[FFmpeg-devel] [PATCH 2/2] lavf/file: Add support for file syncing.

[Andrey Semashev]

On 12/3/18 3:46 PM, Nicolas George wrote:
> Andrey Semashev (2018-12-03):
>> This commit adds support for IO synchronization API to the file backend.
>> ---
>>   libavformat/file.c       | 10 ++++++++++
>>   libavformat/os_support.h |  2 ++
>>   2 files changed, 12 insertions(+)
>>
>> diff --git a/libavformat/file.c b/libavformat/file.c
>> index 1d321c4205..9765fd76c7 100644
>> --- a/libavformat/file.c
>> +++ b/libavformat/file.c
>> @@ -254,6 +254,15 @@ static int64_t file_seek(URLContext *h, int64_t pos, int whence)
>>       return ret < 0 ? AVERROR(errno) : ret;
>>   }
>>   
>> +static int file_sync(URLContext *h)
>> +{
>> +    if (h->flags & AVIO_FLAG_WRITE) {
>> +        FileContext *c = h->priv_data;
> 
>> +        return fsync(c->fd);
> 
> In case of error, it needs to convert errno to an AVERROR code.
> 
>> +    }
>> +    return 0;
>> +}
>> +
>>   static int file_close(URLContext *h)
>>   {
>>       FileContext *c = h->priv_data;
>> @@ -353,6 +362,7 @@ const URLProtocol ff_file_protocol = {
>>       .url_close           = file_close,
>>       .url_get_file_handle = file_get_handle,
>>       .url_check           = file_check,
>> +    .url_sync            = file_sync,
>>       .url_delete          = file_delete,
>>       .url_move            = file_move,
>>       .priv_data_size      = sizeof(FileContext),
>> diff --git a/libavformat/os_support.h b/libavformat/os_support.h
>> index 7a56dc9a7c..fcbdc884ba 100644
>> --- a/libavformat/os_support.h
>> +++ b/libavformat/os_support.h
>> @@ -93,6 +93,8 @@ static inline int is_dos_path(const char *path)
>>   #ifndef S_IWUSR
>>   #define S_IWUSR S_IWRITE
>>   #endif
>> +
> 
>> +#define fsync _commit
> 
> Defining with the arguments would be more robust. A few occasions in the
> same file do not do that, they should.
> 
>>   #endif
>>   
>>   #if CONFIG_NETWORK

Agreed to both comments.