raze-gles/source/libxmp-lite/src/memio.c

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/* Extended Module Player
* Copyright (C) 1996-2016 Claudio Matsuoka and Hipolito Carraro Jr
*
* Permission is hereby granted, free of charge, to any person 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, sublicense,
* 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:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "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. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <stdlib.h>
#include <stddef.h>
#include <limits.h>
#ifndef LIBXMP_CORE_PLAYER
#include <sys/types.h>
#include <sys/stat.h>
#endif
#include "common.h"
#include "memio.h"
static inline ptrdiff_t CAN_READ(MFILE *m)
{
if (m->size >= 0)
return m->pos >= 0 ? m->size - m->pos : 0;
return INT_MAX;
}
int mgetc(MFILE *m)
{
if (CAN_READ(m) >= 1)
return *(const uint8 *)(m->start + m->pos++);
else
return EOF;
}
size_t mread(void *buf, size_t size, size_t num, MFILE *m)
{
size_t should_read = size * num;
ptrdiff_t can_read = CAN_READ(m);
if (!size || !num || can_read <= 0) {
return 0;
}
if (should_read > can_read) {
should_read = can_read;
}
memcpy(buf, m->start + m->pos, should_read);
m->pos += should_read;
return should_read / size;
}
int mseek(MFILE *m, long offset, int whence)
{
switch (whence) {
default:
case SEEK_SET:
if (m->size >= 0 && (offset > m->size || offset < 0))
return -1;
m->pos = offset;
return 0;
case SEEK_CUR:
if (m->size >= 0 && (offset > CAN_READ(m) || offset < -m->pos))
return -1;
m->pos += offset;
return 0;
case SEEK_END:
if (m->size < 0)
return -1;
m->pos = m->size + offset;
return 0;
}
}
long mtell(MFILE *m)
{
return (long)m->pos;
}
int meof(MFILE *m)
{
if (m->size <= 0)
return 0;
else
return CAN_READ(m) <= 0;
}
MFILE *mopen(const void *ptr, long size)
{
MFILE *m;
m = (MFILE *)malloc(sizeof (MFILE));
if (m == NULL)
return NULL;
m->start = (const unsigned char *)ptr;
m->pos = 0;
m->size = size;
return m;
}
int mclose(MFILE *m)
{
free(m);
return 0;
}
#ifndef LIBXMP_CORE_PLAYER
int mstat(MFILE *m, struct stat *st)
{
memset(st, 0, sizeof (struct stat));
st->st_size = m->size;
return 0;
}
#endif