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: 1.5 $
22 // Revision_date : $Date: 2002/04/26 23:30:15 $
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
37 #ifdef GZSTREAM_NAMESPACE
38 namespace GZSTREAM_NAMESPACE
{
41 // ----------------------------------------------------------------------------
42 // Internal classes to implement gzstream. See below for user classes.
43 // ----------------------------------------------------------------------------
45 class gzstreambuf
: public std::streambuf
{
47 static const int bufferSize
= 47+256; // size of data buff
48 // totals 512 bytes under g++ for igzstream at the end.
50 gzFile file
; // file handle for compressed file
51 char buffer
[bufferSize
]; // data buffer
52 char opened
; // open/close state of stream
57 gzstreambuf() : opened(0) {
58 setp( buffer
, buffer
+ (bufferSize
-1));
59 setg( buffer
+ 4, // beginning of putback area
60 buffer
+ 4, // read position
61 buffer
+ 4); // end position
62 // ASSERT: both input & output capabilities will not be used together
64 int is_open() { return opened
; }
65 gzstreambuf
* open( const char* name
, int open_mode
);
67 ~gzstreambuf() { close(); }
69 virtual int overflow( int c
= EOF
);
70 virtual int underflow();
74 class gzstreambase
: virtual public std::ios
{
78 gzstreambase() { init(&buf
); }
79 gzstreambase( const char* name
, int open_mode
);
81 void open( const char* name
, int open_mode
);
83 gzstreambuf
* rdbuf() { return &buf
; }
86 // ----------------------------------------------------------------------------
87 // User classes. Use igzstream and ogzstream analogously to ifstream and
88 // ofstream respectively. They read and write files based on the gz*
89 // function interface of the zlib. Files are compatible with gzip compression.
90 // ----------------------------------------------------------------------------
92 class igzstream
: public gzstreambase
, public std::istream
{
94 igzstream() : std::istream( &buf
) {}
95 igzstream( const char* name
, int open_mode
= std::ios::in
)
96 : gzstreambase( name
, open_mode
), std::istream( &buf
) {}
97 gzstreambuf
* rdbuf() { return gzstreambase::rdbuf(); }
98 void open( const char* name
, int open_mode
= std::ios::in
) {
99 gzstreambase::open( name
, open_mode
);
103 class ogzstream
: public gzstreambase
, public std::ostream
{
105 ogzstream() : std::ostream( &buf
) {}
106 ogzstream( const char* name
, int mode
= std::ios::out
)
107 : gzstreambase( name
, mode
), std::ostream( &buf
) {}
108 gzstreambuf
* rdbuf() { return gzstreambase::rdbuf(); }
109 void open( const char* name
, int open_mode
= std::ios::out
) {
110 gzstreambase::open( name
, open_mode
);
114 #ifdef GZSTREAM_NAMESPACE
115 } // namespace GZSTREAM_NAMESPACE
119 // ============================================================================