source: XMLIO_V2/external/src/POCO/Foundation.save/Poco/DeflatingStream.h @ 80

//
// DeflatingStream.h
//
// $Id: //poco/1.3/Foundation/include/Poco/DeflatingStream.h#2 $
//
// 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>
#if defined(POCO_UNBUNDLED)
#include <zlib.h>
#else
#include "Poco/zlib.h"
#endif


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