jas_stream.c

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/*
 * 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) 1999-2000 Image Power, Inc.
 * Copyright (c) 1999-2000 The University of British Columbia
 * Copyright (c) 2001-2003 Michael David Adams
 * 
 * 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 Library
 *
 * $Id$
 */

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

#include <assert.h>
#if defined(HAVE_FCNTL_H)
#include <fcntl.h>
#endif
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <ctype.h>
#if defined(HAVE_UNISTD_H)
#include <unistd.h>
#endif
#if defined(WIN32) || defined(HAVE_IO_H)
#include <io.h>
#endif

#include "jasper/jas_types.h"
#include "jasper/jas_stream.h"
#include "jasper/jas_malloc.h"
#include "jasper/jas_math.h"
#include "jasper/jas_debug.h"

/******************************************************************************\
* Local function prototypes.
\******************************************************************************/

static int jas_strtoopenmode(const char *s);
static void jas_stream_destroy(jas_stream_t *stream);
static jas_stream_t *jas_stream_create(void);
static void jas_stream_initbuf(jas_stream_t *stream, int bufmode, char *buf,
  int bufsize);

static int mem_read(jas_stream_obj_t *obj, char *buf, int cnt);
static int mem_write(jas_stream_obj_t *obj, char *buf, int cnt);
static long mem_seek(jas_stream_obj_t *obj, long offset, int origin);
static int mem_close(jas_stream_obj_t *obj);

static int sfile_read(jas_stream_obj_t *obj, char *buf, int cnt);
static int sfile_write(jas_stream_obj_t *obj, char *buf, int cnt);
static long sfile_seek(jas_stream_obj_t *obj, long offset, int origin);
static int sfile_close(jas_stream_obj_t *obj);

static int file_read(jas_stream_obj_t *obj, char *buf, int cnt);
static int file_write(jas_stream_obj_t *obj, char *buf, int cnt);
static long file_seek(jas_stream_obj_t *obj, long offset, int origin);
static int file_close(jas_stream_obj_t *obj);

/******************************************************************************\
* Local data.
\******************************************************************************/

static jas_stream_ops_t jas_stream_fileops = {
	file_read,
	file_write,
	file_seek,
	file_close
};

static jas_stream_ops_t jas_stream_sfileops = {
	sfile_read,
	sfile_write,
	sfile_seek,
	sfile_close
};

static jas_stream_ops_t jas_stream_memops = {
	mem_read,
	mem_write,
	mem_seek,
	mem_close
};

/******************************************************************************\
* Code for opening and closing streams.
\******************************************************************************/

static jas_stream_t *jas_stream_create()
{
	jas_stream_t *stream;

	if (!(stream = jas_malloc(sizeof(jas_stream_t)))) {
		return 0;
	}
	stream->openmode_ = 0;
	stream->bufmode_ = 0;
	stream->flags_ = 0;
	stream->bufbase_ = 0;
	stream->bufstart_ = 0;
	stream->bufsize_ = 0;
	stream->ptr_ = 0;
	stream->cnt_ = 0;
	stream->ops_ = 0;
	stream->obj_ = 0;
	stream->rwcnt_ = 0;
	stream->rwlimit_ = -1;

	return stream;
}

jas_stream_t *jas_stream_memopen(char *buf, int bufsize)
{
	jas_stream_t *stream;
	jas_stream_memobj_t *obj;

	if (!(stream = jas_stream_create())) {
		return 0;
	}

	/* A stream associated with a memory buffer is always opened
	for both reading and writing in binary mode. */
	stream->openmode_ = JAS_STREAM_READ | JAS_STREAM_WRITE | JAS_STREAM_BINARY;

	/* Since the stream data is already resident in memory, buffering
	is not necessary. */
	/* But... It still may be faster to use buffering anyways. */
	jas_stream_initbuf(stream, JAS_STREAM_FULLBUF, 0, 0);

	/* Select the operations for a memory stream. */
	stream->ops_ = &jas_stream_memops;

	/* Allocate memory for the underlying memory stream object. */
	if (!(obj = jas_malloc(sizeof(jas_stream_memobj_t)))) {
		jas_stream_destroy(stream);
		return 0;
	}
	stream->obj_ = (void *) obj;

	/* Initialize a few important members of the memory stream object. */
	obj->myalloc_ = 0;
	obj->buf_ = 0;

	/* If the buffer size specified is nonpositive, then the buffer
	is allocated internally and automatically grown as needed. */
	if (bufsize <= 0) {
		obj->bufsize_ = 1024;
		obj->growable_ = 1;
	} else {
		obj->bufsize_ = bufsize;
		obj->growable_ = 0;
	}
	if (buf) {
		obj->buf_ = (unsigned char *) buf;
	} else {
		obj->buf_ = jas_malloc(obj->bufsize_ * sizeof(char));
		obj->myalloc_ = 1;
	}
	if (!obj->buf_) {
		jas_stream_close(stream);
		return 0;
	}

	if (bufsize > 0 && buf) {
		/* If a buffer was supplied by the caller and its length is positive,
		  make the associated buffer data appear in the stream initially. */
		obj->len_ = bufsize;
	} else {
		/* The stream is initially empty. */
		obj->len_ = 0;
	}
	obj->pos_ = 0;
	
	return stream;
}

jas_stream_t *jas_stream_fopen(const char *filename, const char *mode)
{
	jas_stream_t *stream;
	jas_stream_fileobj_t *obj;
	int openflags;

	/* Allocate a stream object. */
	if (!(stream = jas_stream_create())) {
		return 0;
	}

	/* Parse the mode string. */
	stream->openmode_ = jas_strtoopenmode(mode);

	/* Determine the correct flags to use for opening the file. */
	if ((stream->openmode_ & JAS_STREAM_READ) &&
	  (stream->openmode_ & JAS_STREAM_WRITE)) {
		openflags = O_RDWR;
	} else if (stream->openmode_ & JAS_STREAM_READ) {
		openflags = O_RDONLY;
	} else if (stream->openmode_ & JAS_STREAM_WRITE) {
		openflags = O_WRONLY;
	} else {
		openflags = 0;
	}
	if (stream->openmode_ & JAS_STREAM_APPEND) {
		openflags |= O_APPEND;
	}
	if (stream->openmode_ & JAS_STREAM_BINARY) {
		openflags |= O_BINARY;
	}
	if (stream->openmode_ & JAS_STREAM_CREATE) {
		openflags |= O_CREAT | O_TRUNC;
	}

	/* Allocate space for the underlying file stream object. */
	if (!(obj = jas_malloc(sizeof(jas_stream_fileobj_t)))) {
		jas_stream_destroy(stream);
		return 0;
	}
	obj->fd = -1;
	obj->flags = 0;
	obj->pathname[0] = '\0';
	stream->obj_ = (void *) obj;

	/* Select the operations for a file stream object. */
	stream->ops_ = &jas_stream_fileops;

	/* Open the underlying file. */
	if ((obj->fd = open(filename, openflags, JAS_STREAM_PERMS)) < 0) {
		jas_stream_destroy(stream);
		return 0;
	}

	/* By default, use full buffering for this type of stream. */
	jas_stream_initbuf(stream, JAS_STREAM_FULLBUF, 0, 0);

	return stream;
}

jas_stream_t *jas_stream_freopen(const char *path, const char *mode, FILE *fp)
{
	jas_stream_t *stream;
	int openflags;

	/* Eliminate compiler warning about unused variable. */
	path = 0;

	/* Allocate a stream object. */
	if (!(stream = jas_stream_create())) {
		return 0;
	}

	/* Parse the mode string. */
	stream->openmode_ = jas_strtoopenmode(mode);

	/* Determine the correct flags to use for opening the file. */
	if ((stream->openmode_ & JAS_STREAM_READ) &&
	  (stream->openmode_ & JAS_STREAM_WRITE)) {
		openflags = O_RDWR;
	} else if (stream->openmode_ & JAS_STREAM_READ) {
		openflags = O_RDONLY;
	} else if (stream->openmode_ & JAS_STREAM_WRITE) {
		openflags = O_WRONLY;
	} else {
		openflags = 0;
	}
	if (stream->openmode_ & JAS_STREAM_APPEND) {
		openflags |= O_APPEND;
	}
	if (stream->openmode_ & JAS_STREAM_BINARY) {
		openflags |= O_BINARY;
	}
	if (stream->openmode_ & JAS_STREAM_CREATE) {
		openflags |= O_CREAT | O_TRUNC;
	}

	stream->obj_ = JAS_CAST(void *, fp);

	/* Select the operations for a file stream object. */
	stream->ops_ = &jas_stream_sfileops;

	/* By default, use full buffering for this type of stream. */
	jas_stream_initbuf(stream, JAS_STREAM_FULLBUF, 0, 0);

	return stream;
}

jas_stream_t *jas_stream_tmpfile()
{
	jas_stream_t *stream;
	jas_stream_fileobj_t *obj;
	char template[] = "jas_XXXXXX";

	if (!(stream = jas_stream_create())) {
		return 0;
	}

	/* A temporary file stream is always opened for both reading and
	writing in binary mode. */
	stream->openmode_ = JAS_STREAM_READ | JAS_STREAM_WRITE | JAS_STREAM_BINARY;

	/* Allocate memory for the underlying temporary file object. */
	if (!(obj = jas_malloc(sizeof(jas_stream_fileobj_t)))) {
		jas_stream_destroy(stream);
		return 0;
	}
	obj->fd = -1;
	obj->flags = 0;
	obj->pathname[0] = '\0';
	stream->obj_ = obj;

#ifdef HAVE_MKSTEMP
	/* Set a file name template */
	memcpy(obj->pathname, template, JAS_MIN(strlen(template),L_tmpnam)+1); 
	
	/* Try to open a temp file */
	if ((obj->fd = mkstemp(obj->pathname)) < 0) {
		jas_stream_destroy(stream);
		return 0;
	}
#else
	/* Choose a file name. */
	tmpnam(obj->pathname);

	/* Open the underlying file. */
	if ((obj->fd = open(obj->pathname, O_CREAT | O_EXCL | O_RDWR | O_TRUNC | O_BINARY,
	  JAS_STREAM_PERMS)) < 0) {
		jas_stream_destroy(stream);
		return 0;
	}
#endif /* MKSTEMP */

	/* Unlink the file so that it will disappear if the program