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/*
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright © 2022 Keith Packard
*
* 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.
*
* 3. Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* 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 HOLDER 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 "stdio_private.h"
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#define __MALL 0x01
struct __file_mem {
struct __file_ext xfile;
char *buf;
size_t size;
size_t pos;
uint8_t mflags;
};
static int __fmem_put(char c, FILE *f)
{
struct __file_mem *mf = (struct __file_mem *) f;
if ((f->flags & __SWR) && mf->pos < mf->size) {
mf->buf[mf->pos++] = c;
return (unsigned char) c;
}
return _FDEV_ERR;
}
static int __fmem_get(FILE *f)
{
struct __file_mem *mf = (struct __file_mem *) f;
int c;
if ((f->flags & __SRD) && mf->pos < mf->size) {
c = (unsigned char) mf->buf[mf->pos++];
if (c == '\0')
c = _FDEV_EOF;
} else
c = _FDEV_ERR;
return c;
}
static int __fmem_flush(FILE *f)
{
struct __file_mem *mf = (struct __file_mem *) f;
if ((f->flags & __SWR) && mf->pos < mf->size)
mf->buf[mf->pos] = '\0';
return 0;
}
static off_t __fmem_seek(FILE *f, off_t pos, int whence)
{
struct __file_mem *mf = (struct __file_mem *) f;
switch (whence) {
case SEEK_SET:
break;
case SEEK_CUR:
pos += mf->pos;
break;
case SEEK_END:
pos += mf->size;
break;
}
if (pos < 0 || mf->size < (size_t) pos)
return EOF;
mf->pos = pos;
return pos;
}
static int __fmem_close(FILE *f)
{
struct __file_mem *mf = (struct __file_mem *) f;
if (mf->mflags & __MALL)
free (mf->buf);
else
__fmem_flush(f);
free(f);
return 0;
}
FILE *
fmemopen(void *buf, size_t size, const char *mode)
{
int stdio_flags;
uint8_t mflags = 0;
int open_flags;
struct __file_mem *mf;
stdio_flags = __posix_sflags(mode, &open_flags);
if (stdio_flags == 0)
return NULL;
/* Allocate file structure and necessary buffers */
mf = calloc(1, sizeof(struct __file_mem));
if (mf == NULL)
return NULL;
if (buf == NULL) {
buf = malloc(size);
if (!buf) {
free(mf);
return NULL;
}
mflags |= __MALL;
}
*mf = (struct __file_mem) {
.xfile = FDEV_SETUP_EXT(__fmem_put, __fmem_get, __fmem_flush, __fmem_close,
__fmem_seek, NULL, stdio_flags),
.buf = buf,
.size = size,
.pos = 0,
.mflags = mflags,
};
return &(mf->xfile.cfile.file);
}
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