file: Add an avoption for disabling truncating existing files on open

Signed-off-by: Martin Storsjö <martin@martin.st>
This commit is contained in:
Martin Storsjö 2012-09-09 22:42:56 +03:00
parent 5e3572893d
commit 29a9b12b10

View File

@ -20,6 +20,7 @@
*/
#include "libavutil/avstring.h"
#include "libavutil/opt.h"
#include "avformat.h"
#include <fcntl.h>
#if HAVE_IO_H
@ -37,9 +38,23 @@
/* standard file protocol */
typedef struct FileContext {
const AVClass *class;
int fd;
int trunc;
} FileContext;
static const AVOption file_options[] = {
{ "truncate", "Truncate existing files on write", offsetof(FileContext, trunc), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, AV_OPT_FLAG_ENCODING_PARAM },
{ NULL }
};
static const AVClass file_class = {
.class_name = "file",
.item_name = av_default_item_name,
.option = file_options,
.version = LIBAVUTIL_VERSION_INT,
};
static int file_read(URLContext *h, unsigned char *buf, int size)
{
FileContext *c = h->priv_data;
@ -82,9 +97,13 @@ static int file_open(URLContext *h, const char *filename, int flags)
av_strstart(filename, "file:", &filename);
if (flags & AVIO_FLAG_WRITE && flags & AVIO_FLAG_READ) {
access = O_CREAT | O_TRUNC | O_RDWR;
access = O_CREAT | O_RDWR;
if (c->trunc)
access |= O_TRUNC;
} else if (flags & AVIO_FLAG_WRITE) {
access = O_CREAT | O_TRUNC | O_WRONLY;
access = O_CREAT | O_WRONLY;
if (c->trunc)
access |= O_TRUNC;
} else {
access = O_RDONLY;
}
@ -126,6 +145,7 @@ URLProtocol ff_file_protocol = {
.url_get_file_handle = file_get_handle,
.url_check = file_check,
.priv_data_size = sizeof(FileContext),
.priv_data_class = &file_class,
};
#endif /* CONFIG_FILE_PROTOCOL */