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      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: jas_stream.h,v 1.2 2008-05-26 09:41:51 vp153 Exp $
     68  */
     69 
     70 #ifndef JAS_STREAM_H
     71 #define JAS_STREAM_H
     72 
     73 /******************************************************************************\
     74 * Includes.
     75 \******************************************************************************/
     76 
     77 #include <jasper/jas_config.h>
     78 
     79 #include <stdio.h>
     80 #include <limits.h>
     81 #if defined(HAVE_FCNTL_H)
     82 #include <fcntl.h>
     83 #endif
     84 #include <string.h>
     85 #if defined(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     uchar *bufbase_;
    213 
    214     /* The start of the buffer area excluding the extra initial space for
    215       character putback. */
    216     uchar *bufstart_;
    217 
    218     /* The buffer size. */
    219     int bufsize_;
    220 
    221     /* The current position in the buffer. */
    222     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     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 #if defined _WIN32 && !defined __MINGW__ && !defined __MINGW32__
    256     char pathname[MAX_PATH + 1];
    257 #else
    258     char pathname[PATH_MAX + 1];
    259 #endif
    260 } jas_stream_fileobj_t;
    261 
    262 #define	JAS_STREAM_FILEOBJ_DELONCLOSE	0x01
    263 #define JAS_STREAM_FILEOBJ_NOCLOSE	0x02
    264 
    265 /*
    266  * Memory file object.
    267  */
    268 
    269 typedef struct {
    270 
    271     /* The data associated with this file. */
    272     uchar *buf_;
    273 
    274     /* The allocated size of the buffer for holding file data. */
    275     int bufsize_;
    276 
    277     /* The length of the file. */
    278     int_fast32_t len_;
    279 
    280     /* The seek position. */
    281     int_fast32_t pos_;
    282 
    283     /* Is the buffer growable? */
    284     int growable_;
    285 
    286     /* Was the buffer allocated internally? */
    287     int myalloc_;
    288 
    289 } jas_stream_memobj_t;
    290 
    291 /******************************************************************************\
    292 * Macros/functions for opening and closing streams.
    293 \******************************************************************************/
    294 
    295 /* Open a file as a stream. */
    296 jas_stream_t *jas_stream_fopen(const char *filename, const char *mode);
    297 
    298 /* Open a memory buffer as a stream. */
    299 jas_stream_t *jas_stream_memopen(char *buf, int bufsize);
    300 
    301 /* Open a file descriptor as a stream. */
    302 jas_stream_t *jas_stream_fdopen(int fd, const char *mode);
    303 
    304 /* Open a stdio stream as a stream. */
    305 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_stream_t *jas_stream_tmpfile(void);
    309 
    310 /* Close a stream. */
    311 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 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 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 int jas_stream_read(jas_stream_t *stream, void *buf, int cnt);
    363 
    364 /* Write characters from a buffer to a stream. */
    365 int jas_stream_write(jas_stream_t *stream, const void *buf, int cnt);
    366 
    367 /* Write formatted output to a stream. */
    368 int jas_stream_printf(jas_stream_t *stream, const char *fmt, ...);
    369 
    370 /* Write a string to a stream. */
    371 int jas_stream_puts(jas_stream_t *stream, const char *s);
    372 
    373 /* Read a line of input from a stream. */
    374 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 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 int jas_stream_isseekable(jas_stream_t *stream);
    391 
    392 /* Set the current position within the stream. */
    393 long jas_stream_seek(jas_stream_t *stream, long offset, int origin);
    394 
    395 /* Get the current position within the stream. */
    396 long jas_stream_tell(jas_stream_t *stream);
    397 
    398 /* Seek to the beginning of a stream. */
    399 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 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 int jas_stream_copy(jas_stream_t *dst, jas_stream_t *src, int n);
    414 
    415 /* Display stream contents (for debugging purposes). */
    416 int jas_stream_display(jas_stream_t *stream, FILE *fp, int n);
    417 
    418 /* Consume (i.e., discard) characters from stream. */
    419 int jas_stream_gobble(jas_stream_t *stream, int n);
    420 
    421 /* Write a character multiple times to a stream. */
    422 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 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), (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 int jas_stream_fillbuf(jas_stream_t *stream, int getflag);
    461 int jas_stream_flushbuf(jas_stream_t *stream, int c);
    462 int jas_stream_getc_func(jas_stream_t *stream);
    463 int jas_stream_putc_func(jas_stream_t *stream, int c);
    464 
    465 #ifdef __cplusplus
    466 }
    467 #endif
    468 
    469 #endif
    470