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