Aegisub/FFmpegSource2/stdiostream.c

105 lines
3.1 KiB
C

// Copyright (c) 2007-2008 Fredrik Mellbin
//
// 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 "stdiostream.h"
/* StdIoStream methods */
/* read count bytes into buffer starting at file position pos
* return the number of bytes read, -1 on error or 0 on EOF
*/
int StdIoRead(StdIoStream *st, ulonglong pos, void *buffer, int count) {
size_t rd;
if (_fseeki64(st->fp, pos, SEEK_SET)) {
st->error = errno;
return -1;
}
rd = fread(buffer, 1, count, st->fp);
if (rd == 0) {
if (feof(st->fp))
return 0;
st->error = errno;
return -1;
}
return rd;
}
/* scan for a signature sig(big-endian) starting at file position pos
* return position of the first byte of signature or -1 if error/not found
*/
longlong StdIoScan(StdIoStream *st, ulonglong start, unsigned signature) {
int c;
unsigned cmp = 0;
FILE *fp = st->fp;
if (_fseeki64(fp, start, SEEK_SET))
return -1;
while ((c = getc(fp)) != EOF) {
cmp = ((cmp << 8) | c) & 0xffffffff;
if (cmp == signature)
return _ftelli64(fp) - 4;
}
return -1;
}
/* return cache size, this is used to limit readahead */
unsigned StdIoGetCacheSize(StdIoStream *st) {
return CACHESIZE;
}
/* return last error message */
const char *StdIoGetLastError(StdIoStream *st) {
return strerror(st->error);
}
/* memory allocation, this is done via stdlib */
void *StdIoMalloc(StdIoStream *st, size_t size) {
return malloc(size);
}
void *StdIoRealloc(StdIoStream *st, void *mem, size_t size) {
return realloc(mem,size);
}
void StdIoFree(StdIoStream *st, void *mem) {
free(mem);
}
/* progress report handler for lengthy operations
* returns 0 to abort operation, nonzero to continue
*/
int StdIoProgress(StdIoStream *st, ulonglong cur, ulonglong max) {
return 1;
}
void InitStdIoStream(StdIoStream *st) {
memset(st,0,sizeof(st));
st->base.read = StdIoRead;
st->base.scan = StdIoScan;
st->base.getcachesize = StdIoGetCacheSize;
st->base.geterror = StdIoGetLastError;
st->base.memalloc = StdIoMalloc;
st->base.memrealloc = StdIoRealloc;
st->base.memfree = StdIoFree;
st->base.progress = StdIoProgress;
}