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.Optional.absent;
  21 import static com.google.common.base.Optional.of;
  22 import static com.google.common.base.Preconditions.checkArgument;
  23 import static java.lang.System.currentTimeMillis;
  24 import static net.pterodactylus.sone.data.Album.NOT_EMPTY;
  25
  26 import java.io.InputStreamReader;
  27 import java.io.StringWriter;
  28 import java.nio.charset.Charset;
  29 import java.util.HashMap;
  30 import java.util.HashSet;
  31 import java.util.Map;
  32 import java.util.logging.Level;
  33 import java.util.logging.Logger;
  34
  35 import net.pterodactylus.sone.core.event.SoneInsertAbortedEvent;
  36 import net.pterodactylus.sone.core.event.SoneInsertedEvent;
  37 import net.pterodactylus.sone.core.event.SoneInsertingEvent;
  38 import net.pterodactylus.sone.data.Album;
  39 import net.pterodactylus.sone.data.Post;
  40 import net.pterodactylus.sone.data.Reply;
  41 import net.pterodactylus.sone.data.Sone;
  42 import net.pterodactylus.sone.data.Sone.SoneStatus;
  43 import net.pterodactylus.sone.freenet.StringBucket;
  44 import net.pterodactylus.sone.main.SonePlugin;
  45 import net.pterodactylus.util.io.Closer;
  46 import net.pterodactylus.util.logging.Logging;
  47 import net.pterodactylus.util.service.AbstractService;
  48 import net.pterodactylus.util.template.HtmlFilter;
  49 import net.pterodactylus.util.template.ReflectionAccessor;
  50 import net.pterodactylus.util.template.Template;
  51 import net.pterodactylus.util.template.TemplateContext;
  52 import net.pterodactylus.util.template.TemplateContextFactory;
  53 import net.pterodactylus.util.template.TemplateException;
  54 import net.pterodactylus.util.template.TemplateParser;
  55 import net.pterodactylus.util.template.XmlFilter;
  56
  57 import com.google.common.base.Optional;
  58 import com.google.common.collect.FluentIterable;
  59 import com.google.common.collect.Ordering;
  60 import com.google.common.eventbus.EventBus;
  61
  62 import freenet.client.async.ManifestElement;
  63 import freenet.keys.FreenetURI;
  64
  65 /**
  66  * A Sone inserter is responsible for inserting a Sone if it has changed.
  67  *
  68  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  69  */
  70 public class SoneInserter extends AbstractService {
  71
  72         /** The logger. */
  73         private static final Logger logger = Logging.getLogger(SoneInserter.class);
  74
  75         /** The insertion delay (in seconds). */
  76         private static volatile int insertionDelay = 60;
  77
  78         /** The template factory used to create the templates. */
  79         private static final TemplateContextFactory templateContextFactory = new TemplateContextFactory();
  80
  81         static {
  82                 templateContextFactory.addAccessor(Object.class, new ReflectionAccessor());
  83                 templateContextFactory.addFilter("xml", new XmlFilter());
  84                 templateContextFactory.addFilter("html", new HtmlFilter());
  85         }
  86
  87         /** The UTF-8 charset. */
  88         private static final Charset utf8Charset = Charset.forName("UTF-8");
  89
  90         /** The core. */
  91         private final Core core;
  92
  93         /** The event bus. */
  94         private final EventBus eventBus;
  95
  96         /** The Freenet interface. */
  97         private final FreenetInterface freenetInterface;
  98
  99         /** The Sone to insert. */
 100         private volatile Sone sone;
 101
 102         /** Whether a modification has been detected. */
 103         private volatile boolean modified = false;
 104
 105         /** The fingerprint of the last insert. */
 106         private volatile String lastInsertFingerprint;
 107
 108         /**
 109          * Creates a new Sone inserter.
 110          *
 111          * @param core
 112          *            The core
 113          * @param eventBus
 114          *            The event bus
 115          * @param freenetInterface
 116          *            The freenet interface
 117          * @param sone
 118          *            The Sone to insert
 119          */
 120         public SoneInserter(Core core, EventBus eventBus, FreenetInterface freenetInterface, Sone sone) {
 121                 super("Sone Inserter for “" + sone.getName() + "”", false);
 122                 this.core = core;
 123                 this.eventBus = eventBus;
 124                 this.freenetInterface = freenetInterface;
 125                 this.sone = sone;
 126         }
 127
 128         //
 129         // ACCESSORS
 130         //
 131
 132         /**
 133          * Sets the Sone to insert.
 134          *
 135          * @param sone
 136          *              The Sone to insert
 137          * @return This Sone inserter
 138          */
 139         public SoneInserter setSone(Sone sone) {
 140                 checkArgument((this.sone == null) || sone.equals(this.sone), "Sone to insert can not be set to a different Sone");
 141                 this.sone = sone;
 142                 return this;
 143         }
 144
 145         /**
 146          * Changes the insertion delay, i.e. the time the Sone inserter waits after it
 147          * has noticed a Sone modification before it starts the insert.
 148          *
 149          * @param insertionDelay
 150          *            The insertion delay (in seconds)
 151          */
 152         public static void setInsertionDelay(int insertionDelay) {
 153                 SoneInserter.insertionDelay = insertionDelay;
 154         }
 155
 156         /**
 157          * Returns the fingerprint of the last insert.
 158          *
 159          * @return The fingerprint of the last insert
 160          */
 161         public String getLastInsertFingerprint() {
 162                 return lastInsertFingerprint;
 163         }
 164
 165         /**
 166          * Sets the fingerprint of the last insert.
 167          *
 168          * @param lastInsertFingerprint
 169          *            The fingerprint of the last insert
 170          */
 171         public void setLastInsertFingerprint(String lastInsertFingerprint) {
 172                 this.lastInsertFingerprint = lastInsertFingerprint;
 173         }
 174
 175         /**
 176          * Returns whether the Sone inserter has detected a modification of the
 177          * Sone.
 178          *
 179          * @return {@code true} if the Sone has been modified, {@code false}
 180          *         otherwise
 181          */
 182         public boolean isModified() {
 183                 return modified;
 184         }
 185
 186         //
 187         // SERVICE METHODS
 188         //
 189
 190         /**
 191          * {@inheritDoc}
 192          */
 193         @Override
 194         protected void serviceRun() {
 195                 Optional<Long> lastModificationTime = absent();
 196                 String lastInsertedFingerprint = lastInsertFingerprint;
 197                 String lastFingerprint = "";
 198                 while (!shouldStop()) {
 199                         try {
 200                                 /* check every second. */
 201                                 sleep(1000);
 202
 203                                 /* don’t insert locked Sones. */
 204                                 Sone sone = this.sone;
 205                                 if (core.isLocked(sone)) {
 206                                         /* trigger redetection when the Sone is unlocked. */
 207                                         synchronized (sone) {
 208                                                 modified = !sone.getFingerprint().equals(lastInsertedFingerprint);
 209                                         }
 210                                         lastFingerprint = "";
 211                                         lastModificationTime = absent();
 212                                         continue;
 213                                 }
 214
 215                                 boolean insertSoneNow = false;
 216                                 synchronized (sone) {
 217                                         String fingerprint = sone.getFingerprint();
 218                                         if (!fingerprint.equals(lastFingerprint)) {
 219                                                 if (fingerprint.equals(lastInsertedFingerprint)) {
 220                                                         modified = false;
 221                                                         lastModificationTime = absent();
 222                                                         logger.log(Level.FINE, String.format("Sone %s has been reverted to last insert state.", sone));
 223                                                 } else {
 224                                                         lastModificationTime = of(currentTimeMillis());
 225                                                         modified = true;
 226                                                         logger.log(Level.FINE, String.format("Sone %s has been modified, waiting %d seconds before inserting.", sone.getName(), insertionDelay));
 227                                                 }
 228                                                 lastFingerprint = fingerprint;
 229                                         }
 230                                         if (modified && lastModificationTime.isPresent() && ((currentTimeMillis() - lastModificationTime.get()) > (insertionDelay * 1000))) {
 231                                                 lastInsertedFingerprint = fingerprint;
 232                                                 insertSoneNow = true;
 233                                         }
 234                                 }
 235
 236                                 if (insertSoneNow) {
 237                                         InsertInformation insertInformation = new InsertInformation(sone);
 238                                         logger.log(Level.INFO, String.format("Inserting Sone “%s”…", sone.getName()));
 239
 240                                         boolean success = false;
 241                                         try {
 242                                                 sone.setStatus(SoneStatus.inserting);
 243                                                 long insertTime = currentTimeMillis();
 244                                                 insertInformation.setTime(insertTime);
 245                                                 eventBus.post(new SoneInsertingEvent(sone));
 246                                                 FreenetURI finalUri = freenetInterface.insertDirectory(insertInformation.getInsertUri(), insertInformation.generateManifestEntries(), "index.html");
 247                                                 eventBus.post(new SoneInsertedEvent(sone, currentTimeMillis() - insertTime));
 248                                                 /* at this point we might already be stopped. */
 249                                                 if (shouldStop()) {
 250                                                         /* if so, bail out, don’t change anything. */
 251                                                         break;
 252                                                 }
 253                                                 sone.setTime(insertTime);
 254                                                 sone.setLatestEdition(finalUri.getEdition());
 255                                                 core.touchConfiguration();
 256                                                 success = true;
 257                                                 logger.log(Level.INFO, String.format("Inserted Sone “%s” at %s.", sone.getName(), finalUri));
 258                                         } catch (SoneException se1) {
 259                                                 eventBus.post(new SoneInsertAbortedEvent(sone, se1));
 260                                                 logger.log(Level.WARNING, String.format("Could not insert Sone “%s”!", sone.getName()), se1);
 261                                         } finally {
 262                                                 sone.setStatus(SoneStatus.idle);
 263                                         }
 264
 265                                         /*
 266                                          * reset modification counter if Sone has not been modified
 267                                          * while it was inserted.
 268                                          */
 269                                         if (success) {
 270                                                 synchronized (sone) {
 271                                                         if (insertInformation.getFingerprint().equals(sone.getFingerprint())) {
 272                                                                 logger.log(Level.FINE, String.format("Sone “%s” was not modified further, resetting counter…", sone));
 273                                                                 lastModificationTime = absent();
 274                                                                 lastInsertFingerprint = insertInformation.getFingerprint();
 275                                                                 core.touchConfiguration();
 276                                                                 modified = false;
 277                                                         }
 278                                                 }
 279                                         }
 280                                 }
 281                         } catch (Throwable t1) {
 282                                 logger.log(Level.SEVERE, "SoneInserter threw an Exception!", t1);
 283                         }
 284                 }
 285         }
 286
 287         /**
 288          * Container for information that are required to insert a Sone. This
 289          * container merely exists to copy all relevant data without holding a lock
 290          * on the {@link Sone} object for too long.
 291          *
 292          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 293          */
 294         private class InsertInformation {
 295
 296                 private final String fingerprint;
 297
 298                 /** All properties of the Sone, copied for thread safety. */
 299                 private final Map<String, Object> soneProperties = new HashMap<String, Object>();
 300
 301                 /**
 302                  * Creates a new insert information container.
 303                  *
 304                  * @param sone
 305                  *            The sone to insert
 306                  */
 307                 public InsertInformation(Sone sone) {
 308                         this.fingerprint = sone.getFingerprint();
 309                         soneProperties.put("id", sone.getId());
 310                         soneProperties.put("name", sone.getName());
 311                         soneProperties.put("time", sone.getTime());
 312                         soneProperties.put("requestUri", sone.getRequestUri());
 313                         soneProperties.put("insertUri", sone.getInsertUri());
 314                         soneProperties.put("profile", sone.getProfile());
 315                         soneProperties.put("posts", Ordering.from(Post.TIME_COMPARATOR).sortedCopy(sone.getPosts()));
 316                         soneProperties.put("replies", Ordering.from(Reply.TIME_COMPARATOR).reverse().sortedCopy(sone.getReplies()));
 317                         soneProperties.put("likedPostIds", new HashSet<String>(sone.getLikedPostIds()));
 318                         soneProperties.put("likedReplyIds", new HashSet<String>(sone.getLikedReplyIds()));
 319                         soneProperties.put("albums", FluentIterable.from(sone.getRootAlbum().getAlbums()).transformAndConcat(Album.FLATTENER).filter(NOT_EMPTY).toList());
 320                 }
 321
 322                 //
 323                 // ACCESSORS
 324                 //
 325
 326                 private String getFingerprint() {
 327                         return fingerprint;
 328                 }
 329
 330                 /**
 331                  * Returns the insert URI of the Sone.
 332                  *
 333                  * @return The insert URI of the Sone
 334                  */
 335                 public FreenetURI getInsertUri() {
 336                         return (FreenetURI) soneProperties.get("insertUri");
 337                 }
 338
 339                 /**
 340                  * Sets the time of the Sone at the time of the insert.
 341                  *
 342                  * @param time
 343                  *            The time of the Sone
 344                  */
 345                 public void setTime(long time) {
 346                         soneProperties.put("time", time);
 347                 }
 348
 349                 //
 350                 // ACTIONS
 351                 //
 352
 353                 /**
 354                  * Generates all manifest entries required to insert this Sone.
 355                  *
 356                  * @return The manifest entries for the Sone insert
 357                  */
 358                 public HashMap<String, Object> generateManifestEntries() {
 359                         HashMap<String, Object> manifestEntries = new HashMap<String, Object>();
 360
 361                         /* first, create an index.html. */
 362                         manifestEntries.put("index.html", createManifestElement("index.html", "text/html; charset=utf-8", "/templates/insert/index.html"));
 363
 364                         /* now, store the sone. */
 365                         manifestEntries.put("sone.xml", createManifestElement("sone.xml", "text/xml; charset=utf-8", "/templates/insert/sone.xml"));
 366
 367                         return manifestEntries;
 368                 }
 369
 370                 //
 371                 // PRIVATE METHODS
 372                 //
 373
 374                 /**
 375                  * Creates a new manifest element.
 376                  *
 377                  * @param name
 378                  *            The name of the file
 379                  * @param contentType
 380                  *            The content type of the file
 381                  * @param templateName
 382                  *            The name of the template to render
 383                  * @return The manifest element
 384                  */
 385                 @SuppressWarnings("synthetic-access")
 386                 private ManifestElement createManifestElement(String name, String contentType, String templateName) {
 387                         InputStreamReader templateInputStreamReader = null;
 388                         Template template;
 389                         try {
 390                                 templateInputStreamReader = new InputStreamReader(getClass().getResourceAsStream(templateName), utf8Charset);
 391                                 template = TemplateParser.parse(templateInputStreamReader);
 392                         } catch (TemplateException te1) {
 393                                 logger.log(Level.SEVERE, String.format("Could not parse template “%s”!", templateName), te1);
 394                                 return null;
 395                         } finally {
 396                                 Closer.close(templateInputStreamReader);
 397                         }
 398
 399                         TemplateContext templateContext = templateContextFactory.createTemplateContext();
 400                         templateContext.set("core", core);
 401                         templateContext.set("currentSone", soneProperties);
 402                         templateContext.set("currentEdition", core.getUpdateChecker().getLatestEdition());
 403                         templateContext.set("version", SonePlugin.VERSION);
 404                         StringWriter writer = new StringWriter();
 405                         StringBucket bucket = null;
 406                         try {
 407                                 template.render(templateContext, writer);
 408                                 bucket = new StringBucket(writer.toString(), utf8Charset);
 409                                 return new ManifestElement(name, bucket, contentType, bucket.size());
 410                         } catch (TemplateException te1) {
 411                                 logger.log(Level.SEVERE, String.format("Could not render template “%s”!", templateName), te1);
 412                                 return null;
 413                         } finally {
 414                                 Closer.close(writer);
 415                                 if (bucket != null) {
 416                                         bucket.free();
 417                                 }
 418                         }
 419                 }
 420
 421         }
 422
 423 }