Download buffering

      +---------+     +---------+     +-------+
      | httpsrc |     | buffer  |     | demux |
      |        src - sink      src - sink     ....
      +---------+     +----|----+     +-------+

If we know the server is streaming a fixed length file to the client, the application can choose to download the entire file on disk. The buffer element will provide a push or pull based srcpad to the demuxer to navigate in the downloaded file.

This mode is only suitable when the client can determine the length of the file on the server.

In this case, buffering messages will be emitted as usual when the requested range is not within the downloaded area + buffersize. The buffering message will also contain an indication that incremental download is being performed. This flag can be used to let the application control the buffering in a more intelligent way, using the BUFFERING query, for example. See the section called “Buffering strategies ”.