1 // ============================================================================
2 // gzstream, C++ iostream classes wrapping the zlib compression library.
3 // Copyright (C) 2001 Deepak Bandyopadhyay, Lutz Kettner
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.
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.
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 // ============================================================================
21 // Revision : $Revision: 1.2 $
22 // Revision_date : $Date: 2005/04/26 10:30:24 $
23 // Author(s) : Deepak Bandyopadhyay, Lutz Kettner
25 // Standard streambuf implementation following Nicolai Josuttis, "The
26 // Standard C++ Library".
27 // ============================================================================
32 // standard C++ with new header file names and std:: namespace
38 #define GZSTREAM_NAMESPACE gz
40 #ifdef GZSTREAM_NAMESPACE
41 namespace GZSTREAM_NAMESPACE {
44 // ----------------------------------------------------------------------------
45 // Internal classes to implement gzstream. See below for user classes.
46 // ----------------------------------------------------------------------------
48 class gzstreambuf : public std::streambuf {
50 static const int bufferSize = 47+256; // size of data buff
51 // totals 512 bytes under g++ for igzstream at the end.
53 gzFile file; // file handle for compressed file
54 char buffer[bufferSize]; // data buffer
55 char opened; // open/close state of stream
60 gzstreambuf() : file(0), opened(0), mode(0) {
61 setp( buffer, buffer + (bufferSize-1));
62 setg( buffer + 4, // beginning of putback area
63 buffer + 4, // read position
64 buffer + 4); // end position
65 // ASSERT: both input & output capabilities will not be used together
67 int is_open() { return opened; }
68 gzstreambuf* open( const char* name, int open_mode);
70 ~gzstreambuf() { close(); }
72 virtual int overflow( int c = EOF);
73 virtual int underflow();
77 class gzstreambase : virtual public std::ios {
81 gzstreambase() { init(&buf); }
82 gzstreambase( const char* name, int open_mode);
84 void open( const char* name, int open_mode);
86 gzstreambuf* rdbuf() { return &buf; }
89 // ----------------------------------------------------------------------------
90 // User classes. Use igzstream and ogzstream analogously to ifstream and
91 // ofstream respectively. They read and write files based on the gz*
92 // function interface of the zlib. Files are compatible with gzip compression.
93 // ----------------------------------------------------------------------------
95 class igzstream : public gzstreambase, public std::istream {
97 igzstream() : std::istream( &buf) {}
98 igzstream( const char* name, int open_mode = std::ios::in)
99 : gzstreambase( name, open_mode), std::istream( &buf) {}
100 gzstreambuf* rdbuf() { return gzstreambase::rdbuf(); }
101 void open( const char* name, int open_mode = std::ios::in) {
102 gzstreambase::open( name, open_mode);
106 class ogzstream : public gzstreambase, public std::ostream {
108 ogzstream() : std::ostream( &buf) {}
109 ogzstream( const char* name, int mode = std::ios::out)
110 : gzstreambase( name, mode), std::ostream( &buf) {}
111 gzstreambuf* rdbuf() { return gzstreambase::rdbuf(); }
112 void open( const char* name, int open_mode = std::ios::out) {
113 gzstreambase::open( name, open_mode);
117 #ifdef GZSTREAM_NAMESPACE
118 } // namespace GZSTREAM_NAMESPACE
122 // ============================================================================