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- // Copyright 2013 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 "net/websockets/websocket_inflater.h"
- #include <algorithm>
- #include <vector>
- #include "base/check_op.h"
- #include "net/base/io_buffer.h"
- #include "third_party/zlib/zlib.h"
- namespace net {
- namespace {
- class ShrinkableIOBufferWithSize : public IOBufferWithSize {
- public:
- explicit ShrinkableIOBufferWithSize(size_t size) : IOBufferWithSize(size) {}
- void Shrink(int new_size) {
- CHECK_GE(new_size, 0);
- CHECK_LE(new_size, size_);
- size_ = new_size;
- }
- private:
- ~ShrinkableIOBufferWithSize() override = default;
- };
- } // namespace
- WebSocketInflater::WebSocketInflater()
- : input_queue_(kDefaultInputIOBufferCapacity),
- output_buffer_(kDefaultBufferCapacity) {}
- WebSocketInflater::WebSocketInflater(size_t input_queue_capacity,
- size_t output_buffer_capacity)
- : input_queue_(input_queue_capacity),
- output_buffer_(output_buffer_capacity) {
- DCHECK_GT(input_queue_capacity, 0u);
- DCHECK_GT(output_buffer_capacity, 0u);
- }
- bool WebSocketInflater::Initialize(int window_bits) {
- DCHECK_LE(8, window_bits);
- DCHECK_GE(15, window_bits);
- stream_ = std::make_unique<z_stream>();
- memset(stream_.get(), 0, sizeof(*stream_));
- int result = inflateInit2(stream_.get(), -window_bits);
- if (result != Z_OK) {
- inflateEnd(stream_.get());
- stream_.reset();
- return false;
- }
- return true;
- }
- WebSocketInflater::~WebSocketInflater() {
- if (stream_) {
- inflateEnd(stream_.get());
- stream_.reset();
- }
- }
- bool WebSocketInflater::AddBytes(const char* data, size_t size) {
- if (!size)
- return true;
- if (!input_queue_.IsEmpty()) {
- // choked
- input_queue_.Push(data, size);
- return true;
- }
- int result = InflateWithFlush(data, size);
- if (stream_->avail_in > 0)
- input_queue_.Push(&data[size - stream_->avail_in], stream_->avail_in);
- return result == Z_OK || result == Z_BUF_ERROR;
- }
- bool WebSocketInflater::Finish() {
- return AddBytes("\x00\x00\xff\xff", 4);
- }
- scoped_refptr<IOBufferWithSize> WebSocketInflater::GetOutput(size_t size) {
- auto buffer = base::MakeRefCounted<ShrinkableIOBufferWithSize>(size);
- size_t num_bytes_copied = 0;
- while (num_bytes_copied < size && output_buffer_.Size() > 0) {
- size_t num_bytes_to_copy =
- std::min(output_buffer_.Size(), size - num_bytes_copied);
- output_buffer_.Read(&buffer->data()[num_bytes_copied], num_bytes_to_copy);
- num_bytes_copied += num_bytes_to_copy;
- int result = InflateChokedInput();
- if (result != Z_OK && result != Z_BUF_ERROR)
- return nullptr;
- }
- buffer->Shrink(num_bytes_copied);
- return buffer;
- }
- int WebSocketInflater::InflateWithFlush(const char* next_in, size_t avail_in) {
- int result = Inflate(next_in, avail_in, Z_NO_FLUSH);
- if (result != Z_OK && result != Z_BUF_ERROR)
- return result;
- if (CurrentOutputSize() > 0)
- return result;
- // CurrentOutputSize() == 0 means there is no data to be output,
- // so we should make sure it by using Z_SYNC_FLUSH.
- return Inflate(reinterpret_cast<const char*>(stream_->next_in),
- stream_->avail_in,
- Z_SYNC_FLUSH);
- }
- int WebSocketInflater::Inflate(const char* next_in,
- size_t avail_in,
- int flush) {
- stream_->next_in = reinterpret_cast<Bytef*>(const_cast<char*>(next_in));
- stream_->avail_in = avail_in;
- int result = Z_BUF_ERROR;
- do {
- std::pair<char*, size_t> tail = output_buffer_.GetTail();
- if (!tail.second)
- break;
- stream_->next_out = reinterpret_cast<Bytef*>(tail.first);
- stream_->avail_out = tail.second;
- result = inflate(stream_.get(), flush);
- output_buffer_.AdvanceTail(tail.second - stream_->avail_out);
- if (result == Z_STREAM_END) {
- // Received a block with BFINAL set to 1. Reset the decompression state.
- result = inflateReset(stream_.get());
- } else if (tail.second == stream_->avail_out) {
- break;
- }
- } while (result == Z_OK || result == Z_BUF_ERROR);
- return result;
- }
- int WebSocketInflater::InflateChokedInput() {
- if (input_queue_.IsEmpty())
- return InflateWithFlush(nullptr, 0);
- int result = Z_BUF_ERROR;
- while (!input_queue_.IsEmpty()) {
- std::pair<char*, size_t> top = input_queue_.Top();
- result = InflateWithFlush(top.first, top.second);
- input_queue_.Consume(top.second - stream_->avail_in);
- if (result != Z_OK && result != Z_BUF_ERROR)
- return result;
- if (stream_->avail_in > 0) {
- // There are some data which are not consumed.
- break;
- }
- }
- return result;
- }
- WebSocketInflater::OutputBuffer::OutputBuffer(size_t capacity)
- : capacity_(capacity),
- buffer_(capacity_ + 1) // 1 for sentinel
- {}
- WebSocketInflater::OutputBuffer::~OutputBuffer() = default;
- size_t WebSocketInflater::OutputBuffer::Size() const {
- return (tail_ + buffer_.size() - head_) % buffer_.size();
- }
- std::pair<char*, size_t> WebSocketInflater::OutputBuffer::GetTail() {
- DCHECK_LT(tail_, buffer_.size());
- return std::make_pair(&buffer_[tail_],
- std::min(capacity_ - Size(), buffer_.size() - tail_));
- }
- void WebSocketInflater::OutputBuffer::Read(char* dest, size_t size) {
- DCHECK_LE(size, Size());
- size_t num_bytes_copied = 0;
- if (tail_ < head_) {
- size_t num_bytes_to_copy = std::min(size, buffer_.size() - head_);
- DCHECK_LT(head_, buffer_.size());
- memcpy(&dest[num_bytes_copied], &buffer_[head_], num_bytes_to_copy);
- AdvanceHead(num_bytes_to_copy);
- num_bytes_copied += num_bytes_to_copy;
- }
- if (num_bytes_copied == size)
- return;
- DCHECK_LE(head_, tail_);
- size_t num_bytes_to_copy = size - num_bytes_copied;
- DCHECK_LE(num_bytes_to_copy, tail_ - head_);
- DCHECK_LT(head_, buffer_.size());
- memcpy(&dest[num_bytes_copied], &buffer_[head_], num_bytes_to_copy);
- AdvanceHead(num_bytes_to_copy);
- num_bytes_copied += num_bytes_to_copy;
- DCHECK_EQ(size, num_bytes_copied);
- return;
- }
- void WebSocketInflater::OutputBuffer::AdvanceHead(size_t advance) {
- DCHECK_LE(advance, Size());
- head_ = (head_ + advance) % buffer_.size();
- }
- void WebSocketInflater::OutputBuffer::AdvanceTail(size_t advance) {
- DCHECK_LE(advance + Size(), capacity_);
- tail_ = (tail_ + advance) % buffer_.size();
- }
- WebSocketInflater::InputQueue::InputQueue(size_t capacity)
- : capacity_(capacity) {}
- WebSocketInflater::InputQueue::~InputQueue() = default;
- std::pair<char*, size_t> WebSocketInflater::InputQueue::Top() {
- DCHECK(!IsEmpty());
- if (buffers_.size() == 1) {
- return std::make_pair(&buffers_.front()->data()[head_of_first_buffer_],
- tail_of_last_buffer_ - head_of_first_buffer_);
- }
- return std::make_pair(&buffers_.front()->data()[head_of_first_buffer_],
- capacity_ - head_of_first_buffer_);
- }
- void WebSocketInflater::InputQueue::Push(const char* data, size_t size) {
- if (!size)
- return;
- size_t num_copied_bytes = 0;
- if (!IsEmpty())
- num_copied_bytes += PushToLastBuffer(data, size);
- while (num_copied_bytes < size) {
- DCHECK(IsEmpty() || tail_of_last_buffer_ == capacity_);
- buffers_.push_back(base::MakeRefCounted<IOBufferWithSize>(capacity_));
- tail_of_last_buffer_ = 0;
- num_copied_bytes +=
- PushToLastBuffer(&data[num_copied_bytes], size - num_copied_bytes);
- }
- }
- void WebSocketInflater::InputQueue::Consume(size_t size) {
- DCHECK(!IsEmpty());
- DCHECK_LE(size + head_of_first_buffer_, capacity_);
- head_of_first_buffer_ += size;
- if (head_of_first_buffer_ == capacity_) {
- buffers_.pop_front();
- head_of_first_buffer_ = 0;
- }
- if (buffers_.size() == 1 && head_of_first_buffer_ == tail_of_last_buffer_) {
- buffers_.pop_front();
- head_of_first_buffer_ = 0;
- tail_of_last_buffer_ = 0;
- }
- }
- size_t WebSocketInflater::InputQueue::PushToLastBuffer(const char* data,
- size_t size) {
- DCHECK(!IsEmpty());
- size_t num_bytes_to_copy = std::min(size, capacity_ - tail_of_last_buffer_);
- if (!num_bytes_to_copy)
- return 0;
- IOBufferWithSize* buffer = buffers_.back().get();
- memcpy(&buffer->data()[tail_of_last_buffer_], data, num_bytes_to_copy);
- tail_of_last_buffer_ += num_bytes_to_copy;
- return num_bytes_to_copy;
- }
- } // namespace net
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