The added API is nghttp2_session_change_stream_priority(). This
provides the same functionality to re-prioritize stream when PRIORITY
frame. is received, but we do it without PRIORITY frame. This could
be useful for server to change pushed stream's priority silently.
This commits enables HTTP/2 server push from HTTP/2 backend to be
relayed to HTTP/2 frontend. To use this feature, --http2-bridge or
--client is required. Server push via Link header field contiues to
work.
To validate actual response body length against the value declared in
content-length response header field, we first check request method.
If request method is HEAD, respose body must be 0 regardless of the
value in content-length. nghttp2_session_upgrade() has no parameter
to indicate the request method is HEAD, so we failed to validate
response body if HEAD is used with HTTP Upgrade. New
nghttp2_session_upgrade2() accepts new parameter to indicate that
request method is HEAD or not to fix this issue. Although, this issue
affects client side only, we deprecate nghttp2_session_upgrade() in
favor of nghttp2_session_upgrade2() for both client and server side.
This function is useful for the client application to know that there
is a chance that request can be sent. If this function returns 0,
there is zero chance to make a request.
This commit also set error_code passed to
nghttp2_on_stream_close_callback to NGHTTP2_REFUSED_STREAM if request
is not sent.
Application can utilize this framework to send/receive user defined
extension frames. These frames are expected not to change existing
protocol behaviour.
The control process handles signals, reads configuration, reads
private keys, and bind port (which may be privileged one). It never
drop privileges, so that it can execute new binary with the same
privilege. It forks worker process. The worker process handles all
incoming connections. It drops privilege.
The intention of this stream API is give server application about
stream dependency information, so that it can utilize it for better
scheduling of stream processing. We have no plan to add object
oriented API based on stream object.
The overall meaning is the same. I added a paragraph to introduce nghttp2_hd_inflate_hd(), and added an explanation of using NGHTTP2_NV_FLAG_NO_INDEX for security sensitive headers.
The overall meaning of the tutorial is the same. I added text describing frame types where it helps explain the callbacks better, e.g. introducing the HEADERS frame before on_header_callback().
Also fixed a couple of typos:
- Fixed ``reacb`` typo to ``readcb``
- Added parens to some functions, e.g. ``on_frame_recv_callback`` => ``on_frame_recv_callback()``
The overall meaning of the tutorial is the same, except for a couple of changes:
- app_context struct was called "app_content", fixed the typo
- nghttp2_session_server_new2() is mentioned, but the example uses nghttp2_session_server_new() instead, changed the text to match
Previously h2load used default flow control window as described in
HTTP/2 and SPDY specification. The window size is 64KiB, which is a
bit small, and cannot utilize full server performance when response
size is not too small. Basically, we do this kind of benchmarking
test to measure server's throughput, and optimal performance. Smaller
window certainly degrades performance even in local testing because
server is so fast that it has to wait for WINDOW_UPDATE from h2load.
To make default behaviour suitable for peak performance test, we
decided to disable flow control in h2load by setting large enough
window size.
Most users used h2load without -w or -W options, so they were
implicitly throttled by flow control and the result was affected by
that negatively. Now flow control is disabled by default, the result
may improve depending on the implementations.
The existing nghttp2_session_consume() affects both connection and
stream level flow control windows. The new functions only affects
either connection or stream. There is some interesting use cases.
For example, we may want to pause a stream by not sending
WINDOW_UPDATE, meanwhile we want to continue to process other streams.
In this case, we use nghttp2_session_consume_connection() to tell
library that only connection level window is recovered. The relevant
discussion: https://code.google.com/p/chromium/issues/detail?id=473259
Previously nghttp2_session_send() and nghttp2_session_mem_send() did
not send 24 bytes client magic byte string (MAGIC). We made
nghttp2_session_recv() and nghttp2_session_mem_recv() process MAGIC by
default, so it is natural to make library send MAGIC as well. This
commit makes nghttp2_session_send() and nghttp2_session_mem_send()
send MAGIC. This commit also replace "connection preface" with
"client magic", since we call MAGIC as "connection preface" but it is
just a part of connection preface. NGHTTP2_CLIENT_CONNECTION_PREFACE
macro was replaced with NGHTTP2_CLIENT_MAGIC. The already deprecated
NGHTTP2_CLIENT_CONNECTION_HEADER macro was removed permanently.
nghttp2_option_set_no_recv_client_preface() was renamed as
nghttp2_option_set_no_recv_client_magic(). NGHTTP2_ERR_BAD_PREFACE
was renamed as NGHTTP2_ERR_BAD_CLIENT_MAGIC.
To avoid buffer copy in nghttp2_data_source_read_callback, this commit
introduces NGHTTP2_DATA_FLAG_NO_COPY and nghttp2_send_data_callback.
By using NGHTTP2_DATA_FLAG_NO_COPY in
nghttp2_data_source_read_callback, application can avoid to copy
application data to given buffer. Instead, application has to
implement nghttp2_send_data_callback to send complete DATA frame by
itself. We see noticeable performance increase in nghttpd and
tiny-nghttpd using this new feature. On the other hand, nghttpx does
not show such difference, probably because buffer copy is not
bottleneck. Using nghttp2_send_data_callback adds complexity, so it
is recommended to measure the performance to see whether this extra
complexity worth it.
Previously API reference is gigantic one rst file and it is a bit hard
to use, especially when browsing similar functions. This commit
splits API reference into smaller fine grained files. The macros,
enums, types are now in its own file. Each API function has its own
file now. API reference doc is now index to above documentation
files. The apiref-header.rst is renamed as programmers-guide.rst and
becomes standalone document.
Tatsuhiro Tsujikawa
Syohei YOSHIDA
Zhuoyun Wei
Nora
Tom Harwood
Alexis La Goutte
Viacheslav Biriukov