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Diffstat (limited to 'server/_build/default/lib/cowboy/src/cowboy_stream.erl')
| -rw-r--r-- | server/_build/default/lib/cowboy/src/cowboy_stream.erl | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/server/_build/default/lib/cowboy/src/cowboy_stream.erl b/server/_build/default/lib/cowboy/src/cowboy_stream.erl new file mode 100644 index 0000000..2dad6d0 --- /dev/null +++ b/server/_build/default/lib/cowboy/src/cowboy_stream.erl @@ -0,0 +1,193 @@ +%% Copyright (c) 2015-2017, Loïc Hoguin <essen@ninenines.eu> +%% +%% 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_stream). + +-type state() :: any(). +-type human_reason() :: atom(). + +-type streamid() :: any(). +-export_type([streamid/0]). + +-type fin() :: fin | nofin. +-export_type([fin/0]). + +%% @todo Perhaps it makes more sense to have resp_body in this module? + +-type resp_command() + :: {response, cowboy:http_status(), cowboy:http_headers(), cowboy_req:resp_body()}. +-export_type([resp_command/0]). + +-type commands() :: [{inform, cowboy:http_status(), cowboy:http_headers()} + | resp_command() + | {headers, cowboy:http_status(), cowboy:http_headers()} + | {data, fin(), cowboy_req:resp_body()} + | {trailers, cowboy:http_headers()} + | {push, binary(), binary(), binary(), inet:port_number(), + binary(), binary(), cowboy:http_headers()} + | {flow, pos_integer()} + | {spawn, pid(), timeout()} + | {error_response, cowboy:http_status(), cowboy:http_headers(), iodata()} + | {switch_protocol, cowboy:http_headers(), module(), state()} + | {internal_error, any(), human_reason()} + | {set_options, map()} + | {log, logger:level(), io:format(), list()} + | stop]. +-export_type([commands/0]). + +-type reason() :: normal | switch_protocol + | {internal_error, timeout | {error | exit | throw, any()}, human_reason()} + | {socket_error, closed | atom(), human_reason()} + | {stream_error, cow_http2:error(), human_reason()} + | {connection_error, cow_http2:error(), human_reason()} + | {stop, cow_http2:frame() | {exit, any()}, human_reason()}. +-export_type([reason/0]). + +-type partial_req() :: map(). %% @todo Take what's in cowboy_req with everything? optional. +-export_type([partial_req/0]). + +-callback init(streamid(), cowboy_req:req(), cowboy:opts()) -> {commands(), state()}. +-callback data(streamid(), fin(), binary(), State) -> {commands(), State} when State::state(). +-callback info(streamid(), any(), State) -> {commands(), State} when State::state(). +-callback terminate(streamid(), reason(), state()) -> any(). +-callback early_error(streamid(), reason(), partial_req(), Resp, cowboy:opts()) + -> Resp when Resp::resp_command(). + +%% @todo To optimize the number of active timers we could have a command +%% that enables a timeout that is called in the absence of any other call, +%% similar to what gen_server does. However the nice thing about this is +%% that the connection process can keep a single timer around (the same +%% one that would be used to detect half-closed sockets) and use this +%% timer and other events to trigger the timeout in streams at their +%% intended time. +%% +%% This same timer can be used to try and send PING frames to help detect +%% that the connection is indeed unresponsive. + +-export([init/3]). +-export([data/4]). +-export([info/3]). +-export([terminate/3]). +-export([early_error/5]). +-export([make_error_log/5]). + +%% Note that this and other functions in this module do NOT catch +%% exceptions. We want the exception to go all the way down to the +%% protocol code. +%% +%% OK the failure scenario is not so clear. The problem is +%% that the failure at any point in init/3 will result in the +%% corresponding state being lost. I am unfortunately not +%% confident we can do anything about this. If the crashing +%% handler just created a process, we'll never know about it. +%% Therefore at this time I choose to leave all failure handling +%% to the protocol process. +%% +%% Note that a failure in init/3 will result in terminate/3 +%% NOT being called. This is because the state is not available. + +-spec init(streamid(), cowboy_req:req(), cowboy:opts()) + -> {commands(), {module(), state()} | undefined}. +init(StreamID, Req, Opts) -> + case maps:get(stream_handlers, Opts, [cowboy_stream_h]) of + [] -> + {[], undefined}; + [Handler|Tail] -> + %% We call the next handler and remove it from the list of + %% stream handlers. This means that handlers that run after + %% it have no knowledge it exists. Should user require this + %% knowledge they can just define a separate option that will + %% be left untouched. + {Commands, State} = Handler:init(StreamID, Req, Opts#{stream_handlers => Tail}), + {Commands, {Handler, State}} + end. + +-spec data(streamid(), fin(), binary(), {Handler, State} | undefined) + -> {commands(), {Handler, State} | undefined} + when Handler::module(), State::state(). +data(_, _, _, undefined) -> + {[], undefined}; +data(StreamID, IsFin, Data, {Handler, State0}) -> + {Commands, State} = Handler:data(StreamID, IsFin, Data, State0), + {Commands, {Handler, State}}. + +-spec info(streamid(), any(), {Handler, State} | undefined) + -> {commands(), {Handler, State} | undefined} + when Handler::module(), State::state(). +info(_, _, undefined) -> + {[], undefined}; +info(StreamID, Info, {Handler, State0}) -> + {Commands, State} = Handler:info(StreamID, Info, State0), + {Commands, {Handler, State}}. + +-spec terminate(streamid(), reason(), {module(), state()} | undefined) -> ok. +terminate(_, _, undefined) -> + ok; +terminate(StreamID, Reason, {Handler, State}) -> + _ = Handler:terminate(StreamID, Reason, State), + ok. + +-spec early_error(streamid(), reason(), partial_req(), Resp, cowboy:opts()) + -> Resp when Resp::resp_command(). +early_error(StreamID, Reason, PartialReq, Resp, Opts) -> + case maps:get(stream_handlers, Opts, [cowboy_stream_h]) of + [] -> + Resp; + [Handler|Tail] -> + %% This is the same behavior as in init/3. + Handler:early_error(StreamID, Reason, + PartialReq, Resp, Opts#{stream_handlers => Tail}) + end. + +-spec make_error_log(init | data | info | terminate | early_error, + list(), error | exit | throw, any(), list()) + -> {log, error, string(), list()}. +make_error_log(init, [StreamID, Req, Opts], Class, Exception, Stacktrace) -> + {log, error, + "Unhandled exception ~p:~p in cowboy_stream:init(~p, Req, Opts)~n" + "Stacktrace: ~p~n" + "Req: ~p~n" + "Opts: ~p~n", + [Class, Exception, StreamID, Stacktrace, Req, Opts]}; +make_error_log(data, [StreamID, IsFin, Data, State], Class, Exception, Stacktrace) -> + {log, error, + "Unhandled exception ~p:~p in cowboy_stream:data(~p, ~p, Data, State)~n" + "Stacktrace: ~p~n" + "Data: ~p~n" + "State: ~p~n", + [Class, Exception, StreamID, IsFin, Stacktrace, Data, State]}; +make_error_log(info, [StreamID, Msg, State], Class, Exception, Stacktrace) -> + {log, error, + "Unhandled exception ~p:~p in cowboy_stream:info(~p, Msg, State)~n" + "Stacktrace: ~p~n" + "Msg: ~p~n" + "State: ~p~n", + [Class, Exception, StreamID, Stacktrace, Msg, State]}; +make_error_log(terminate, [StreamID, Reason, State], Class, Exception, Stacktrace) -> + {log, error, + "Unhandled exception ~p:~p in cowboy_stream:terminate(~p, Reason, State)~n" + "Stacktrace: ~p~n" + "Reason: ~p~n" + "State: ~p~n", + [Class, Exception, StreamID, Stacktrace, Reason, State]}; +make_error_log(early_error, [StreamID, Reason, PartialReq, Resp, Opts], + Class, Exception, Stacktrace) -> + {log, error, + "Unhandled exception ~p:~p in cowboy_stream:early_error(~p, Reason, PartialReq, Resp, Opts)~n" + "Stacktrace: ~p~n" + "Reason: ~p~n" + "PartialReq: ~p~n" + "Resp: ~p~n" + "Opts: ~p~n", + [Class, Exception, StreamID, Stacktrace, Reason, PartialReq, Resp, Opts]}. |