EOS) {
+      // Note: Don't signal SR_EOS this iteration, unless out_len is zero
+      state_ = ST_COMPLETE;
+    } else if (result == SR_ERROR) {
+      state_ = ST_ERROR;
+      error_ = -1; // TODO: propagate error
+      break;
+    } else if ((out_len == 0) && (state_ == ST_FLUSHING)) {
+      // If there is no output AND no more input, then something is wrong
+      state_ = ST_ERROR;
+      error_ = -1; // TODO: better error code?
+      break;
+    }
+
+    len_ -= in_len;
+    if (len_ > 0)
+      memmove(buffer_, buffer_ + in_len, len_);
+
+    if (out_len == 0)
+      continue;
+
+    if (read)
+      *read = out_len;
+    return SR_SUCCESS;
+  }
+
+  if (error)
+    *error = error_;
+  return SR_ERROR;
+}
+
+StreamResult
+TransformAdapter::Write(const void * data, size_t data_len,
+                        size_t * written, int * error) {
+  if (direction_read_)
+    return SR_EOS;
+
+  size_t bytes_written = 0;
+  while (state_ != ST_ERROR) {
+    if (state_ == ST_COMPLETE)
+      return SR_EOS;
+
+    if (len_ < sizeof(buffer_)) {
+      // Process buffered data
+      size_t in_len = data_len;
+      size_t out_len = sizeof(buffer_) - len_;
+      StreamResult result = transform_->Transform(data, &in_len,
+                                                  buffer_ + len_, &out_len,
+                                                  (state_ == ST_FLUSHING));
+
+      ASSERT(result != SR_BLOCK);
+      if (result == SR_EOS) {
+        // Note: Don't signal SR_EOS this iteration, unless no data written
+        state_ = ST_COMPLETE;
+      } else if (result == SR_ERROR) {
+        ASSERT(false); // When this happens, think about what should be done
+        state_ = ST_ERROR;
+        error_ = -1; // TODO: propagate error
+        break;
+      }
+
+      len_ = out_len;
+      bytes_written = in_len;
+    }
+
+    size_t pos = 0;
+    while (pos < len_) {
+      size_t subwritten;
+      StreamResult result = StreamAdapterInterface::Write(buffer_ + pos,
+                                                          len_ - pos,
+                                                          &subwritten,
+                                                          &error_);
+      if (result == SR_BLOCK) {
+        ASSERT(false); // TODO: we should handle this
+        return SR_BLOCK;
+      } else if (result == SR_ERROR) {
+        state_ = ST_ERROR;
+        break;
+      } else if (result == SR_EOS) {
+        state_ = ST_COMPLETE;
+        break;
+      }
+
+      pos += subwritten;
+    }
+
+    len_ -= pos;
+    if (len_ > 0)
+      memmove(buffer_, buffer_ + pos, len_);
+
+    if (bytes_written == 0)
+      continue;
+
+    if (written)
+      *written = bytes_written;
+    return SR_SUCCESS;
+  }
+
+  if (error)
+    *error = error_;
+  return SR_ERROR;
+}
+
+void
+TransformAdapter::Close() {
+  if (!direction_read_ && (state_ == ST_PROCESSING)) {
+    state_ = ST_FLUSHING;
+    do {
+      Write(0, 0, NULL, NULL);
+    } while (state_ == ST_FLUSHING);
+  }
+  state_ = ST_COMPLETE;
+  StreamAdapterInterface::Close();
+}
+
+} // namespace rtc