jas_stream.h Source File

jas_stream.h
1 /*
2 * Copyright (c) 1999-2000 Image Power, Inc. and the University of
3 * British Columbia.
4 * Copyright (c) 2001-2003 Michael David Adams.
5 * All rights reserved.
6 */
7
8 /* __START_OF_JASPER_LICENSE__
9 *
10 * JasPer License Version 2.0
11 *
12 * Copyright (c) 2001-2006 Michael David Adams
13 * Copyright (c) 1999-2000 Image Power, Inc.
14 * Copyright (c) 1999-2000 The University of British Columbia
15 *
16 * All rights reserved.
17 *
18 * Permission is hereby granted, free of charge, to any person (the
19 * "User") obtaining a copy of this software and associated documentation
20 * files (the "Software"), to deal in the Software without restriction,
21 * including without limitation the rights to use, copy, modify, merge,
22 * publish, distribute, and/or sell copies of the Software, and to permit
23 * persons to whom the Software is furnished to do so, subject to the
24 * following conditions:
25 *
26 * 1. The above copyright notices and this permission notice (which
27 * includes the disclaimer below) shall be included in all copies or
28 * substantial portions of the Software.
29 *
30 * 2. The name of a copyright holder shall not be used to endorse or
31 * promote products derived from the Software without specific prior
32 * written permission.
33 *
34 * THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS
35 * LICENSE. NO USE OF THE SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER
36 * THIS DISCLAIMER. THE SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS
37 * "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
38 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
39 * PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN NO
40 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL
41 * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING
42 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
43 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
44 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. NO ASSURANCES ARE
45 * PROVIDED BY THE COPYRIGHT HOLDERS THAT THE SOFTWARE DOES NOT INFRINGE
46 * THE PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OF ANY OTHER ENTITY.
47 * EACH COPYRIGHT HOLDER DISCLAIMS ANY LIABILITY TO THE USER FOR CLAIMS
48 * BROUGHT BY ANY OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL
49 * PROPERTY RIGHTS OR OTHERWISE. AS A CONDITION TO EXERCISING THE RIGHTS
50 * GRANTED HEREUNDER, EACH USER HEREBY ASSUMES SOLE RESPONSIBILITY TO SECURE
51 * ANY OTHER INTELLECTUAL PROPERTY RIGHTS NEEDED, IF ANY. THE SOFTWARE
52 * IS NOT FAULT-TOLERANT AND IS NOT INTENDED FOR USE IN MISSION-CRITICAL
53 * SYSTEMS, SUCH AS THOSE USED IN THE OPERATION OF NUCLEAR FACILITIES,
54 * AIRCRAFT NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL
55 * SYSTEMS, DIRECT LIFE SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH
56 * THE FAILURE OF THE SOFTWARE OR SYSTEM COULD LEAD DIRECTLY TO DEATH,
57 * PERSONAL INJURY, OR SEVERE PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH
58 * RISK ACTIVITIES"). THE COPYRIGHT HOLDERS SPECIFICALLY DISCLAIM ANY
59 * EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR HIGH RISK ACTIVITIES.
60 *
61 * __END_OF_JASPER_LICENSE__
62 */
63
64 /*
65 * I/O Stream Class
66 *
67 * $Id$
68 */
69
70 #ifndef JAS_STREAM_H
71 #define JAS_STREAM_H
72
73 /******************************************************************************\
74 * Includes.
75 \******************************************************************************/
76
77 /* The configuration header file should be included first. */
78 #include <jasper/jas_config.h>
79
80 #include <stdio.h>
81 #if defined(JAS_HAVE_FCNTL_H)
82 #include <fcntl.h>
83 #endif
84 #include <string.h>
85 #if defined(JAS_HAVE_UNISTD_H)
86 #include <unistd.h>
87 #endif
88 #include <jasper/jas_types.h>
89
90 #ifdef __cplusplus
91 extern "C" {
92 #endif
93
94 /******************************************************************************\
95 * Constants.
96 \******************************************************************************/
97
98 /* On most UNIX systems, we probably need to define O_BINARY ourselves. */
99 #ifndef O_BINARY
100 #define O_BINARY 0
101 #endif
102
103 /*
104 * Stream open flags.
105 */
106
107 /* The stream was opened for reading. */
108 #define JAS_STREAM_READ 0x0001
109 /* The stream was opened for writing. */
110 #define JAS_STREAM_WRITE 0x0002
111 /* The stream was opened for appending. */
112 #define JAS_STREAM_APPEND 0x0004
113 /* The stream was opened in binary mode. */
114 #define JAS_STREAM_BINARY 0x0008
115 /* The stream should be created/truncated. */
116 #define JAS_STREAM_CREATE 0x0010
117
118
119 /*
120 * Stream buffering flags.
121 */
122
123 /* The stream is unbuffered. */
124 #define JAS_STREAM_UNBUF 0x0000
125 /* The stream is line buffered. */
126 #define JAS_STREAM_LINEBUF 0x0001
127 /* The stream is fully buffered. */
128 #define JAS_STREAM_FULLBUF 0x0002
129 /* The buffering mode mask. */
130 #define JAS_STREAM_BUFMODEMASK 0x000f
131
132 /* The memory associated with the buffer needs to be deallocated when the
133 stream is destroyed. */
134 #define JAS_STREAM_FREEBUF 0x0008
135 /* The buffer is currently being used for reading. */
136 #define JAS_STREAM_RDBUF 0x0010
137 /* The buffer is currently being used for writing. */
138 #define JAS_STREAM_WRBUF 0x0020
139
140 /*
141 * Stream error flags.
142 */
143
144 /* The end-of-file has been encountered (on reading). */
145 #define JAS_STREAM_EOF 0x0001
146 /* An I/O error has been encountered on the stream. */
147 #define JAS_STREAM_ERR 0x0002
148 /* The read/write limit has been exceeded. */
149 #define JAS_STREAM_RWLIMIT 0x0004
150 /* The error mask. */
151 #define JAS_STREAM_ERRMASK \
152 (JAS_STREAM_EOF | JAS_STREAM_ERR | JAS_STREAM_RWLIMIT)
153
154 /*
155 * Other miscellaneous constants.
156 */
157
158 /* The default buffer size (for fully-buffered operation). */
159 #define JAS_STREAM_BUFSIZE 8192
160 /* The default permission mask for file creation. */
161 #define JAS_STREAM_PERMS 0666
162
163 /* The maximum number of characters that can always be put back on a stream. */
164 #define JAS_STREAM_MAXPUTBACK 16
165
166 /******************************************************************************\
167 * Types.
168 \******************************************************************************/
169
170 /*
171 * Generic file object.
172 */
173
174 typedef void jas_stream_obj_t;
175
176 /*
177 * Generic file object operations.
178 */
179
180 typedef struct {
181
182 /* Read characters from a file object. */
183 int (*read_)(jas_stream_obj_t *obj, char *buf, int cnt);
184
185 /* Write characters to a file object. */
186 int (*write_)(jas_stream_obj_t *obj, char *buf, int cnt);
187
188 /* Set the position for a file object. */
189 long (*seek_)(jas_stream_obj_t *obj, long offset, int origin);
190
191 /* Close a file object. */
192 int (*close_)(jas_stream_obj_t *obj);
193
194 } jas_stream_ops_t;
195
196 /*
197 * Stream object.
198 */
199
200 typedef struct {
201
202 /* The mode in which the stream was opened. */
203 int openmode_;
204
205 /* The buffering mode. */
206 int bufmode_;
207
208 /* The stream status. */
209 int flags_;
210
211 /* The start of the buffer area to use for reading/writing. */
212 jas_uchar *bufbase_;
213
214 /* The start of the buffer area excluding the extra initial space for
215 character putback. */
216 jas_uchar *bufstart_;
217
218 /* The buffer size. */
219 int bufsize_;
220
221 /* The current position in the buffer. */
222 jas_uchar *ptr_;
223
224 /* The number of characters that must be read/written before
225 the buffer needs to be filled/flushed. */
226 int cnt_;
227
228 /* A trivial buffer to be used for unbuffered operation. */
229 jas_uchar tinybuf_[JAS_STREAM_MAXPUTBACK + 1];
230
231 /* The operations for the underlying stream file object. */
232 jas_stream_ops_t *ops_;
233
234 /* The underlying stream file object. */
235 jas_stream_obj_t *obj_;
236
237 /* The number of characters read/written. */
238 long rwcnt_;
239
240 /* The maximum number of characters that may be read/written. */
241 long rwlimit_;
242
243 } jas_stream_t;
244
245 /*
246 * Regular file object.
247 */
248
249 /*
250 * File descriptor file object.
251 */
252 typedef struct {
253 int fd;
254 int flags;
255 char pathname[L_tmpnam + 1];
256 } jas_stream_fileobj_t;
257
258 #define JAS_STREAM_FILEOBJ_DELONCLOSE 0x01
259 #define JAS_STREAM_FILEOBJ_NOCLOSE 0x02
260
261 /*
262 * Memory file object.
263 */
264
265 typedef struct {
266
267 /* The data associated with this file. */
268 jas_uchar *buf_;
269
270 /* The allocated size of the buffer for holding file data. */
271 size_t bufsize_;
272
273 /* The length of the file. */
274 int_fast32_t len_;
275
276 /* The seek position. */
277 int_fast32_t pos_;
278
279 /* Is the buffer growable? */
280 int growable_;
281
282 /* Was the buffer allocated internally? */
283 int myalloc_;
284
285 } jas_stream_memobj_t;
286
287 /******************************************************************************\
288 * Macros/functions for opening and closing streams.
289 \******************************************************************************/
290
291 /* Open a file as a stream. */
292 JAS_DLLEXPORT jas_stream_t *jas_stream_fopen(const char *filename, const char *mode);
293
294 /* Open a memory buffer as a stream. */
295 JAS_DLLEXPORT jas_stream_t *jas_stream_memopen(char *buf, int bufsize);
296
297 /* Do not use this function.
298 It will eventually replace jas_stream_memopen. */
299 JAS_DLLEXPORT jas_stream_t *jas_stream_memopen2(char *buf, size_t bufsize);
300
301 /* Open a file descriptor as a stream. */
302 JAS_DLLEXPORT jas_stream_t *jas_stream_fdopen(int fd, const char *mode);
303
304 /* Open a stdio stream as a stream. */
305 JAS_DLLEXPORT jas_stream_t *jas_stream_freopen(const char *path, const char *mode, FILE *fp);
306
307 /* Open a temporary file as a stream. */
308 JAS_DLLEXPORT jas_stream_t *jas_stream_tmpfile(void);
309
310 /* Close a stream. */
311 JAS_DLLEXPORT int jas_stream_close(jas_stream_t *stream);
312
313 /******************************************************************************\
314 * Macros/functions for getting/setting the stream state.
315 \******************************************************************************/
316
317 /* Get the EOF indicator for a stream. */
318 #define jas_stream_eof(stream) \
319 (((stream)->flags_ & JAS_STREAM_EOF) != 0)
320
321 /* Get the error indicator for a stream. */
322 #define jas_stream_error(stream) \
323 (((stream)->flags_ & JAS_STREAM_ERR) != 0)
324
325 /* Clear the error indicator for a stream. */
326 #define jas_stream_clearerr(stream) \
327 ((stream)->flags_ &= ~(JAS_STREAM_ERR | JAS_STREAM_EOF))
328
329 /* Get the read/write limit for a stream. */
330 #define jas_stream_getrwlimit(stream) \
331 (((const jas_stream_t *)(stream))->rwlimit_)
332
333 /* Set the read/write limit for a stream. */
334 JAS_DLLEXPORT int jas_stream_setrwlimit(jas_stream_t *stream, long rwlimit);
335
336 /* Get the read/write count for a stream. */
337 #define jas_stream_getrwcount(stream) \
338 (((const jas_stream_t *)(stream))->rwcnt_)
339
340 /* Set the read/write count for a stream. */
341 JAS_DLLEXPORT long jas_stream_setrwcount(jas_stream_t *stream, long rwcnt);
342
343 /******************************************************************************\
344 * Macros/functions for I/O.
345 \******************************************************************************/
346
347 /* Read a character from a stream. */
348 #if defined(DEBUG)
349 #define jas_stream_getc(stream) jas_stream_getc_func(stream)
350 #else
351 #define jas_stream_getc(stream) jas_stream_getc_macro(stream)
352 #endif
353
354 /* Write a character to a stream. */
355 #if defined(DEBUG)
356 #define jas_stream_putc(stream, c) jas_stream_putc_func(stream, c)
357 #else
358 #define jas_stream_putc(stream, c) jas_stream_putc_macro(stream, c)
359 #endif
360
361 /* Read characters from a stream into a buffer. */
362 JAS_DLLEXPORT int jas_stream_read(jas_stream_t *stream, void *buf, int cnt);
363
364 /* Write characters from a buffer to a stream. */
365 JAS_DLLEXPORT int jas_stream_write(jas_stream_t *stream, const void *buf, int cnt);
366
367 /* Write formatted output to a stream. */
368 JAS_DLLEXPORT int jas_stream_printf(jas_stream_t *stream, const char *fmt, ...);
369
370 /* Write a string to a stream. */
371 JAS_DLLEXPORT int jas_stream_puts(jas_stream_t *stream, const char *s);
372
373 /* Read a line of input from a stream. */
374 JAS_DLLEXPORT char *jas_stream_gets(jas_stream_t *stream, char *buf, int bufsize);
375
376 /* Look at the next character to be read from a stream without actually
377 removing it from the stream. */
378 #define jas_stream_peekc(stream) \
379 (((stream)->cnt_ <= 0) ? jas_stream_fillbuf(stream, 0) : \
380 ((int)(*(stream)->ptr_)))
381
382 /* Put a character back on a stream. */
383 JAS_DLLEXPORT int jas_stream_ungetc(jas_stream_t *stream, int c);
384
385 /******************************************************************************\
386 * Macros/functions for getting/setting the stream position.
387 \******************************************************************************/
388
389 /* Is it possible to seek on this stream? */
390 JAS_DLLEXPORT int jas_stream_isseekable(jas_stream_t *stream);
391
392 /* Set the current position within the stream. */
393 JAS_DLLEXPORT long jas_stream_seek(jas_stream_t *stream, long offset, int origin);
394
395 /* Get the current position within the stream. */
396 JAS_DLLEXPORT long jas_stream_tell(jas_stream_t *stream);
397
398 /* Seek to the beginning of a stream. */
399 JAS_DLLEXPORT int jas_stream_rewind(jas_stream_t *stream);
400
401 /******************************************************************************\
402 * Macros/functions for flushing.
403 \******************************************************************************/
404
405 /* Flush any pending output to a stream. */
406 JAS_DLLEXPORT int jas_stream_flush(jas_stream_t *stream);
407
408 /******************************************************************************\
409 * Miscellaneous macros/functions.
410 \******************************************************************************/
411
412 /* Copy data from one stream to another. */
413 JAS_DLLEXPORT int jas_stream_copy(jas_stream_t *dst, jas_stream_t *src, int n);
414
415 /* Display stream contents (for debugging purposes). */
416 JAS_DLLEXPORT int jas_stream_display(jas_stream_t *stream, FILE *fp, int n);
417
418 /* Consume (i.e., discard) characters from stream. */
419 JAS_DLLEXPORT int jas_stream_gobble(jas_stream_t *stream, int n);
420
421 /* Write a character multiple times to a stream. */
422 JAS_DLLEXPORT int jas_stream_pad(jas_stream_t *stream, int n, int c);
423
424 /* Get the size of the file associated with the specified stream.
425 The specified stream must be seekable. */
426 JAS_DLLEXPORT long jas_stream_length(jas_stream_t *stream);
427
428 /******************************************************************************\
429 * Internal functions.
430 \******************************************************************************/
431
432 /* The following functions are for internal use only! If you call them
433 directly, you will die a horrible, miserable, and painful death! */
434
435 /* Read a character from a stream. */
436 #define jas_stream_getc_macro(stream) \
437 ((!((stream)->flags_ & (JAS_STREAM_ERR | JAS_STREAM_EOF | \
438 JAS_STREAM_RWLIMIT))) ? \
439 (((stream)->rwlimit_ >= 0 && (stream)->rwcnt_ >= (stream)->rwlimit_) ? \
440 (stream->flags_ |= JAS_STREAM_RWLIMIT, EOF) : \
441 jas_stream_getc2(stream)) : EOF)
442 #define jas_stream_getc2(stream) \
443 ((--(stream)->cnt_ < 0) ? jas_stream_fillbuf(stream, 1) : \
444 (++(stream)->rwcnt_, (int)(*(stream)->ptr_++)))
445
446 /* Write a character to a stream. */
447 #define jas_stream_putc_macro(stream, c) \
448 ((!((stream)->flags_ & (JAS_STREAM_ERR | JAS_STREAM_EOF | \
449 JAS_STREAM_RWLIMIT))) ? \
450 (((stream)->rwlimit_ >= 0 && (stream)->rwcnt_ >= (stream)->rwlimit_) ? \
451 (stream->flags_ |= JAS_STREAM_RWLIMIT, EOF) : \
452 jas_stream_putc2(stream, c)) : EOF)
453 #define jas_stream_putc2(stream, c) \
454 (((stream)->bufmode_ |= JAS_STREAM_WRBUF, --(stream)->cnt_ < 0) ? \
455 jas_stream_flushbuf((stream), (jas_uchar)(c)) : \
456 (++(stream)->rwcnt_, (int)(*(stream)->ptr_++ = (c))))
457
458 /* These prototypes need to be here for the sake of the stream_getc and
459 stream_putc macros. */
460 JAS_DLLEXPORT int jas_stream_fillbuf(jas_stream_t *stream, int getflag);
461 JAS_DLLEXPORT int jas_stream_flushbuf(jas_stream_t *stream, int c);
462 JAS_DLLEXPORT int jas_stream_getc_func(jas_stream_t *stream);
463 JAS_DLLEXPORT int jas_stream_putc_func(jas_stream_t *stream, int c);
464
465 #ifdef __cplusplus
466 }
467 #endif
468
469 #endif