-module(erlcount_dispatch). -behaviour(gen_fsm). -export([start_link/0, complete/4]). -export([init/1, dispatching/2, listening/2, handle_event/3, handle_sync_event/4, handle_info/3, terminate/3, code_change/4]). -define(POOL, erlcount). -record(data, {regex=[], refs=[]}). %%% PUBLIC API start_link() -> gen_fsm:start_link(?MODULE, [], []). complete(Pid, Regex, Ref, Count) -> gen_fsm:send_all_state_event(Pid, {complete, Regex, Ref, Count}). %%% GEN_FSM %% Two states: dispatching and listening init([]) -> %% Move the get_env stuff to the supervisor's init. {ok, Re} = application:get_env(regex), {ok, Dir} = application:get_env(directory), {ok, MaxFiles} = application:get_env(max_files), ppool:start_pool(?POOL, MaxFiles, {erlcount_counter, start_link, []}), case lists:all(fun valid_regex/1, Re) of true -> %% creates a regex entry of the form [{Re, Count}] self() ! {start, Dir}, {ok, dispatching, #data{regex=[{R,0} || R <- Re]}}; false -> {stop, invalid_regex} end. dispatching({continue, File, Continuation}, Data = #data{regex=Re, refs=Refs}) -> F = fun({Regex,_Count}, NewRefs) -> Ref = make_ref(), ppool:async_queue(?POOL, [self(), Ref, File, Regex]), [Ref|NewRefs] end, NewRefs = lists:foldl(F, Refs, Re), gen_fsm:send_event(self(), Continuation()), {next_state, dispatching, Data#data{refs = NewRefs}}; dispatching(done, Data) -> %% This is a special case. We can not assume that all messages have NOT %% been received by the time we hit 'done'. As such, we directly move to %% listening/2 without waiting for an external event. listening(done, Data). listening(done, #data{regex=Re, refs=[]}) -> % all received! [io:format("Regex ~s has ~p results~n", [R,C]) || {R, C} <- Re], {stop, normal, done}; listening(done, Data) -> % entries still missing {next_state, listening, Data}. handle_event({complete, Regex, Ref, Count}, State, Data = #data{regex=Re, refs=Refs}) -> {Regex, OldCount} = lists:keyfind(Regex, 1, Re), NewRe = lists:keyreplace(Regex, 1, Re, {Regex, OldCount+Count}), NewData = Data#data{regex=NewRe, refs=Refs--[Ref]}, case State of dispatching -> {next_state, dispatching, NewData}; listening -> listening(done, NewData) end. handle_sync_event(Event, _From, State, Data) -> io:format("Unexpected event: ~p~n", [Event]), {next_state, State, Data}. handle_info({start, Dir}, State, Data) -> gen_fsm:send_event(self(), erlcount_lib:find_erl(Dir)), {next_state, State, Data}. terminate(_Reason, _State, _Data) -> ok. code_change(_OldVsn, State, Data, _Extra) -> {ok, State, Data}. %%% PRIVATE valid_regex(Re) -> try re:run("", Re) of _ -> true catch error:badarg -> false end.