source: GTP/trunk/Lib/Vis/Preprocessing/src/gzstream.h @ 1264

Revision 1264, 4.9 KB checked in by mattausch, 18 years ago (diff)
RevLine 
[372]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: 1.1 $
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#ifndef GZSTREAM_H
30#define GZSTREAM_H 1
31
32#include <zlib.h>
33
34// standard C++ with new header file names and std:: namespace
35#include <iostream>
36#include <fstream>
37using namespace std;
38
39#ifdef GZSTREAM_NAMESPACE
40namespace GZSTREAM_NAMESPACE {
41#endif
42
43// ----------------------------------------------------------------------------
44// Internal classes to implement gzstream. See below for user classes.
45// ----------------------------------------------------------------------------
46
47   // size of data buff
48#define gzbufferSize  303   
49
50
51
52//  #define STREAMBUF std::streambuf
53//  #define ISTREAM std::istream
54//  #define OSTREAM std::ostream
55
56#define STREAMBUF streambuf
57#define ISTREAM istream
58#define OSTREAM ostream
59
60class gzstreambuf : public STREAMBUF {
61
62private:
63    // totals 512 bytes under g++ for igzstream at the end.
64
65    gzFile           file;               // file handle for compressed file
66    char             buffer[gzbufferSize]; // data buffer
67    char             opened;             // open/close state of stream
68    int              mode;               // I/O mode
69
70    int flush_buffer();
71public:
72    gzstreambuf() : opened(0) {
73        setp( buffer, buffer + (gzbufferSize-1));
74        setg( buffer + 4,     // beginning of putback area
75              buffer + 4,     // read position
76              buffer + 4);    // end position     
77        // ASSERT: both input & output capabilities will not be used together
78    }
[1264]79    int is_open() const { return opened; }
[372]80    gzstreambuf* open( const char* name, int open_mode);
81    gzstreambuf* close();
82    ~gzstreambuf() { close(); }
83 
84    virtual int     overflow( int c = EOF);
85    virtual int     underflow();
86    virtual int     sync();
87
88};
89
90class gzstreambase : virtual public ios {
91
92protected:
93    gzstreambuf buf;
94public:
95  gzstreambase() { init(&buf); }
96  gzstreambase( const char* name, int open_mode);
97  ~gzstreambase();
98  void open( const char* name, int open_mode);
99  void close();
100  gzstreambuf* rdbuf() { return &buf; }
[1264]101  int is_open() const { return buf.is_open(); }
[372]102};
103
104// ----------------------------------------------------------------------------
105// User classes. Use igzstream and ogzstream analogously to ifstream and
106// ofstream respectively. They read and write files based on the gz*
107// function interface of the zlib. Files are compatible with gzip compression.
108// ----------------------------------------------------------------------------
109
110 
111
112  class igzstream : public gzstreambase, public ISTREAM {
113 
114  public:
115    igzstream() : gzstreambase(), ISTREAM( &buf )  {}
116   
117    igzstream( const char* name, int open_mode = std::ios::in)
118      : gzstreambase( name, open_mode), ISTREAM( &buf) {}
119   
120    gzstreambuf* rdbuf() { return gzstreambase::rdbuf(); }
121   
122    void open( const char* name, int open_mode = std::ios::in) {
123      gzstreambase::open( name, open_mode);
124    }
125  };
126 
127class ogzstream : public gzstreambase, public OSTREAM {
128 
129public:
130  ogzstream() : OSTREAM( &buf) {}
131  ogzstream( const char* name, int mode = std::ios::out)
132    : gzstreambase( name, mode), OSTREAM( &buf) {} 
133  gzstreambuf* rdbuf() { return gzstreambase::rdbuf(); }
134  void open( const char* name, int open_mode = std::ios::out) {
135    gzstreambase::open( name, open_mode);
136  }
137 
138};
139
140#ifdef GZSTREAM_NAMESPACE
141} // namespace GZSTREAM_NAMESPACE
142#endif
143
144#endif // GZSTREAM_H
145// ============================================================================
146// EOF //
147
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