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
40 #define GZSTREAM_NAMESPACE gz
42 #ifdef GZSTREAM_NAMESPACE
43 namespace GZSTREAM_NAMESPACE {
46 // ----------------------------------------------------------------------------
47 // Internal classes to implement gzstream. See below for user classes.
48 // ----------------------------------------------------------------------------
50 class gzstreambuf : public std::streambuf {
52 static const int bufferSize = 47+256; // size of data buff
53 // totals 512 bytes under g++ for igzstream at the end.
55 gzFile file; // file handle for compressed file
56 char buffer[bufferSize]; // data buffer
57 char opened; // open/close state of stream
62 gzstreambuf() : opened(0) {
63 setp( buffer, buffer + (bufferSize-1));
64 setg( buffer + 4, // beginning of putback area
65 buffer + 4, // read position
66 buffer + 4); // end position
67 // ASSERT: both input & output capabilities will not be used together
69 int is_open() { return opened; }
70 gzstreambuf* open( const char* name, int open_mode);
72 ~gzstreambuf() { close(); }
74 virtual int overflow( int c = EOF);
75 virtual int underflow();
79 class gzstreambase : virtual public std::ios {
83 gzstreambase() { init(&buf); }
84 gzstreambase( const char* name, int open_mode);
86 void open( const char* name, int open_mode);
88 gzstreambuf* rdbuf() { return &buf; }
91 // ----------------------------------------------------------------------------
92 // User classes. Use igzstream and ogzstream analogously to ifstream and
93 // ofstream respectively. They read and write files based on the gz*
94 // function interface of the zlib. Files are compatible with gzip compression.
95 // ----------------------------------------------------------------------------
97 class igzstream : public gzstreambase, public std::istream {
99 igzstream() : std::istream( &buf) {}
100 igzstream( const char* name, int open_mode = std::ios::in)
101 : gzstreambase( name, open_mode), std::istream( &buf) {}
102 gzstreambuf* rdbuf() { return gzstreambase::rdbuf(); }
103 void open( const char* name, int open_mode = std::ios::in) {
104 gzstreambase::open( name, open_mode);
108 class ogzstream : public gzstreambase, public std::ostream {
110 ogzstream() : std::ostream( &buf) {}
111 ogzstream( const char* name, int mode = std::ios::out)
112 : gzstreambase( name, mode), std::ostream( &buf) {}
113 gzstreambuf* rdbuf() { return gzstreambase::rdbuf(); }
114 void open( const char* name, int open_mode = std::ios::out) {
115 gzstreambase::open( name, open_mode);
119 #ifdef GZSTREAM_NAMESPACE
120 } // namespace GZSTREAM_NAMESPACE
124 // ============================================================================