From 631eb5a4e09bea50955554b982c67fc9a0ff3abd Mon Sep 17 00:00:00 2001 From: =?utf8?q?David=20=E2=80=98Bombe=E2=80=99=20Roden?= Date: Wed, 2 Jan 2013 13:31:10 +0100 Subject: [PATCH] Add reactor engine. --- .../net/pterodactylus/reactor/engine/Engine.java | 235 +++++++++++++++++++++ 1 file changed, 235 insertions(+) create mode 100644 src/main/java/net/pterodactylus/reactor/engine/Engine.java diff --git a/src/main/java/net/pterodactylus/reactor/engine/Engine.java b/src/main/java/net/pterodactylus/reactor/engine/Engine.java new file mode 100644 index 0000000..123781f --- /dev/null +++ b/src/main/java/net/pterodactylus/reactor/engine/Engine.java @@ -0,0 +1,235 @@ +/* + * Reactor - Engine.java - Copyright © 2013 David Roden + * + * 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 3 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, see . + */ + +package net.pterodactylus.reactor.engine; + +import java.util.Map; +import java.util.Set; +import java.util.SortedMap; +import java.util.concurrent.TimeUnit; + +import net.pterodactylus.reactor.Query; +import net.pterodactylus.reactor.Reaction; +import net.pterodactylus.reactor.Trigger; +import net.pterodactylus.reactor.states.AbstractState; + +import org.apache.log4j.Logger; + +import com.google.common.collect.Maps; +import com.google.common.collect.Sets; +import com.google.common.util.concurrent.AbstractExecutionThreadService; +import com.google.common.util.concurrent.Uninterruptibles; + +/** + * Reactor main engine. + * + * @author David ‘Bombe’ Roden + */ +public class Engine extends AbstractExecutionThreadService { + + /** The logger. */ + private static final Logger logger = Logger.getLogger(Engine.class); + + /** All defined reactions. */ + private final Set reactions = Sets.newHashSet(); + + /** Reaction states. */ + private final Map reactionExecutions = Maps.newHashMap(); + + // + // ACCESSORS + // + + /** + * Adds the given reaction to this engine. + * + * @param reaction + * The reaction to add to this engine + */ + @SuppressWarnings("synthetic-access") + public void addReaction(Reaction reaction) { + reactions.add(reaction); + reactionExecutions.put(reaction, new ReactionExecution()); + } + + // + // ABSTRACTSERVICE METHODS + // + + /** + * {@inheritDoc} + */ + @Override + public void run() { + while (isRunning()) { + + /* delay if we have no reactions. */ + if (reactions.isEmpty()) { + logger.trace("Sleeping for 1 second while no Reactions available."); + Uninterruptibles.sleepUninterruptibly(1, TimeUnit.SECONDS); + continue; + } + + /* find next reaction. */ + SortedMap nextReactions = Maps.newTreeMap(); + for (Reaction reaction : reactions) { + ReactionExecution reactionExecution = reactionExecutions.get(reaction); + nextReactions.put(reactionExecution.lastExecutionTime() + reaction.updateInterval(), reaction); + } + Reaction nextReaction = nextReactions.get(nextReactions.firstKey()); + ReactionExecution reactionExecution = reactionExecutions.get(nextReaction); + logger.debug(String.format("Next Reaction: %s.", nextReaction)); + + /* wait until the next reaction has to run. */ + while (isRunning()) { + long waitTime = (reactionExecution.lastExecutionTime() + nextReaction.updateInterval()) - System.currentTimeMillis(); + logger.debug(String.format("Time to wait for next Reaction: %d millseconds.", waitTime)); + if (waitTime <= 0) { + break; + } + try { + logger.debug(String.format("Waiting for %d milliseconds.", waitTime)); + TimeUnit.MILLISECONDS.sleep(waitTime); + } catch (InterruptedException ie1) { + /* we’re looping! */ + } + } + + /* are we still running? */ + if (!isRunning()) { + break; + } + + /* run reaction. */ + reactionExecution.setLastExecutionTime(System.currentTimeMillis()); + Query query = nextReaction.query(); + net.pterodactylus.reactor.State state; + try { + logger.debug("Querying system..."); + state = query.state(); + logger.debug("System queried."); + } catch (Throwable t1) { + logger.warn("Querying system failed!", t1); + state = new AbstractState(t1) { + /* no further state. */ + }; + } + logger.debug(String.format("State is %s.", state)); + reactionExecution.addState(state); + + /* only run trigger if we have collected two states. */ + boolean triggerHit = false; + if (reactionExecution.previousState() != null) { + Trigger trigger = nextReaction.trigger(); + logger.debug("Checking Trigger for changes..."); + triggerHit = trigger.triggers(reactionExecution.currentState(), reactionExecution.previousState()); + } + + /* run action if trigger was hit. */ + logger.debug(String.format("Trigger was hit: %s.", triggerHit)); + if (triggerHit) { + logger.info("Executing Action..."); + nextReaction.action().execute(reactionExecution.currentState(), reactionExecution.previousState()); + } + } + } + + /** + * Stores execution states of a {@link Reaction}. + * + * @author David ‘Bombe’ Roden + */ + private static class ReactionExecution { + + /** The time the reaction was last executed. */ + private long lastExecutionTime; + + /** The previous state of the reaction. */ + private net.pterodactylus.reactor.State previousState; + + /** The current state of the reaction. */ + private net.pterodactylus.reactor.State currentState; + + // + // ACCESSORS + // + + /** + * Returns the time the reaction was last executed. If the reaction was + * not yet executed, this method returns {@code 0}. + * + * @return The last execution time of the reaction (in milliseconds + * since Jan 1, 1970 UTC) + */ + public long lastExecutionTime() { + return lastExecutionTime; + } + + /** + * Returns the current state of the reaction. If the reaction was not + * yet executed, this method returns {@code null}. + * + * @return The current state of the reaction + */ + public net.pterodactylus.reactor.State currentState() { + return currentState; + } + + /** + * Returns the previous state of the reaction. If the reaction was not + * yet executed at least twice, this method returns {@code null}. + * + * @return The previous state of the reaction + */ + public net.pterodactylus.reactor.State previousState() { + return previousState; + } + + /** + * Sets the last execution time of the reaction. + * + * @param lastExecutionTime + * The last execution time of the reaction (in milliseconds + * since Jan 1, 1970 UTC) + * @return This execution + */ + public ReactionExecution setLastExecutionTime(long lastExecutionTime) { + this.lastExecutionTime = lastExecutionTime; + return this; + } + + // + // ACTIONS + // + + /** + * Adds the given state as current state and moves the current state + * into the previous state. + * + * @param state + * The new current state + * @return This execution + */ + public ReactionExecution addState(net.pterodactylus.reactor.State state) { + previousState = currentState; + currentState = state; + return this; + } + + } + +} -- 2.7.4