jas_stream.h

Unique net-enabled GUI system based state of the art coding solutions with strong XML support.

	/* The stream status. */
	int flags_;

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

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

	/* The buffer size. */
	int bufsize_;

	/* The current position in the buffer. */
	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. */
	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.
 */

/* Note: This is simply a file descriptor. */
typedef int jas_stream_fileobj_t;

/*
 * Memory file object.
 */

typedef struct {

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

	/* The allocated size of the buffer for holding file data. */
	int 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_stream_t *jas_stream_fopen(const char *filename, const char *mode);

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

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

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

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

/* Close a stream. */
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. */
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. */
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. */
int jas_stream_read(jas_stream_t *stream, void *buf, int cnt);

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

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

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

/* Read a line of input from a stream. */
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. */
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? */
int jas_stream_isseekable(jas_stream_t *stream);

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

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

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

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

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

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

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

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

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

/* Get the size of the file associated with the specified stream.
  The specified stream must be seekable. */
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), (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. */
int jas_stream_fillbuf(jas_stream_t *stream, int getflag);
int jas_stream_flushbuf(jas_stream_t *stream, int c);
int jas_stream_getc_func(jas_stream_t *stream);
int jas_stream_putc_func(jas_stream_t *stream, int c);

#ifdef __cplusplus
}
#endif

#endif