De-inline SimpleStringBuilder methods

Bug: webrtc:8982
Change-Id: Iadc83f6de48aad9e66952b6d3ff917672e87e247
Reviewed-on: https://webrtc-review.googlesource.com/61042
Commit-Queue: Tommi <tommi@webrtc.org>
Reviewed-by: Tommi <tommi@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22378}

rtc_base/strings/string_builder.cc

@@ -18,4 +18,95 @@ SimpleStringBuilder::SimpleStringBuilder(rtc::ArrayView<char> buffer)
   RTC_DCHECK(IsConsistent());
 }
 
+SimpleStringBuilder& SimpleStringBuilder::operator<<(const char* str) {
+  return Append(str);
+}
+
+SimpleStringBuilder& SimpleStringBuilder::operator<<(char ch) {
+  return Append(&ch, 1);
+}
+
+SimpleStringBuilder& SimpleStringBuilder::operator<<(const std::string& str) {
+  return Append(str.c_str(), str.length());
+}
+
+// Numeric conversion routines.
+//
+// We use std::[v]snprintf instead of std::to_string because:
+// * std::to_string relies on the current locale for formatting purposes,
+//   and therefore concurrent calls to std::to_string from multiple threads
+//   may result in partial serialization of calls
+// * snprintf allows us to print the number directly into our buffer.
+// * avoid allocating a std::string (potential heap alloc).
+// TODO(tommi): Switch to std::to_chars in C++17.
+
+SimpleStringBuilder& SimpleStringBuilder::operator<<(int i) {
+  return AppendFormat("%d", i);
+}
+
+SimpleStringBuilder& SimpleStringBuilder::operator<<(unsigned i) {
+  return AppendFormat("%u", i);
+}
+
+SimpleStringBuilder& SimpleStringBuilder::operator<<(long i) {  // NOLINT
+  return AppendFormat("%ld", i);
+}
+
+SimpleStringBuilder& SimpleStringBuilder::operator<<(long long i) {  // NOLINT
+  return AppendFormat("%lld", i);
+}
+
+SimpleStringBuilder& SimpleStringBuilder::operator<<(
+    unsigned long i) {  // NOLINT
+  return AppendFormat("%lu", i);
+}
+
+SimpleStringBuilder& SimpleStringBuilder::operator<<(
+    unsigned long long i) {  // NOLINT
+  return AppendFormat("%llu", i);
+}
+
+SimpleStringBuilder& SimpleStringBuilder::operator<<(float f) {
+  return AppendFormat("%f", f);
+}
+
+SimpleStringBuilder& SimpleStringBuilder::operator<<(double f) {
+  return AppendFormat("%f", f);
+}
+
+SimpleStringBuilder& SimpleStringBuilder::operator<<(long double f) {
+  return AppendFormat("%Lf", f);
+}
+
+SimpleStringBuilder& SimpleStringBuilder::AppendFormat(const char* fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+  const int len =
+      std::vsnprintf(&buffer_[size_], buffer_.size() - size_, fmt, args);
+  if (len >= 0) {
+    const size_t chars_added = rtc::SafeMin(len, buffer_.size() - 1 - size_);
+    size_ += chars_added;
+    RTC_DCHECK_EQ(len, chars_added) << "Buffer size was insufficient";
+  } else {
+    // This should never happen, but we're paranoid, so re-write the
+    // terminator in case vsnprintf() overwrote it.
+    RTC_NOTREACHED();
+    buffer_[size_] = '\0';
+  }
+  va_end(args);
+  RTC_DCHECK(IsConsistent());
+  return *this;
+}
+
+SimpleStringBuilder& SimpleStringBuilder::Append(const char* str,
+                                                 size_t length) {
+  const size_t chars_added =
+      rtc::strcpyn(&buffer_[size_], buffer_.size() - size_, str, length);
+  size_ += chars_added;
+  RTC_DCHECK_EQ(chars_added, length == SIZE_UNKNOWN ? std::strlen(str) : length)
+      << "Buffer size was insufficient";
+  RTC_DCHECK(IsConsistent());
+  return *this;
+}
+
 }  // namespace rtc