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Diffstat (limited to 'decoder/gzstream.cc')
| -rw-r--r-- | decoder/gzstream.cc | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/decoder/gzstream.cc b/decoder/gzstream.cc new file mode 100644 index 00000000..9703e6ad --- /dev/null +++ b/decoder/gzstream.cc @@ -0,0 +1,165 @@ +// ============================================================================ +// 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: 1.1 $ +// Revision_date : $Date: 2006/03/30 04:05:52 $ +// Author(s) : Deepak Bandyopadhyay, Lutz Kettner +// +// Standard streambuf implementation following Nicolai Josuttis, "The +// Standard C++ Library". +// ============================================================================ + +#include "gzstream.h" +#include <iostream> +#include <cstring> + +#ifdef GZSTREAM_NAMESPACE +namespace GZSTREAM_NAMESPACE { +#endif + +// ---------------------------------------------------------------------------- +// Internal classes to implement gzstream. See header file for user classes. +// ---------------------------------------------------------------------------- + +// -------------------------------------- +// class gzstreambuf: +// -------------------------------------- + +gzstreambuf* gzstreambuf::open( const char* name, 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; + 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'; + 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 mode) { + init( &buf); + open( name, mode); +} + +gzstreambase::~gzstreambase() { + buf.close(); +} + +void gzstreambase::open( const char* name, int open_mode) { + if ( ! buf.open( name, 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 // |