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gzstream.h
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1#ifdef SOPLEX_WITH_ZLIB
2
3// ============================================================================
4// gzstream, C++ iostream classes wrapping the zlib compression library.
5// Copyright (C) 2001 Deepak Bandyopadhyay, Lutz Kettner
6//
7// This library is free software; you can redistribute it and/or
8// modify it under the terms of the GNU Lesser General Public
9// License as published by the Free Software Foundation; either
10// version 2.1 of the License, or (at your option) any later version.
11//
12// This library is distributed in the hope that it will be useful,
13// but WITHOUT ANY WARRANTY; without even the implied warranty of
14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15// Lesser General Public License for more details.
16//
17// You should have received a copy of the GNU Lesser General Public
18// License along with this library; if not, write to the Free Software
19// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20// ============================================================================
21//
22// File : gzstream.h
23// Revision : $Revision: 1.8 $
24// Revision_date : $Date: 2005/11/09 13:53:50 $
25// Author(s) : Deepak Bandyopadhyay, Lutz Kettner
26//
27// Standard streambuf implementation following Nicolai Josuttis, "The
28// Standard C++ Library".
29// ============================================================================
30
31/**@file gzstream.h
32 * @brief Utilities for handling gzipped input and output streams.
33 */
34#ifndef GZSTREAM_H
35#define GZSTREAM_H 1
36
37// standard C++ with new header file names and std:: namespace
38#include <iostream>
39#include <fstream>
40#include <zlib.h>
41
42#define GZSTREAM_NAMESPACE gzstream
43
44#ifdef GZSTREAM_NAMESPACE
45namespace GZSTREAM_NAMESPACE
46{
47#endif
48
49// ----------------------------------------------------------------------------
50// Internal classes to implement gzstream. See below for user classes.
51// ----------------------------------------------------------------------------
52
53// ----------------------------------------------------------------------------
54// class gzstreambuf
55// ----------------------------------------------------------------------------
56
57/**@class gzstreambuf
58 @brief Internal class to implement gzstream.
59*/
60class gzstreambuf
61 : public std::streambuf
62{
63private:
64
65 //------------------------------------
66 /**@name Types */
67 ///@{
68 ///
69 static const int bufferSize = 47 + 256; ///< size of data buff
70 // totals 512 bytes under g++ for igzstream at the end.
71 ///@}
72
73 //------------------------------------
74 /**@name Data */
75 ///@{
76 gzFile file; ///< file handle for compressed file
77 char buffer[bufferSize]; ///< data buffer
78 char opened; ///< open/close state of stream
79 unsigned int mode; ///< I/O mode
80 ///@}
81
82 //------------------------------------
83 /**@name Internal helpers */
84 ///@{
85 ///
86 int flush_buffer();
87 ///@}
88
89public:
90
91 //------------------------------------
92 /**@name Construction / destruction */
93 ///@{
94 /// default constructor
95 gzstreambuf()
96 : file(0)
97 , opened(0)
98 , mode(0)
99 {
100 setp(buffer, buffer + (bufferSize - 1));
101 setg(buffer + 4, // beginning of putback area
102 buffer + 4, // read position
103 buffer + 4); // end position
104 // ASSERT: both input & output capabilities will not be used together
105 }
106 /// destructor
107 ~gzstreambuf()
108 {
109 close();
110 }
111 ///@}
112
113 //------------------------------------
114 /**@name Interface */
115 ///@{
116 ///
117 int is_open()
118 {
119 return opened;
120 }
121 ///
122 gzstreambuf* open(const char* name, int open_mode);
123 ///
124 gzstreambuf* close();
125 ///
126 virtual int overflow(int c = EOF);
127 ///
128 virtual int underflow();
129 ///
130 virtual int sync();
131 ///@}
132};
133
134// ----------------------------------------------------------------------------
135// class gzstreambase
136// ----------------------------------------------------------------------------
137
138/**@class gzstreambase
139 @brief Internal class to implement gzstream.
140*/
141class gzstreambase
142 : virtual public std::ios
143{
144protected:
145
146 //------------------------------------
147 /**@name Data */
148 ///@{
149 ///
150 gzstreambuf buf;
151 ///@}
152
153public:
154
155 //------------------------------------
156 /**@name Construction / destruction */
157 ///@{
158 /// default constructor
159 gzstreambase()
160 {
161 init(&buf);
162 }
163 /// full constructor
164 gzstreambase(const char* _name, int _open_mode);
165 /// destructor
166 ~gzstreambase();
167 ///@}
168
169 //------------------------------------
170 /**@name Interface */
171 ///@{
172 ///
173 void open(const char* _name, int _open_mode);
174 ///
175 void close();
176 ///
177 gzstreambuf* rdbuf()
178 {
179 return &buf;
180 }
181 ///@}
182};
183
184// ----------------------------------------------------------------------------
185// User classes. Use igzstream and ogzstream analogously to ifstream and
186// ofstream respectively. They read and write files based on the gz*
187// function interface of the zlib. Files are compatible with gzip compression.
188// ----------------------------------------------------------------------------
189
190// ----------------------------------------------------------------------------
191// class igzstream
192// ----------------------------------------------------------------------------
193
194/**@class igzstream
195 @brief Class to implement a gzip'd input stream.
196*/
197class igzstream
198 : public std::istream
199 , public gzstreambase
200{
201public:
202
203 //------------------------------------
204 /**@name Construction / destruction */
205 ///@{
206 /// default constructor
207 igzstream()
208 : std::istream(&buf)
209 {}
210 /// full constructor
211 igzstream(const char* _name,
212 int _open_mode = std::ios::in)
213 : std::istream(&buf)
214 , gzstreambase(_name, _open_mode)
215 {}
216 ///@}
217
218 //------------------------------------
219 /**@name Interface */
220 ///@{
221 ///
222 gzstreambuf* rdbuf()
223 {
224 return gzstreambase::rdbuf();
225 }
226 ///
227 void open(const char* _name,
228 int _open_mode = std::ios::in)
229 {
230 gzstreambase::open(_name, _open_mode);
231 }
232 ///@}
233};
234
235// ----------------------------------------------------------------------------
236// class ogzstream
237// ----------------------------------------------------------------------------
238
239/**@class ogzstream
240 @brief Class to implement a gzip'd output stream.
241*/
242class ogzstream
243 : public gzstreambase
244 , public std::ostream
245{
246public:
247
248 //------------------------------------
249 /**@name Construction / destruction */
250 ///@{
251 /// default constructor
252 ogzstream()
253 : std::ostream(&buf)
254 {}
255 /// full constructor
256 explicit
257 ogzstream(const char* _name,
258 int _open_mode = std::ios::out)
259 : gzstreambase(_name, _open_mode)
260 , std::ostream(&buf)
261 {}
262 ///@}
263
264 //------------------------------------
265 /**@name Interface */
266 ///@{
267 ///
268 gzstreambuf* rdbuf()
269 {
270 return gzstreambase::rdbuf();
271 }
272 ///
273 void open(const char* _name,
274 int _open_mode = std::ios::out)
275 {
276 gzstreambase::open(_name, _open_mode);
277 }
278};
279
280#ifdef GZSTREAM_NAMESPACE
281} // namespace GZSTREAM_NAMESPACE
282#endif
283
284#endif // GZSTREAM_H
285// ============================================================================
286// EOF //
287
288#endif