deflatingstream.h

This software aims to create an applet and panel tools to manage a wireless interface card, such as

//
// DeflatingStream.h
//
// $Id: //poco/Main/Foundation/include/Foundation/DeflatingStream.h#5 $
//
// Definition of the DeflatingStream class.
//
// Copyright (c) 2004, Guenter Obiltschnig/Applied Informatics.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
//
// 2. 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.
//
// 3. Redistributions in any form must be accompanied by information on
//    how to obtain complete source code for this software and any
//    accompanying software that uses this software.  The source code
//    must either be included in the distribution or be available for no
//    more than the cost of distribution plus a nominal fee, and must be
//    freely redistributable under reasonable conditions.  For an
//    executable file, complete source code means the source code for all
//    modules it contains.  It does not include source code for modules or
//    files that typically accompany the major components of the operating
//    system on which the executable file runs.
//
// 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.
//


#ifndef Foundation_DeflatingStream_INCLUDED
#define Foundation_DeflatingStream_INCLUDED


#ifndef Foundation_Foundation_INCLUDED
#include "Foundation/Foundation.h"
#endif
#ifndef Foundation_BufferedStreamBuf_INCLUDED
#include "Foundation/BufferedStreamBuf.h"
#endif
#ifndef STD_ISTREAM_INCLUDED
#include <istream>
#define STD_ISTREAM_INCLUDED
#endif
#ifndef STD_OSTREAM_INCLUDED
#include <ostream>
#define STD_OSTREAM_INCLUDED
#endif
#ifndef ZLIB_H
#include "Foundation/zlib.h"
#endif


Foundation_BEGIN


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();
};


Foundation_END


#endif // Foundation_DeflatingStream_INCLUDED