mirror of
https://github.com/ninenines/cowboy.git
synced 2025-07-14 12:20:24 +00:00
a45813c60f
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.
20 lines
505 B
Erlang
20 lines
505 B
Erlang
%% Feel free to use, reuse and abuse the code in this file.
|
|
|
|
-module(ws_subprotocol).
|
|
|
|
-export([init/2]).
|
|
-export([websocket_handle/2]).
|
|
-export([websocket_info/2]).
|
|
|
|
init(Req, Opts) ->
|
|
[Protocol | _] = cowboy_req:parse_header(<<"sec-websocket-protocol">>, Req),
|
|
Req2 = cowboy_req:set_resp_header(<<"sec-websocket-protocol">>, Protocol, Req),
|
|
{cowboy_websocket, Req2, Opts, #{
|
|
idle_timeout => 1000
|
|
}}.
|
|
|
|
websocket_handle(_Frame, State) ->
|
|
{ok, State}.
|
|
|
|
websocket_info(_Info, State) ->
|
|
{ok, State}.
|