Add background trust updater.

diff --git a/src/main/java/net/pterodactylus/sone/core/TrustUpdater.java b/src/main/java/net/pterodactylus/sone/core/TrustUpdater.java
new file mode 100644 (file)
index 0000000..6221d39
--- /dev/null
+++ b/src/main/java/net/pterodactylus/sone/core/TrustUpdater.java
@@ -0,0 +1,265 @@
+/*
+ * Sone - TrustUpdater.java - Copyright © 2012 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 <http://www.gnu.org/licenses/>.
+ */
+
+package net.pterodactylus.sone.core;
+
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import net.pterodactylus.sone.freenet.plugin.PluginException;
+import net.pterodactylus.sone.freenet.wot.DefaultIdentity;
+import net.pterodactylus.sone.freenet.wot.Identity;
+import net.pterodactylus.sone.freenet.wot.OwnIdentity;
+import net.pterodactylus.sone.freenet.wot.Trust;
+import net.pterodactylus.sone.freenet.wot.WebOfTrustConnector;
+import net.pterodactylus.sone.freenet.wot.WebOfTrustException;
+import net.pterodactylus.util.logging.Logging;
+import net.pterodactylus.util.service.AbstractService;
+
+/**
+ * Updates identity’s trust in a background thread because getting updates from
+ * the WebOfTrust plugin can potentially last quite long.
+ *
+ * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+ */
+public class TrustUpdater extends AbstractService {
+
+       /** The logger. */
+       private static final Logger logger = Logging.getLogger(TrustUpdater.class);
+
+       /** Stop job. */
+       private static final TrustUpdateJob stopJob = new TrustUpdateJob(null, null);
+
+       /** The web of trust connector. */
+       private final WebOfTrustConnector webOfTrustConnector;
+
+       /** The queue for jobs. */
+       private final BlockingQueue<TrustUpdateJob> updateJobs = new LinkedBlockingQueue<TrustUpdateJob>();
+
+       /**
+        * Creates a new trust updater.
+        *
+        * @param webOfTrustConnector
+        *            The web of trust connector
+        */
+       public TrustUpdater(WebOfTrustConnector webOfTrustConnector) {
+               super("Trust Updater");
+               this.webOfTrustConnector = webOfTrustConnector;
+       }
+
+       //
+       // ACTIONS
+       //
+
+       /**
+        * Retrieves the trust relation between the truster and the trustee. This
+        * method will return immediately and perform a trust update in the
+        * background.
+        *
+        * @param truster
+        *            The identity giving the trust
+        * @param trustee
+        *            The identity receiving the trust
+        */
+       public void getTrust(OwnIdentity truster, Identity trustee) {
+               updateJobs.add(new GetTrustJob(truster, trustee));
+       }
+
+       /**
+        * Updates the trust relation between the truster and the trustee. This
+        * method will return immediately and perform a trust update in the
+        * background.
+        *
+        * @param truster
+        *            The identity giving the trust
+        * @param trustee
+        *            The identity receiving the trust
+        * @param score
+        *            The new level of trust (from -100 to 100, may be {@code null}
+        *            to remove the trust completely)
+        * @param comment
+        *            The comment of the trust relation
+        */
+       public void setTrust(OwnIdentity truster, Identity trustee, Integer score, String comment) {
+               updateJobs.add(new SetTrustJob(truster, trustee, score, comment));
+       }
+
+       //
+       // SERVICE METHODS
+       //
+
+       /**
+        * {@inheritDoc}
+        */
+       @Override
+       protected void serviceRun() {
+               while (!shouldStop()) {
+                       try {
+                               TrustUpdateJob updateJob = updateJobs.take();
+                               if (shouldStop() || (updateJob == stopJob)) {
+                                       break;
+                               }
+                               updateJob.run();
+                       } catch (InterruptedException ie1) {
+                               /* happens, ignore, loop. */
+                       }
+               }
+       }
+
+       /**
+        * {@inheritDoc}
+        */
+       @Override
+       protected void serviceStop() {
+               try {
+                       updateJobs.put(stopJob);
+               } catch (InterruptedException ie1) {
+                       /* the queue is unbounded so it should never block. */
+               }
+       }
+
+       /**
+        * Base class for trust update jobs.
+        *
+        * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+        */
+       private static class TrustUpdateJob {
+
+               /** The identity giving the trust. */
+               protected final OwnIdentity truster;
+
+               /** The identity receiving the trust. */
+               protected final Identity trustee;
+
+               /**
+                * Creates a new trust update job.
+                *
+                * @param truster
+                *            The identity giving the trust
+                * @param trustee
+                *            The identity receiving the trust
+                */
+               public TrustUpdateJob(OwnIdentity truster, Identity trustee) {
+                       this.truster = truster;
+                       this.trustee = trustee;
+               }
+
+               //
+               // ACCESSORS
+               //
+
+               /**
+                * Performs the actual update operation.
+                * <p>
+                * The implementation of this class does nothing.
+                */
+               public void run() {
+                       /* does nothing. */
+               }
+
+       }
+
+       /**
+        * Update job that sets the trust relation between two identities.
+        *
+        * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+        */
+       private static class SetTrustJob extends TrustUpdateJob {
+
+               /** The score of the relation. */
+               private final Integer score;
+
+               /** The comment of the relation. */
+               private final String comment;
+
+               /**
+                * Creates a new set trust job.
+                *
+                * @param truster
+                *            The identity giving the trust
+                * @param trustee
+                *            The identity receiving the trust
+                * @param score
+                *            The score of the trust (from -100 to 100, may be
+                *            {@code null} to remote the trust relation completely)
+                * @param comment
+                *            The comment of the trust relation
+                */
+               public SetTrustJob(OwnIdentity truster, Identity trustee, Integer score, String comment) {
+                       super(truster, trustee);
+                       this.score = score;
+                       this.comment = comment;
+               }
+
+               /**
+                * {@inheritDoc}
+                */
+               @Override
+               @SuppressWarnings("synthetic-access")
+               public void run() {
+                       try {
+                               if (score != null) {
+                                       truster.setTrust(trustee, score, comment);
+                               } else {
+                                       truster.removeTrust(trustee);
+                               }
+                       } catch (WebOfTrustException wote1) {
+                               logger.log(Level.WARNING, "Could not set Trust value for " + truster + " -> " + trustee + " to " + score + " (" + comment + ")!", wote1);
+                       }
+               }
+
+       }
+
+       /**
+        * Update job that retrieves the trust relation between two identities.
+        *
+        * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+        */
+       private class GetTrustJob extends TrustUpdateJob {
+
+               /**
+                * Creates a new trust update job.
+                *
+                * @param truster
+                *            The identity giving the trust
+                * @param trustee
+                *            The identity receiving the trust
+                */
+               public GetTrustJob(OwnIdentity truster, Identity trustee) {
+                       super(truster, trustee);
+               }
+
+               /**
+                * {@inheritDoc}
+                */
+               @Override
+               @SuppressWarnings("synthetic-access")
+               public void run() {
+                       try {
+                               Trust trust = webOfTrustConnector.getTrust(truster, trustee);
+                               if (trustee instanceof DefaultIdentity) {
+                                       ((DefaultIdentity) trustee).setTrust(truster, trust);
+                               }
+                       } catch (PluginException pe1) {
+                               logger.log(Level.WARNING, "Could not get Trust value for " + truster + " -> " + trustee + "!", pe1);
+                       }
+               }
+       }
+
+}