// ============================================================================ // 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: 1.7 $ // Revision_date : $Date: 2003/01/08 14:41:27 $ // Author(s) : Deepak Bandyopadhyay, Lutz Kettner // // Standard streambuf implementation following Nicolai Josuttis, "The // Standard C++ Library". // ============================================================================ #include <gzstream.h> #include <iostream> #include <cstring> // for memcpy #include <stdexcept> #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; const int Nmode=10; char fmode[Nmode]; char* fmodeptr = fmode; if ( mode & std::ios::in) *fmodeptr++ = 'r'; else if ( mode & std::ios::out) *fmodeptr++ = 'w'; *fmodeptr++ = 'b'; while (fmodeptr<fmode+Nmode) // hopefully wil help valgrind *fmodeptr++ = '\0'; file = gzopen( name, fmode); if (!file) handle_gzerror(); 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; else handle_gzerror(); } return (gzstreambuf*)0; } void gzstreambuf::handle_gzerror() { int errnum; const char *errmsg=gzerror(file,&errnum); if (errnum==Z_DATA_ERROR) errmsg="CRC error reading gzip"; throw std::runtime_error(std::string("gzstreambuf error: ")+errmsg); } 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; std::memcpy( buffer + (4 - n_putback), gptr() - n_putback, n_putback); int num = gzread( file, buffer+4, bufferSize-4); if (num <= 0) // ERROR or EOF { if (gzeof(file)) return EOF; handle_gzerror(); } // 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) handle_gzerror(); 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 //