My Project  2.0.19
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> /* IWYU pragma: export */
79 
80 #include <stdio.h>
81 #include <limits.h>
82 #if defined(JAS_HAVE_FCNTL_H)
83 #include <fcntl.h>
84 #endif
85 #include <jasper/jas_types.h>
86 
87 #ifdef __cplusplus
88 extern "C" {
89 #endif
90 
91 /******************************************************************************\
92 * Constants.
93 \******************************************************************************/
94 
95 /* On most UNIX systems, we probably need to define O_BINARY ourselves. */
96 #ifndef O_BINARY
97 #define O_BINARY 0
98 #endif
99 
100 #ifdef PATH_MAX
101 #define JAS_PATH_MAX PATH_MAX
102 #else
103 #define JAS_PATH_MAX 4096
104 #endif
105 
106 /*
107  * Stream open flags.
108  */
109 
110 /* The stream was opened for reading. */
111 #define JAS_STREAM_READ 0x0001
112 /* The stream was opened for writing. */
113 #define JAS_STREAM_WRITE 0x0002
114 /* The stream was opened for appending. */
115 #define JAS_STREAM_APPEND 0x0004
116 /* The stream was opened in binary mode. */
117 #define JAS_STREAM_BINARY 0x0008
118 /* The stream should be created/truncated. */
119 #define JAS_STREAM_CREATE 0x0010
120 
121 
122 /*
123  * Stream buffering flags.
124  */
125 
126 /* The stream is unbuffered. */
127 #define JAS_STREAM_UNBUF 0x0000
128 /* The stream is line buffered. */
129 #define JAS_STREAM_LINEBUF 0x0001
130 /* The stream is fully buffered. */
131 #define JAS_STREAM_FULLBUF 0x0002
132 /* The buffering mode mask. */
133 #define JAS_STREAM_BUFMODEMASK 0x000f
134 
135 /* The memory associated with the buffer needs to be deallocated when the
136  stream is destroyed. */
137 #define JAS_STREAM_FREEBUF 0x0008
138 /* The buffer is currently being used for reading. */
139 #define JAS_STREAM_RDBUF 0x0010
140 /* The buffer is currently being used for writing. */
141 #define JAS_STREAM_WRBUF 0x0020
142 
143 /*
144  * Stream error flags.
145  */
146 
147 /* The end-of-file has been encountered (on reading). */
148 #define JAS_STREAM_EOF 0x0001
149 /* An I/O error has been encountered on the stream. */
150 #define JAS_STREAM_ERR 0x0002
151 /* The read/write limit has been exceeded. */
152 #define JAS_STREAM_RWLIMIT 0x0004
153 /* The error mask. */
154 #define JAS_STREAM_ERRMASK \
155  (JAS_STREAM_EOF | JAS_STREAM_ERR | JAS_STREAM_RWLIMIT)
156 
157 /*
158  * Other miscellaneous constants.
159  */
160 
161 /* The default buffer size (for fully-buffered operation). */
162 #define JAS_STREAM_BUFSIZE 8192
163 /* The default permission mask for file creation. */
164 #define JAS_STREAM_PERMS 0666
165 
166 /* The maximum number of characters that can always be put back on a stream. */
167 #define JAS_STREAM_MAXPUTBACK 16
168 
169 /******************************************************************************\
170 * Types.
171 \******************************************************************************/
172 
173 /*
174  * Generic file object.
175  */
176 
177 typedef void jas_stream_obj_t;
178 
179 /*
180  * Generic file object operations.
181  */
182 
183 typedef struct {
184 
185  /* Read characters from a file object. */
186  int (*read_)(jas_stream_obj_t *obj, char *buf, unsigned cnt);
187 
188  /* Write characters to a file object. */
189  int (*write_)(jas_stream_obj_t *obj, char *buf, unsigned cnt);
190 
191  /* Set the position for a file object. */
192  long (*seek_)(jas_stream_obj_t *obj, long offset, int origin);
193 
194  /* Close a file object. */
195  int (*close_)(jas_stream_obj_t *obj);
196 
197 } jas_stream_ops_t;
198 
199 /*
200  * Stream object.
201  */
202 
203 typedef struct {
204 
205  /* The mode in which the stream was opened. */
206  int openmode_;
207 
208  /* The buffering mode. */
209  int bufmode_;
210 
211  /* The stream status. */
212  int flags_;
213 
214  /* The start of the buffer area to use for reading/writing. */
215  jas_uchar *bufbase_;
216 
217  /* The start of the buffer area excluding the extra initial space for
218  character putback. */
219  jas_uchar *bufstart_;
220 
221  /* The buffer size. */
222  int bufsize_;
223 
224  /* The current position in the buffer. */
225  jas_uchar *ptr_;
226 
227  /* The number of characters that must be read/written before
228  the buffer needs to be filled/flushed. */
229  int cnt_;
230 
231  /* A trivial buffer to be used for unbuffered operation. */
232  jas_uchar tinybuf_[JAS_STREAM_MAXPUTBACK + 1];
233 
234  /* The operations for the underlying stream file object. */
235  const jas_stream_ops_t *ops_;
236 
237  /* The underlying stream file object. */
238  jas_stream_obj_t *obj_;
239 
240  /* The number of characters read/written. */
241  long rwcnt_;
242 
243  /* The maximum number of characters that may be read/written. */
244  long rwlimit_;
245 
246 } jas_stream_t;
247 
248 /*
249  * Regular file object.
250  */
251 
252 /*
253  * File descriptor file object.
254  */
255 typedef struct {
256  int fd;
257  int flags;
258  char pathname[JAS_PATH_MAX + 1];
259 } jas_stream_fileobj_t;
260 
261 #define JAS_STREAM_FILEOBJ_DELONCLOSE 0x01
262 #define JAS_STREAM_FILEOBJ_NOCLOSE 0x02
263 
264 /*
265  * Memory file object.
266  */
267 
268 typedef struct {
269 
270  /* The data associated with this file. */
271  jas_uchar *buf_;
272 
273  /* The allocated size of the buffer for holding file data. */
274  size_t bufsize_;
275 
276  /* The length of the file. */
277  uint_fast32_t len_;
278 
279  /* The seek position. */
280  uint_fast32_t pos_;
281 
282  /* Is the buffer growable? */
283  int growable_;
284 
285  /* Was the buffer allocated internally? */
286  int myalloc_;
287 
288 } jas_stream_memobj_t;
289 
290 /******************************************************************************\
291 * Macros/functions for opening and closing streams.
292 \******************************************************************************/
293 
294 /* Open a file as a stream. */
295 JAS_DLLEXPORT jas_stream_t *jas_stream_fopen(const char *filename, const char *mode);
296 
297 /* Open a memory buffer as a stream. */
298 JAS_DLLEXPORT jas_stream_t *jas_stream_memopen(char *buf, int bufsize);
299 
300 /* Do not use this function.
301 It will eventually replace jas_stream_memopen. */
302 JAS_DLLEXPORT jas_stream_t *jas_stream_memopen2(char *buf, size_t bufsize);
303 
304 /* Open a file descriptor as a stream. */
305 JAS_DLLEXPORT jas_stream_t *jas_stream_fdopen(int fd, const char *mode);
306 
307 /* Open a stdio stream as a stream. */
308 JAS_DLLEXPORT jas_stream_t *jas_stream_freopen(const char *path, const char *mode, FILE *fp);
309 
310 /* Open a temporary file as a stream. */
311 JAS_DLLEXPORT jas_stream_t *jas_stream_tmpfile(void);
312 
313 /* Close a stream. */
314 JAS_DLLEXPORT int jas_stream_close(jas_stream_t *stream);
315 
316 /******************************************************************************\
317 * Macros/functions for getting/setting the stream state.
318 \******************************************************************************/
319 
320 /* Get the EOF indicator for a stream. */
321 #define jas_stream_eof(stream) \
322  (((stream)->flags_ & JAS_STREAM_EOF) != 0)
323 
324 /* Get the error indicator for a stream. */
325 #define jas_stream_error(stream) \
326  (((stream)->flags_ & JAS_STREAM_ERR) != 0)
327 
328 /* Clear the error indicator for a stream. */
329 #define jas_stream_clearerr(stream) \
330  ((stream)->flags_ &= ~(JAS_STREAM_ERR | JAS_STREAM_EOF))
331 
332 /* Get the read/write limit for a stream. */
333 #define jas_stream_getrwlimit(stream) \
334  (((const jas_stream_t *)(stream))->rwlimit_)
335 
336 /* Set the read/write limit for a stream. */
337 JAS_DLLEXPORT int jas_stream_setrwlimit(jas_stream_t *stream, long rwlimit);
338 
339 /* Get the read/write count for a stream. */
340 #define jas_stream_getrwcount(stream) \
341  (((const jas_stream_t *)(stream))->rwcnt_)
342 
343 /* Set the read/write count for a stream. */
344 JAS_DLLEXPORT long jas_stream_setrwcount(jas_stream_t *stream, long rwcnt);
345 
346 /******************************************************************************\
347 * Macros/functions for I/O.
348 \******************************************************************************/
349 
350 /* Read a character from a stream. */
351 #if defined(DEBUG)
352 #define jas_stream_getc(stream) jas_stream_getc_func(stream)
353 #else
354 #define jas_stream_getc(stream) jas_stream_getc_macro(stream)
355 #endif
356 
357 /* Write a character to a stream. */
358 #if defined(DEBUG)
359 #define jas_stream_putc(stream, c) jas_stream_putc_func(stream, c)
360 #else
361 #define jas_stream_putc(stream, c) jas_stream_putc_macro(stream, c)
362 #endif
363 
364 /* Read characters from a stream into a buffer. */
365 JAS_DLLEXPORT int jas_stream_read(jas_stream_t *stream, void *buf, unsigned cnt);
366 
367 /* Write characters from a buffer to a stream. */
368 JAS_DLLEXPORT int jas_stream_write(jas_stream_t *stream, const void *buf, unsigned cnt);
369 
370 /* Write formatted output to a stream. */
371 JAS_DLLEXPORT int jas_stream_printf(jas_stream_t *stream, const char *fmt, ...);
372 
373 /* Write a string to a stream. */
374 JAS_DLLEXPORT int jas_stream_puts(jas_stream_t *stream, const char *s);
375 
376 /* Read a line of input from a stream. */
377 JAS_DLLEXPORT char *jas_stream_gets(jas_stream_t *stream, char *buf, int bufsize);
378 
379 /* Look at the next character to be read from a stream without actually
380  removing it from the stream. */
381 #define jas_stream_peekc(stream) \
382  (((stream)->cnt_ <= 0) ? jas_stream_fillbuf(stream, 0) : \
383  ((int)(*(stream)->ptr_)))
384 
385 /* Put a character back on a stream. */
386 JAS_DLLEXPORT int jas_stream_ungetc(jas_stream_t *stream, int c);
387 
388 /******************************************************************************\
389 * Macros/functions for getting/setting the stream position.
390 \******************************************************************************/
391 
392 /* Is it possible to seek on this stream? */
393 JAS_ATTRIBUTE_PURE
394 JAS_DLLEXPORT int jas_stream_isseekable(jas_stream_t *stream);
395 
396 /* Set the current position within the stream. */
397 JAS_DLLEXPORT long jas_stream_seek(jas_stream_t *stream, long offset, int origin);
398 
399 /* Get the current position within the stream. */
400 JAS_ATTRIBUTE_PURE
401 JAS_DLLEXPORT long jas_stream_tell(jas_stream_t *stream);
402 
403 /* Seek to the beginning of a stream. */
404 JAS_DLLEXPORT int jas_stream_rewind(jas_stream_t *stream);
405 
406 /******************************************************************************\
407 * Macros/functions for flushing.
408 \******************************************************************************/
409 
410 /* Flush any pending output to a stream. */
411 JAS_DLLEXPORT int jas_stream_flush(jas_stream_t *stream);
412 
413 /******************************************************************************\
414 * Miscellaneous macros/functions.
415 \******************************************************************************/
416 
417 /* Copy data from one stream to another. */
418 JAS_DLLEXPORT int jas_stream_copy(jas_stream_t *dst, jas_stream_t *src, int n);
419 
420 /* Display stream contents (for debugging purposes). */
421 JAS_DLLEXPORT int jas_stream_display(jas_stream_t *stream, FILE *fp, int n);
422 
423 /* Consume (i.e., discard) characters from stream. */
424 JAS_DLLEXPORT int jas_stream_gobble(jas_stream_t *stream, int n);
425 
426 /* Write a character multiple times to a stream. */
427 JAS_DLLEXPORT int jas_stream_pad(jas_stream_t *stream, int n, int c);
428 
429 /* Get the size of the file associated with the specified stream.
430  The specified stream must be seekable. */
431 JAS_ATTRIBUTE_PURE
432 JAS_DLLEXPORT long jas_stream_length(jas_stream_t *stream);
433 
434 /******************************************************************************\
435 * Internal functions.
436 \******************************************************************************/
437 
438 /* The following functions are for internal use only! If you call them
439 directly, you will die a horrible, miserable, and painful death! */
440 
441 /* Read a character from a stream. */
442 #define jas_stream_getc_macro(stream) \
443  ((!((stream)->flags_ & (JAS_STREAM_ERR | JAS_STREAM_EOF | \
444  JAS_STREAM_RWLIMIT))) ? \
445  (((stream)->rwlimit_ >= 0 && (stream)->rwcnt_ >= (stream)->rwlimit_) ? \
446  (stream->flags_ |= JAS_STREAM_RWLIMIT, EOF) : \
447  jas_stream_getc2(stream)) : EOF)
448 #define jas_stream_getc2(stream) \
449  ((--(stream)->cnt_ < 0) ? jas_stream_fillbuf(stream, 1) : \
450  (++(stream)->rwcnt_, (int)(*(stream)->ptr_++)))
451 
452 /* Write a character to a stream. */
453 #define jas_stream_putc_macro(stream, c) \
454  ((!((stream)->flags_ & (JAS_STREAM_ERR | JAS_STREAM_EOF | \
455  JAS_STREAM_RWLIMIT))) ? \
456  (((stream)->rwlimit_ >= 0 && (stream)->rwcnt_ >= (stream)->rwlimit_) ? \
457  (stream->flags_ |= JAS_STREAM_RWLIMIT, EOF) : \
458  jas_stream_putc2(stream, c)) : EOF)
459 #define jas_stream_putc2(stream, c) \
460  (((stream)->bufmode_ |= JAS_STREAM_WRBUF, --(stream)->cnt_ < 0) ? \
461  jas_stream_flushbuf((stream), (jas_uchar)(c)) : \
462  (++(stream)->rwcnt_, (int)(*(stream)->ptr_++ = (c))))
463 
464 /* These prototypes need to be here for the sake of the stream_getc and
465 stream_putc macros. */
466 JAS_DLLEXPORT int jas_stream_fillbuf(jas_stream_t *stream, int getflag);
467 JAS_DLLEXPORT int jas_stream_flushbuf(jas_stream_t *stream, int c);
468 JAS_DLLEXPORT int jas_stream_getc_func(jas_stream_t *stream);
469 JAS_DLLEXPORT int jas_stream_putc_func(jas_stream_t *stream, int c);
470 
471 #ifdef __cplusplus
472 }
473 #endif
474 
475 #endif