// ============================================================================// gzstream, C++ iostream classes wrapping the zlib compression library.// Copyright (C) 2001  Deepak Bandyopadhyay, Lutz Kettner//// This library is free software; you can redistribute it and/or// modify it under the terms of the GNU Lesser General Public// License as published by the Free Software Foundation; either// version 2.1 of the License, or (at your option) any later version.//// This library is distributed in the hope that it will be useful,// but WITHOUT ANY WARRANTY; without even the implied warranty of// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU// Lesser General Public License for more details.//// You should have received a copy of the GNU Lesser General Public// License along with this library; if not, write to the Free Software// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA// ============================================================================//// File          : gzstream.h// Revision      : $Revision: 1.5 $// Revision_date : $Date: 2002/04/26 23:30:15 $// Author(s)     : Deepak Bandyopadhyay, Lutz Kettner// // Standard streambuf implementation following Nicolai Josuttis, "The // Standard C++ Library".// ============================================================================#ifndef GZSTREAM_H#define GZSTREAM_H 1// standard C++ with new header file names and std:: namespace#include <iostream>#include <fstream>#include <zlib.h>#ifdef GZSTREAM_NAMESPACEnamespace GZSTREAM_NAMESPACE {#endif// ----------------------------------------------------------------------------// Internal classes to implement gzstream. See below for user classes.// ----------------------------------------------------------------------------class gzstreambuf : public std::streambuf {private:    static const int bufferSize = 47+256;    // size of data buff    // totals 512 bytes under g++ for igzstream at the end.    gzFile           file;               // file handle for compressed file    char             buffer[bufferSize]; // data buffer    char             opened;             // open/close state of stream    int              mode;               // I/O mode    int flush_buffer();public:    gzstreambuf() : opened(0) {        setp( buffer, buffer + (bufferSize-1));        setg( buffer + 4,     // beginning of putback area              buffer + 4,     // read position              buffer + 4);    // end position              // ASSERT: both input & output capabilities will not be used together    }    int is_open() { return opened; }    gzstreambuf* open( const char* name, int open_mode);    gzstreambuf* close();    ~gzstreambuf() { close(); }        virtual int     overflow( int c = EOF);    virtual int     underflow();    virtual int     sync();};class gzstreambase : virtual public std::ios {protected:    gzstreambuf buf;public:    gzstreambase() { init(&buf); }    gzstreambase( const char* name, int open_mode);    ~gzstreambase();    void open( const char* name, int open_mode);    void close();    gzstreambuf* rdbuf() { return &buf; }};// ----------------------------------------------------------------------------// User classes. Use igzstream and ogzstream analogously to ifstream and// ofstream respectively. They read and write files based on the gz* // function interface of the zlib. Files are compatible with gzip compression.// ----------------------------------------------------------------------------class igzstream : public gzstreambase, public std::istream {public:    igzstream() : std::istream( &buf) {}     igzstream( const char* name, int open_mode = std::ios::in)        : gzstreambase( name, open_mode), std::istream( &buf) {}      gzstreambuf* rdbuf() { return gzstreambase::rdbuf(); }    void open( const char* name, int open_mode = std::ios::in) {        gzstreambase::open( name, open_mode);    }};class ogzstream : public gzstreambase, public std::ostream {public:    ogzstream() : std::ostream( &buf) {}    ogzstream( const char* name, int mode = std::ios::out)        : gzstreambase( name, mode), std::ostream( &buf) {}      gzstreambuf* rdbuf() { return gzstreambase::rdbuf(); }    void open( const char* name, int open_mode = std::ios::out) {        gzstreambase::open( name, open_mode);    }};#ifdef GZSTREAM_NAMESPACE} // namespace GZSTREAM_NAMESPACE#endif#endif // GZSTREAM_H// ============================================================================// EOF //