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 com.google.common.base.Optional.absent;
  21 import static com.google.common.base.Optional.of;
  22 import static com.google.common.collect.Maps.newTreeMap;
  23 import static java.lang.String.format;
  24
  25 import java.util.HashMap;
  26 import java.util.Map;
  27 import java.util.Map.Entry;
  28 import java.util.SortedMap;
  29
  30 import net.pterodactylus.rhynodge.Filter;
  31 import net.pterodactylus.rhynodge.Query;
  32 import net.pterodactylus.rhynodge.Reaction;
  33 import net.pterodactylus.rhynodge.State;
  34 import net.pterodactylus.rhynodge.Trigger;
  35 import net.pterodactylus.rhynodge.states.AbstractState;
  36 import net.pterodactylus.rhynodge.states.FailedState;
  37 import net.pterodactylus.rhynodge.states.StateManager;
  38
  39 import com.google.common.base.Optional;
  40 import com.google.common.collect.Maps;
  41 import com.google.common.util.concurrent.AbstractExecutionThreadService;
  42 import org.apache.commons.lang3.tuple.Pair;
  43 import org.apache.log4j.Logger;
  44
  45 /**
  46  * Rhynodge main engine.
  47  *
  48  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  49  */
  50 public class Engine extends AbstractExecutionThreadService {
  51
  52         /** The logger. */
  53         private static final Logger logger = Logger.getLogger(Engine.class);
  54
  55         /** The state manager. */
  56         private final StateManager stateManager;
  57
  58         /** All defined reactions. */
  59         /* synchronize on itself. */
  60         private final Map<String, Reaction> reactions = new HashMap<String, Reaction>();
  61
  62         /**
  63          * Creates a new engine.
  64          *
  65          * @param stateManager
  66          *            The state manager
  67          */
  68         public Engine(StateManager stateManager) {
  69                 this.stateManager = stateManager;
  70         }
  71
  72         //
  73         // ACCESSORS
  74         //
  75
  76         /**
  77          * Adds the given reaction to this engine.
  78          *
  79          * @param name
  80          *            The name of the reaction
  81          * @param reaction
  82          *            The reaction to add to this engine
  83          */
  84         public void addReaction(String name, Reaction reaction) {
  85                 synchronized (reactions) {
  86                         reactions.put(name, reaction);
  87                         reactions.notifyAll();
  88                 }
  89         }
  90
  91         /**
  92          * Removes the reaction with the given name.
  93          *
  94          * @param name
  95          *            The name of the reaction to remove
  96          */
  97         public void removeReaction(String name) {
  98                 synchronized (reactions) {
  99                         if (!reactions.containsKey(name)) {
 100                                 return;
 101                         }
 102                         reactions.remove(name);
 103                         reactions.notifyAll();
 104                 }
 105         }
 106
 107         //
 108         // ABSTRACTSERVICE METHODS
 109         //
 110
 111         /**
 112          * {@inheritDoc}
 113          */
 114         @Override
 115         public void run() {
 116                 while (isRunning()) {
 117                         Optional<Pair<String, Reaction>> nextReaction = getNextReaction();
 118                         if (!nextReaction.isPresent()) {
 119                                 continue;
 120                         }
 121
 122                         String reactionName = nextReaction.get().getLeft();
 123                         logger.debug(format("Next Reaction: %s.", reactionName));
 124
 125                         /* wait until the next reaction has to run. */
 126                         Optional<net.pterodactylus.rhynodge.State> lastState = stateManager.loadLastState(reactionName);
 127                         long lastStateTime = lastState.isPresent() ? lastState.get().time() : 0;
 128                         int lastStateFailCount = lastState.isPresent() ? lastState.get().failCount() : 0;
 129                         long waitTime = (lastStateTime + nextReaction.get().getRight().updateInterval()) - System.currentTimeMillis();
 130                         logger.debug(format("Time to wait for next Reaction: %d millseconds.", waitTime));
 131                         if (waitTime > 0) {
 132                                 synchronized (reactions) {
 133                                         try {
 134                                                 logger.info(format("Waiting until %tc.", lastStateTime + nextReaction.get().getRight().updateInterval()));
 135                                                 reactions.wait(waitTime);
 136                                         } catch (InterruptedException ie1) {
 137                                                 /* we’re looping! */
 138                                         }
 139                                 }
 140
 141                                 /* re-start loop to check for new reactions. */
 142                                 continue;
 143                         }
 144
 145                         /* run reaction. */
 146                         logger.info(format("Running Query for %s...", reactionName));
 147                         Query query = nextReaction.get().getRight().query();
 148                         net.pterodactylus.rhynodge.State state;
 149                         try {
 150                                 logger.debug("Querying system...");
 151                                 state = query.state();
 152                                 if (state == null) {
 153                                         state = FailedState.INSTANCE;
 154                                 }
 155                                 logger.debug("System queried.");
 156                         } catch (Throwable t1) {
 157                                 logger.warn("Querying system failed!", t1);
 158                                 state = new AbstractState(t1) {
 159                                         /* no further state. */
 160                                 };
 161                         }
 162                         logger.debug(format("State is %s.", state));
 163
 164                         /* convert states. */
 165                         for (Filter filter : nextReaction.get().getRight().filters()) {
 166                                 if (state.success()) {
 167                                         net.pterodactylus.rhynodge.State newState = filter.filter(state);
 168                                         //logger.debug(String.format("Old state is %s, new state is %s.", state, newState));
 169                                         state = newState;
 170                                 }
 171                         }
 172                         if (!state.success()) {
 173                                 state.setFailCount(lastStateFailCount + 1);
 174                         }
 175                         Optional<net.pterodactylus.rhynodge.State> lastSuccessfulState = stateManager.loadLastSuccessfulState(reactionName);
 176
 177                         /* merge states. */
 178                         boolean triggerHit = false;
 179                         Trigger trigger = nextReaction.get().getRight().trigger();
 180                         if (lastSuccessfulState.isPresent() && lastSuccessfulState.get().success() && state.success()) {
 181                                 net.pterodactylus.rhynodge.State newState = trigger.mergeStates(lastSuccessfulState.get(), state);
 182
 183                                 /* save new state. */
 184                                 stateManager.saveState(reactionName, newState);
 185
 186                                 triggerHit = trigger.triggers();
 187                         } else {
 188                                 /* save first or error state. */
 189                                 stateManager.saveState(reactionName, state);
 190                         }
 191
 192                         /* run action if trigger was hit. */
 193                         logger.debug(format("Trigger was hit: %s.", triggerHit));
 194                         if (triggerHit) {
 195                                 logger.info("Executing Action...");
 196                                 nextReaction.get().getRight().action().execute(trigger.output(nextReaction.get().getRight()));
 197                         }
 198
 199                 }
 200         }
 201
 202         private Optional<Pair<String, Reaction>> getNextReaction() {
 203                 while (isRunning()) {
 204                         synchronized (reactions) {
 205                                 if (reactions.isEmpty()) {
 206                                         logger.debug("Sleeping while no Reactions available.");
 207                                         try {
 208                                                 reactions.wait();
 209                                         } catch (InterruptedException ie1) {
 210                                                 /* ignore, we’re looping anyway. */
 211                                         }
 212                                         continue;
 213                                 }
 214                         }
 215
 216                         /* find next reaction. */
 217                         SortedMap<Long, Pair<String, Reaction>> nextReactions = newTreeMap();
 218                         synchronized (reactions) {
 219                                 for (Entry<String, Reaction> reactionEntry : reactions.entrySet()) {
 220                                         Optional<net.pterodactylus.rhynodge.State> state = stateManager.loadLastState(reactionEntry.getKey());
 221                                         long stateTime = state.isPresent() ? state.get().time() : 0;
 222                                         nextReactions.put(stateTime + reactionEntry.getValue().updateInterval(), Pair.of(reactionEntry.getKey(), reactionEntry.getValue()));
 223                                 }
 224                                 return of(nextReactions.get(nextReactions.firstKey()));
 225                         }
 226                 }
 227                 return absent();
 228         }
 229
 230 }