source: GTP/trunk/App/Demos/Vis/FriendlyCulling/Converter/gzstream.cpp @ 2961

Revision 2961, 5.0 KB checked in by mattausch, 16 years ago (diff)
Line 
1// ============================================================================
2// gzstream, C++ iostream classes wrapping the zlib compression library.
3// Copyright (C) 2001  Deepak Bandyopadhyay, Lutz Kettner
4//
5// This library is free software; you can redistribute it and/or
6// modify it under the terms of the GNU Lesser General Public
7// License as published by the Free Software Foundation; either
8// version 2.1 of the License, or (at your option) any later version.
9//
10// This library is distributed in the hope that it will be useful,
11// but WITHOUT ANY WARRANTY; without even the implied warranty of
12// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13// Lesser General Public License for more details.
14//
15// You should have received a copy of the GNU Lesser General Public
16// License along with this library; if not, write to the Free Software
17// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18// ============================================================================
19//
20// File          : gzstream.C
21// Revision      : $Revision: 1.1 $
22// Revision_date : $Date: 2004/02/16 14:46:00 $
23// Author(s)     : Deepak Bandyopadhyay, Lutz Kettner
24//
25// Standard streambuf implementation following Nicolai Josuttis, "The
26// Standard C++ Library".
27// ============================================================================
28
29#include "gzstream.h"
30#include <string.h>  // for memcpy
31
32#ifdef GZSTREAM_NAMESPACE
33namespace GZSTREAM_NAMESPACE {
34#endif
35
36// ----------------------------------------------------------------------------
37// Internal classes to implement gzstream. See header file for user classes.
38// ----------------------------------------------------------------------------
39
40// --------------------------------------
41// class gzstreambuf:
42// --------------------------------------
43
44gzstreambuf*
45gzstreambuf::open( const char* name, int open_mode) {
46  if ( is_open() )
47    return (gzstreambuf*)0;
48  mode = open_mode;
49  // no append nor read/write mode
50  if ((mode & std::ios::ate) || (mode & std::ios::app)
51      || ((mode & std::ios::in) && (mode & std::ios::out)))
52    return (gzstreambuf*)0;
53  char fmode[10];
54  char* fmodeptr = fmode;
55  if ( mode & std::ios::in)
56    *fmodeptr++ = 'r';
57  else
58    if ( mode & std::ios::out)
59      *fmodeptr++ = 'w';
60  *fmodeptr++ = 'b';
61  *fmodeptr = '\0';
62  file = gzopen( name, fmode);
63  if (file == 0)
64    return (gzstreambuf*)0;
65  opened = 1;
66  return this;
67}
68 
69gzstreambuf *
70gzstreambuf::close() {
71  if ( is_open()) {
72    sync();
73    opened = 0;
74    if ( gzclose( file) == Z_OK)
75      return this;
76  }
77  return (gzstreambuf*)0;
78}
79 
80int
81gzstreambuf::underflow() { // used for input buffer only
82  if ( gptr() && ( gptr() < egptr()))
83    return * reinterpret_cast<unsigned char *>( gptr());
84 
85  if ( ! (mode & std::ios::in) || ! opened)
86    return EOF;
87  // Josuttis' implementation of inbuf
88  int n_putback = gptr() - eback();
89  if ( n_putback > 4)
90    n_putback = 4;
91  memcpy( buffer + (4 - n_putback), gptr() - n_putback, n_putback);
92 
93  int num = gzread( file, buffer+4, gzbufferSize-4);
94  if (num <= 0) // ERROR or EOF
95    return EOF;
96 
97  // reset buffer pointers
98  setg( buffer + (4 - n_putback),   // beginning of putback area
99        buffer + 4,                 // read position
100        buffer + 4 + num);          // end of buffer
101 
102  // return next character
103  return * reinterpret_cast<unsigned char *>( gptr());   
104}
105 
106int
107gzstreambuf::flush_buffer() {
108  // Separate the writing of the buffer from overflow() and
109  // sync() operation.
110  int w = pptr() - pbase();
111  if ( gzwrite( file, pbase(), w) != w)
112    return EOF;
113  pbump( -w);
114  return w;
115}
116 
117int
118gzstreambuf::overflow( int c) { // used for output buffer only
119  if ( ! ( mode & std::ios::out) || ! opened)
120    return EOF;
121  if (c != EOF) {
122    *pptr() = c;
123    pbump(1);
124  }
125  if ( flush_buffer() == EOF)
126    return EOF;
127  return c;
128}
129 
130int
131gzstreambuf::sync() {
132  // Changed to use flush_buffer() instead of overflow( EOF)
133  // which caused improper behavior with std::endl and flush(),
134  // bug reported by Vincent Ricard.
135  if ( pptr() && pptr() > pbase()) {
136    if ( flush_buffer() == EOF)
137      return -1;
138  }
139  return 0;
140}
141 
142 
143  // --------------------------------------
144  // class gzstreambase:
145// --------------------------------------
146
147gzstreambase::gzstreambase( const char* name, int mode)
148{
149  init( &buf);
150  open( name, mode);
151}
152 
153  gzstreambase::~gzstreambase()
154  {
155    buf.close();
156  }
157 
158  void
159  gzstreambase::open( const char* name, int open_mode) {
160    if ( ! buf.open( name, open_mode))
161      clear( rdstate() | std::ios::badbit);
162}
163
164void gzstreambase::close() {
165    if ( buf.is_open())
166        if ( ! buf.close())
167            clear( rdstate() | std::ios::badbit);
168}
169
170#ifdef GZSTREAM_NAMESPACE
171} // namespace GZSTREAM_NAMESPACE
172#endif
173
174// ============================================================================
175// EOF //
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