Switch out use of std::string and std::vector for large allocations for a buffer class that doesn...

courgette/streams.cc

-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Streams classes.
 //
 // These memory-resident streams are used for serializing data into a sequential
 // region of memory.
 //
 // Streams are divided into SourceStreams for reading and SinkStreams for
 // writing.  Streams are aggregated into Sets which allows several streams to be
@@ skipping 163 matching lines @@
 }
 
 bool SourceStream::Skip(size_t byte_count) {
   if (current_ + byte_count > end_)
     return false;
   current_ += byte_count;
   return true;
 }
 
 CheckBool SinkStream::Write(const void* data, size_t byte_count) {
-  buffer_.append(static_cast<const char*>(data), byte_count);
-  //TODO(tommi): return error on failure.
-  return true;
+  return buffer_.append(static_cast<const char*>(data), byte_count);
 }
 
 CheckBool SinkStream::WriteVarint32(uint32 value) {
   uint8 buffer[Varint::kMax32];
   uint8* end = Varint::Encode32(buffer, value);
   return Write(buffer, end - buffer);
 }
 
 CheckBool SinkStream::WriteVarint32Signed(int32 value) {
   // Encode signed numbers so that numbers nearer zero have shorter
   // varint encoding.
   //  0000xxxx encoded as 000xxxx0.
   //  1111xxxx encoded as 000yyyy1 where yyyy is complement of xxxx.
   bool ret;
   if (value < 0)
     ret = WriteVarint32(~value * 2 + 1);
   else
     ret = WriteVarint32(value * 2);
   return ret;
 }
 
 CheckBool SinkStream::WriteSizeVarint32(size_t value) {
   uint32 narrowed_value = static_cast<uint32>(value);
   // On 32-bit, the compiler should figure out this test always fails.
   LOG_ASSERT(value == narrowed_value);
   return WriteVarint32(narrowed_value);
 }
 
 CheckBool SinkStream::Append(SinkStream* other) {
-  bool ret = Write(other->buffer_.c_str(), other->buffer_.size());
+  bool ret = Write(other->buffer_.data(), other->buffer_.size());
   if (ret)
     other->Retire();
   return ret;
 }
 
 void SinkStream::Retire() {
   buffer_.clear();
-  buffer_.reserve(0);  // Non-binding request to reduce storage.
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
 SourceStreamSet::SourceStreamSet()
     : count_(kMaxStreams) {
 }
 
 SourceStreamSet::~SourceStreamSet() {
 }
@@ skipping 148 matching lines @@
     ret = control_stream->WriteSizeVarint32(lengths[i]);
   }
 
   for (size_t i = 0; ret && i < stream_count; ++i) {
     ret = this->stream(i)->Append(set->stream(i));
   }
   return ret;
 }
 
 }  // namespace