1 /*
2 *
3 * Copyright (c) 1997
4 * Christian Michelsen Research AS
5 * Advanced Computing
6 * Fantoftvegen 38, 5036 BERGEN, Norway
7 * http://www.cmr.no
8 *
9 * Permission to use, copy, modify, distribute and sell this software
10 * and its documentation for any purpose is hereby granted without fee,
11 * provided that the above copyright notice appear in all copies and
12 * that both that copyright notice and this permission notice appear
13 * in supporting documentation. Christian Michelsen Research AS makes no
14 * representations about the suitability of this software for any
15 * purpose. It is provided "as is" without express or implied warranty.
16 *
17 */
18
19 #ifndef ZSTREAM__H
20 #define ZSTREAM__H
21
22 /*
23 * zstream.h - C++ interface to the 'zlib' general purpose compression library
24 * $Id: zstream.h,v 1.1 1999/05/04 19:30:27 tromey Exp $
25 */
26
27 #include <strstream.h>
28 #include <string.h>
29 #include <stdio.h>
30 #include "zlib.h"
31
32 #if defined(_WIN32)
33 # include <fcntl.h>
34 # include <io.h>
35 # define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)
36 #else
37 # define SET_BINARY_MODE(file)
38 #endif
39
40 class zstringlen {
41 public:
42 zstringlen(class izstream&);
43 zstringlen(class ozstream&, const char*);
44 size_t value() const { return val.word; }
45 private:
46 struct Val { unsigned char byte; size_t word; } val;
47 };
48
49 // ----------------------------- izstream -----------------------------
50
51 class izstream
52 {
53 public:
54 izstream() : m_fp(0) {}
55 izstream(FILE* fp) : m_fp(0) { open(fp); }
56 izstream(const char* name) : m_fp(0) { open(name); }
57 ~izstream() { close(); }
58
59 /* Opens a gzip (.gz) file for reading.
60 * open() can be used to read a file which is not in gzip format;
61 * in this case read() will directly read from the file without
62 * decompression. errno can be checked to distinguish two error
63 * cases (if errno is zero, the zlib error is Z_MEM_ERROR).
64 */
65 void open(const char* name) {
66 if (m_fp) close();
67 m_fp = ::gzopen(name, "rb");
68 }
69
70 void open(FILE* fp) {
71 SET_BINARY_MODE(fp);
72 if (m_fp) close();
73 m_fp = ::gzdopen(fileno(fp), "rb");
74 }
75
76 /* Flushes all pending input if necessary, closes the compressed file
77 * and deallocates all the (de)compression state. The return value is
78 * the zlib error number (see function error() below).
79 */
80 int close() {
81 int r = ::gzclose(m_fp);
82 m_fp = 0; return r;
83 }
84
85 /* Binary read the given number of bytes from the compressed file.
86 */
87 int read(void* buf, size_t len) {
88 return ::gzread(m_fp, buf, len);
89 }
90
91 /* Returns the error message for the last error which occurred on the
92 * given compressed file. errnum is set to zlib error number. If an
93 * error occurred in the file system and not in the compression library,
94 * errnum is set to Z_ERRNO and the application may consult errno
95 * to get the exact error code.
96 */
97 const char* error(int* errnum) {
98 return ::gzerror(m_fp, errnum);
99 }
100
101 gzFile fp() { return m_fp; }
102
103 private:
104 gzFile m_fp;
105 };
106
107 /*
108 * Binary read the given (array of) object(s) from the compressed file.
109 * If the input file was not in gzip format, read() copies the objects number
110 * of bytes into the buffer.
111 * returns the number of uncompressed bytes actually read
112 * (0 for end of file, -1 for error).
113 */
114 template <class T, class Items>
115 inline int read(izstream& zs, T* x, Items items) {
116 return ::gzread(zs.fp(), x, items*sizeof(T));
117 }
118
119 /*
120 * Binary input with the '>' operator.
121 */
122 template <class T>
123 inline izstream& operator>(izstream& zs, T& x) {
124 ::gzread(zs.fp(), &x, sizeof(T));
125 return zs;
126 }
127
128
129 inline zstringlen::zstringlen(izstream& zs) {
130 zs > val.byte;
131 if (val.byte == 255) zs > val.word;
132 else val.word = val.byte;
133 }
134
135 /*
136 * Read length of string + the string with the '>' operator.
137 */
138 inline izstream& operator>(izstream& zs, char* x) {
139 zstringlen len(zs);
140 ::gzread(zs.fp(), x, len.value());
141 x[len.value()] = '\0';
142 return zs;
143 }
144
145 inline char* read_string(izstream& zs) {
146 zstringlen len(zs);
147 char* x = new char[len.value()+1];
148 ::gzread(zs.fp(), x, len.value());
149 x[len.value()] = '\0';
150 return x;
151 }
152
153 // ----------------------------- ozstream -----------------------------
154
155 class ozstream
156 {
157 public:
158 ozstream() : m_fp(0), m_os(0) {
159 }
160 ozstream(FILE* fp, int level = Z_DEFAULT_COMPRESSION)
161 : m_fp(0), m_os(0) {
162 open(fp, level);
163 }
164 ozstream(const char* name, int level = Z_DEFAULT_COMPRESSION)
165 : m_fp(0), m_os(0) {
166 open(name, level);
167 }
168 ~ozstream() {
169 close();
170 }
171
172 /* Opens a gzip (.gz) file for writing.
173 * The compression level parameter should be in 0..9
174 * errno can be checked to distinguish two error cases
175 * (if errno is zero, the zlib error is Z_MEM_ERROR).
176 */
177 void open(const char* name, int level = Z_DEFAULT_COMPRESSION) {
178 char mode[4] = "wb\0";
179 if (level != Z_DEFAULT_COMPRESSION) mode[2] = '0'+level;
180 if (m_fp) close();
181 m_fp = ::gzopen(name, mode);
182 }
183
184 /* open from a FILE pointer.
185 */
186 void open(FILE* fp, int level = Z_DEFAULT_COMPRESSION) {
187 SET_BINARY_MODE(fp);
188 char mode[4] = "wb\0";
189 if (level != Z_DEFAULT_COMPRESSION) mode[2] = '0'+level;
190 if (m_fp) close();
191 m_fp = ::gzdopen(fileno(fp), mode);
192 }
193
194 /* Flushes all pending output if necessary, closes the compressed file
195 * and deallocates all the (de)compression state. The return value is
196 * the zlib error number (see function error() below).
197 */
198 int close() {
199 if (m_os) {
200 ::gzwrite(m_fp, m_os->str(), m_os->pcount());
201 delete[] m_os->str(); delete m_os; m_os = 0;
202 }
203 int r = ::gzclose(m_fp); m_fp = 0; return r;
204 }
205
206 /* Binary write the given number of bytes into the compressed file.
207 */
208 int write(const void* buf, size_t len) {
209 return ::gzwrite(m_fp, (voidp) buf, len);
210 }
211
212 /* Flushes all pending output into the compressed file. The parameter
213 * _flush is as in the deflate() function. The return value is the zlib
214 * error number (see function gzerror below). flush() returns Z_OK if
215 * the flush_ parameter is Z_FINISH and all output could be flushed.
216 * flush() should be called only when strictly necessary because it can
217 * degrade compression.
218 */
219 int flush(int _flush) {
220 os_flush();
221 return ::gzflush(m_fp, _flush);
222 }
223
224 /* Returns the error message for the last error which occurred on the
225 * given compressed file. errnum is set to zlib error number. If an
226 * error occurred in the file system and not in the compression library,
227 * errnum is set to Z_ERRNO and the application may consult errno
228 * to get the exact error code.
229 */
230 const char* error(int* errnum) {
231 return ::gzerror(m_fp, errnum);
232 }
233
234 gzFile fp() { return m_fp; }
235
236 ostream& os() {
237 if (m_os == 0) m_os = new ostrstream;
238 return *m_os;
239 }
240
241 void os_flush() {
242 if (m_os && m_os->pcount()>0) {
243 ostrstream* oss = new ostrstream;
244 oss->fill(m_os->fill());
245 oss->flags(m_os->flags());
246 oss->precision(m_os->precision());
247 oss->width(m_os->width());
248 ::gzwrite(m_fp, m_os->str(), m_os->pcount());
249 delete[] m_os->str(); delete m_os; m_os = oss;
250 }
251 }
252
253 private:
254 gzFile m_fp;
255 ostrstream* m_os;
256 };
257
258 /*
259 * Binary write the given (array of) object(s) into the compressed file.
260 * returns the number of uncompressed bytes actually written
261 * (0 in case of error).
262 */
263 template <class T, class Items>
264 inline int write(ozstream& zs, const T* x, Items items) {
265 return ::gzwrite(zs.fp(), (voidp) x, items*sizeof(T));
266 }
267
268 /*
269 * Binary output with the '<' operator.
270 */
271 template <class T>
272 inline ozstream& operator<(ozstream& zs, const T& x) {
273 ::gzwrite(zs.fp(), (voidp) &x, sizeof(T));
274 return zs;
275 }
276
277 inline zstringlen::zstringlen(ozstream& zs, const char* x) {
278 val.byte = 255; val.word = ::strlen(x);
279 if (val.word < 255) zs < (val.byte = val.word);
280 else zs < val;
281 }
282
283 /*
284 * Write length of string + the string with the '<' operator.
285 */
286 inline ozstream& operator<(ozstream& zs, const char* x) {
287 zstringlen len(zs, x);
288 ::gzwrite(zs.fp(), (voidp) x, len.value());
289 return zs;
290 }
291
292 #ifdef _MSC_VER
293 inline ozstream& operator<(ozstream& zs, char* const& x) {
294 return zs < (const char*) x;
295 }
296 #endif
297
298 /*
299 * Ascii write with the << operator;
300 */
301 template <class T>
302 inline ostream& operator<<(ozstream& zs, const T& x) {
303 zs.os_flush();
304 return zs.os() << x;
305 }
306
307 #endif