It is now tested both via cowboy_req:read_body and
via cowboy_req:cast.
Removes a bad example from the guide of body reading
with period of infinity, which does not work.
While we are identified as a supervisor in the tree,
we no longer manage children processes at that point,
so do not need to trap exit signals. Users can still
enable trap_exit if they prefer to.
We must add it even if we don't end up compressing because
it indicates that we might. This indication doesn't mean
that the user agent's accept-encoding values will ever
result in content encoding being applied.
The previous behavior was to accept them and drop the
content-length header as per the RFC recommendation.
But since this behavior is not normal it is safer to
just reject such requests than risk security issues.
In the cowboy_compress_h stream handler.
Otherwise this could cause issues with caching, with the
etag being the same for compressed/uncompressed content.
Users that wish to send etags AND compress will have to
do it manually for the time being.
The read buffer was changed into an iovec to avoid doing
too many binary concatenations and allocations.
Decompression happens transparently: when decoding gzip,
the content-encoding header is removed (we only decode
when "gzip" is the only encoding so nothing remains).
We always add a content_decoded key to the Req object.
This key contains a list of codings that were decoded,
in the reverse order in which they were. Currently it
can only be empty or contain <<"gzip">> but future
improvements or user handlers may see it contain more
values.
The option to disable decompression was renamed to
decompress_enabled and defaults to true.
It is no longer possible to enable/disable decompression
in the middle of reading the body: this ensures that the
data we pass forward is always valid.
Various smaller improvements were made to the code,
tests and manual pages.
A new option reset_idle_timeout_on_send has been added.
When set to 'true', the idle timeout is reset not only
when data is received, but also when data is sent.
This allows sending large responses without having to
worry about timeouts triggering.
The default is currently unchanged but might change in
a future release.
LH: Greatly reworked the implementation so that the
timeout gets reset on almost all socket writes.
This essentially completely supersets the original
work. Tests are mostly the same although I
refactored a bit to avoid test code duplication.
This commit also changes HTTP/2 behavior a little when
data is received: Cowboy will not attempt to update the
window before running stream handler commands to avoid
sending WINDOW_UPDATE frames twice. Now it has some
small heuristic to ensure they can only be sent once
at most.
Sending extra response prevented by terminating all streams except
the one currently executing.
LH: Reworded some variables to make what happens more obvious.
Doing so will let us notice when the connection is gone instead
of waiting for timeouts, at least in the cases where the remote
socket was closed properly. Timeouts are still needed in case
of TCP half-open problems.
This change means that the order of stream handler commands is
more important than before because socket errors may occur
during the processing of commands.
Note: This commit makes cowboy depend on cowlib master.
Graceful shutdown for HTTP/2:
1. A GOAWAY frame with the last stream id set to 2^31-1 is sent and a
timer is started (goaway_initial_timeout, default 1000ms), to wait
for any in-flight requests sent by the client, and the status is set
to 'closing_initiated'. If the client responds with GOAWAY and closes
the connection, we're done.
2. A second GOAWAY frame is sent with the actual last stream id and the
status is set to 'closing'. If no streams exist, the connection
terminates. Otherwise a second timer (goaway_complete_timeout,
default 3000ms) is started, to wait for the streams to complete. New
streams are not accepted when status is 'closing'.
3. If all streams haven't completed after the second timeout, the
connection is forcefully terminated.
Graceful shutdown for HTTP/1.x:
1. If a request is currently being handled, it is waited for and the
response is sent back to the client with the header "Connection:
close". Then, the connection is closed.
2. If the current request handler is not finished within the time
configured in transport option 'shutdown' (default 5000ms), the
connection process is killed by its supervisor (ranch).
Implemented for HTTP/1.x and HTTP/2 in the following scenarios:
* When receiving exit signal 'shutdown' from the supervisor (e.g. when
cowboy:stop_listener/3 is called).
* When a connection process is requested to terminate using
sys:terminate/2,3.
LH: Edited tests a bit and added todos for useful tests to add.
When calling cowboy_req:reply/4 with a body a crash will occur
resulting in a 500 response. When calling cowboy_req:stream_reply/2,3
and then attempting to send a body a crash will occur.
This is mostly to ensure that the GOAWAY frame is properly
received on Windows in some tests, but should be benefitial
also in production in particular when clients are slower.
This resulted in a badarith error due to the current flow being
set to infinity when the body has been fully read. A test case
has been added reproducing the issue.
The flow control is now only set to infinity when we are
skipping the request body of the stream that is being
terminated. This fixes a bug where it was set to infinity
while reading a subsequent request's body, leading to a
crash.
The timeout is no longer reset on stream termination.
Timeout handling is already done when receiving data
from the socket and doing a reset on stream termination
was leading to the wrong timeout being set or the right
timeout being reset needlessly.
This reduces the number of times we need to ask for more packets,
and as a result we get a fairly large boost in performance,
especially with HTTP/1.1.
Unfortunately this makes Cowboy require at least Erlang/OTP 21.3+
because the ssl application did not have active,N. For simplicity
the version required will be Erlang/OTP 22+.
In addition this change improves hibernate handling in
cowboy_websocket. Hibernate will now work for HTTP/2 transport
as well, and stray or unrelated messages will no longer cancel
hibernate (the process will handle the message and go back into
hibernation).
Thanks go to Stressgrid for benchmarking an early version of this
commit: https://stressgrid.com/blog/cowboy_performance_part_2/
When sending a complete response it is far more efficient
to send the headers and the body in one Transport:send/2
call instead of two or more, at least for small responses.
This is the HTTP/2 counterpart to what was done for HTTP/1.1
many years ago in bfab8d4b22.
In HTTP/2's case however the implementation is a little
more difficult due to flow control. On the other hand the
optimization will apply not only for headers/body but also
for the body of multiple separate responses, which may need
to be sent all at the same time when we receive a WINDOW_UPDATE
frame.
When a body is sent using sendfile however a separate call
is still made.
