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// ============================================================================ |
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// gzstream, C++ iostream classes wrapping the zlib compression library. |
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// Copyright (C) 2001 Deepak Bandyopadhyay, Lutz Kettner |
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// |
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// This library is free software; you can redistribute it and/or |
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// modify it under the terms of the GNU Lesser General Public |
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// License as published by the Free Software Foundation; either |
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// version 2.1 of the License, or (at your option) any later version. |
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// |
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// This library is distributed in the hope that it will be useful, |
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// but WITHOUT ANY WARRANTY; without even the implied warranty of |
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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// Lesser General Public License for more details. |
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// |
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// You should have received a copy of the GNU Lesser General Public |
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// License along with this library; if not, write to the Free Software |
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// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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// ============================================================================ |
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// |
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// File : gzstream.C |
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// Revision : $Revision$ |
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// Revision_date : $Date$ |
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// Author(s) : Deepak Bandyopadhyay, Lutz Kettner |
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// |
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// Standard streambuf implementation following Nicolai Josuttis, "The |
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// Standard C++ Library". |
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// ============================================================================ |
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|
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#include <iostream> |
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#include <string.h> // for memcpy |
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#include "io/gzstream.hpp" |
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|
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namespace OpenMD { |
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|
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// ---------------------------------------------------------------------------- |
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// Internal classes to implement gzstream. See header file for user classes. |
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// ---------------------------------------------------------------------------- |
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|
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// -------------------------------------- |
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// class gzstreambuf: |
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// -------------------------------------- |
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|
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gzstreambuf* gzstreambuf::open( const char* name, int open_mode) { |
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if ( is_open()) |
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return (gzstreambuf*)0; |
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mode = open_mode; |
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// no append nor read/write mode |
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if ((mode & std::ios::ate) || (mode & std::ios::app) |
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|| ((mode & std::ios::in) && (mode & std::ios::out))) |
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return (gzstreambuf*)0; |
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char fmode[10]; |
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char* fmodeptr = fmode; |
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if ( mode & std::ios::in) |
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*fmodeptr++ = 'r'; |
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else if ( mode & std::ios::out) |
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*fmodeptr++ = 'w'; |
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*fmodeptr++ = 'b'; |
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*fmodeptr = '\0'; |
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file = gzopen( name, fmode); |
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if (file == 0) |
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return (gzstreambuf*)0; |
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opened = 1; |
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return this; |
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} |
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|
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gzstreambuf * gzstreambuf::close() { |
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if ( is_open()) { |
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sync(); |
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opened = 0; |
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if ( gzclose( file) == Z_OK) |
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return this; |
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} |
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return (gzstreambuf*)0; |
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} |
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|
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int gzstreambuf::underflow() { // used for input buffer only |
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if ( gptr() && ( gptr() < egptr())) |
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return * reinterpret_cast<unsigned char *>( gptr()); |
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|
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if ( ! (mode & std::ios::in) || ! opened) |
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return EOF; |
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// Josuttis' implementation of inbuf |
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int n_putback = gptr() - eback(); |
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if ( n_putback > 4) |
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n_putback = 4; |
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memcpy( buffer + (4 - n_putback), gptr() - n_putback, n_putback); |
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|
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int num = gzread( file, buffer+4, bufferSize-4); |
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if (num <= 0) // ERROR or EOF |
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return EOF; |
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|
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// reset buffer pointers |
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setg( buffer + (4 - n_putback), // beginning of putback area |
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buffer + 4, // read position |
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buffer + 4 + num); // end of buffer |
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|
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// return next character |
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return * reinterpret_cast<unsigned char *>( gptr()); |
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} |
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|
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int gzstreambuf::flush_buffer() { |
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// Separate the writing of the buffer from overflow() and |
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// sync() operation. |
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int w = pptr() - pbase(); |
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if ( gzwrite( file, pbase(), w) != w) |
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return EOF; |
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pbump( -w); |
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return w; |
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} |
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|
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int gzstreambuf::overflow( int c) { // used for output buffer only |
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if ( ! ( mode & std::ios::out) || ! opened) |
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return EOF; |
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if (c != EOF) { |
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*pptr() = c; |
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pbump(1); |
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} |
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if ( flush_buffer() == EOF) |
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return EOF; |
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return c; |
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} |
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|
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int gzstreambuf::sync() { |
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// Changed to use flush_buffer() instead of overflow( EOF) |
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// which caused improper behavior with std::endl and flush(), |
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// bug reported by Vincent Ricard. |
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if ( pptr() && pptr() > pbase()) { |
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if ( flush_buffer() == EOF) |
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return -1; |
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} |
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return 0; |
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} |
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|
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// -------------------------------------- |
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// class gzstreambase: |
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// -------------------------------------- |
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|
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gzstreambase::gzstreambase( const char* name, int mode) { |
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init( &buf); |
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open( name, mode); |
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} |
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|
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gzstreambase::~gzstreambase() { |
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buf.close(); |
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} |
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|
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void gzstreambase::open( const char* name, int open_mode) { |
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if ( ! buf.open( name, open_mode)) |
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clear( rdstate() | std::ios::badbit); |
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} |
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|
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void gzstreambase::close() { |
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if ( buf.is_open()) |
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if ( ! buf.close()) |
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clear( rdstate() | std::ios::badbit); |
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} |
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|
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|
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} // namespace GZSTREAM_NAMESPACE |
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|
