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// ============================================================================
// 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.C
// Revision : $Revision: 1.3 $
// Revision_date : $Date: 2006/01/05 16:22:35 $
// Author(s) : Deepak Bandyopadhyay, Lutz Kettner
//
// Standard streambuf implementation following Nicolai Josuttis, "The
// Standard C++ Library".
// ============================================================================
#include "gzstream.h"
#include <iostream>
#include <string.h> // for memcpy
#ifdef GZSTREAM_NAMESPACE
namespace GZSTREAM_NAMESPACE {
#endif
const int gzstreambuf::bufferSize = 47+256; // size of data buff
// ----------------------------------------------------------------------------
// Internal classes to implement gzstream. See header file for user classes.
// ----------------------------------------------------------------------------
// --------------------------------------
// class gzstreambuf:
// --------------------------------------
gzstreambuf* gzstreambuf::open(const char* name, int compression_level, int open_mode) {
if ( is_open())
return (gzstreambuf*)0;
mode = open_mode;
// no append nor read/write mode
if ((mode & std::ios::ate) || (mode & std::ios::app)
|| ((mode & std::ios::in) && (mode & std::ios::out)))
return (gzstreambuf*)0;
if (compression_level < 1)
compression_level = 1;
else if (compression_level > 9)
compression_level = 9;
char fmode[10];
char* fmodeptr = fmode;
if ( mode & std::ios::in)
*fmodeptr++ = 'r';
else if ( mode & std::ios::out)
*fmodeptr++ = 'w';
*fmodeptr++ = 'b';
*fmodeptr++ = '0'+compression_level;
*fmodeptr = '\0';
file = gzopen( name, fmode);
if (file == 0)
return (gzstreambuf*)0;
opened = 1;
return this;
}
gzstreambuf * gzstreambuf::close() {
if ( is_open()) {
sync();
opened = 0;
if ( gzclose( file) == Z_OK)
return this;
}
return (gzstreambuf*)0;
}
int gzstreambuf::underflow() { // used for input buffer only
if ( gptr() && ( gptr() < egptr()))
return * reinterpret_cast<unsigned char *>( gptr());
if ( ! (mode & std::ios::in) || ! opened)
return EOF;
// Josuttis' implementation of inbuf
int n_putback = gptr() - eback();
if ( n_putback > 4)
n_putback = 4;
memcpy( buffer + (4 - n_putback), gptr() - n_putback, n_putback);
int num = gzread( file, buffer+4, bufferSize-4);
if (num <= 0) // ERROR or EOF
return EOF;
// reset buffer pointers
setg( buffer + (4 - n_putback), // beginning of putback area
buffer + 4, // read position
buffer + 4 + num); // end of buffer
// return next character
return * reinterpret_cast<unsigned char *>( gptr());
}
int gzstreambuf::flush_buffer() {
// Separate the writing of the buffer from overflow() and
// sync() operation.
int w = pptr() - pbase();
if ( gzwrite( file, pbase(), w) != w)
return EOF;
pbump( -w);
return w;
}
int gzstreambuf::overflow( int c) { // used for output buffer only
if ( ! ( mode & std::ios::out) || ! opened)
return EOF;
if (c != EOF) {
*pptr() = c;
pbump(1);
}
if ( flush_buffer() == EOF)
return EOF;
return c;
}
int gzstreambuf::sync() {
// Changed to use flush_buffer() instead of overflow( EOF)
// which caused improper behavior with std::endl and flush(),
// bug reported by Vincent Ricard.
if ( pptr() && pptr() > pbase()) {
if ( flush_buffer() == EOF)
return -1;
}
return 0;
}
// --------------------------------------
// class gzstreambase:
// --------------------------------------
gzstreambase::gzstreambase( const char* name, int compression_level, int mode) {
init( &buf);
open( name, compression_level, mode);
}
gzstreambase::~gzstreambase() {
buf.close();
}
void gzstreambase::open( const char* name, int compression_level, int open_mode) {
if ( ! buf.open( name, compression_level, open_mode))
clear( rdstate() | std::ios::badbit);
}
void gzstreambase::close() {
if ( buf.is_open())
if ( ! buf.close())
clear( rdstate() | std::ios::badbit);
}
#ifdef GZSTREAM_NAMESPACE
} // namespace GZSTREAM_NAMESPACE
#endif
// ============================================================================
// EOF //
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