If stream with dpri value of no_data, we check any its descendant has
stream with dpri value of top. If so, we have to distribute of its
portion of weight to its descendants.
Now previous padding options are removed and instead we added
select_padding_callback to select padding length for each frame
by application. If this callback is not implemented by application,
no padding is added.
This change also fixes the broken session_detect_idle_stream()
if stream_id is our side.
This stream inflater can inflate incoming header block in streaming
fashion. Currently, we buffer up single name/value pair, but we chose
far more smaller buffer size than HTTP/2 frame size.
Now, in nghttp2_on_frame_recv_callback, nva and nvlen in
HEADERS and PUSH_PROMISE frames are always NULL and 0 respectively.
The header name/value pairs are emitted successive
nghttp2_on_header_callback functions. The end of header fields are
signaled with nghttp2_on_end_headers_callback function.
Since NGHTTP2_ERR_PAUSE for nghttp2_on_frame_recv_callback is
introduced to handle header block, it is now deprecated.
Instead, nghttp2_on_header_callback can be paused using
NGHTTP2_ERR_PAUSE.
Tatsuhiro Tsujikawa