1 files changed, 145 insertions, 0 deletions
diff --git a/test/cowboy_error_h.erl b/test/cowboy_error_h.erl
new file mode 100644
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+++ b/test/cowboy_error_h.erl
@@ -0,0 +1,145 @@
+%% Copyright (c) 2014, 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(cowboy_error_h).
+-behaviour(gen_event).
+
+%% Public interface.
+-export([ignore/3]).
+
+%% gen_event.
+-export([init/1]).
+-export([handle_event/2]).
+-export([handle_call/2]).
+-export([handle_info/2]).
+-export([terminate/2]).
+-export([code_change/3]).
+
+%% Public interface.
+
+%% Ignore crashes from Pid occuring in M:F/A.
+ignore(M, F, A) ->
+	gen_event:call(error_logger, ?MODULE, {expect, {self(), M, F, A}}).
+
+%% gen_event.
+
+init(_) ->
+	spawn(fun() -> error_logger:tty(false) end),
+	{ok, []}.
+
+%% Ignore supervisor and progress reports.
+handle_event({info_report, _, {_, progress, _}}, State) ->
+	{ok, State};
+handle_event({info_report, _, {_, std_info, _}}, State) ->
+	{ok, State};
+handle_event({error_report, _, {_, supervisor_report, _}}, State) ->
+	{ok, State};
+%% Ignore gun retry failures.
+handle_event({error_report, _, {_, crash_report,
+		[[{initial_call, {gun, init, _}}, _, _,
+			{error_info, {error, gone, _}}|_]|_]}},
+		State) ->
+	{ok, State};
+%% Ignore emulator reports that are a duplicate of what Ranch gives us.
+%%
+%% The emulator always sends strings for errors, which makes it very
+%% difficult to extract the information we need, hence the regexps.
+handle_event(Event = {error, GL, {emulator, _, Msg}}, State)
+		when node(GL) =:= node() ->
+	Result = re:run(Msg,
+		"Error in process ([^\s]+).+? with exit value: "
+			".+?{stacktrace,\\[{([^,]+),([^,]+),(.+)",
+		[{capture, all_but_first, list}]),
+	case Result of
+		nomatch ->
+			write_event(Event),
+			{ok, State};
+		{match, [PidStr, MStr, FStr, Rest]} ->
+			A = case Rest of
+				"[]" ++ _ ->
+					0;
+				"[" ++ Rest2 ->
+					count_args(Rest2, 1, 0);
+				_ ->
+					{match, [AStr]} = re:run(Rest, "([^,]+).+",
+						[{capture, all_but_first, list}]),
+					list_to_integer(AStr)
+			end,
+			Crash = {list_to_pid(PidStr), list_to_existing_atom(MStr),
+				list_to_existing_atom(FStr), A},
+			case lists:member(Crash, State) of
+				true ->
+					{ok, lists:delete(Crash, State)};
+				false ->
+					write_event(Event),
+					{ok, State}
+			end
+	end;
+handle_event(Event = {error, GL,
+		{_, "Ranch listener" ++ _, [_, _, Pid, {[_, _,
+			{stacktrace, [{M, F, A, _}|_]}|_], _}]}},
+		State) when node(GL) =:= node() ->
+	A2 = if is_list(A) -> length(A); true -> A end,
+	Crash = {Pid, M, F, A2},
+	case lists:member(Crash, State) of
+		true ->
+			{ok, lists:delete(Crash, State)};
+		false ->
+			write_event(Event),
+			{ok, State}
+	end;
+handle_event(Event = {_, GL, _}, State) when node(GL) =:= node() ->
+	write_event(Event),
+	{ok, State};
+handle_event(_, State) ->
+	{ok, State}.
+
+handle_call({expect, Crash}, State) ->
+	{ok, ok, [Crash, Crash|State]};
+handle_call(_, State) ->
+	{ok, {error, bad_query}, State}.
+
+handle_info(_, State) ->
+	{ok, State}.
+
+terminate(_, _) ->
+	spawn(fun() -> error_logger:tty(true) end),
+	ok.
+
+code_change(_, State, _) ->
+	{ok, State}.
+
+%% Internal.
+
+write_event(Event) ->
+	error_logger_tty_h:write_event(
+		{erlang:universaltime(), Event},
+		io).
+
+count_args("]" ++ _, N, 0) ->
+	N;
+count_args("]" ++ Tail, N, Levels) ->
+	count_args(Tail, N, Levels - 1);
+count_args("[" ++ Tail, N, Levels) ->
+	count_args(Tail, N, Levels + 1);
+count_args("}" ++ Tail, N, Levels) ->
+	count_args(Tail, N, Levels - 1);
+count_args("{" ++ Tail, N, Levels) ->
+	count_args(Tail, N, Levels + 1);
+count_args("," ++ Tail, N, Levels = 0) ->
+	count_args(Tail, N + 1, Levels);
+count_args("," ++ Tail, N, Levels) ->
+	count_args(Tail, N, Levels);
+count_args([_|Tail], N, Levels) ->
+	count_args(Tail, N, Levels).