The new module is a merge of the Cowboy and Gun HTTP/2
state machines. Using a common code will help future
developments rather than duplicating the work.
A notable change is in how streams are terminated
when the handler stops before the body is sent. The
cowboy_stream:terminate function is now called only
after the body has been sent fully (or the stream
is reset in-between), not when the stop command is
returned. This will most likely have an impact on
metrics but will be closer to reality.
I had to comment a broken test in rfc7231_SUITE that
was cheating, cheating is no longer possible.
This depends on Cowlib master for the time being. A
new Cowlib version will be released once both Cowboy
and Gun are ported to use cow_http2_machine and I'm
satisfied with it.
This command is currently not documented. It allows disabling
the reading of incoming data from the socket, and can be used
as a poor man's flow control.
This feature is currently experimental. It will become the
preferred way to use Websocket handlers once it becomes
documented.
A commands-based interface enables adding commands without
having to change the interface much. It mirrors the interface
of stream handlers or gen_statem. It will enable adding
commands that have been needed for some time but were not
implemented for fear of making the interface too complex.
This commit reworks the logging that Cowboy does via
error_logger to make the module that will do the actual
logging configurable.
The logger module interface must be the same as logger
and lager: a separate function per log level with the
same log levels they support.
The default behavior remains to call error_logger,
although some messages were downgraded to warnings
instead of errors. Since error_logger only supports
three different log levels, some messages may get
downgraded/upgraded depending on what the original
log level was to make them compatible with error_logger.
The {log, Level, Format, Args} command was also
added to stream handlers. Stream handlers should
use this command to log messages because it allows
writing a stream handler to intercept some of those
messages and extract information or block them as
necessary.
The logger option only applies to Cowboy itself,
not to the messages Ranch logs, so more work remains
to be done in that area.
