jas_stream.h

Go to the documentation of this file.

/*
 * 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__
 */
 
#ifndef JAS_STREAM_H
#define JAS_STREAM_H
 
/******************************************************************************\
* Includes.
\******************************************************************************/
 
/* The configuration header file should be included first. */
#include <jasper/jas_config.h> /* IWYU pragma: export */
 
#include <stdio.h>
#if defined(JAS_HAVE_FCNTL_H)
#include <fcntl.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. */
        ssize_t (*read_)(jas_stream_obj_t *obj, char *buf, size_t cnt);
 
        /* Write characters to a file object. */
        ssize_t (*write_)(jas_stream_obj_t *obj, const char *buf, size_t 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;
 
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. */
        const 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;
 
/* Delete underlying file object upon stream close. */
#define JAS_STREAM_FILEOBJ_DELONCLOSE   0x01
/* Do not close underlying file object upon stream close. */
#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. */
        size_t len_;
 
        /* The seek position. */
        size_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.
\******************************************************************************/
 
JAS_EXPORT
jas_stream_t *jas_stream_fopen(const char *filename, const char *mode);
 
JAS_EXPORT
jas_stream_t *jas_stream_memopen(char *buffer, size_t buffer_size);
 
JAS_DEPRECATED
JAS_EXPORT
jas_stream_t *jas_stream_memopen2(char *buffer, size_t buffer_size);
 
JAS_EXPORT
jas_stream_t *jas_stream_fdopen(int fd, const char *mode);
 
JAS_EXPORT
jas_stream_t *jas_stream_freopen(const char *path, const char *mode, FILE *fp);
 
JAS_EXPORT
jas_stream_t *jas_stream_tmpfile(void);
 
JAS_EXPORT
int jas_stream_close(jas_stream_t *stream);
 
/******************************************************************************\
* Macros/functions for getting/setting the stream state.
\******************************************************************************/
 
#define jas_stream_eof(stream) \
        (((stream)->flags_ & JAS_STREAM_EOF) != 0)
 
#define jas_stream_error(stream) \
        (((stream)->flags_ & JAS_STREAM_ERR) != 0)
 
#define jas_stream_clearerr(stream) \
        ((stream)->flags_ &= ~(JAS_STREAM_ERR | JAS_STREAM_EOF))
 
#define jas_stream_getrwlimit(stream) \
        (((const jas_stream_t *)(stream))->rwlimit_)
 
JAS_EXPORT long jas_stream_setrwlimit(jas_stream_t *stream, long rwlimit);
 
#define jas_stream_getrwcount(stream) \
        (((const jas_stream_t *)(stream))->rwcnt_)
 
JAS_EXPORT
long jas_stream_setrwcount(jas_stream_t *stream, long rw_count);
 
/******************************************************************************\
* Macros/functions for I/O.
\******************************************************************************/
 
/* Read a character from a stream. */
#ifndef NDEBUG
 
#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. */
#ifndef NDEBUG
 
#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
 
JAS_EXPORT
size_t jas_stream_read(jas_stream_t *stream, void *buffer, size_t count);
 
JAS_EXPORT
unsigned jas_stream_peek(jas_stream_t *stream, void *buffer, size_t count);
 
JAS_EXPORT
size_t jas_stream_write(jas_stream_t *stream, const void *buffer,
  size_t count);
 
JAS_EXPORT
int jas_stream_printf(jas_stream_t *stream, const char *format, ...);
 
JAS_EXPORT
int jas_stream_puts(jas_stream_t *stream, const char *s);
 
JAS_EXPORT
char *jas_stream_gets(jas_stream_t *stream, char *buffer, int buffer_size);
 
#define jas_stream_peekc(stream) \
        (((stream)->cnt_ <= 0) ? jas_stream_fillbuf(stream, 0) : \
          ((int)(*(stream)->ptr_)))
 
JAS_EXPORT
int jas_stream_ungetc(jas_stream_t *stream, int c);
 
/******************************************************************************\
* Macros/functions for getting/setting the stream position.
\******************************************************************************/
 
JAS_EXPORT
JAS_ATTRIBUTE_PURE
int jas_stream_isseekable(jas_stream_t *stream);
 
JAS_EXPORT
long jas_stream_seek(jas_stream_t *stream, long offset, int origin);
 
JAS_EXPORT
long jas_stream_tell(jas_stream_t *stream);
 
JAS_EXPORT
int jas_stream_rewind(jas_stream_t *stream);
 
/******************************************************************************\
* Macros/functions for flushing.
\******************************************************************************/
 
JAS_EXPORT
int jas_stream_flush(jas_stream_t *stream);
 
/******************************************************************************\
* Miscellaneous macros/functions.
\******************************************************************************/
 
JAS_EXPORT
int jas_stream_copy(jas_stream_t *destination, jas_stream_t *source,
  ssize_t count);
 
JAS_EXPORT
int jas_stream_display(jas_stream_t *stream, FILE *fp, int count);
 
JAS_EXPORT
ssize_t jas_stream_gobble(jas_stream_t *stream, size_t count);
 
JAS_EXPORT
ssize_t jas_stream_pad(jas_stream_t *stream, size_t count, int value);
 
JAS_EXPORT
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! */
 
/* These prototypes need to be here for the sake of the stream_getc and
stream_putc macros. */
/* Library users must not invoke these functions directly. */
JAS_EXPORT int jas_stream_fillbuf(jas_stream_t *stream, int getflag);
JAS_EXPORT int jas_stream_flushbuf(jas_stream_t *stream, int c);
JAS_EXPORT int jas_stream_getc_func(jas_stream_t *stream);
JAS_EXPORT int jas_stream_putc_func(jas_stream_t *stream, int c);
 
/* Read a character from a stream. */
static inline int jas_stream_getc2(jas_stream_t *stream)
{
        if (--stream->cnt_ < 0)
                return jas_stream_fillbuf(stream, 1);
 
        ++stream->rwcnt_;
        return (int)(*stream->ptr_++);
}
 
static inline int jas_stream_getc_macro(jas_stream_t *stream)
{
        if (stream->flags_ & (JAS_STREAM_ERR | JAS_STREAM_EOF | JAS_STREAM_RWLIMIT))
                return EOF;
 
        if (stream->rwlimit_ >= 0 && stream->rwcnt_ >= stream->rwlimit_) {
                stream->flags_ |= JAS_STREAM_RWLIMIT;
                return EOF;
        }
 
        return jas_stream_getc2(stream);
}
 
/* Write a character to a stream. */
static inline int jas_stream_putc2(jas_stream_t *stream, jas_uchar c)
{
        stream->bufmode_ |= JAS_STREAM_WRBUF;
 
        if (--stream->cnt_ < 0)
                return jas_stream_flushbuf(stream, c);
        else {
                ++stream->rwcnt_;
                return (int)(*stream->ptr_++ = c);
        }
}
 
static inline int jas_stream_putc_macro(jas_stream_t *stream, jas_uchar c)
{
        if (stream->flags_ & (JAS_STREAM_ERR | JAS_STREAM_EOF | JAS_STREAM_RWLIMIT))
            return EOF;
 
        if (stream->rwlimit_ >= 0 && stream->rwcnt_ >= stream->rwlimit_) {
                stream->flags_ |= JAS_STREAM_RWLIMIT;
                return EOF;
        }
 
        return jas_stream_putc2(stream, c);
}
 
#ifdef __cplusplus
}
#endif
 
#endif