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         /** The insert listener manager. */
  87         private SoneInsertListenerManager soneInsertListenerManager;
  88
  89         /** Whether a modification has been detected. */
  90         private volatile boolean modified = false;
  91
  92         /** The fingerprint of the last insert. */
  93         private volatile String lastInsertFingerprint;
  94
  95         /**
  96          * Creates a new Sone inserter.
  97          *
  98          * @param core
  99          *            The core
 100          * @param freenetInterface
 101          *            The freenet interface
 102          * @param sone
 103          *            The Sone to insert
 104          */
 105         public SoneInserter(Core core, FreenetInterface freenetInterface, Sone sone) {
 106                 super("Sone Inserter for “" + sone.getName() + "”", false);
 107                 this.core = core;
 108                 this.freenetInterface = freenetInterface;
 109                 this.sone = sone;
 110                 this.soneInsertListenerManager = new SoneInsertListenerManager(sone);
 111         }
 112
 113         //
 114         // LISTENER MANAGEMENT
 115         //
 116
 117         /**
 118          * Adds a listener for Sone insert events.
 119          *
 120          * @param soneInsertListener
 121          *            The Sone insert listener
 122          */
 123         public void addSoneInsertListener(SoneInsertListener soneInsertListener) {
 124                 soneInsertListenerManager.addListener(soneInsertListener);
 125         }
 126
 127         /**
 128          * Removes a listener for Sone insert events.
 129          *
 130          * @param soneInsertListener
 131          *            The Sone insert listener
 132          */
 133         public void removeSoneInsertListener(SoneInsertListener soneInsertListener) {
 134                 soneInsertListenerManager.removeListener(soneInsertListener);
 135         }
 136
 137         //
 138         // ACCESSORS
 139         //
 140
 141         /**
 142          * Changes the insertion delay, i.e. the time the Sone inserter waits after
 143          * it has noticed a Sone modification before it starts the insert.
 144          *
 145          * @param insertionDelay
 146          *            The insertion delay (in seconds)
 147          */
 148         public static void setInsertionDelay(int insertionDelay) {
 149                 SoneInserter.insertionDelay = insertionDelay;
 150         }
 151
 152         /**
 153          * Returns the fingerprint of the last insert.
 154          *
 155          * @return The fingerprint of the last insert
 156          */
 157         public String getLastInsertFingerprint() {
 158                 return lastInsertFingerprint;
 159         }
 160
 161         /**
 162          * Sets the fingerprint of the last insert.
 163          *
 164          * @param lastInsertFingerprint
 165          *            The fingerprint of the last insert
 166          */
 167         public void setLastInsertFingerprint(String lastInsertFingerprint) {
 168                 this.lastInsertFingerprint = lastInsertFingerprint;
 169         }
 170
 171         /**
 172          * Returns whether the Sone inserter has detected a modification of the
 173          * Sone.
 174          *
 175          * @return {@code true} if the Sone has been modified, {@code false}
 176          *         otherwise
 177          */
 178         public boolean isModified() {
 179                 return modified;
 180         }
 181
 182         //
 183         // SERVICE METHODS
 184         //
 185
 186         /**
 187          * {@inheritDoc}
 188          */
 189         @Override
 190         protected void serviceRun() {
 191                 long lastModificationTime = 0;
 192                 String lastFingerprint = "";
 193                 while (!shouldStop()) { try {
 194                         /* check every seconds. */
 195                         sleep(1000);
 196
 197                         /* don’t insert locked Sones. */
 198                         if (core.isLocked(sone)) {
 199                                 /* trigger redetection when the Sone is unlocked. */
 200                                 synchronized (sone) {
 201                                         modified = !sone.getFingerprint().equals(lastInsertFingerprint);
 202                                 }
 203                                 lastFingerprint = "";
 204                                 lastModificationTime = 0;
 205                                 continue;
 206                         }
 207
 208                         InsertInformation insertInformation = null;
 209                         synchronized (sone) {
 210                                 String fingerprint = sone.getFingerprint();
 211                                 if (!fingerprint.equals(lastFingerprint)) {
 212                                         if (fingerprint.equals(lastInsertFingerprint)) {
 213                                                 modified = false;
 214                                                 lastModificationTime = 0;
 215                                                 logger.log(Level.FINE, "Sone %s has been reverted to last insert state.", sone);
 216                                         } else {
 217                                                 lastModificationTime = System.currentTimeMillis();
 218                                                 modified = true;
 219                                                 logger.log(Level.FINE, "Sone %s has been modified, waiting %d seconds before inserting.", new Object[] { sone.getName(), insertionDelay });
 220                                         }
 221                                         lastFingerprint = fingerprint;
 222                                 }
 223                                 if (modified && (lastModificationTime > 0) && ((System.currentTimeMillis() - lastModificationTime) > (insertionDelay * 1000))) {
 224                                         lastInsertFingerprint = fingerprint;
 225                                         insertInformation = new InsertInformation(sone);
 226                                 }
 227                         }
 228
 229                         if (insertInformation != null) {
 230                                 logger.log(Level.INFO, "Inserting Sone “%s”…", new Object[] { sone.getName() });
 231
 232                                 boolean success = false;
 233                                 try {
 234                                         core.setSoneStatus(sone, SoneStatus.inserting);
 235                                         long insertTime = System.currentTimeMillis();
 236                                         insertInformation.setTime(insertTime);
 237                                         soneInsertListenerManager.fireInsertStarted();
 238                                         FreenetURI finalUri = freenetInterface.insertDirectory(insertInformation.getInsertUri(), insertInformation.generateManifestEntries(), "index.html");
 239                                         soneInsertListenerManager.fireInsertFinished(System.currentTimeMillis() - insertTime);
 240                                         /* at this point we might already be stopped. */
 241                                         if (shouldStop()) {
 242                                                 /* if so, bail out, don’t change anything. */
 243                                                 break;
 244                                         }
 245                                         sone.setTime(insertTime);
 246                                         sone.setLatestEdition(finalUri.getEdition());
 247                                         core.touchConfiguration();
 248                                         success = true;
 249                                         logger.log(Level.INFO, "Inserted Sone “%s” at %s.", new Object[] { sone.getName(), finalUri });
 250                                 } catch (SoneException se1) {
 251                                         soneInsertListenerManager.fireInsertAborted(se1);
 252                                         logger.log(Level.WARNING, "Could not insert Sone “" + sone.getName() + "”!", se1);
 253                                 } finally {
 254                                         core.setSoneStatus(sone, SoneStatus.idle);
 255                                 }
 256
 257                                 /*
 258                                  * reset modification counter if Sone has not been modified
 259                                  * while it was inserted.
 260                                  */
 261                                 if (success) {
 262                                         synchronized (sone) {
 263                                                 if (lastInsertFingerprint.equals(sone.getFingerprint())) {
 264                                                         logger.log(Level.FINE, "Sone “%s” was not modified further, resetting counter…", new Object[] { sone });
 265                                                         lastModificationTime = 0;
 266                                                         modified = false;
 267                                                 }
 268                                         }
 269                                 }
 270                         }
 271                 } catch (Throwable t1) {
 272                         logger.log(Level.SEVERE, "SoneInserter threw an Exception!", t1);
 273                 }}
 274         }
 275
 276         /**
 277          * Container for information that are required to insert a Sone. This
 278          * container merely exists to copy all relevant data without holding a lock
 279          * on the {@link Sone} object for too long.
 280          *
 281          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 282          */
 283         private class InsertInformation {
 284
 285                 /** All properties of the Sone, copied for thread safety. */
 286                 private final Map<String, Object> soneProperties = new HashMap<String, Object>();
 287
 288                 /**
 289                  * Creates a new insert information container.
 290                  *
 291                  * @param sone
 292                  *            The sone to insert
 293                  */
 294                 public InsertInformation(Sone sone) {
 295                         soneProperties.put("id", sone.getId());
 296                         soneProperties.put("name", sone.getName());
 297                         soneProperties.put("time", sone.getTime());
 298                         soneProperties.put("requestUri", sone.getRequestUri());
 299                         soneProperties.put("insertUri", sone.getInsertUri());
 300                         soneProperties.put("profile", sone.getProfile());
 301                         soneProperties.put("posts", new ListBuilder<Post>(new ArrayList<Post>(sone.getPosts())).sort(Post.TIME_COMPARATOR).get());
 302                         soneProperties.put("replies", new ListBuilder<Reply>(new ArrayList<Reply>(sone.getReplies())).sort(new ReverseComparator<Reply>(Reply.TIME_COMPARATOR)).get());
 303                         soneProperties.put("likedPostIds", new HashSet<String>(sone.getLikedPostIds()));
 304                         soneProperties.put("likedReplyIds", new HashSet<String>(sone.getLikedReplyIds()));
 305                 }
 306
 307                 //
 308                 // ACCESSORS
 309                 //
 310
 311                 /**
 312                  * Returns the insert URI of the Sone.
 313                  *
 314                  * @return The insert URI of the Sone
 315                  */
 316                 public FreenetURI getInsertUri() {
 317                         return (FreenetURI) soneProperties.get("insertUri");
 318                 }
 319
 320                 /**
 321                  * Sets the time of the Sone at the time of the insert.
 322                  *
 323                  * @param time
 324                  *            The time of the Sone
 325                  */
 326                 public void setTime(long time) {
 327                         soneProperties.put("time", time);
 328                 }
 329
 330                 //
 331                 // ACTIONS
 332                 //
 333
 334                 /**
 335                  * Generates all manifest entries required to insert this Sone.
 336                  *
 337                  * @return The manifest entries for the Sone insert
 338                  */
 339                 public HashMap<String, Object> generateManifestEntries() {
 340                         HashMap<String, Object> manifestEntries = new HashMap<String, Object>();
 341
 342                         /* first, create an index.html. */
 343                         manifestEntries.put("index.html", createManifestElement("index.html", "text/html; charset=utf-8", "/templates/insert/index.html"));
 344
 345                         /* now, store the sone. */
 346                         manifestEntries.put("sone.xml", createManifestElement("sone.xml", "text/xml; charset=utf-8", "/templates/insert/sone.xml"));
 347
 348                         return manifestEntries;
 349                 }
 350
 351                 //
 352                 // PRIVATE METHODS
 353                 //
 354
 355                 /**
 356                  * Creates a new manifest element.
 357                  *
 358                  * @param name
 359                  *            The name of the file
 360                  * @param contentType
 361                  *            The content type of the file
 362                  * @param templateName
 363                  *            The name of the template to render
 364                  * @return The manifest element
 365                  */
 366                 @SuppressWarnings("synthetic-access")
 367                 private ManifestElement createManifestElement(String name, String contentType, String templateName) {
 368                         InputStreamReader templateInputStreamReader = null;
 369                         Template template;
 370                         try {
 371                                 templateInputStreamReader = new InputStreamReader(getClass().getResourceAsStream(templateName), utf8Charset);
 372                                 template = TemplateParser.parse(templateInputStreamReader);
 373                         } catch (TemplateException te1) {
 374                                 logger.log(Level.SEVERE, "Could not parse template “" + templateName + "”!", te1);
 375                                 return null;
 376                         } finally {
 377                                 Closer.close(templateInputStreamReader);
 378                         }
 379
 380                         TemplateContext templateContext = templateContextFactory.createTemplateContext();
 381                         templateContext.set("core", core);
 382                         templateContext.set("currentSone", soneProperties);
 383                         templateContext.set("currentEdition", core.getUpdateChecker().getLatestEdition());
 384                         templateContext.set("version", SonePlugin.VERSION);
 385                         StringWriter writer = new StringWriter();
 386                         StringBucket bucket = null;
 387                         try {
 388                                 template.render(templateContext, writer);
 389                                 bucket = new StringBucket(writer.toString(), utf8Charset);
 390                                 return new ManifestElement(name, bucket, contentType, bucket.size());
 391                         } catch (TemplateException te1) {
 392                                 logger.log(Level.SEVERE, "Could not render template “" + templateName + "”!", te1);
 393                                 return null;
 394                         } finally {
 395                                 Closer.close(writer);
 396                                 if (bucket != null) {
 397                                         bucket.free();
 398                                 }
 399                         }
 400                 }
 401
 402         }
 403
 404 }