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.h
21 // Revision      : $Revision: 1.5 $
22 // Revision_date : $Date: 2002/04/26 23:30:15 $
23 // Author(s)     : Deepak Bandyopadhyay, Lutz Kettner
24 //
25 // Standard streambuf implementation following Nicolai Josuttis, "The
26 // Standard C++ Library".
27 // ============================================================================
28 
29 #ifndef GZSTREAM_H
30 #define GZSTREAM_H 1
31 
32 // standard C++ with new header file names and std:: namespace
33 #include <iostream>
34 #include <fstream>
35 #include <zlib.h>
36 
37 #ifdef GZSTREAM_NAMESPACE
38 namespace GZSTREAM_NAMESPACE {
39 #endif
40 
41 // ----------------------------------------------------------------------------
42 // Internal classes to implement gzstream. See below for user classes.
43 // ----------------------------------------------------------------------------
44 
45 class gzstreambuf : public std::streambuf {
46 private:
47     static const int bufferSize = 47+256;    // size of data buff
48     // totals 512 bytes under g++ for igzstream at the end.
49 
50     gzFile           file;               // file handle for compressed file
51     char             buffer[bufferSize]; // data buffer
52     char             opened;             // open/close state of stream
53     int              mode;               // I/O mode
54 
55     int flush_buffer();
56 public:
gzstreambuf()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
63     }
is_open()64     int is_open() { return opened; }
65     gzstreambuf* open( const char* name, int open_mode);
66     gzstreambuf* close();
~gzstreambuf()67     ~gzstreambuf() { close(); }
68 
69     virtual int     overflow( int c = EOF);
70     virtual int     underflow();
71     virtual int     sync();
72 };
73 
74 class gzstreambase : virtual public std::ios {
75 protected:
76     gzstreambuf buf;
77 public:
gzstreambase()78     gzstreambase() { init(&buf); }
79     gzstreambase( const char* name, int open_mode);
80     ~gzstreambase();
81     void open( const char* name, int open_mode);
82     void close();
rdbuf()83     gzstreambuf* rdbuf() { return &buf; }
is_open()84     int is_open() { return buf.is_open(); }
85 };
86 
87 // ----------------------------------------------------------------------------
88 // User classes. Use igzstream and ogzstream analogously to ifstream and
89 // ofstream respectively. They read and write files based on the gz*
90 // function interface of the zlib. Files are compatible with gzip compression.
91 // ----------------------------------------------------------------------------
92 
93 class igzstream : public gzstreambase, public std::istream {
94 public:
igzstream()95     igzstream() : std::istream( &buf) {}
96     igzstream( const char* name, int open_mode = std::ios::in)
gzstreambase(name,open_mode)97         : gzstreambase( name, open_mode), std::istream( &buf) {}
98     igzstream( std::basic_string<char> name, int open_mode = std::ios::in)
99         : gzstreambase( name.c_str(), open_mode), std::istream( &buf) {}
rdbuf()100     gzstreambuf* rdbuf() { return gzstreambase::rdbuf(); }
101     void open( const char* name, int open_mode = std::ios::in) {
102         gzstreambase::open( name, open_mode);
103     }
104     void open( std::string name, int open_mode = std::ios::in) {
105         gzstreambase::open( name.c_str(), open_mode);
106     }
107 };
108 
109 class ogzstream : public gzstreambase, public std::ostream {
110 public:
ogzstream()111     ogzstream() : std::ostream( &buf) {}
112     ogzstream( const char* name, int mode = std::ios::out)
gzstreambase(name,mode)113         : gzstreambase( name, mode), std::ostream( &buf) {}
114     ogzstream( std::string name, int mode = std::ios::out)
115         : gzstreambase( name.c_str(), mode), std::ostream( &buf) {}
rdbuf()116     gzstreambuf* rdbuf() { return gzstreambase::rdbuf(); }
117     void open( const char* name, int open_mode = std::ios::out) {
118         gzstreambase::open( name, open_mode);
119     }
120     void open( std::string name, int open_mode = std::ios::out) {
121         gzstreambase::open( name.c_str(), open_mode);
122     }
123 };
124 
125 #ifdef GZSTREAM_NAMESPACE
126 } // namespace GZSTREAM_NAMESPACE
127 #endif
128 
129 #endif // GZSTREAM_H
130 // ============================================================================
131 // EOF //
132 
133