blob: 6f468223ce5f186e73d4e3810cd504fae8fbb6f1 [file] [log] [blame]
// 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 <deque>
#include <vector>
#include "base/logging.h"
#include "net/base/io_buffer.h"
#include "third_party/zlib/zlib.h"
namespace net {
namespace {
class ShrinkableIOBufferWithSize : public IOBufferWithSize {
public:
explicit ShrinkableIOBufferWithSize(int size)
: IOBufferWithSize(size) {}
void Shrink(int new_size) {
DCHECK_LE(new_size, size_);
size_ = new_size;
}
private:
virtual ~ShrinkableIOBufferWithSize() {}
};
} // 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_.reset(new 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) {
scoped_refptr<ShrinkableIOBufferWithSize> buffer =
new 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 NULL;
}
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(NULL, 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
head_(0),
tail_(0) {}
WebSocketInflater::OutputBuffer::~OutputBuffer() {}
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), head_of_first_buffer_(0), tail_of_last_buffer_(0) {}
WebSocketInflater::InputQueue::~InputQueue() {}
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(new 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