%%%---------------------------------------------------------------------- %%% File : ejabberd_batch.erl %%% Author : Paweł Chmielowski %%% Purpose : Batch tasks manager %%% Created : 8 mar 2022 by Paweł Chmielowski %%% %%% %%% ejabberd, Copyright (C) 2002-2022 ProcessOne %%% %%% This program is free software; you can redistribute it and/or %%% modify it under the terms of the GNU General Public License as %%% published by the Free Software Foundation; either version 2 of the %%% License, or (at your option) any later version. %%% %%% This program is distributed in the hope that it will be useful, %%% but WITHOUT ANY WARRANTY; without even the implied warranty of %%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU %%% General Public License for more details. %%% %%% You should have received a copy of the GNU General Public License along %%% with this program; if not, write to the Free Software Foundation, Inc., %%% 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. %%% %%%---------------------------------------------------------------------- -module(ejabberd_batch). -author("pawel@process-one.net"). -behaviour(gen_server). -include("logger.hrl"). %% API -export([start_link/0]). %% gen_server callbacks -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]). -export([register_task/5, task_status/1, abort_task/1]). -define(SERVER, ?MODULE). -record(state, {tasks = #{}}). -record(task, {state = not_started, pid, steps, done_steps}). %%%=================================================================== %%% API %%%=================================================================== %% @doc Spawns the server and registers the local name (unique) -spec(start_link() -> {ok, Pid :: pid()} | ignore | {error, Reason :: term()}). start_link() -> gen_server:start_link({local, ?SERVER}, ?MODULE, [], []). register_task(Type, Steps, Rate, JobState, JobFun) -> gen_server:call(?MODULE, {register_task, Type, Steps, Rate, JobState, JobFun}). task_status(Type) -> gen_server:call(?MODULE, {task_status, Type}). abort_task(Type) -> gen_server:call(?MODULE, {abort_task, Type}). %%%=================================================================== %%% gen_server callbacks %%%=================================================================== %% @private %% @doc Initializes the server -spec(init(Args :: term()) -> {ok, State :: #state{}} | {ok, State :: #state{}, timeout() | hibernate} | {stop, Reason :: term()} | ignore). init([]) -> {ok, #state{}}. %% @private %% @doc Handling call messages -spec(handle_call(Request :: term(), From :: {pid(), Tag :: term()}, State :: #state{}) -> {reply, Reply :: term(), NewState :: #state{}} | {reply, Reply :: term(), NewState :: #state{}, timeout() | hibernate} | {noreply, NewState :: #state{}} | {noreply, NewState :: #state{}, timeout() | hibernate} | {stop, Reason :: term(), Reply :: term(), NewState :: #state{}} | {stop, Reason :: term(), NewState :: #state{}}). handle_call({register_task, Type, Steps, Rate, JobState, JobFun}, _From, #state{tasks = Tasks} = State) -> case maps:get(Type, Tasks, #task{}) of #task{state = S} when S == completed; S == not_started; S == aborted; S == failed -> Pid = spawn(fun() -> work_loop(Type, JobState, JobFun, Rate, erlang:monotonic_time(second), 0) end), Tasks2 = maps:put(Type, #task{state = working, pid = Pid, steps = Steps, done_steps = 0}, Tasks), {reply, ok, #state{tasks = Tasks2}}; #task{state = working} -> {reply, {error, in_progress}, State} end; handle_call({task_status, Type}, _From, #state{tasks = Tasks} = State) -> case maps:get(Type, Tasks, none) of none -> {reply, not_started, State}; #task{state = not_started} -> {reply, not_started, State}; #task{state = failed, done_steps = Steps, pid = Error} -> {reply, {failed, Steps, Error}, State}; #task{state = aborted, done_steps = Steps} -> {reply, {aborted, Steps}, State}; #task{state = working, done_steps = Steps} -> {reply, {working, Steps}, State}; #task{state = completed, done_steps = Steps} -> {reply, {completed, Steps}, State} end; handle_call({abort_task, Type}, _From, #state{tasks = Tasks} = State) -> case maps:get(Type, Tasks, none) of #task{state = working, pid = Pid} = T -> Pid ! abort, Tasks2 = maps:put(Type, T#task{state = aborted, pid = none}, Tasks), {reply, aborted, State#state{tasks = Tasks2}}; _ -> {reply, not_started, State} end; handle_call(_Request, _From, State = #state{}) -> {reply, ok, State}. %% @private %% @doc Handling cast messages -spec(handle_cast(Request :: term(), State :: #state{}) -> {noreply, NewState :: #state{}} | {noreply, NewState :: #state{}, timeout() | hibernate} | {stop, Reason :: term(), NewState :: #state{}}). handle_cast({task_finished, Type, Pid}, #state{tasks = Tasks} = State) -> case maps:get(Type, Tasks, none) of #task{state = working, pid = Pid2} = T when Pid == Pid2 -> Tasks2 = maps:put(Type, T#task{state = completed, pid = none}, Tasks), {noreply, State#state{tasks = Tasks2}}; _ -> {noreply, State} end; handle_cast({task_progress, Type, Pid, Count}, #state{tasks = Tasks} = State) -> case maps:get(Type, Tasks, none) of #task{state = working, pid = Pid2, done_steps = Steps} = T when Pid == Pid2 -> Tasks2 = maps:put(Type, T#task{done_steps = Steps + Count}, Tasks), {noreply, State#state{tasks = Tasks2}}; _ -> {noreply, State} end; handle_cast({task_error, Type, Pid, Error}, #state{tasks = Tasks} = State) -> case maps:get(Type, Tasks, none) of #task{state = working, pid = Pid2} = T when Pid == Pid2 -> Tasks2 = maps:put(Type, T#task{state = failed, pid = Error}, Tasks), {noreply, State#state{tasks = Tasks2}}; _ -> {noreply, State} end; handle_cast(_Request, State = #state{}) -> {noreply, State}. %% @private %% @doc Handling all non call/cast messages -spec(handle_info(Info :: timeout() | term(), State :: #state{}) -> {noreply, NewState :: #state{}} | {noreply, NewState :: #state{}, timeout() | hibernate} | {stop, Reason :: term(), NewState :: #state{}}). handle_info(_Info, State = #state{}) -> {noreply, State}. %% @private %% @doc This function is called by a gen_server when it is about to %% terminate. It should be the opposite of Module:init/1 and do any %% necessary cleaning up. When it returns, the gen_server terminates %% with Reason. The return value is ignored. -spec(terminate(Reason :: (normal | shutdown | {shutdown, term()} | term()), State :: #state{}) -> term()). terminate(_Reason, _State = #state{}) -> ok. %% @private %% @doc Convert process state when code is changed -spec(code_change(OldVsn :: term() | {down, term()}, State :: #state{}, Extra :: term()) -> {ok, NewState :: #state{}} | {error, Reason :: term()}). code_change(_OldVsn, State = #state{}, _Extra) -> {ok, State}. %%%=================================================================== %%% Internal functions %%%=================================================================== work_loop(Task, JobState, JobFun, Rate, StartDate, CurrentProgress) -> try JobFun(JobState) of {ok, _NewState, 0} -> gen_server:cast(?MODULE, {task_finished, Task, self()}); {ok, NewState, Count} -> gen_server:cast(?MODULE, {task_progress, Task, self(), Count}), NewProgress = CurrentProgress + Count, TimeSpent = erlang:monotonic_time(second) - StartDate, SleepTime = max(0, NewProgress/Rate*60 - TimeSpent), receive abort -> ok after round(SleepTime*1000) -> work_loop(Task, NewState, JobFun, Rate, StartDate, NewProgress) end; {error, Error} -> gen_server:cast(?MODULE, {task_error, Task, self(), Error}) catch _:_ -> gen_server:cast(?MODULE, {task_error, Task, self(), internal_error}) end.