Source/WebCore/Modules/websockets/WebSocketDeflater.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2012 Google Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
  * copyright notice, this list of conditions and the following disclaimer
  * in the documentation and/or other materials provided with the
  * distribution.
  *     * Neither the name of Google Inc. nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "config.h"
 #include "WebSocketDeflater.h"

 #if USE(ZLIB)

 #include "Logging.h"
 #include <wtf/FastMalloc.h>
 #include <wtf/HashMap.h>
 #include <wtf/StdLibExtras.h>
 #include <wtf/text/StringHash.h>
 #include <wtf/text/WTFString.h>
 #include <zlib.h>

 namespace WebCore {

 static const int defaultMemLevel = 1;
 static const size_t bufferIncrementUnit = 4096;

 WebSocketDeflater::WebSocketDeflater(int windowBits, ContextTakeOverMode contextTakeOverMode)
     : m_windowBits(windowBits)
     , m_contextTakeOverMode(contextTakeOverMode)
 {
     ASSERT(m_windowBits >= 8);
     ASSERT(m_windowBits <= 15);
     m_stream = std::make_unique<z_stream>();
     memset(m_stream.get(), 0, sizeof(z_stream));
 }

 bool WebSocketDeflater::initialize()
 {
     return deflateInit2(m_stream.get(), Z_DEFAULT_COMPRESSION, Z_DEFLATED, -m_windowBits, defaultMemLevel, Z_DEFAULT_STRATEGY) == Z_OK;
 }

 WebSocketDeflater::~WebSocketDeflater()
 {
     int result = deflateEnd(m_stream.get());
     if (result != Z_OK)
         LOG(Network, "WebSocketDeflater %p Destructor deflateEnd() failed: %d is returned", this, result);
 }

 static void setStreamParameter(z_stream* stream, const char* inputData, size_t inputLength, char* outputData, size_t outputLength)
 {
     stream->next_in = reinterpret_cast<Bytef*>(const_cast<char*>(inputData));
     stream->avail_in = inputLength;
     stream->next_out = reinterpret_cast<Bytef*>(outputData);
     stream->avail_out = outputLength;
 }

 bool WebSocketDeflater::addBytes(const char* data, size_t length)
 {
     if (!length)
         return false;

     size_t maxLength = deflateBound(m_stream.get(), length);
     size_t writePosition = m_buffer.size();
     m_buffer.grow(writePosition + maxLength);
     setStreamParameter(m_stream.get(), data, length, m_buffer.data() + writePosition, maxLength);
     int result = deflate(m_stream.get(), Z_NO_FLUSH);
     if (result != Z_OK || m_stream->avail_in > 0)
         return false;

     m_buffer.shrink(writePosition + maxLength - m_stream->avail_out);
     return true;
 }

 bool WebSocketDeflater::finish()
 {
     while (true) {
         size_t writePosition = m_buffer.size();
         m_buffer.grow(writePosition + bufferIncrementUnit);
         size_t availableCapacity = m_buffer.size() - writePosition;
         setStreamParameter(m_stream.get(), 0, 0, m_buffer.data() + writePosition, availableCapacity);
         int result = deflate(m_stream.get(), Z_SYNC_FLUSH);
         m_buffer.shrink(writePosition + availableCapacity - m_stream->avail_out);
         if (result == Z_OK)
             break;
         if (result != Z_BUF_ERROR)
             return false;
     }
     // Remove 4 octets from the tail as the specification requires.
     if (m_buffer.size() <= 4)
         return false;
     m_buffer.shrink(m_buffer.size() - 4);
     return true;
 }

 void WebSocketDeflater::reset()
 {
     m_buffer.clear();
     if (m_contextTakeOverMode == DoNotTakeOverContext)
         deflateReset(m_stream.get());
 }

 WebSocketInflater::WebSocketInflater(int windowBits)
     : m_windowBits(windowBits)
 {
     m_stream = std::make_unique<z_stream>();
     memset(m_stream.get(), 0, sizeof(z_stream));
 }

 bool WebSocketInflater::initialize()
 {
     return inflateInit2(m_stream.get(), -m_windowBits) == Z_OK;
 }

 WebSocketInflater::~WebSocketInflater()
 {
     int result = inflateEnd(m_stream.get());
     if (result != Z_OK)
         LOG(Network, "WebSocketInflater %p Destructor inflateEnd() failed: %d is returned", this, result);
 }

 bool WebSocketInflater::addBytes(const char* data, size_t length)
 {
     if (!length)
         return false;

     size_t consumedSoFar = 0;
     while (consumedSoFar < length) {
         size_t writePosition = m_buffer.size();
         m_buffer.grow(writePosition + bufferIncrementUnit);
         size_t availableCapacity = m_buffer.size() - writePosition;
         size_t remainingLength = length - consumedSoFar;
         setStreamParameter(m_stream.get(), data + consumedSoFar, remainingLength, m_buffer.data() + writePosition, availableCapacity);
         int result = inflate(m_stream.get(), Z_NO_FLUSH);
         consumedSoFar += remainingLength - m_stream->avail_in;
         m_buffer.shrink(writePosition + availableCapacity - m_stream->avail_out);
         if (result == Z_BUF_ERROR)
             continue;
         if (result == Z_STREAM_END) {
             // Received a block with BFINAL set to 1. Reset decompression state.
             if (inflateReset(m_stream.get()) != Z_OK)
                 return false;
             continue;
         }
         if (result != Z_OK)
             return false;
         ASSERT(remainingLength > m_stream->avail_in);
     }
     ASSERT(consumedSoFar == length);
     return true;
 }

 bool WebSocketInflater::finish()
 {
     static const char* strippedFields = "\0\0\xff\xff";
     static const size_t strippedLength = 4;

     // Appends 4 octests of 0x00 0x00 0xff 0xff
     size_t consumedSoFar = 0;
     while (consumedSoFar < strippedLength) {
         size_t writePosition = m_buffer.size();
         m_buffer.grow(writePosition + bufferIncrementUnit);
         size_t availableCapacity = m_buffer.size() - writePosition;
         size_t remainingLength = strippedLength - consumedSoFar;
         setStreamParameter(m_stream.get(), strippedFields + consumedSoFar, remainingLength, m_buffer.data() + writePosition, availableCapacity);
         int result = inflate(m_stream.get(), Z_FINISH);
         consumedSoFar += remainingLength - m_stream->avail_in;
         m_buffer.shrink(writePosition + availableCapacity - m_stream->avail_out);
         if (result == Z_BUF_ERROR)
             continue;
         if (result != Z_OK && result != Z_STREAM_END)
             return false;
         ASSERT(remainingLength > m_stream->avail_in);
     }
     ASSERT(consumedSoFar == strippedLength);

     return true;
 }

 void WebSocketInflater::reset()
 {
     m_buffer.clear();
 }

 } // namespace WebCore

 #endif // USE(ZLIB)
	/*
	* Copyright (C) 2012 Google Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are
	* met:
	*
	* * Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* * Redistributions in binary form must reproduce the above
	* copyright notice, this list of conditions and the following disclaimer
	* in the documentation and/or other materials provided with the
	* distribution.
	* * Neither the name of Google Inc. nor the names of its
	* contributors may be used to endorse or promote products derived from
	* this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "config.h"
	#include "WebSocketDeflater.h"

	#if USE(ZLIB)

	#include "Logging.h"
	#include <wtf/FastMalloc.h>
	#include <wtf/HashMap.h>
	#include <wtf/StdLibExtras.h>
	#include <wtf/text/StringHash.h>
	#include <wtf/text/WTFString.h>
	#include <zlib.h>

	namespace WebCore {

	static const int defaultMemLevel = 1;
	static const size_t bufferIncrementUnit = 4096;

	WebSocketDeflater::WebSocketDeflater(int windowBits, ContextTakeOverMode contextTakeOverMode)
	: m_windowBits(windowBits)
	, m_contextTakeOverMode(contextTakeOverMode)
	{
	ASSERT(m_windowBits >= 8);
	ASSERT(m_windowBits <= 15);
	m_stream = std::make_unique<z_stream>();
	memset(m_stream.get(), 0, sizeof(z_stream));
	}

	bool WebSocketDeflater::initialize()
	{
	return deflateInit2(m_stream.get(), Z_DEFAULT_COMPRESSION, Z_DEFLATED, -m_windowBits, defaultMemLevel, Z_DEFAULT_STRATEGY) == Z_OK;
	}

	WebSocketDeflater::~WebSocketDeflater()
	{
	int result = deflateEnd(m_stream.get());
	if (result != Z_OK)
	LOG(Network, "WebSocketDeflater %p Destructor deflateEnd() failed: %d is returned", this, result);
	}

	static void setStreamParameter(z_stream* stream, const char* inputData, size_t inputLength, char* outputData, size_t outputLength)
	{
	stream->next_in = reinterpret_cast<Bytef>(const_cast<char>(inputData));
	stream->avail_in = inputLength;
	stream->next_out = reinterpret_cast<Bytef*>(outputData);
	stream->avail_out = outputLength;
	}

	bool WebSocketDeflater::addBytes(const char* data, size_t length)
	{
	if (!length)
	return false;

	size_t maxLength = deflateBound(m_stream.get(), length);
	size_t writePosition = m_buffer.size();
	m_buffer.grow(writePosition + maxLength);
	setStreamParameter(m_stream.get(), data, length, m_buffer.data() + writePosition, maxLength);
	int result = deflate(m_stream.get(), Z_NO_FLUSH);
	if (result != Z_OK \|\| m_stream->avail_in > 0)
	return false;

	m_buffer.shrink(writePosition + maxLength - m_stream->avail_out);
	return true;
	}

	bool WebSocketDeflater::finish()
	{
	while (true) {
	size_t writePosition = m_buffer.size();
	m_buffer.grow(writePosition + bufferIncrementUnit);
	size_t availableCapacity = m_buffer.size() - writePosition;
	setStreamParameter(m_stream.get(), 0, 0, m_buffer.data() + writePosition, availableCapacity);
	int result = deflate(m_stream.get(), Z_SYNC_FLUSH);
	m_buffer.shrink(writePosition + availableCapacity - m_stream->avail_out);
	if (result == Z_OK)
	break;
	if (result != Z_BUF_ERROR)
	return false;
	}
	// Remove 4 octets from the tail as the specification requires.
	if (m_buffer.size() <= 4)
	return false;
	m_buffer.shrink(m_buffer.size() - 4);
	return true;
	}

	void WebSocketDeflater::reset()
	{
	m_buffer.clear();
	if (m_contextTakeOverMode == DoNotTakeOverContext)
	deflateReset(m_stream.get());
	}

	WebSocketInflater::WebSocketInflater(int windowBits)
	: m_windowBits(windowBits)
	{
	m_stream = std::make_unique<z_stream>();
	memset(m_stream.get(), 0, sizeof(z_stream));
	}

	bool WebSocketInflater::initialize()
	{
	return inflateInit2(m_stream.get(), -m_windowBits) == Z_OK;
	}

	WebSocketInflater::~WebSocketInflater()
	{
	int result = inflateEnd(m_stream.get());
	if (result != Z_OK)
	LOG(Network, "WebSocketInflater %p Destructor inflateEnd() failed: %d is returned", this, result);
	}

	bool WebSocketInflater::addBytes(const char* data, size_t length)
	{
	if (!length)
	return false;

	size_t consumedSoFar = 0;
	while (consumedSoFar < length) {
	size_t writePosition = m_buffer.size();
	m_buffer.grow(writePosition + bufferIncrementUnit);
	size_t availableCapacity = m_buffer.size() - writePosition;
	size_t remainingLength = length - consumedSoFar;
	setStreamParameter(m_stream.get(), data + consumedSoFar, remainingLength, m_buffer.data() + writePosition, availableCapacity);
	int result = inflate(m_stream.get(), Z_NO_FLUSH);
	consumedSoFar += remainingLength - m_stream->avail_in;
	m_buffer.shrink(writePosition + availableCapacity - m_stream->avail_out);
	if (result == Z_BUF_ERROR)
	continue;
	if (result == Z_STREAM_END) {
	// Received a block with BFINAL set to 1. Reset decompression state.
	if (inflateReset(m_stream.get()) != Z_OK)
	return false;
	continue;
	}
	if (result != Z_OK)
	return false;
	ASSERT(remainingLength > m_stream->avail_in);
	}
	ASSERT(consumedSoFar == length);
	return true;
	}

	bool WebSocketInflater::finish()
	{
	static const char* strippedFields = "\0\0\xff\xff";
	static const size_t strippedLength = 4;

	// Appends 4 octests of 0x00 0x00 0xff 0xff
	size_t consumedSoFar = 0;
	while (consumedSoFar < strippedLength) {
	size_t writePosition = m_buffer.size();
	m_buffer.grow(writePosition + bufferIncrementUnit);
	size_t availableCapacity = m_buffer.size() - writePosition;
	size_t remainingLength = strippedLength - consumedSoFar;
	setStreamParameter(m_stream.get(), strippedFields + consumedSoFar, remainingLength, m_buffer.data() + writePosition, availableCapacity);
	int result = inflate(m_stream.get(), Z_FINISH);
	consumedSoFar += remainingLength - m_stream->avail_in;
	m_buffer.shrink(writePosition + availableCapacity - m_stream->avail_out);
	if (result == Z_BUF_ERROR)
	continue;
	if (result != Z_OK && result != Z_STREAM_END)
	return false;
	ASSERT(remainingLength > m_stream->avail_in);
	}
	ASSERT(consumedSoFar == strippedLength);

	return true;
	}

	void WebSocketInflater::reset()
	{
	m_buffer.clear();
	}

	} // namespace WebCore

	#endif // USE(ZLIB)