topical media & game development
lib-of-vs-libs-Poco-include-Poco-DeflatingStream.h / h
//
// DeflatingStream.h
//
//
//
// Library: Foundation
// Package: Streams
// Module: ZLibStream
//
// Definition of the DeflatingStream class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
//
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
ifndef Foundation_DeflatingStream_INCLUDED
define Foundation_DeflatingStream_INCLUDED
include "Poco/Foundation.h"
include "Poco/BufferedStreamBuf.h"
include <istream>
include <ostream>
include "Poco/zlib.h"
namespace Poco {
class Foundation_API DeflatingStreamBuf: public BufferedStreamBuf
This is the streambuf class used by DeflatingInputStream and DeflatingOutputStream.
The actual work is delegated to zlib 1.2.1 (see
http://www.gzip.org).
Both zlib (deflate) streams and gzip streams are supported.
Output streams should always call close() to ensure
proper completion of compression.
A compression level (0 to 9) can be specified in the constructor.
{
public:
enum StreamType
{
STREAM_ZLIB,
STREAM_GZIP
};
DeflatingStreamBuf(std::istream& istr, StreamType type, int level);
DeflatingStreamBuf(std::ostream& ostr, StreamType type, int level);
~DeflatingStreamBuf();
int close();
protected:
int readFromDevice(char* buffer, std::streamsize length);
int writeToDevice(const char* buffer, std::streamsize length);
private:
enum
{
STREAM_BUFFER_SIZE = 1024,
DEFLATE_BUFFER_SIZE = 32768
};
std::istream* _pIstr;
std::ostream* _pOstr;
char* _buffer;
z_stream _zstr;
bool _eof;
};
class Foundation_API DeflatingIOS: public virtual std::ios
The base class for DeflatingOutputStream and DeflatingInputStream.
This class is needed to ensure the correct initialization
order of the stream buffer and base classes.
{
public:
DeflatingIOS(std::ostream& ostr, DeflatingStreamBuf::StreamType type = DeflatingStreamBuf::STREAM_ZLIB, int level = Z_DEFAULT_COMPRESSION);
DeflatingIOS(std::istream& istr, DeflatingStreamBuf::StreamType type = DeflatingStreamBuf::STREAM_ZLIB, int level = Z_DEFAULT_COMPRESSION);
~DeflatingIOS();
DeflatingStreamBuf* rdbuf();
protected:
DeflatingStreamBuf _buf;
};
class Foundation_API DeflatingOutputStream: public DeflatingIOS, public std::ostream
This stream compresses all data passing through it
using zlib's deflate algorithm.
After all data has been written to the stream, close()
must be called to ensure completion of compression.
Example:
std::ofstream ostr("data.gz", std::ios::binary);
DeflatingOutputStream deflater(ostr, DeflatingStreamBuf::STREAM_GZIP);
deflater << "Hello, world!" << std::endl;
deflater.close();
ostr.close();
{
public:
DeflatingOutputStream(std::ostream& ostr, DeflatingStreamBuf::StreamType type = DeflatingStreamBuf::STREAM_ZLIB, int level = Z_DEFAULT_COMPRESSION);
~DeflatingOutputStream();
int close();
};
class Foundation_API DeflatingInputStream: public DeflatingIOS, public std::istream
This stream compresses all data passing through it
using zlib's deflate algorithm.
{
public:
DeflatingInputStream(std::istream& istr, DeflatingStreamBuf::StreamType type = DeflatingStreamBuf::STREAM_ZLIB, int level = Z_DEFAULT_COMPRESSION);
~DeflatingInputStream();
};
} // namespace Poco
endif // Foundation_DeflatingStream_INCLUDED
(C) Æliens
04/09/2009
You may not copy or print any of this material without explicit permission of the author or the publisher.
In case of other copyright issues, contact the author.
