beetle-pce-fast-libretro/mednafen/file.c
2018-04-19 08:29:27 +02:00

143 lines
2.9 KiB
C

/* Mednafen - Multi-system Emulator
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <streams/file_stream.h>
#include "file.h"
#include "mednafen-endian.h"
struct MDFNFILE *file_open(const char *path)
{
int64_t size = 0;
const char *ld = NULL;
struct MDFNFILE *file = (struct MDFNFILE*)calloc(1, sizeof(*file));
if (!file)
return NULL;
if (!filestream_read_file(path, (void**)&file->data, &size))
goto error;
ld = (const char*)strrchr(path, '.');
file->size = size;
file->ext = strdup(ld ? ld + 1 : "");
return file;
error:
if (file)
free(file);
return NULL;
}
int file_close(struct MDFNFILE *file)
{
if (!file)
return 0;
if (file->ext)
free(file->ext);
file->ext = NULL;
if (file->data)
free(file->data);
file->data = NULL;
free(file);
return 1;
}
uint64_t file_read(struct MDFNFILE *file, void *ptr,
size_t element_size, size_t nmemb)
{
uint32_t total = element_size * nmemb;
if (file->location >= file->size)
return 0;
if ((file->location + total) > file->size)
{
int64_t ak = file->size - file->location;
memcpy((uint8_t*)ptr, file->data + file->location, ak);
file->location = file->size;
return(ak / element_size);
}
memcpy((uint8_t*)ptr, file->data + file->location, total);
file->location += total;
return nmemb;
}
int file_seek(struct MDFNFILE *file, int64_t offset, int whence)
{
switch(whence)
{
case SEEK_SET:
if (offset >= file->size)
return -1;
file->location = offset;
break;
case SEEK_CUR:
if ((offset + file->location) > file->size)
return -1;
file->location += offset;
break;
}
return 0;
}
char *file_fgets(struct MDFNFILE *file, char *s, int len)
{
int pos = 0;
if (!len)
return(NULL);
if (file->location >= len)
return(NULL);
while(pos < (len - 1) && file->location < len)
{
int v = file->data[file->location];
s[pos] = v;
file->location++;
pos++;
if (v == '\n')
break;
}
if (len)
s[pos] = 0;
return s;
}