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✏️ Editing: jas_stream.h

/*
 * Copyright (c) 1999-2000 Image Power, Inc. and the University of
 *   British Columbia.
 * Copyright (c) 2001-2003 Michael David Adams.
 * All rights reserved.
 */

/* __START_OF_JASPER_LICENSE__
 * 
 * JasPer License Version 2.0
 * 
 * Copyright (c) 2001-2006 Michael David Adams
 * Copyright (c) 1999-2000 Image Power, Inc.
 * Copyright (c) 1999-2000 The University of British Columbia
 * 
 * All rights reserved.
 * 
 * Permission is hereby granted, free of charge, to any person (the
 * "User") obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, and/or sell copies of the Software, and to permit
 * persons to whom the Software is furnished to do so, subject to the
 * following conditions:
 * 
 * 1.  The above copyright notices and this permission notice (which
 * includes the disclaimer below) shall be included in all copies or
 * substantial portions of the Software.
 * 
 * 2.  The name of a copyright holder shall not be used to endorse or
 * promote products derived from the Software without specific prior
 * written permission.
 * 
 * THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS
 * LICENSE.  NO USE OF THE SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER
 * THIS DISCLAIMER.  THE SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS
 * "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.  IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL
 * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING
 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.  NO ASSURANCES ARE
 * PROVIDED BY THE COPYRIGHT HOLDERS THAT THE SOFTWARE DOES NOT INFRINGE
 * THE PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OF ANY OTHER ENTITY.
 * EACH COPYRIGHT HOLDER DISCLAIMS ANY LIABILITY TO THE USER FOR CLAIMS
 * BROUGHT BY ANY OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL
 * PROPERTY RIGHTS OR OTHERWISE.  AS A CONDITION TO EXERCISING THE RIGHTS
 * GRANTED HEREUNDER, EACH USER HEREBY ASSUMES SOLE RESPONSIBILITY TO SECURE
 * ANY OTHER INTELLECTUAL PROPERTY RIGHTS NEEDED, IF ANY.  THE SOFTWARE
 * IS NOT FAULT-TOLERANT AND IS NOT INTENDED FOR USE IN MISSION-CRITICAL
 * SYSTEMS, SUCH AS THOSE USED IN THE OPERATION OF NUCLEAR FACILITIES,
 * AIRCRAFT NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL
 * SYSTEMS, DIRECT LIFE SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH
 * THE FAILURE OF THE SOFTWARE OR SYSTEM COULD LEAD DIRECTLY TO DEATH,
 * PERSONAL INJURY, OR SEVERE PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH
 * RISK ACTIVITIES").  THE COPYRIGHT HOLDERS SPECIFICALLY DISCLAIM ANY
 * EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR HIGH RISK ACTIVITIES.
 * 
 * __END_OF_JASPER_LICENSE__
 */

/*
 * I/O Stream Class
 *
 * $Id$
 */

#ifndef JAS_STREAM_H
#define JAS_STREAM_H

/******************************************************************************\
* Includes.
\******************************************************************************/

/* The configuration header file should be included first. */
#include <jasper/jas_config.h>

#include <stdio.h>
#if defined(JAS_HAVE_FCNTL_H)
#include <fcntl.h>
#endif
#include <string.h>
#if defined(JAS_HAVE_UNISTD_H)
#include <unistd.h>
#endif
#include <jasper/jas_types.h>

#ifdef __cplusplus
extern "C" {
#endif

/******************************************************************************\
* Constants.
\******************************************************************************/

/* On most UNIX systems, we probably need to define O_BINARY ourselves. */
#ifndef O_BINARY
#define O_BINARY	0
#endif

/*
 * Stream open flags.
 */

/* The stream was opened for reading. */
#define JAS_STREAM_READ	0x0001
/* The stream was opened for writing. */
#define JAS_STREAM_WRITE	0x0002
/* The stream was opened for appending. */
#define JAS_STREAM_APPEND	0x0004
/* The stream was opened in binary mode. */
#define JAS_STREAM_BINARY	0x0008
/* The stream should be created/truncated. */
#define JAS_STREAM_CREATE	0x0010

/*
 * Stream buffering flags.
 */

/* The stream is unbuffered. */
#define JAS_STREAM_UNBUF	0x0000
/* The stream is line buffered. */
#define JAS_STREAM_LINEBUF	0x0001
/* The stream is fully buffered. */
#define JAS_STREAM_FULLBUF	0x0002
/* The buffering mode mask. */
#define	JAS_STREAM_BUFMODEMASK	0x000f

/* The memory associated with the buffer needs to be deallocated when the
  stream is destroyed. */
#define JAS_STREAM_FREEBUF	0x0008
/* The buffer is currently being used for reading. */
#define JAS_STREAM_RDBUF	0x0010
/* The buffer is currently being used for writing. */
#define JAS_STREAM_WRBUF	0x0020

/*
 * Stream error flags.
 */

/* The end-of-file has been encountered (on reading). */
#define JAS_STREAM_EOF	0x0001
/* An I/O error has been encountered on the stream. */
#define JAS_STREAM_ERR	0x0002
/* The read/write limit has been exceeded. */
#define	JAS_STREAM_RWLIMIT	0x0004
/* The error mask. */
#define JAS_STREAM_ERRMASK \
	(JAS_STREAM_EOF | JAS_STREAM_ERR | JAS_STREAM_RWLIMIT)

/*
 * Other miscellaneous constants.
 */

/* The default buffer size (for fully-buffered operation). */
#define JAS_STREAM_BUFSIZE	8192
/* The default permission mask for file creation. */
#define JAS_STREAM_PERMS	0666

/* The maximum number of characters that can always be put back on a stream. */
#define	JAS_STREAM_MAXPUTBACK	16

/******************************************************************************\
* Types.
\******************************************************************************/

/*
 * Generic file object.
 */

typedef void jas_stream_obj_t;

/*
 * Generic file object operations.
 */

typedef struct {

/* Read characters from a file object. */
	int (*read_)(jas_stream_obj_t *obj, char *buf, int cnt);

/* Write characters to a file object. */
	int (*write_)(jas_stream_obj_t *obj, char *buf, int cnt);

/* Set the position for a file object. */
	long (*seek_)(jas_stream_obj_t *obj, long offset, int origin);

/* Close a file object. */
	int (*close_)(jas_stream_obj_t *obj);

} jas_stream_ops_t;

/*
 * Stream object.
 */

typedef struct {

/* The mode in which the stream was opened. */
	int openmode_;

/* The buffering mode. */
	int bufmode_;

/* The stream status. */
	int flags_;

/* The start of the buffer area to use for reading/writing. */
	jas_uchar *bufbase_;

/* The start of the buffer area excluding the extra initial space for
	  character putback. */
	jas_uchar *bufstart_;

/* The buffer size. */
	int bufsize_;

/* The current position in the buffer. */
	jas_uchar *ptr_;

/* The number of characters that must be read/written before
	the buffer needs to be filled/flushed. */
	int cnt_;

/* A trivial buffer to be used for unbuffered operation. */
	jas_uchar tinybuf_[JAS_STREAM_MAXPUTBACK + 1];

/* The operations for the underlying stream file object. */
	jas_stream_ops_t *ops_;

/* The underlying stream file object. */
	jas_stream_obj_t *obj_;

/* The number of characters read/written. */
	long rwcnt_;

/* The maximum number of characters that may be read/written. */
	long rwlimit_;

} jas_stream_t;

/*
 * Regular file object.
 */

/*
 * File descriptor file object.
 */
typedef struct {
	int fd;
	int flags;
	char pathname[L_tmpnam + 1];
} jas_stream_fileobj_t;

#define	JAS_STREAM_FILEOBJ_DELONCLOSE	0x01
#define JAS_STREAM_FILEOBJ_NOCLOSE	0x02

/*
 * Memory file object.
 */

typedef struct {

/* The data associated with this file. */
	jas_uchar *buf_;

/* The allocated size of the buffer for holding file data. */
	size_t bufsize_;

/* The length of the file. */
	int_fast32_t len_;

/* The seek position. */
	int_fast32_t pos_;

/* Is the buffer growable? */
	int growable_;

/* Was the buffer allocated internally? */
	int myalloc_;

} jas_stream_memobj_t;

/******************************************************************************\
* Macros/functions for opening and closing streams.
\******************************************************************************/

/* Open a file as a stream. */
JAS_DLLEXPORT jas_stream_t *jas_stream_fopen(const char *filename, const char *mode);

/* Open a memory buffer as a stream. */
JAS_DLLEXPORT jas_stream_t *jas_stream_memopen(char *buf, int bufsize);

/* Do not use this function.
It will eventually replace jas_stream_memopen. */
JAS_DLLEXPORT jas_stream_t *jas_stream_memopen2(char *buf, size_t bufsize);

/* Open a file descriptor as a stream. */
JAS_DLLEXPORT jas_stream_t *jas_stream_fdopen(int fd, const char *mode);

/* Open a stdio stream as a stream. */
JAS_DLLEXPORT jas_stream_t *jas_stream_freopen(const char *path, const char *mode, FILE *fp);

/* Open a temporary file as a stream. */
JAS_DLLEXPORT jas_stream_t *jas_stream_tmpfile(void);

/* Close a stream. */
JAS_DLLEXPORT int jas_stream_close(jas_stream_t *stream);

/******************************************************************************\
* Macros/functions for getting/setting the stream state.
\******************************************************************************/

/* Get the EOF indicator for a stream. */
#define jas_stream_eof(stream) \
	(((stream)->flags_ & JAS_STREAM_EOF) != 0)

/* Get the error indicator for a stream. */
#define jas_stream_error(stream) \
	(((stream)->flags_ & JAS_STREAM_ERR) != 0)

/* Clear the error indicator for a stream. */
#define jas_stream_clearerr(stream) \
	((stream)->flags_ &= ~(JAS_STREAM_ERR | JAS_STREAM_EOF))

/* Get the read/write limit for a stream. */
#define	jas_stream_getrwlimit(stream) \
	(((const jas_stream_t *)(stream))->rwlimit_)

/* Set the read/write limit for a stream. */
JAS_DLLEXPORT int jas_stream_setrwlimit(jas_stream_t *stream, long rwlimit);

/* Get the read/write count for a stream. */
#define	jas_stream_getrwcount(stream) \
	(((const jas_stream_t *)(stream))->rwcnt_)

/* Set the read/write count for a stream. */
JAS_DLLEXPORT long jas_stream_setrwcount(jas_stream_t *stream, long rwcnt);

/******************************************************************************\
* Macros/functions for I/O.
\******************************************************************************/

/* Read a character from a stream. */
#if defined(DEBUG)
#define	jas_stream_getc(stream)	jas_stream_getc_func(stream)
#else
#define jas_stream_getc(stream)	jas_stream_getc_macro(stream)
#endif

/* Write a character to a stream. */
#if defined(DEBUG)
#define jas_stream_putc(stream, c)	jas_stream_putc_func(stream, c)
#else
#define jas_stream_putc(stream, c)	jas_stream_putc_macro(stream, c)
#endif

/* Read characters from a stream into a buffer. */
JAS_DLLEXPORT int jas_stream_read(jas_stream_t *stream, void *buf, int cnt);

/* Write characters from a buffer to a stream. */
JAS_DLLEXPORT int jas_stream_write(jas_stream_t *stream, const void *buf, int cnt);

/* Write formatted output to a stream. */
JAS_DLLEXPORT int jas_stream_printf(jas_stream_t *stream, const char *fmt, ...);

/* Write a string to a stream. */
JAS_DLLEXPORT int jas_stream_puts(jas_stream_t *stream, const char *s);

/* Read a line of input from a stream. */
JAS_DLLEXPORT char *jas_stream_gets(jas_stream_t *stream, char *buf, int bufsize);

/* Look at the next character to be read from a stream without actually
  removing it from the stream. */
#define	jas_stream_peekc(stream) \
	(((stream)->cnt_ <= 0) ? jas_stream_fillbuf(stream, 0) : \
	  ((int)(*(stream)->ptr_)))

/* Put a character back on a stream. */
JAS_DLLEXPORT int jas_stream_ungetc(jas_stream_t *stream, int c);

/******************************************************************************\
* Macros/functions for getting/setting the stream position.
\******************************************************************************/

/* Is it possible to seek on this stream? */
JAS_DLLEXPORT int jas_stream_isseekable(jas_stream_t *stream);

/* Set the current position within the stream. */
JAS_DLLEXPORT long jas_stream_seek(jas_stream_t *stream, long offset, int origin);

/* Get the current position within the stream. */
JAS_DLLEXPORT long jas_stream_tell(jas_stream_t *stream);

/* Seek to the beginning of a stream. */
JAS_DLLEXPORT int jas_stream_rewind(jas_stream_t *stream);

/******************************************************************************\
* Macros/functions for flushing.
\******************************************************************************/

/* Flush any pending output to a stream. */
JAS_DLLEXPORT int jas_stream_flush(jas_stream_t *stream);

/******************************************************************************\
* Miscellaneous macros/functions.
\******************************************************************************/

/* Copy data from one stream to another. */
JAS_DLLEXPORT int jas_stream_copy(jas_stream_t *dst, jas_stream_t *src, int n);

/* Display stream contents (for debugging purposes). */
JAS_DLLEXPORT int jas_stream_display(jas_stream_t *stream, FILE *fp, int n);

/* Consume (i.e., discard) characters from stream. */
JAS_DLLEXPORT int jas_stream_gobble(jas_stream_t *stream, int n);

/* Write a character multiple times to a stream. */
JAS_DLLEXPORT int jas_stream_pad(jas_stream_t *stream, int n, int c);

/* Get the size of the file associated with the specified stream.
  The specified stream must be seekable. */
JAS_DLLEXPORT long jas_stream_length(jas_stream_t *stream);

/******************************************************************************\
* Internal functions.
\******************************************************************************/

/* The following functions are for internal use only!  If you call them
directly, you will die a horrible, miserable, and painful death! */

/* Read a character from a stream. */
#define jas_stream_getc_macro(stream) \
	((!((stream)->flags_ & (JAS_STREAM_ERR | JAS_STREAM_EOF | \
	  JAS_STREAM_RWLIMIT))) ? \
	  (((stream)->rwlimit_ >= 0 && (stream)->rwcnt_ >= (stream)->rwlimit_) ? \
	  (stream->flags_ |= JAS_STREAM_RWLIMIT, EOF) : \
	  jas_stream_getc2(stream)) : EOF)
#define jas_stream_getc2(stream) \
	((--(stream)->cnt_ < 0) ? jas_stream_fillbuf(stream, 1) : \
	  (++(stream)->rwcnt_, (int)(*(stream)->ptr_++)))

/* Write a character to a stream. */
#define jas_stream_putc_macro(stream, c) \
	((!((stream)->flags_ & (JAS_STREAM_ERR | JAS_STREAM_EOF | \
	  JAS_STREAM_RWLIMIT))) ? \
	  (((stream)->rwlimit_ >= 0 && (stream)->rwcnt_ >= (stream)->rwlimit_) ? \
	  (stream->flags_ |= JAS_STREAM_RWLIMIT, EOF) : \
	  jas_stream_putc2(stream, c)) : EOF)
#define jas_stream_putc2(stream, c) \
	(((stream)->bufmode_ |= JAS_STREAM_WRBUF, --(stream)->cnt_ < 0) ? \
	  jas_stream_flushbuf((stream), (jas_uchar)(c)) : \
	  (++(stream)->rwcnt_, (int)(*(stream)->ptr_++ = (c))))

/* These prototypes need to be here for the sake of the stream_getc and
stream_putc macros. */
JAS_DLLEXPORT int jas_stream_fillbuf(jas_stream_t *stream, int getflag);
JAS_DLLEXPORT int jas_stream_flushbuf(jas_stream_t *stream, int c);
JAS_DLLEXPORT int jas_stream_getc_func(jas_stream_t *stream);
JAS_DLLEXPORT int jas_stream_putc_func(jas_stream_t *stream, int c);

#ifdef __cplusplus
}
#endif

#endif

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