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                                 synchronized (sone) {
 167                                         modified = !sone.getFingerprint().equals(lastInsertFingerprint);
 168                                 }
 169                                 lastFingerprint = "";
 170                                 lastModificationTime = 0;
 171                                 continue;
 172                         }
 173
 174                         InsertInformation insertInformation = null;
 175                         synchronized (sone) {
 176                                 String fingerprint = sone.getFingerprint();
 177                                 if (!fingerprint.equals(lastFingerprint)) {
 178                                         if (fingerprint.equals(lastInsertFingerprint)) {
 179                                                 modified = false;
 180                                                 lastModificationTime = 0;
 181                                                 logger.log(Level.FINE, "Sone %s has been reverted to last insert state.", sone);
 182                                         } else {
 183                                                 lastModificationTime = System.currentTimeMillis();
 184                                                 modified = true;
 185                                                 sone.setTime(lastModificationTime);
 186                                                 logger.log(Level.FINE, "Sone %s has been modified, waiting %d seconds before inserting.", new Object[] { sone.getName(), insertionDelay });
 187                                         }
 188                                         lastFingerprint = fingerprint;
 189                                 }
 190                                 if (modified && (lastModificationTime > 0) && ((System.currentTimeMillis() - lastModificationTime) > (insertionDelay * 1000))) {
 191                                         lastInsertFingerprint = fingerprint;
 192                                         insertInformation = new InsertInformation(sone);
 193                                 }
 194                         }
 195
 196                         if (insertInformation != null) {
 197                                 logger.log(Level.INFO, "Inserting Sone “%s”…", new Object[] { sone.getName() });
 198
 199                                 boolean success = false;
 200                                 try {
 201                                         core.setSoneStatus(sone, SoneStatus.inserting);
 202                                         FreenetURI finalUri = freenetInterface.insertDirectory(insertInformation.getInsertUri().setKeyType("USK").setSuggestedEdition(0), insertInformation.generateManifestEntries(), "index.html");
 203                                         /* at this point we might already be stopped. */
 204                                         if (shouldStop()) {
 205                                                 /* if so, bail out, don’t change anything. */
 206                                                 break;
 207                                         }
 208                                         sone.setLatestEdition(finalUri.getEdition());
 209                                         success = true;
 210                                         logger.log(Level.INFO, "Inserted Sone “%s” at %s.", new Object[] { sone.getName(), finalUri });
 211                                 } catch (SoneException se1) {
 212                                         logger.log(Level.WARNING, "Could not insert Sone “" + sone.getName() + "”!", se1);
 213                                 } finally {
 214                                         core.setSoneStatus(sone, SoneStatus.idle);
 215                                 }
 216
 217                                 /*
 218                                  * reset modification counter if Sone has not been modified
 219                                  * while it was inserted.
 220                                  */
 221                                 if (success) {
 222                                         synchronized (sone) {
 223                                                 if (lastInsertFingerprint.equals(sone.getFingerprint())) {
 224                                                         logger.log(Level.FINE, "Sone “%s” was not modified further, resetting counter…", new Object[] { sone });
 225                                                         core.saveSone(sone);
 226                                                         lastModificationTime = 0;
 227                                                         modified = false;
 228                                                 }
 229                                         }
 230                                 }
 231                         }
 232                 }
 233         }
 234
 235         /**
 236          * Container for information that are required to insert a Sone. This
 237          * container merely exists to copy all relevant data without holding a lock
 238          * on the {@link Sone} object for too long.
 239          *
 240          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 241          */
 242         private class InsertInformation {
 243
 244                 /** All properties of the Sone, copied for thread safety. */
 245                 private final Map<String, Object> soneProperties = new HashMap<String, Object>();
 246
 247                 /**
 248                  * Creates a new insert information container.
 249                  *
 250                  * @param sone
 251                  *            The sone to insert
 252                  */
 253                 public InsertInformation(Sone sone) {
 254                         soneProperties.put("id", sone.getId());
 255                         soneProperties.put("name", sone.getName());
 256                         soneProperties.put("time", sone.getTime());
 257                         soneProperties.put("requestUri", sone.getRequestUri());
 258                         soneProperties.put("insertUri", sone.getInsertUri());
 259                         soneProperties.put("profile", sone.getProfile());
 260                         soneProperties.put("posts", new ArrayList<Post>(sone.getPosts()));
 261                         soneProperties.put("replies", new HashSet<Reply>(sone.getReplies()));
 262                         soneProperties.put("likedPostIds", new HashSet<String>(sone.getLikedPostIds()));
 263                         soneProperties.put("likedReplyIds", new HashSet<String>(sone.getLikedReplyIds()));
 264                 }
 265
 266                 //
 267                 // ACCESSORS
 268                 //
 269
 270                 /**
 271                  * Returns the insert URI of the Sone.
 272                  *
 273                  * @return The insert URI of the Sone
 274                  */
 275                 public FreenetURI getInsertUri() {
 276                         return (FreenetURI) soneProperties.get("insertUri");
 277                 }
 278
 279                 //
 280                 // ACTIONS
 281                 //
 282
 283                 /**
 284                  * Generates all manifest entries required to insert this Sone.
 285                  *
 286                  * @return The manifest entries for the Sone insert
 287                  */
 288                 public HashMap<String, Object> generateManifestEntries() {
 289                         HashMap<String, Object> manifestEntries = new HashMap<String, Object>();
 290
 291                         /* first, create an index.html. */
 292                         manifestEntries.put("index.html", createManifestElement("index.html", "text/html; charset=utf-8", "/templates/insert/index.html"));
 293
 294                         /* now, store the sone. */
 295                         manifestEntries.put("sone.xml", createManifestElement("sone.xml", "text/xml; charset=utf-8", "/templates/insert/sone.xml"));
 296
 297                         return manifestEntries;
 298                 }
 299
 300                 //
 301                 // PRIVATE METHODS
 302                 //
 303
 304                 /**
 305                  * Creates a new manifest element.
 306                  *
 307                  * @param name
 308                  *            The name of the file
 309                  * @param contentType
 310                  *            The content type of the file
 311                  * @param templateName
 312                  *            The name of the template to render
 313                  * @return The manifest element
 314                  */
 315                 @SuppressWarnings("synthetic-access")
 316                 private ManifestElement createManifestElement(String name, String contentType, String templateName) {
 317                         InputStreamReader templateInputStreamReader;
 318                         Template template = templateFactory.createTemplate(templateInputStreamReader = new InputStreamReader(getClass().getResourceAsStream(templateName), utf8Charset));
 319                         try {
 320                                 template.parse();
 321                         } catch (TemplateException te1) {
 322                                 logger.log(Level.SEVERE, "Could not parse template “" + templateName + "”!", te1);
 323                                 return null;
 324                         } finally {
 325                                 Closer.close(templateInputStreamReader);
 326                         }
 327
 328                         template.set("currentSone", soneProperties);
 329                         template.set("version", SonePlugin.VERSION);
 330                         StringWriter writer = new StringWriter();
 331                         StringBucket bucket = null;
 332                         try {
 333                                 template.render(writer);
 334                                 bucket = new StringBucket(writer.toString(), utf8Charset);
 335                                 return new ManifestElement(name, bucket, contentType, bucket.size());
 336                         } catch (TemplateException te1) {
 337                                 logger.log(Level.SEVERE, "Could not render template “" + templateName + "”!", te1);
 338                                 return null;
 339                         } finally {
 340                                 Closer.close(writer);
 341                                 if (bucket != null) {
 342                                         bucket.free();
 343                                 }
 344                         }
 345                 }
 346
 347         }
 348
 349 }