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cowboy/test/handlers/loop_handler_body_h.erl
Loïc Hoguin a45813c60f
Allow passing options to sub protocols
Before this commit we had an issue where configuring a
Websocket connection was simply not possible without
doing magic, adding callbacks or extra return values.
The init/2 function only allowed setting hibernate
and timeout options.

After this commit, when switching to a different
type of handler you can either return

  {module, Req, State}

or

  {module, Req, State, Opts}

where Opts is any value (as far as the sub protocol
interface is concerned) and is ultimately checked
by the custom handlers.

A large protocol like Websocket would accept only
a map there, with many different options, while a
small interface like loop handlers would allow
passing hibernate and nothing else.

For Websocket, hibernate must be set from the
websocket_init/1 callback, because init/2 executes
in a separate process.

Sub protocols now have two callbacks: one with the
Opts value, one without.

The loop handler code was largely reworked and
simplified. It does not need to manage a timeout
or read from the socket anymore, it's the job of
the protocol code. A lot of unnecessary stuff was
therefore removed.

Websocket compression must now be enabled from
the handler options instead of per listener. This
means that a project can have two separate Websocket
handlers with different options. Compression is
still disabled by default, and the idle_timeout
value was changed from inifnity to 60000 (60 seconds),
as that's safer and is also a good value for mobile
devices.
2017-02-18 18:26:20 +01:00

22 lines
538 B
Erlang

%% This module implements a loop handler that reads
%% the request body after sending itself a message,
%% checks that its size is exactly 100000 bytes,
%% then sends a 200 reply back.
-module(loop_handler_body_h).
-export([init/2]).
-export([info/3]).
-export([terminate/3]).
init(Req, _) ->
self() ! timeout,
{cowboy_loop, Req, undefined, hibernate}.
info(timeout, Req0, State) ->
{ok, Body, Req} = cowboy_req:read_body(Req0),
100000 = byte_size(Body),
{stop, cowboy_req:reply(200, Req), State}.
terminate(stop, _, _) ->
ok.