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