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.Trigger;
  34 import net.pterodactylus.rhynodge.states.AbstractState;
  35 import net.pterodactylus.rhynodge.states.FailedState;
  36 import net.pterodactylus.rhynodge.states.StateManager;
  37
  38 import com.google.common.base.Optional;
  39 import com.google.common.util.concurrent.AbstractExecutionThreadService;
  40 import org.apache.commons.lang3.tuple.Pair;
  41 import org.apache.log4j.Logger;
  42
  43 /**
  44  * Rhynodge main engine.
  45  *
  46  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  47  */
  48 public class Engine extends AbstractExecutionThreadService {
  49
  50         /** The logger. */
  51         private static final Logger logger = Logger.getLogger(Engine.class);
  52
  53         /** The state manager. */
  54         private final StateManager stateManager;
  55
  56         /** All defined reactions. */
  57         /* synchronize on itself. */
  58         private final Map<String, Reaction> reactions = new HashMap<String, Reaction>();
  59
  60         /**
  61          * Creates a new engine.
  62          *
  63          * @param stateManager
  64          *            The state manager
  65          */
  66         public Engine(StateManager stateManager) {
  67                 this.stateManager = stateManager;
  68         }
  69
  70         //
  71         // ACCESSORS
  72         //
  73
  74         /**
  75          * Adds the given reaction to this engine.
  76          *
  77          * @param name
  78          *            The name of the reaction
  79          * @param reaction
  80          *            The reaction to add to this engine
  81          */
  82         public void addReaction(String name, Reaction reaction) {
  83                 synchronized (reactions) {
  84                         reactions.put(name, reaction);
  85                         reactions.notifyAll();
  86                 }
  87         }
  88
  89         /**
  90          * Removes the reaction with the given name.
  91          *
  92          * @param name
  93          *            The name of the reaction to remove
  94          */
  95         public void removeReaction(String name) {
  96                 synchronized (reactions) {
  97                         if (!reactions.containsKey(name)) {
  98                                 return;
  99                         }
 100                         reactions.remove(name);
 101                         reactions.notifyAll();
 102                 }
 103         }
 104
 105         //
 106         // ABSTRACTSERVICE METHODS
 107         //
 108
 109         /**
 110          * {@inheritDoc}
 111          */
 112         @Override
 113         public void run() {
 114                 while (isRunning()) {
 115                         Optional<NextReaction> nextReaction = getNextReaction();
 116                         if (!nextReaction.isPresent()) {
 117                                 continue;
 118                         }
 119
 120                         String reactionName = nextReaction.get().getKey();
 121                         logger.debug(format("Next Reaction: %s.", reactionName));
 122
 123                         /* wait until the next reaction has to run. */
 124                         Optional<net.pterodactylus.rhynodge.State> lastState = stateManager.loadLastState(reactionName);
 125                         int lastStateFailCount = lastState.isPresent() ? lastState.get().failCount() : 0;
 126                         long waitTime = nextReaction.get().getNextTime() - System.currentTimeMillis();
 127                         logger.debug(format("Time to wait for next Reaction: %d millseconds.", waitTime));
 128                         if (waitTime > 0) {
 129                                 waitForNextReactionToStart(nextReaction, waitTime);
 130
 131                                 /* re-start loop to check for new reactions. */
 132                                 continue;
 133                         }
 134
 135                         /* run reaction. */
 136                         logger.info(format("Running Query for %s...", reactionName));
 137                         Query query = nextReaction.get().getReaction().query();
 138                         net.pterodactylus.rhynodge.State state;
 139                         try {
 140                                 logger.debug("Querying system...");
 141                                 state = query.state();
 142                                 if (state == null) {
 143                                         state = FailedState.INSTANCE;
 144                                 }
 145                                 logger.debug("System queried.");
 146                         } catch (Throwable t1) {
 147                                 logger.warn("Querying system failed!", t1);
 148                                 state = new AbstractState(t1) {
 149                                         /* no further state. */
 150                                 };
 151                         }
 152                         logger.debug(format("State is %s.", state));
 153
 154                         /* convert states. */
 155                         for (Filter filter : nextReaction.get().getReaction().filters()) {
 156                                 if (state.success()) {
 157                                         net.pterodactylus.rhynodge.State newState = filter.filter(state);
 158                                         //logger.debug(String.format("Old state is %s, new state is %s.", state, newState));
 159                                         state = newState;
 160                                 }
 161                         }
 162                         if (!state.success()) {
 163                                 state.setFailCount(lastStateFailCount + 1);
 164                         }
 165                         Optional<net.pterodactylus.rhynodge.State> lastSuccessfulState = stateManager.loadLastSuccessfulState(reactionName);
 166
 167                         /* merge states. */
 168                         boolean triggerHit = false;
 169                         Trigger trigger = nextReaction.get().getReaction().trigger();
 170                         if (lastSuccessfulState.isPresent() && lastSuccessfulState.get().success() && state.success()) {
 171                                 net.pterodactylus.rhynodge.State newState = trigger.mergeStates(lastSuccessfulState.get(), state);
 172
 173                                 /* save new state. */
 174                                 stateManager.saveState(reactionName, newState);
 175
 176                                 triggerHit = trigger.triggers();
 177                         } else {
 178                                 /* save first or error state. */
 179                                 stateManager.saveState(reactionName, state);
 180                         }
 181
 182                         /* run action if trigger was hit. */
 183                         logger.debug(format("Trigger was hit: %s.", triggerHit));
 184                         if (triggerHit) {
 185                                 logger.info("Executing Action...");
 186                                 nextReaction.get().getReaction().action().execute(trigger.output(nextReaction.get().getReaction()));
 187                         }
 188
 189                 }
 190         }
 191
 192         private void waitForNextReactionToStart(Optional<NextReaction> nextReaction, long waitTime) {
 193                 synchronized (reactions) {
 194                         try {
 195                                 logger.info(format("Waiting until %tc.", nextReaction.get().getNextTime()));
 196                                 reactions.wait(waitTime);
 197                         } catch (InterruptedException ie1) {
 198                                 /* we’re looping! */
 199                         }
 200                 }
 201         }
 202
 203         private Optional<NextReaction> getNextReaction() {
 204                 while (isRunning()) {
 205                         synchronized (reactions) {
 206                                 if (reactions.isEmpty()) {
 207                                         logger.debug("Sleeping while no Reactions available.");
 208                                         try {
 209                                                 reactions.wait();
 210                                         } catch (InterruptedException ie1) {
 211                                                 /* ignore, we’re looping anyway. */
 212                                         }
 213                                         continue;
 214                                 }
 215                         }
 216
 217                         /* find next reaction. */
 218                         SortedMap<Long, Pair<String, Reaction>> nextReactions = newTreeMap();
 219                         synchronized (reactions) {
 220                                 for (Entry<String, Reaction> reactionEntry : reactions.entrySet()) {
 221                                         Optional<net.pterodactylus.rhynodge.State> state = stateManager.loadLastState(reactionEntry.getKey());
 222                                         long stateTime = state.isPresent() ? state.get().time() : 0;
 223                                         nextReactions.put(stateTime + reactionEntry.getValue().updateInterval(), Pair.of(reactionEntry.getKey(), reactionEntry.getValue()));
 224                                 }
 225                                 Pair<String, Reaction> keyReaction = nextReactions.get(nextReactions.firstKey());
 226                                 return of(new NextReaction(keyReaction.getKey(), keyReaction.getValue(), nextReactions.firstKey()));
 227                         }
 228                 }
 229                 return absent();
 230         }
 231
 232         private static class NextReaction {
 233
 234                 private final String key;
 235                 private final Reaction reaction;
 236                 private final long nextTime;
 237
 238                 private NextReaction(String key, Reaction reaction, long nextTime) {
 239                         this.key = key;
 240                         this.reaction = reaction;
 241                         this.nextTime = nextTime;
 242                 }
 243
 244                 public String getKey() {
 245                         return key;
 246                 }
 247
 248                 public Reaction getReaction() {
 249                         return reaction;
 250                 }
 251
 252                 public long getNextTime() {
 253                         return nextTime;
 254                 }
 255
 256         }
 257
 258 }