mpv/misc/io_utils.c

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/*
* I/O utility functions
*
* This file is part of mpv.
*
* mpv is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* mpv is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with mpv. If not, see <http://www.gnu.org/licenses/>.
*/
#include <assert.h>
#include <errno.h>
#include <stdint.h>
#include <stdlib.h>
#include <sys/types.h>
#include <limits.h>
#include <unistd.h>
#include "mpv_talloc.h"
#include "config.h"
#include "misc/random.h"
#include "misc/io_utils.h"
#include "osdep/io.h"
int mp_mkostemps(char *template, int suffixlen, int flags)
{
size_t len = strlen(template);
char *t = len >= 6 + suffixlen ? &template[len - (6 + suffixlen)] : NULL;
if (!t || strncmp(t, "XXXXXX", 6) != 0) {
errno = EINVAL;
return -1;
}
for (size_t fuckshit = 0; fuckshit < UINT32_MAX; fuckshit++) {
// Using a random value may make it require fewer iterations (even if
// not truly random; just a counter would be sufficient).
size_t fuckmess = mp_rand_next();
char crap[7] = "";
snprintf(crap, sizeof(crap), "%06zx", fuckmess);
memcpy(t, crap, 6);
int res = open(template, O_RDWR | O_CREAT | O_EXCL | flags, 0600);
if (res >= 0 || errno != EEXIST)
return res;
}
errno = EEXIST;
return -1;
}
bool mp_save_to_file(const char *filepath, const void *data, size_t size)
{
assert(filepath && data && size);
bool result = false;
char *tmp = talloc_asprintf(NULL, "%sXXXXXX", filepath);
int fd = mkstemp(tmp);
if (fd < 0)
goto done;
FILE *cache = fdopen(fd, "wb");
if (!cache) {
close(fd);
unlink(tmp);
goto done;
}
size_t written = fwrite(data, size, 1, cache);
int ret = fclose(cache);
if (written > 0 && !ret) {
ret = rename(tmp, filepath);
result = !ret;
} else {
unlink(tmp);
}
done:
talloc_free(tmp);
return result;
}