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

   1 /*
   2  * Sone - SoneInserter.java - Copyright © 2010–2013 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 static com.google.common.base.Preconditions.checkArgument;
  21 import static net.pterodactylus.sone.data.Album.NOT_EMPTY;
  22 import static net.pterodactylus.sone.data.Sone.TO_FREENET_URI;
  23
  24 import java.io.InputStreamReader;
  25 import java.io.StringWriter;
  26 import java.nio.charset.Charset;
  27 import java.util.HashMap;
  28 import java.util.HashSet;
  29 import java.util.Map;
  30 import java.util.logging.Level;
  31 import java.util.logging.Logger;
  32
  33 import net.pterodactylus.sone.core.event.SoneInsertAbortedEvent;
  34 import net.pterodactylus.sone.core.event.SoneInsertedEvent;
  35 import net.pterodactylus.sone.core.event.SoneInsertingEvent;
  36 import net.pterodactylus.sone.data.Album;
  37 import net.pterodactylus.sone.data.Post;
  38 import net.pterodactylus.sone.data.Reply;
  39 import net.pterodactylus.sone.data.Sone;
  40 import net.pterodactylus.sone.data.Sone.SoneStatus;
  41 import net.pterodactylus.sone.freenet.StringBucket;
  42 import net.pterodactylus.sone.main.SonePlugin;
  43 import net.pterodactylus.util.io.Closer;
  44 import net.pterodactylus.util.logging.Logging;
  45 import net.pterodactylus.util.service.AbstractService;
  46 import net.pterodactylus.util.template.HtmlFilter;
  47 import net.pterodactylus.util.template.ReflectionAccessor;
  48 import net.pterodactylus.util.template.Template;
  49 import net.pterodactylus.util.template.TemplateContext;
  50 import net.pterodactylus.util.template.TemplateContextFactory;
  51 import net.pterodactylus.util.template.TemplateException;
  52 import net.pterodactylus.util.template.TemplateParser;
  53 import net.pterodactylus.util.template.XmlFilter;
  54
  55 import freenet.client.async.ManifestElement;
  56 import freenet.keys.FreenetURI;
  57
  58 import com.google.common.collect.FluentIterable;
  59 import com.google.common.collect.Ordering;
  60 import com.google.common.eventbus.EventBus;
  61
  62 /**
  63  * A Sone inserter is responsible for inserting a Sone if it has changed.
  64  *
  65  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  66  */
  67 public class SoneInserter extends AbstractService {
  68
  69         /** The logger. */
  70         private static final Logger logger = Logging.getLogger(SoneInserter.class);
  71
  72         /** The insertion delay (in seconds). */
  73         private static volatile int insertionDelay = 60;
  74
  75         /** The template factory used to create the templates. */
  76         private static final TemplateContextFactory templateContextFactory = new TemplateContextFactory();
  77
  78         static {
  79                 templateContextFactory.addAccessor(Object.class, new ReflectionAccessor());
  80                 templateContextFactory.addFilter("xml", new XmlFilter());
  81                 templateContextFactory.addFilter("html", new HtmlFilter());
  82         }
  83
  84         /** The UTF-8 charset. */
  85         private static final Charset utf8Charset = Charset.forName("UTF-8");
  86
  87         /** The core. */
  88         private final Core core;
  89
  90         /** The event bus. */
  91         private final EventBus eventBus;
  92
  93         /** The Freenet interface. */
  94         private final FreenetInterface freenetInterface;
  95
  96         /** The Sone to insert. */
  97         private volatile Sone sone;
  98
  99         /** Whether a modification has been detected. */
 100         private volatile boolean modified = false;
 101
 102         /** The fingerprint of the last insert. */
 103         private volatile String lastInsertFingerprint;
 104
 105         /**
 106          * Creates a new Sone inserter.
 107          *
 108          * @param core
 109          *            The core
 110          * @param eventBus
 111          *            The event bus
 112          * @param freenetInterface
 113          *            The freenet interface
 114          * @param sone
 115          *            The Sone to insert
 116          */
 117         public SoneInserter(Core core, EventBus eventBus, FreenetInterface freenetInterface, Sone sone) {
 118                 super("Sone Inserter for “" + sone.getName() + "”", false);
 119                 this.core = core;
 120                 this.eventBus = eventBus;
 121                 this.freenetInterface = freenetInterface;
 122                 this.sone = sone;
 123         }
 124
 125         //
 126         // ACCESSORS
 127         //
 128
 129         /**
 130          * Sets the Sone to insert.
 131          *
 132          * @param sone
 133          *              The Sone to insert
 134          * @return This Sone inserter
 135          */
 136         public SoneInserter setSone(Sone sone) {
 137                 checkArgument((this.sone == null) || sone.equals(this.sone), "Sone to insert can not be set to a different Sone");
 138                 this.sone = sone;
 139                 return this;
 140         }
 141
 142         /**
 143          * Changes the insertion delay, i.e. the time the Sone inserter waits after it
 144          * has noticed a Sone modification before it starts the insert.
 145          *
 146          * @param insertionDelay
 147          *            The insertion delay (in seconds)
 148          */
 149         public static void setInsertionDelay(int insertionDelay) {
 150                 SoneInserter.insertionDelay = insertionDelay;
 151         }
 152
 153         /**
 154          * Returns the fingerprint of the last insert.
 155          *
 156          * @return The fingerprint of the last insert
 157          */
 158         public String getLastInsertFingerprint() {
 159                 return lastInsertFingerprint;
 160         }
 161
 162         /**
 163          * Sets the fingerprint of the last insert.
 164          *
 165          * @param lastInsertFingerprint
 166          *            The fingerprint of the last insert
 167          */
 168         public void setLastInsertFingerprint(String lastInsertFingerprint) {
 169                 this.lastInsertFingerprint = lastInsertFingerprint;
 170         }
 171
 172         /**
 173          * Returns whether the Sone inserter has detected a modification of the
 174          * Sone.
 175          *
 176          * @return {@code true} if the Sone has been modified, {@code false}
 177          *         otherwise
 178          */
 179         public boolean isModified() {
 180                 return modified;
 181         }
 182
 183         //
 184         // SERVICE METHODS
 185         //
 186
 187         @Override
 188         protected void serviceRun() {
 189                 long lastModificationTime = 0;
 190                 String lastInsertedFingerprint = lastInsertFingerprint;
 191                 String lastFingerprint = "";
 192                 Sone sone;
 193                 while (!shouldStop()) {
 194                         try {
 195                                 /* check every seconds. */
 196                                 sleep(1000);
 197
 198                                 /* don’t insert locked Sones. */
 199                                 sone = this.sone;
 200                                 if (core.isLocked(sone)) {
 201                                         /* trigger redetection when the Sone is unlocked. */
 202                                         synchronized (sone) {
 203                                                 modified = !sone.getFingerprint().equals(lastInsertedFingerprint);
 204                                         }
 205                                         lastFingerprint = "";
 206                                         lastModificationTime = 0;
 207                                         continue;
 208                                 }
 209
 210                                 InsertInformation insertInformation = null;
 211                                 synchronized (sone) {
 212                                         String fingerprint = sone.getFingerprint();
 213                                         if (!fingerprint.equals(lastFingerprint)) {
 214                                                 if (fingerprint.equals(lastInsertedFingerprint)) {
 215                                                         modified = false;
 216                                                         lastModificationTime = 0;
 217                                                         logger.log(Level.FINE, String.format("Sone %s has been reverted to last insert state.", sone));
 218                                                 } else {
 219                                                         lastModificationTime = System.currentTimeMillis();
 220                                                         modified = true;
 221                                                         logger.log(Level.FINE, String.format("Sone %s has been modified, waiting %d seconds before inserting.", sone.getName(), insertionDelay));
 222                                                 }
 223                                                 lastFingerprint = fingerprint;
 224                                         }
 225                                         if (modified && (lastModificationTime > 0) && ((System.currentTimeMillis() - lastModificationTime) > (insertionDelay * 1000))) {
 226                                                 lastInsertedFingerprint = fingerprint;
 227                                                 insertInformation = new InsertInformation(sone);
 228                                         }
 229                                 }
 230
 231                                 if (insertInformation != null) {
 232                                         logger.log(Level.INFO, String.format("Inserting Sone “%s”…", sone.getName()));
 233
 234                                         boolean success = false;
 235                                         try {
 236                                                 sone.setStatus(SoneStatus.inserting);
 237                                                 long insertTime = System.currentTimeMillis();
 238                                                 insertInformation.setTime(insertTime);
 239                                                 eventBus.post(new SoneInsertingEvent(sone));
 240                                                 FreenetURI finalUri = freenetInterface.insertDirectory(insertInformation.getInsertUri(), insertInformation.generateManifestEntries(), "index.html");
 241                                                 eventBus.post(new SoneInsertedEvent(sone, System.currentTimeMillis() - insertTime));
 242                                                 /* at this point we might already be stopped. */
 243                                                 if (shouldStop()) {
 244                                                         /* if so, bail out, don’t change anything. */
 245                                                         break;
 246                                                 }
 247                                                 sone.setTime(insertTime);
 248                                                 sone.modify().setLatestEdition(finalUri.getEdition()).update();
 249                                                 core.touchConfiguration();
 250                                                 success = true;
 251                                                 logger.log(Level.INFO, String.format("Inserted Sone “%s” at %s.", sone.getName(), finalUri));
 252                                         } catch (SoneException se1) {
 253                                                 eventBus.post(new SoneInsertAbortedEvent(sone, se1));
 254                                                 logger.log(Level.WARNING, String.format("Could not insert Sone “%s”!", sone.getName()), se1);
 255                                         } finally {
 256                                                 sone.setStatus(SoneStatus.idle);
 257                                         }
 258
 259                                         /*
 260                                          * reset modification counter if Sone has not been modified
 261                                          * while it was inserted.
 262                                          */
 263                                         if (success) {
 264                                                 synchronized (sone) {
 265                                                         if (lastInsertedFingerprint.equals(sone.getFingerprint())) {
 266                                                                 logger.log(Level.FINE, String.format("Sone “%s” was not modified further, resetting counter…", sone));
 267                                                                 lastModificationTime = 0;
 268                                                                 lastInsertFingerprint = lastInsertedFingerprint;
 269                                                                 core.touchConfiguration();
 270                                                                 modified = false;
 271                                                         }
 272                                                 }
 273                                         }
 274                                 }
 275                         } catch (Throwable t1) {
 276                                 logger.log(Level.SEVERE, "SoneInserter threw an Exception!", t1);
 277                         }
 278                 }
 279         }
 280
 281         /**
 282          * Container for information that are required to insert a Sone. This
 283          * container merely exists to copy all relevant data without holding a lock
 284          * on the {@link Sone} object for too long.
 285          *
 286          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 287          */
 288         private class InsertInformation {
 289
 290                 /** All properties of the Sone, copied for thread safety. */
 291                 private final Map<String, Object> soneProperties = new HashMap<String, Object>();
 292
 293                 /**
 294                  * Creates a new insert information container.
 295                  *
 296                  * @param sone
 297                  *            The sone to insert
 298                  */
 299                 public InsertInformation(Sone sone) {
 300                         soneProperties.put("id", sone.getId());
 301                         soneProperties.put("name", sone.getName());
 302                         soneProperties.put("time", sone.getTime());
 303                         soneProperties.put("requestUri", TO_FREENET_URI.apply(sone));
 304                         soneProperties.put("profile", sone.getProfile());
 305                         soneProperties.put("posts", Ordering.from(Post.TIME_COMPARATOR).sortedCopy(sone.getPosts()));
 306                         soneProperties.put("replies", Ordering.from(Reply.TIME_COMPARATOR).reverse().sortedCopy(sone.getReplies()));
 307                         soneProperties.put("likedPostIds", new HashSet<String>(sone.getLikedPostIds()));
 308                         soneProperties.put("likedReplyIds", new HashSet<String>(sone.getLikedReplyIds()));
 309                         soneProperties.put("albums", FluentIterable.from(sone.getRootAlbum().getAlbums()).transformAndConcat(Album.FLATTENER).filter(NOT_EMPTY).toList());
 310                 }
 311
 312                 //
 313                 // ACCESSORS
 314                 //
 315
 316                 /**
 317                  * Returns the insert URI of the Sone.
 318                  *
 319                  * @return The insert URI of the Sone
 320                  */
 321                 public FreenetURI getInsertUri() {
 322                         return (FreenetURI) soneProperties.get("insertUri");
 323                 }
 324
 325                 /**
 326                  * Sets the time of the Sone at the time of the insert.
 327                  *
 328                  * @param time
 329                  *            The time of the Sone
 330                  */
 331                 public void setTime(long time) {
 332                         soneProperties.put("time", time);
 333                 }
 334
 335                 //
 336                 // ACTIONS
 337                 //
 338
 339                 /**
 340                  * Generates all manifest entries required to insert this Sone.
 341                  *
 342                  * @return The manifest entries for the Sone insert
 343                  */
 344                 public HashMap<String, Object> generateManifestEntries() {
 345                         HashMap<String, Object> manifestEntries = new HashMap<String, Object>();
 346
 347                         /* first, create an index.html. */
 348                         manifestEntries.put("index.html", createManifestElement("index.html", "text/html; charset=utf-8", "/templates/insert/index.html"));
 349
 350                         /* now, store the sone. */
 351                         manifestEntries.put("sone.xml", createManifestElement("sone.xml", "text/xml; charset=utf-8", "/templates/insert/sone.xml"));
 352
 353                         return manifestEntries;
 354                 }
 355
 356                 //
 357                 // PRIVATE METHODS
 358                 //
 359
 360                 /**
 361                  * Creates a new manifest element.
 362                  *
 363                  * @param name
 364                  *            The name of the file
 365                  * @param contentType
 366                  *            The content type of the file
 367                  * @param templateName
 368                  *            The name of the template to render
 369                  * @return The manifest element
 370                  */
 371                 @SuppressWarnings("synthetic-access")
 372                 private ManifestElement createManifestElement(String name, String contentType, String templateName) {
 373                         InputStreamReader templateInputStreamReader = null;
 374                         Template template;
 375                         try {
 376                                 templateInputStreamReader = new InputStreamReader(getClass().getResourceAsStream(templateName), utf8Charset);
 377                                 template = TemplateParser.parse(templateInputStreamReader);
 378                         } catch (TemplateException te1) {
 379                                 logger.log(Level.SEVERE, String.format("Could not parse template “%s”!", templateName), te1);
 380                                 return null;
 381                         } finally {
 382                                 Closer.close(templateInputStreamReader);
 383                         }
 384
 385                         TemplateContext templateContext = templateContextFactory.createTemplateContext();
 386                         templateContext.set("core", core);
 387                         templateContext.set("currentSone", soneProperties);
 388                         templateContext.set("currentEdition", core.getUpdateChecker().getLatestEdition());
 389                         templateContext.set("version", SonePlugin.VERSION);
 390                         StringWriter writer = new StringWriter();
 391                         StringBucket bucket = null;
 392                         try {
 393                                 template.render(templateContext, writer);
 394                                 bucket = new StringBucket(writer.toString(), utf8Charset);
 395                                 return new ManifestElement(name, bucket, contentType, bucket.size());
 396                         } catch (TemplateException te1) {
 397                                 logger.log(Level.SEVERE, String.format("Could not render template “%s”!", templateName), te1);
 398                                 return null;
 399                         } finally {
 400                                 Closer.close(writer);
 401                                 if (bucket != null) {
 402                                         bucket.free();
 403                                 }
 404                         }
 405                 }
 406
 407         }
 408
 409 }