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

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