Add Gun Websocket handlers and protocol support

This functionality can be used to implement custom protocols
on top of Websocket, but may also be used to decode frame
contents on the fly if necessary.

The default_protocol option defines what module should be
used when no protocol was selected.

The protocols option is a list of key/value pairs used to
select the handler depending on the protocol that the server
accepted.

The feature is currently experimental.

1 files changed, 35 insertions, 0 deletions

diff --git a/src/gun_ws_handler.erl b/src/gun_ws_handler.erl
new file mode 100644
index 0000000..4356ab5
--- /dev/null
+++ b/src/gun_ws_handler.erl
@@ -0,0 +1,35 @@
+%% Copyright (c) 2017, Loïc Hoguin <[email protected]>
+%%
+%% Permission to use, copy, modify, and/or distribute this software for any
+%% purpose with or without fee is hereby granted, provided that the above
+%% copyright notice and this permission notice appear in all copies.
+%%
+%% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+%% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+%% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+%% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+%% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+%% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+%% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+-module(gun_ws_handler).
+
+-export([init/3]).
+-export([handle/2]).
+
+-record(state, {
+	reply_to :: pid(),
+	frag_buffer = <<>> :: binary()
+}).
+
+init(ReplyTo, _, _) ->
+	#state{reply_to=ReplyTo}.
+
+handle({fragment, nofin, _, Payload}, State=#state{frag_buffer=SoFar}) ->
+	State#state{frag_buffer= << SoFar/binary, Payload/binary >>};
+handle({fragment, fin, Type, Payload}, State=#state{reply_to=ReplyTo, frag_buffer=SoFar}) ->
+	ReplyTo ! {gun_ws, self(), {Type, << SoFar/binary, Payload/binary >>}},
+	State#state{frag_buffer= <<>>};
+handle(Frame, State=#state{reply_to=ReplyTo}) ->
+	ReplyTo ! {gun_ws, self(), Frame},
+	State.