Previously, there is inconsistency when on_frame_recv_callback
is called between HEADERS/PUSH_PROMISE and the other frames.
For former case, it is called before header block, in latter
case, it is called after whole frame is received. To make it
consistent, we call on_frame_recv_callback for HEADERS/PUSH_PROMISE
after its frame is fully received. Since on_frame_recv_callback
can signal the end of header block, we replaced on_end_headers_callback
with on_begin_headers_callback, which is called when the reception
of the header block is started.
nghttp2_data is added to nghttp2_frame union. When DATA is
received, nghttp2_on_frame_recv_callback is called. When DATA is
sent, nghttp2_on_frame_send_callback is called.
Now incoming data is processed in very small buffer (up to 8 bytes)
using state machine. GOAWAY debug data can get to 16K - 1, and we
don't have callback for it. Since we don't want to buffer that
amount of data just for debugging, we currently discard it.
This change also makes parse_error callback not function.
It probably be removed from API.
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.
We tried several times about this subject, but for the current
HTTP/2.0 priority scheme, we think it is best to serve the highest
priroty streams first (interleaving streams if there are several
higest ones). There are an issue when aggregating several frontend
connections to one connection in backend, but it is HTTP/2.0
spec issue, rather than implementation.
Previously we use largest stream ID received so far as last-stream-ID,
and it is irrevant that it is passed to the callback (thus upper layer).
Now the stream ID which is passed to callback is eligible to
last-stream-ID.
nghttp2_session_client_new2 and nghttp2_session_server_new2 take
additional parameters which specifies session options.
nghttp2_set_option is somewhat crumsy because of type checking.
Now we use nghttp2_opt_set, which specifies individual options with
types. We changed the value of nghttp2_opt, so this change will
require re-compile.
It is not clear that SETTINGS_ENABLE_PUSH = 0 disallows HEADERS
to the reserved streams. For now, we just check the reception
and transmission of PUSH_PROMISE against SETTINGS_ENABLE_PUSH.
Now we have SETTINGS synchronization, flow control error can be
detected strictly. If DATA frame is received with length > 0 and
current received window size is equal to or larger than local
window size (latter happens when we shirnk window size), it is
subject to FLOW_CONTROL_ERROR,
Use NGHTTP2_ERR_INVALID_STREAM_STATE when trying to send DATA or
WINDOW_UPDATE to reserved stream.
Also a bit refactored nghttp2_session_predicate_window_update_send
and nghttp2_session_predicate_data_send
The NGHTTP2_ERR_PAUSE library error code is introduced to pause
the execution of nghttp2_session_mem_recv() when that error code
is returned from nghttp2_on_frame_recv_callback or
nghttp2_on_data_chunk_recv_callback. If this happens, the parameters
available for both callbacks are retained until the application
calls nghttp2_session_continue(). The application must retain
input bytes which was used to produce the frame.
After successful call of nghttp2_session_continue, the application
can continue to call nghttp2_session_mem_recv() to process
additional data.
We call on_stream_close_callback even if stream->state is
NGHTTP2_STREAM_INITIAL. This will happen while sending request
HEADERS, a local endpoint receives RST_STREAM for that
stream. It may be PROTOCOL_ERROR, but without notifying stream
closure will hang the stream in a local endpoint.
Following cases are now treated as connection error of type
PROTOCOL_ERROR.
* Receiving HEADERS from client in reserved (local)
* Receiving PUSH_PROMISE against peer-initiated stream
* Receiving WINDOW_UPDATE against in reserved (local, remote)
Now NGHTTP2_OPT_NO_AUTO_WINDOW_UPDATE is split into 2 options:
NGHTTP2_OPT_NO_AUTO_STREAM_WINDOW_UPDATE and
NGHTTP2_OPT_NO_AUTO_CONNECTION_WINDOW_UPDATE.
This is preparation for the upcoming removal of END_FLOW_CONTROL
flag. For nghttpx, instead of using END_FLOW_CONTROL to disable
connection-level flow control, increase window size by large
enough value, which is friendly way to current chromium
implementation.
Tatsuhiro Tsujikawa