src/main/java/net/pterodactylus/rhynodge/engine/Engine.java

   1 /*
   2  * Rhynodge - Engine.java - Copyright © 2013 David Roden
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.pterodactylus.rhynodge.engine;
  19
  20 import jakarta.inject.Inject;
  21 import jakarta.inject.Singleton;
  22 import kotlin.Unit;
  23 import kotlin.jvm.functions.Function0;
  24 import kotlin.jvm.functions.Function1;
  25 import net.pterodactylus.rhynodge.Reaction;
  26 import net.pterodactylus.rhynodge.actions.EmailAction;
  27 import net.pterodactylus.rhynodge.states.StateManager;
  28 import org.apache.log4j.Logger;
  29
  30 import java.util.Map;
  31 import java.util.Optional;
  32 import java.util.concurrent.*;
  33
  34 import static java.lang.System.currentTimeMillis;
  35 import static java.util.concurrent.TimeUnit.MILLISECONDS;
  36 import static net.pterodactylus.util.exception.ExceptionsKt.suppressException;
  37
  38 /**
  39  * Rhynodge main engine.
  40  *
  41  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  42  */
  43 @Singleton
  44 public class Engine {
  45
  46         private final StateManager stateManager;
  47         private final ScheduledExecutorService executorService;
  48         private final Map<String, Future<?>> scheduledFutures = new ConcurrentHashMap<>();
  49         private final EmailAction errorEmailAction;
  50
  51         @Inject
  52         public Engine(StateManager stateManager, EmailAction errorEmailAction) {
  53                 this.stateManager = stateManager;
  54                 this.errorEmailAction = errorEmailAction;
  55                 executorService = new ScheduledThreadPoolExecutor(1);
  56         }
  57
  58         //
  59         // ACCESSORS
  60         //
  61
  62         /**
  63          * Adds the given reaction to this engine.
  64          *
  65          * @param name
  66          *              The name of the reaction
  67          * @param reaction
  68          *              The reaction to add to this engine
  69          */
  70         public void addReaction(String name, Reaction reaction) {
  71                 ReactionState reactionState = new ReactionState(stateManager, name);
  72                 Optional<net.pterodactylus.rhynodge.State> lastState = reactionState.loadLastState();
  73                 long lastExecutionTime = lastState.map(net.pterodactylus.rhynodge.State::time).orElse(0L);
  74                 long nextExecutionTime = lastExecutionTime + reaction.updateInterval();
  75                 ReactionRunner reactionRunner = new ReactionRunner(reaction, reactionState, errorEmailAction);
  76                 ScheduledFuture<?> future = executorService.scheduleWithFixedDelay(suppressException(wrapRunnable(reactionRunner), logExceptionForReaction(reaction))::invoke, nextExecutionTime - currentTimeMillis(), reaction.updateInterval(), MILLISECONDS);
  77                 scheduledFutures.put(name, future);
  78         }
  79
  80         private Function1<Exception, Unit> logExceptionForReaction(Reaction reaction) {
  81                 return (Exception e) -> {
  82                         logger.warn("Exception during Reaction “%s”!".formatted(reaction.name()), e);
  83                         return Unit.INSTANCE;
  84                 };
  85         }
  86
  87         private Function0<Unit> wrapRunnable(Runnable runnable) {
  88                 return () -> {
  89                         runnable.run();
  90                         return Unit.INSTANCE;
  91                 };
  92         }
  93
  94         /**
  95          * Removes the reaction with the given name.
  96          *
  97          * @param name
  98          *              The name of the reaction to remove
  99          */
 100         public void removeReaction(String name) {
 101                 if (!scheduledFutures.containsKey(name)) {
 102                         return;
 103                 }
 104                 scheduledFutures.remove(name).cancel(true);
 105         }
 106
 107         private static final Logger logger = Logger.getLogger(Engine.class);
 108
 109 }