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/*
* Copyright (c) 2001-2002, David Janssens
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "cio.h"
#include <setjmp.h>
static unsigned char *cio_start; /* pointer to the start of the stream */
static unsigned char *cio_end; /* pointer to the end of the stream */
static unsigned char *cio_bp; /* pointer to the present position */
extern jmp_buf j2k_error;
/*
* Number of bytes written.
*/
int cio_numbytes()
{
return cio_bp - cio_start;
}
/*
* Get position in byte stream.
*/
int cio_tell()
{
return cio_bp - cio_start;
}
/*
* Set position in byte stream.
*
* pos : position, in number of bytes, from the beginning of the stream
*/
void cio_seek(int pos)
{
cio_bp = cio_start + pos;
}
/*
* Number of bytes left before the end of the stream.
*/
int cio_numbytesleft()
{
return cio_end - cio_bp;
}
/*
* Get pointer to the current position in the stream.
*/
unsigned char *cio_getbp()
{
return cio_bp;
}
/*
* Initialize byte IO
*
* bp : destination/source stream
* len : length of the stream
*/
void cio_init(unsigned char *bp, int len)
{
cio_start = bp;
cio_end = bp + len;
cio_bp = bp;
}
/*
* Write a byte.
*/
void cio_byteout(unsigned char v)
{
if (cio_bp >= cio_end)
longjmp(j2k_error, 1);
*cio_bp++ = v;
}
/*
* Read a byte.
*/
unsigned char cio_bytein()
{
if (cio_bp >= cio_end)
longjmp(j2k_error, 1);
return *cio_bp++;
}
/*
* Write some bytes.
*
* v : value to write
* n : number of bytes to write
*/
void cio_write(unsigned int v, int n)
{
int i;
for (i = n - 1; i >= 0; i--) {
cio_byteout((unsigned char) ((v >> (i << 3)) & 0xff));
}
}
/*
* Read some bytes.
*
* n : number of bytes to read
*
* return : value of the n bytes read
*/
unsigned int cio_read(int n)
{
int i;
unsigned int v;
v = 0;
for (i = n - 1; i >= 0; i--) {
v += cio_bytein() << (i << 3);
}
return v;
}
/*
* Skip some bytes.
*
* n : number of bytes to skip
*/
void cio_skip(int n)
{
cio_bp += n;
}
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