Another experimental stream handler. It enables tracing for
the connection process and any children processes based on
the matching of the request. It can be used to do ad-hoc
tracing by sending a specific header, path, method or other.
It is meant to be used both for tests and production. Some
configuration scenarios are NOT safe for production, beware.
It's important to understand that, at this time, tracing
is enabled on the scale of the entire connection including
any future request processes. Keep this in mind when trying
to use it in production. The only way to stop tracing is
by having the callback function exit (by calling exit/1
explicitly). This can be done after a certain number of
events for example. Tracing can generate a lot of events,
so it's a good idea to stop after a small number of events
(between 1000 and 10000 should be good) and to avoid tracing
the whole world.
Documentation will follow at a later time.
It collects metrics and passes them to a configurable callback
once the stream terminates. It will be documented in a future
release. More tests incoming.
This should work very similar to normal supervisors,
in particular during the shutdown sequence when the
connection process goes down or switches to Websocket.
Processes that need to enforce the shutdown timeout
will be required to trap exits, just like in a supervisor.
In a vanilla Cowboy, this only matters at connection
shutdown, as Cowboy will otherwise wait for the request
process to be down before stopping the stream.
Tests are currently missing.
Breaking changes with previous commit. This is a very large change,
and I am giving up on making a single commit that fixes everything.
More commits will follow slowly adding back features, introducing
new tests and fixing the documentation.
This change contains most of the work toward unifying the interface
for handling both HTTP/1.1 and HTTP/2. HTTP/1.1 connections are now
no longer 1 process per connection; instead by default 1 process per
request is also created. This has a number of pros and cons.
Because it has cons, we also allow users to use a lower-level API
that acts on "streams" (requests/responses) directly at the connection
process-level. If performance is a concern, one can always write a
stream handler. The performance in this case will be even greater
than with Cowboy 1, although all the special handlers are unavailable.
When switching to Websocket, after the handler returns from init/2,
Cowboy stops the stream and the Websocket protocol takes over the
connection process. Websocket then calls websocket_init/2 for any
additional initialization such as timers, because the process is
different in init/2 and websocket_*/* functions. This however would
allow us to use websocket_init/2 for sending messages on connect,
instead of sending ourselves a message and be subject to races.
Note that websocket_init/2 is optional.
This is all a big change and while most of the tests pass, some
functionality currently doesn't. SPDY is broken and will be removed
soon in favor of HTTP/2. Automatic compression is currently disabled.
The cowboy_req interface probably still have a few functions that
need to be updated. The docs and examples do not refer the current
functionality anymore.
Everything will be fixed over time. Feedback is more than welcome.
Open a ticket!
First and foremost: yes, you can still use Cowboy as a rebar dependency.
This commit only removes the use of rebar when *developing* Cowboy, not
when *using* Cowboy.
Over the past two years I went from very happy with rebar to unsatisfied
and most recently found it counter productive in many ways, from having
insane default configuration to various unefficient operations. The earlier
reversal from 'rebar ct' to 'ct_run' made my workflow much more natural,
as I always needed to look at 'logs/raw.log' to find out what was wrong,
anyway. Why not let 'ct_run' output it directly instead? Removing rebar
made my life easier.
If you wonder why I don't patch rebar, there's two reasons. First is that
the direction taken by rebar isn't compatible with my views, and this
would be a huge fight to steer it in another direction. I got other,
more important fights to make. Second is that I'd rather patch OTP so
that everyone benefits from it, not just users of rebar.
Anyway this isn't my personal blog so I will stop babbling here. There's
a few important things to note relative to this commit:
* You don't need rebar to work on Cowboy anymore
* The eunit tests are now ran through common_test
Ping me if it doesn't work out for you.
When missing rebar couldn't build docs because it expects the ebin/
folder to exist before it runs edoc. This commit allows users to
build docs without first having to run make.
