Allow HTTP handlers to skip the handle/2 step in init/3

You can now return {shutdown, Req, State} from Handler:init/3
to skip the handle/2 step.

Also allow init/3 function to send responses.

include/http.hrl

@@ -66,5 +66,5 @@
 	buffer     = <<>>      :: binary(),
 
 	%% Response.
-	resp_state = locked    :: locked | waiting | chunks | done
+	resp_state = waiting   :: locked | waiting | chunks | done
 }).

src/cowboy_http_protocol.erl

@@ -205,6 +205,8 @@ handler_init(Req, State=#state{listener=ListenerPid,
 	try Handler:init({Transport:name(), http}, Req, Opts) of
 		{ok, Req2, HandlerState} ->
 			handler_loop(HandlerState, Req2, State);
+		{shutdown, Req2, HandlerState} ->
+			handler_terminate(HandlerState, Req2, State);
 		%% @todo {upgrade, transport, Module}
 		{upgrade, protocol, Module} ->
 			Module:upgrade(ListenerPid, Handler, Opts, Req)
@@ -220,7 +222,7 @@ handler_init(Req, State=#state{listener=ListenerPid,
 
 -spec handler_loop(any(), #http_req{}, #state{}) -> ok.
 handler_loop(HandlerState, Req, State=#state{handler={Handler, Opts}}) ->
-	try Handler:handle(Req#http_req{resp_state=waiting}, HandlerState) of
+	try Handler:handle(Req, HandlerState) of
 		{ok, Req2, HandlerState2} ->
 			next_request(HandlerState2, Req2, State)
 	catch Class:Reason ->

test/http_SUITE.erl

@@ -95,6 +95,7 @@ init_http_dispatch() ->
 			{[<<"chunked_response">>], chunked_handler, []},
 			{[<<"websocket">>], websocket_handler, []},
 			{[<<"ws_timeout_hibernate">>], ws_timeout_hibernate_handler, []},
+			{[<<"init_shutdown">>], http_handler_init_shutdown, []},
 			{[<<"headers">>, <<"dupe">>], http_handler,
 				[{headers, [{<<"Connection">>, <<"close">>}]}]},
 			{[], http_handler, []}
@@ -224,7 +225,8 @@ raw(Config) ->
 		{"GET / HTTP/1.1\r\nHost: localhost\r\n", 408},
 		{"GET / HTTP/1.1\r\nHost: localhost\r\n\r", 408},
 		{"GET http://localhost/ HTTP/1.1\r\n\r\n", 501},
-		{"GET / HTTP/1.2\r\nHost: localhost\r\n\r\n", 505}
+		{"GET / HTTP/1.2\r\nHost: localhost\r\n\r\n", 505},
+		{"GET /init_shutdown HTTP/1.1\r\nHost: localhost\r\n\r\n", 666}
 	],
 	[{Packet, StatusCode} = raw_req(Packet, Config)
 		|| {Packet, StatusCode} <- Tests].

test/http_handler_init_shutdown.erl

@@ -0,0 +1,17 @@
+%% Feel free to use, reuse and abuse the code in this file.
+
+-module(http_handler_init_shutdown).
+-behaviour(cowboy_http_handler).
+-export([init/3, handle/2, terminate/2]).
+
+init({_Transport, http}, Req, _Opts) ->
+	Req2 = cowboy_http_req:reply(<<"666 Init Shutdown Testing">>,
+		[{'Connection', <<"close">>}], [], Req),
+	{shutdown, Req2, undefined}.
+
+handle(Req, State) ->
+	Req2 = cowboy_http_req:reply(200, [], "Hello world!", Req),
+	{ok, Req2, State}.
+
+terminate(_Req, _State) ->
+	ok.