%% This module behaves differently depending on a specific header.
-module(stream_handler_h).
-behavior(cowboy_stream).
-export([init/3]).
-export([data/4]).
-export([info/3]).
-export([terminate/3]).
-export([early_error/5]).
%% For switch_protocol.
-export([takeover/7]).
-record(state, {
pid,
test
}).
init(StreamID, Req, Opts) ->
Pid = list_to_pid(binary_to_list(cowboy_req:header(<<"x-test-pid">>, Req))),
Test = binary_to_atom(cowboy_req:header(<<"x-test-case">>, Req), latin1),
State = #state{pid=Pid, test=Test},
Pid ! {Pid, self(), init, StreamID, Req, Opts},
{init_commands(StreamID, Req, State), State}.
init_commands(_, _, #state{test=crash_in_init}) ->
error(crash);
init_commands(_, _, #state{test=crash_in_data}) ->
[];
init_commands(_, _, #state{test=crash_in_info}) ->
[];
init_commands(_, _, #state{test=crash_in_terminate}) ->
[{response, 200, #{<<"content-length">> => <<"12">>}, <<"Hello world!">>}, stop];
init_commands(_, _, #state{test=crash_in_early_error}) ->
error(crash);
init_commands(_, _, State=#state{test=shutdown_on_stream_stop}) ->
Spawn = init_process(false, State),
[{headers, 200, #{}}, {spawn, Spawn, 5000}, stop];
init_commands(_, _, State=#state{test=shutdown_on_socket_close}) ->
Spawn = init_process(false, State),
[{headers, 200, #{}}, {spawn, Spawn, 5000}];
init_commands(_, _, State=#state{test=shutdown_timeout_on_stream_stop}) ->
Spawn = init_process(true, State),
[{headers, 200, #{}}, {spawn, Spawn, 2000}, stop];
init_commands(_, _, State=#state{test=shutdown_timeout_on_socket_close}) ->
Spawn = init_process(true, State),
[{headers, 200, #{}}, {spawn, Spawn, 2000}];
init_commands(_, _, State=#state{test=switch_protocol_after_headers}) ->
[{headers, 200, #{}}, {switch_protocol, #{}, ?MODULE, State}];
init_commands(_, _, State=#state{test=switch_protocol_after_headers_data}) ->
[{headers, 200, #{}}, {data, fin, <<"{}">>}, {switch_protocol, #{}, ?MODULE, State}];
init_commands(_, _, State=#state{test=switch_protocol_after_response}) ->
[{response, 200, #{}, <<"{}">>}, {switch_protocol, #{}, ?MODULE, State}];
init_commands(_, _, State=#state{test=terminate_on_switch_protocol}) ->
[{switch_protocol, #{}, ?MODULE, State}];
init_commands(_, _, #state{test=terminate_on_stop}) ->
[{response, 204, #{}, <<>>}];
init_commands(_, _, _) ->
[{headers, 200, #{}}].
init_process(TrapExit, #state{pid=Pid}) ->
Self = self(),
Spawn = spawn_link(fun() ->
process_flag(trap_exit, TrapExit),
Pid ! {Pid, Self, spawned, self()},
receive {Pid, ready} -> ok after 1000 -> error(timeout) end,
Self ! {self(), ready},
receive after 5000 ->
Pid ! {Pid, Self, still_alive, self()}
end
end),
receive {Spawn, ready} -> ok after 1000 -> error(timeout) end,
Spawn.
data(_, _, _, #state{test=crash_in_data}) ->
error(crash);
data(StreamID, IsFin, Data, State=#state{pid=Pid}) ->
Pid ! {Pid, self(), data, StreamID, IsFin, Data, State},
{[], State}.
info(_, Resp={response, _, _, _}, State) ->
{[Resp], State};
info(_, crash, #state{test=crash_in_info}) ->
error(crash);
info(StreamID, Info, State=#state{pid=Pid}) ->
Pid ! {Pid, self(), info, StreamID, Info, State},
case Info of
please_stop -> {[stop], State};
_ -> {[Info], State}
end.
terminate(StreamID, Reason, State=#state{pid=Pid, test=crash_in_terminate}) ->
Pid ! {Pid, self(), terminate, StreamID, Reason, State},
error(crash);
terminate(StreamID, Reason, State=#state{pid=Pid}) ->
Pid ! {Pid, self(), terminate, StreamID, Reason, State},
ok.
%% This clause can only test for early errors that reached the required headers.
early_error(StreamID, Reason, PartialReq, Resp, Opts) ->
Pid = list_to_pid(binary_to_list(cowboy_req:header(<<"x-test-pid">>, PartialReq))),
Pid ! {Pid, self(), early_error, StreamID, Reason, PartialReq, Resp, Opts},
case cowboy_req:header(<<"x-test-case">>, PartialReq) of
<<"crash_in_early_error",_/bits>> -> error(crash);
_ -> Resp
end.
%% @todo It would be good if we could allow this function to return normally.
-spec takeover(_, _, _, _, _, _, _) -> no_return().
takeover(Parent, Ref, Socket, Transport, Opts, Buffer, State=#state{pid=Pid}) ->
Pid ! {Pid, self(), takeover, Parent, Ref, Socket, Transport, Opts, Buffer, State},
exit(normal).
