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 static java.lang.System.currentTimeMillis;
  21 import static java.util.concurrent.TimeUnit.MILLISECONDS;
  22
  23 import java.util.Map;
  24 import java.util.Optional;
  25 import java.util.concurrent.ConcurrentHashMap;
  26 import java.util.concurrent.Future;
  27 import java.util.concurrent.ScheduledExecutorService;
  28 import java.util.concurrent.ScheduledFuture;
  29 import java.util.concurrent.ScheduledThreadPoolExecutor;
  30
  31 import net.pterodactylus.rhynodge.Reaction;
  32 import net.pterodactylus.rhynodge.states.StateManager;
  33
  34 /**
  35  * Rhynodge main engine.
  36  *
  37  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  38  */
  39 public class Engine {
  40
  41         private final StateManager stateManager;
  42         private final ScheduledExecutorService executorService;
  43         private final Map<String, Future<?>> scheduledFutures = new ConcurrentHashMap<>();
  44
  45         /**
  46          * Creates a new engine.
  47          *
  48          * @param stateManager
  49          *              The state manager
  50          */
  51         public Engine(StateManager stateManager) {
  52                 this.stateManager = stateManager;
  53                 executorService = new ScheduledThreadPoolExecutor(10);
  54         }
  55
  56         //
  57         // ACCESSORS
  58         //
  59
  60         /**
  61          * Adds the given reaction to this engine.
  62          *
  63          * @param name
  64          *              The name of the reaction
  65          * @param reaction
  66          *              The reaction to add to this engine
  67          */
  68         public void addReaction(String name, Reaction reaction) {
  69                 ReactionState reactionState = new ReactionState(stateManager, name);
  70                 Optional<net.pterodactylus.rhynodge.State> lastState = reactionState.loadLastState();
  71                 long lastExecutionTime = lastState.map(net.pterodactylus.rhynodge.State::time).orElse(0L);
  72                 long nextExecutionTime = lastExecutionTime + reaction.updateInterval();
  73                 ReactionRunner reactionRunner = new ReactionRunner(reaction, reactionState);
  74                 ScheduledFuture<?> future = executorService.scheduleWithFixedDelay(reactionRunner, nextExecutionTime - currentTimeMillis(), reaction.updateInterval(), MILLISECONDS);
  75                 scheduledFutures.put(name, future);
  76         }
  77
  78         /**
  79          * Removes the reaction with the given name.
  80          *
  81          * @param name
  82          *              The name of the reaction to remove
  83          */
  84         public void removeReaction(String name) {
  85                 if (!scheduledFutures.containsKey(name)) {
  86                         return;
  87                 }
  88                 scheduledFutures.remove(name).cancel(true);
  89         }
  90
  91 }