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// Copyright (c) 2012 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.
#include "content/browser/speech/chunked_byte_buffer.h"
#include <algorithm>
#include "base/basictypes.h"
#include "base/lazy_instance.h"
#include "base/logging.h"
namespace {
static const size_t kHeaderLength = sizeof(uint32);
COMPILE_ASSERT(sizeof(size_t) >= kHeaderLength,
ChunkedByteBufferNotSupportedOnThisArchitecture);
uint32 ReadBigEndian32(const uint8* buffer) {
return (static_cast<uint32>(buffer[3])) |
(static_cast<uint32>(buffer[2]) << 8) |
(static_cast<uint32>(buffer[1]) << 16) |
(static_cast<uint32>(buffer[0]) << 24);
}
} // namespace
namespace content {
ChunkedByteBuffer::ChunkedByteBuffer()
: partial_chunk_(new Chunk()),
total_bytes_stored_(0) {
}
ChunkedByteBuffer::~ChunkedByteBuffer() {
Clear();
}
void ChunkedByteBuffer::Append(const uint8* start, size_t length) {
size_t remaining_bytes = length;
const uint8* next_data = start;
while (remaining_bytes > 0) {
DCHECK(partial_chunk_ != NULL);
size_t insert_length = 0;
bool header_completed = false;
bool content_completed = false;
std::vector<uint8>* insert_target;
if (partial_chunk_->header.size() < kHeaderLength) {
const size_t bytes_to_complete_header =
kHeaderLength - partial_chunk_->header.size();
insert_length = std::min(bytes_to_complete_header, remaining_bytes);
insert_target = &partial_chunk_->header;
header_completed = (remaining_bytes >= bytes_to_complete_header);
} else {
DCHECK_LT(partial_chunk_->content->size(),
partial_chunk_->ExpectedContentLength());
const size_t bytes_to_complete_chunk =
partial_chunk_->ExpectedContentLength() -
partial_chunk_->content->size();
insert_length = std::min(bytes_to_complete_chunk, remaining_bytes);
insert_target = partial_chunk_->content.get();
content_completed = (remaining_bytes >= bytes_to_complete_chunk);
}
DCHECK_GT(insert_length, 0U);
DCHECK_LE(insert_length, remaining_bytes);
DCHECK_LE(next_data + insert_length, start + length);
insert_target->insert(insert_target->end(),
next_data,
next_data + insert_length);
next_data += insert_length;
remaining_bytes -= insert_length;
if (header_completed) {
DCHECK_EQ(partial_chunk_->header.size(), kHeaderLength);
if (partial_chunk_->ExpectedContentLength() == 0) {
// Handle zero-byte chunks.
chunks_.push_back(partial_chunk_.release());
partial_chunk_.reset(new Chunk());
} else {
partial_chunk_->content->reserve(
partial_chunk_->ExpectedContentLength());
}
} else if (content_completed) {
DCHECK_EQ(partial_chunk_->content->size(),
partial_chunk_->ExpectedContentLength());
chunks_.push_back(partial_chunk_.release());
partial_chunk_.reset(new Chunk());
}
}
DCHECK_EQ(next_data, start + length);
total_bytes_stored_ += length;
}
void ChunkedByteBuffer::Append(const std::string& string) {
Append(reinterpret_cast<const uint8*>(string.data()), string.size());
}
bool ChunkedByteBuffer::HasChunks() const {
return !chunks_.empty();
}
scoped_ptr< std::vector<uint8> > ChunkedByteBuffer::PopChunk() {
if (chunks_.empty())
return scoped_ptr< std::vector<uint8> >();
scoped_ptr<Chunk> chunk(*chunks_.begin());
chunks_.weak_erase(chunks_.begin());
DCHECK_EQ(chunk->header.size(), kHeaderLength);
DCHECK_EQ(chunk->content->size(), chunk->ExpectedContentLength());
total_bytes_stored_ -= chunk->content->size();
total_bytes_stored_ -= kHeaderLength;
return chunk->content.Pass();
}
void ChunkedByteBuffer::Clear() {
chunks_.clear();
partial_chunk_.reset(new Chunk());
total_bytes_stored_ = 0;
}
ChunkedByteBuffer::Chunk::Chunk()
: content(new std::vector<uint8>()) {
}
ChunkedByteBuffer::Chunk::~Chunk() {
}
size_t ChunkedByteBuffer::Chunk::ExpectedContentLength() const {
DCHECK_EQ(header.size(), kHeaderLength);
return static_cast<size_t>(ReadBigEndian32(&header[0]));
}
} // namespace content
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