src/main/java/net/pterodactylus/sone/core/SoneInserter.java

   1 /*
   2  * Sone - SoneInserter.java - Copyright © 2010 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.sone.core;
  19
  20 import java.io.InputStreamReader;
  21 import java.io.StringWriter;
  22 import java.nio.charset.Charset;
  23 import java.util.ArrayList;
  24 import java.util.HashMap;
  25 import java.util.HashSet;
  26 import java.util.Map;
  27 import java.util.logging.Level;
  28 import java.util.logging.Logger;
  29
  30 import net.pterodactylus.sone.core.Core.SoneStatus;
  31 import net.pterodactylus.sone.data.Post;
  32 import net.pterodactylus.sone.data.Reply;
  33 import net.pterodactylus.sone.data.Sone;
  34 import net.pterodactylus.sone.freenet.StringBucket;
  35 import net.pterodactylus.sone.main.SonePlugin;
  36 import net.pterodactylus.util.collection.ListBuilder;
  37 import net.pterodactylus.util.collection.ReverseComparator;
  38 import net.pterodactylus.util.io.Closer;
  39 import net.pterodactylus.util.logging.Logging;
  40 import net.pterodactylus.util.service.AbstractService;
  41 import net.pterodactylus.util.template.HtmlFilter;
  42 import net.pterodactylus.util.template.ReflectionAccessor;
  43 import net.pterodactylus.util.template.Template;
  44 import net.pterodactylus.util.template.TemplateContext;
  45 import net.pterodactylus.util.template.TemplateContextFactory;
  46 import net.pterodactylus.util.template.TemplateException;
  47 import net.pterodactylus.util.template.TemplateParser;
  48 import net.pterodactylus.util.template.XmlFilter;
  49 import freenet.client.async.ManifestElement;
  50 import freenet.keys.FreenetURI;
  51
  52 /**
  53  * A Sone inserter is responsible for inserting a Sone if it has changed.
  54  *
  55  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  56  */
  57 public class SoneInserter extends AbstractService {
  58
  59         /** The logger. */
  60         private static final Logger logger = Logging.getLogger(SoneInserter.class);
  61
  62         /** The insertion delay (in seconds). */
  63         private static volatile int insertionDelay = 60;
  64
  65         /** The template factory used to create the templates. */
  66         private static final TemplateContextFactory templateContextFactory = new TemplateContextFactory();
  67
  68         static {
  69                 templateContextFactory.addAccessor(Object.class, new ReflectionAccessor());
  70                 templateContextFactory.addFilter("xml", new XmlFilter());
  71                 templateContextFactory.addFilter("html", new HtmlFilter());
  72         }
  73
  74         /** The UTF-8 charset. */
  75         private static final Charset utf8Charset = Charset.forName("UTF-8");
  76
  77         /** The core. */
  78         private final Core core;
  79
  80         /** The Freenet interface. */
  81         private final FreenetInterface freenetInterface;
  82
  83         /** The Sone to insert. */
  84         private final Sone sone;
  85
  86         /** Whether a modification has been detected. */
  87         private volatile boolean modified = false;
  88
  89         /** The fingerprint of the last insert. */
  90         private volatile String lastInsertFingerprint;
  91
  92         /**
  93          * Creates a new Sone inserter.
  94          *
  95          * @param core
  96          *            The core
  97          * @param freenetInterface
  98          *            The freenet interface
  99          * @param sone
 100          *            The Sone to insert
 101          */
 102         public SoneInserter(Core core, FreenetInterface freenetInterface, Sone sone) {
 103                 super("Sone Inserter for “" + sone.getName() + "”", false);
 104                 this.core = core;
 105                 this.freenetInterface = freenetInterface;
 106                 this.sone = sone;
 107         }
 108
 109         //
 110         // ACCESSORS
 111         //
 112
 113         /**
 114          * Changes the insertion delay, i.e. the time the Sone inserter waits after
 115          * it has noticed a Sone modification before it starts the insert.
 116          *
 117          * @param insertionDelay
 118          *            The insertion delay (in seconds)
 119          */
 120         public static void setInsertionDelay(int insertionDelay) {
 121                 SoneInserter.insertionDelay = insertionDelay;
 122         }
 123
 124         /**
 125          * Returns the fingerprint of the last insert.
 126          *
 127          * @return The fingerprint of the last insert
 128          */
 129         public String getLastInsertFingerprint() {
 130                 return lastInsertFingerprint;
 131         }
 132
 133         /**
 134          * Sets the fingerprint of the last insert.
 135          *
 136          * @param lastInsertFingerprint
 137          *            The fingerprint of the last insert
 138          */
 139         public void setLastInsertFingerprint(String lastInsertFingerprint) {
 140                 this.lastInsertFingerprint = lastInsertFingerprint;
 141         }
 142
 143         /**
 144          * Returns whether the Sone inserter has detected a modification of the
 145          * Sone.
 146          *
 147          * @return {@code true} if the Sone has been modified, {@code false}
 148          *         otherwise
 149          */
 150         public boolean isModified() {
 151                 return modified;
 152         }
 153
 154         //
 155         // SERVICE METHODS
 156         //
 157
 158         /**
 159          * {@inheritDoc}
 160          */
 161         @Override
 162         protected void serviceRun() {
 163                 long lastModificationTime = 0;
 164                 String lastFingerprint = "";
 165                 while (!shouldStop()) { try {
 166                         /* check every seconds. */
 167                         sleep(1000);
 168
 169                         /* don’t insert locked Sones. */
 170                         if (core.isLocked(sone)) {
 171                                 /* trigger redetection when the Sone is unlocked. */
 172                                 synchronized (sone) {
 173                                         modified = !sone.getFingerprint().equals(lastInsertFingerprint);
 174                                 }
 175                                 lastFingerprint = "";
 176                                 lastModificationTime = 0;
 177                                 continue;
 178                         }
 179
 180                         InsertInformation insertInformation = null;
 181                         synchronized (sone) {
 182                                 String fingerprint = sone.getFingerprint();
 183                                 if (!fingerprint.equals(lastFingerprint)) {
 184                                         if (fingerprint.equals(lastInsertFingerprint)) {
 185                                                 modified = false;
 186                                                 lastModificationTime = 0;
 187                                                 logger.log(Level.FINE, "Sone %s has been reverted to last insert state.", sone);
 188                                         } else {
 189                                                 lastModificationTime = System.currentTimeMillis();
 190                                                 modified = true;
 191                                                 logger.log(Level.FINE, "Sone %s has been modified, waiting %d seconds before inserting.", new Object[] { sone.getName(), insertionDelay });
 192                                         }
 193                                         lastFingerprint = fingerprint;
 194                                 }
 195                                 if (modified && (lastModificationTime > 0) && ((System.currentTimeMillis() - lastModificationTime) > (insertionDelay * 1000))) {
 196                                         lastInsertFingerprint = fingerprint;
 197                                         insertInformation = new InsertInformation(sone);
 198                                 }
 199                         }
 200
 201                         if (insertInformation != null) {
 202                                 logger.log(Level.INFO, "Inserting Sone “%s”…", new Object[] { sone.getName() });
 203
 204                                 boolean success = false;
 205                                 try {
 206                                         core.setSoneStatus(sone, SoneStatus.inserting);
 207                                         long insertTime = System.currentTimeMillis();
 208                                         insertInformation.setTime(insertTime);
 209                                         FreenetURI finalUri = freenetInterface.insertDirectory(insertInformation.getInsertUri(), insertInformation.generateManifestEntries(), "index.html");
 210                                         /* at this point we might already be stopped. */
 211                                         if (shouldStop()) {
 212                                                 /* if so, bail out, don’t change anything. */
 213                                                 break;
 214                                         }
 215                                         sone.setTime(insertTime);
 216                                         sone.setLatestEdition(finalUri.getEdition());
 217                                         core.saveSone(sone);
 218                                         success = true;
 219                                         logger.log(Level.INFO, "Inserted Sone “%s” at %s.", new Object[] { sone.getName(), finalUri });
 220                                 } catch (SoneException se1) {
 221                                         logger.log(Level.WARNING, "Could not insert Sone “" + sone.getName() + "”!", se1);
 222                                 } finally {
 223                                         core.setSoneStatus(sone, SoneStatus.idle);
 224                                 }
 225
 226                                 /*
 227                                  * reset modification counter if Sone has not been modified
 228                                  * while it was inserted.
 229                                  */
 230                                 if (success) {
 231                                         synchronized (sone) {
 232                                                 if (lastInsertFingerprint.equals(sone.getFingerprint())) {
 233                                                         logger.log(Level.FINE, "Sone “%s” was not modified further, resetting counter…", new Object[] { sone });
 234                                                         lastModificationTime = 0;
 235                                                         modified = false;
 236                                                 }
 237                                         }
 238                                 }
 239                         }
 240                 } catch (Throwable t1) {
 241                         logger.log(Level.SEVERE, "SoneInserter threw an Exception!", t1);
 242                 }}
 243         }
 244
 245         /**
 246          * Container for information that are required to insert a Sone. This
 247          * container merely exists to copy all relevant data without holding a lock
 248          * on the {@link Sone} object for too long.
 249          *
 250          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 251          */
 252         private class InsertInformation {
 253
 254                 /** All properties of the Sone, copied for thread safety. */
 255                 private final Map<String, Object> soneProperties = new HashMap<String, Object>();
 256
 257                 /**
 258                  * Creates a new insert information container.
 259                  *
 260                  * @param sone
 261                  *            The sone to insert
 262                  */
 263                 public InsertInformation(Sone sone) {
 264                         soneProperties.put("id", sone.getId());
 265                         soneProperties.put("name", sone.getName());
 266                         soneProperties.put("time", sone.getTime());
 267                         soneProperties.put("requestUri", sone.getRequestUri());
 268                         soneProperties.put("insertUri", sone.getInsertUri());
 269                         soneProperties.put("profile", sone.getProfile());
 270                         soneProperties.put("posts", new ListBuilder<Post>(new ArrayList<Post>(sone.getPosts())).sort(Post.TIME_COMPARATOR).get());
 271                         soneProperties.put("replies", new ListBuilder<Reply>(new ArrayList<Reply>(sone.getReplies())).sort(new ReverseComparator<Reply>(Reply.TIME_COMPARATOR)).get());
 272                         soneProperties.put("likedPostIds", new HashSet<String>(sone.getLikedPostIds()));
 273                         soneProperties.put("likedReplyIds", new HashSet<String>(sone.getLikedReplyIds()));
 274                 }
 275
 276                 //
 277                 // ACCESSORS
 278                 //
 279
 280                 /**
 281                  * Returns the insert URI of the Sone.
 282                  *
 283                  * @return The insert URI of the Sone
 284                  */
 285                 public FreenetURI getInsertUri() {
 286                         return (FreenetURI) soneProperties.get("insertUri");
 287                 }
 288
 289                 /**
 290                  * Sets the time of the Sone at the time of the insert.
 291                  *
 292                  * @param time
 293                  *            The time of the Sone
 294                  */
 295                 public void setTime(long time) {
 296                         soneProperties.put("time", time);
 297                 }
 298
 299                 //
 300                 // ACTIONS
 301                 //
 302
 303                 /**
 304                  * Generates all manifest entries required to insert this Sone.
 305                  *
 306                  * @return The manifest entries for the Sone insert
 307                  */
 308                 public HashMap<String, Object> generateManifestEntries() {
 309                         HashMap<String, Object> manifestEntries = new HashMap<String, Object>();
 310
 311                         /* first, create an index.html. */
 312                         manifestEntries.put("index.html", createManifestElement("index.html", "text/html; charset=utf-8", "/templates/insert/index.html"));
 313
 314                         /* now, store the sone. */
 315                         manifestEntries.put("sone.xml", createManifestElement("sone.xml", "text/xml; charset=utf-8", "/templates/insert/sone.xml"));
 316
 317                         return manifestEntries;
 318                 }
 319
 320                 //
 321                 // PRIVATE METHODS
 322                 //
 323
 324                 /**
 325                  * Creates a new manifest element.
 326                  *
 327                  * @param name
 328                  *            The name of the file
 329                  * @param contentType
 330                  *            The content type of the file
 331                  * @param templateName
 332                  *            The name of the template to render
 333                  * @return The manifest element
 334                  */
 335                 @SuppressWarnings("synthetic-access")
 336                 private ManifestElement createManifestElement(String name, String contentType, String templateName) {
 337                         InputStreamReader templateInputStreamReader = null;
 338                         Template template;
 339                         try {
 340                                 templateInputStreamReader = new InputStreamReader(getClass().getResourceAsStream(templateName), utf8Charset);
 341                                 template = TemplateParser.parse(templateInputStreamReader);
 342                         } catch (TemplateException te1) {
 343                                 logger.log(Level.SEVERE, "Could not parse template “" + templateName + "”!", te1);
 344                                 return null;
 345                         } finally {
 346                                 Closer.close(templateInputStreamReader);
 347                         }
 348
 349                         TemplateContext templateContext = templateContextFactory.createTemplateContext();
 350                         templateContext.set("currentSone", soneProperties);
 351                         templateContext.set("currentEdition", core.getUpdateChecker().getLatestEdition());
 352                         templateContext.set("version", SonePlugin.VERSION);
 353                         StringWriter writer = new StringWriter();
 354                         StringBucket bucket = null;
 355                         try {
 356                                 template.render(templateContext, writer);
 357                                 bucket = new StringBucket(writer.toString(), utf8Charset);
 358                                 return new ManifestElement(name, bucket, contentType, bucket.size());
 359                         } catch (TemplateException te1) {
 360                                 logger.log(Level.SEVERE, "Could not render template “" + templateName + "”!", te1);
 361                                 return null;
 362                         } finally {
 363                                 Closer.close(writer);
 364                                 if (bucket != null) {
 365                                         bucket.free();
 366                                 }
 367                         }
 368                 }
 369
 370         }
 371
 372 }