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
  22 import java.io.InputStreamReader;
  23 import java.io.StringWriter;
  24 import java.nio.charset.Charset;
  25 import java.util.HashMap;
  26 import java.util.HashSet;
  27 import java.util.Map;
  28 import java.util.logging.Level;
  29 import java.util.logging.Logger;
  30
  31 import net.pterodactylus.sone.core.event.SoneInsertAbortedEvent;
  32 import net.pterodactylus.sone.core.event.SoneInsertedEvent;
  33 import net.pterodactylus.sone.core.event.SoneInsertingEvent;
  34 import net.pterodactylus.sone.data.Album;
  35 import net.pterodactylus.sone.data.Post;
  36 import net.pterodactylus.sone.data.Reply;
  37 import net.pterodactylus.sone.data.Sone;
  38 import net.pterodactylus.sone.data.Sone.SoneStatus;
  39 import net.pterodactylus.sone.freenet.StringBucket;
  40 import net.pterodactylus.sone.main.SonePlugin;
  41 import net.pterodactylus.util.io.Closer;
  42 import net.pterodactylus.util.logging.Logging;
  43 import net.pterodactylus.util.service.AbstractService;
  44 import net.pterodactylus.util.template.HtmlFilter;
  45 import net.pterodactylus.util.template.ReflectionAccessor;
  46 import net.pterodactylus.util.template.Template;
  47 import net.pterodactylus.util.template.TemplateContext;
  48 import net.pterodactylus.util.template.TemplateContextFactory;
  49 import net.pterodactylus.util.template.TemplateException;
  50 import net.pterodactylus.util.template.TemplateParser;
  51 import net.pterodactylus.util.template.XmlFilter;
  52
  53 import com.google.common.collect.FluentIterable;
  54 import com.google.common.collect.Ordering;
  55 import com.google.common.eventbus.EventBus;
  56
  57 import freenet.client.async.ManifestElement;
  58 import freenet.keys.FreenetURI;
  59
  60 /**
  61  * A Sone inserter is responsible for inserting a Sone if it has changed.
  62  *
  63  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  64  */
  65 public class SoneInserter extends AbstractService {
  66
  67         /** The logger. */
  68         private static final Logger logger = Logging.getLogger(SoneInserter.class);
  69
  70         /** The insertion delay (in seconds). */
  71         private static volatile int insertionDelay = 60;
  72
  73         /** The template factory used to create the templates. */
  74         private static final TemplateContextFactory templateContextFactory = new TemplateContextFactory();
  75
  76         static {
  77                 templateContextFactory.addAccessor(Object.class, new ReflectionAccessor());
  78                 templateContextFactory.addFilter("xml", new XmlFilter());
  79                 templateContextFactory.addFilter("html", new HtmlFilter());
  80         }
  81
  82         /** The UTF-8 charset. */
  83         private static final Charset utf8Charset = Charset.forName("UTF-8");
  84
  85         /** The core. */
  86         private final Core core;
  87
  88         /** The event bus. */
  89         private final EventBus eventBus;
  90
  91         /** The Freenet interface. */
  92         private final FreenetInterface freenetInterface;
  93
  94         /** The Sone to insert. */
  95         private volatile Sone sone;
  96
  97         /** Whether a modification has been detected. */
  98         private volatile boolean modified = false;
  99
 100         /** The fingerprint of the last insert. */
 101         private volatile String lastInsertFingerprint;
 102
 103         /**
 104          * Creates a new Sone inserter.
 105          *
 106          * @param core
 107          *            The core
 108          * @param eventBus
 109          *            The event bus
 110          * @param freenetInterface
 111          *            The freenet interface
 112          * @param sone
 113          *            The Sone to insert
 114          */
 115         public SoneInserter(Core core, EventBus eventBus, FreenetInterface freenetInterface, Sone sone) {
 116                 super("Sone Inserter for “" + sone.getName() + "”", false);
 117                 this.core = core;
 118                 this.eventBus = eventBus;
 119                 this.freenetInterface = freenetInterface;
 120                 this.sone = sone;
 121         }
 122
 123         //
 124         // ACCESSORS
 125         //
 126
 127         /**
 128          * Sets the Sone to insert.
 129          *
 130          * @param sone
 131          *              The Sone to insert
 132          * @return This Sone inserter
 133          */
 134         public SoneInserter setSone(Sone sone) {
 135                 checkArgument((this.sone == null) || sone.equals(this.sone), "Sone to insert can not be set to a different Sone");
 136                 this.sone = sone;
 137                 return this;
 138         }
 139
 140         /**
 141          * Changes the insertion delay, i.e. the time the Sone inserter waits after it
 142          * has noticed a Sone modification before it starts the insert.
 143          *
 144          * @param insertionDelay
 145          *            The insertion delay (in seconds)
 146          */
 147         public static void setInsertionDelay(int insertionDelay) {
 148                 SoneInserter.insertionDelay = insertionDelay;
 149         }
 150
 151         /**
 152          * Returns the fingerprint of the last insert.
 153          *
 154          * @return The fingerprint of the last insert
 155          */
 156         public String getLastInsertFingerprint() {
 157                 return lastInsertFingerprint;
 158         }
 159
 160         /**
 161          * Sets the fingerprint of the last insert.
 162          *
 163          * @param lastInsertFingerprint
 164          *            The fingerprint of the last insert
 165          */
 166         public void setLastInsertFingerprint(String lastInsertFingerprint) {
 167                 this.lastInsertFingerprint = lastInsertFingerprint;
 168         }
 169
 170         /**
 171          * Returns whether the Sone inserter has detected a modification of the
 172          * Sone.
 173          *
 174          * @return {@code true} if the Sone has been modified, {@code false}
 175          *         otherwise
 176          */
 177         public boolean isModified() {
 178                 return modified;
 179         }
 180
 181         //
 182         // SERVICE METHODS
 183         //
 184
 185         /**
 186          * {@inheritDoc}
 187          */
 188         @Override
 189         protected void serviceRun() {
 190                 long lastModificationTime = 0;
 191                 String lastInsertedFingerprint = lastInsertFingerprint;
 192                 String lastFingerprint = "";
 193                 Sone sone;
 194                 while (!shouldStop()) {
 195                         try {
 196                                 /* check every seconds. */
 197                                 sleep(1000);
 198
 199                                 /* don’t insert locked Sones. */
 200                                 sone = this.sone;
 201                                 if (core.isLocked(sone)) {
 202                                         /* trigger redetection when the Sone is unlocked. */
 203                                         synchronized (sone) {
 204                                                 modified = !sone.getFingerprint().equals(lastInsertedFingerprint);
 205                                         }
 206                                         lastFingerprint = "";
 207                                         lastModificationTime = 0;
 208                                         continue;
 209                                 }
 210
 211                                 InsertInformation insertInformation = null;
 212                                 synchronized (sone) {
 213                                         String fingerprint = sone.getFingerprint();
 214                                         if (!fingerprint.equals(lastFingerprint)) {
 215                                                 if (fingerprint.equals(lastInsertedFingerprint)) {
 216                                                         modified = false;
 217                                                         lastModificationTime = 0;
 218                                                         logger.log(Level.FINE, String.format("Sone %s has been reverted to last insert state.", sone));
 219                                                 } else {
 220                                                         lastModificationTime = System.currentTimeMillis();
 221                                                         modified = true;
 222                                                         logger.log(Level.FINE, String.format("Sone %s has been modified, waiting %d seconds before inserting.", sone.getName(), insertionDelay));
 223                                                 }
 224                                                 lastFingerprint = fingerprint;
 225                                         }
 226                                         if (modified && (lastModificationTime > 0) && ((System.currentTimeMillis() - lastModificationTime) > (insertionDelay * 1000))) {
 227                                                 lastInsertedFingerprint = fingerprint;
 228                                                 insertInformation = new InsertInformation(sone);
 229                                         }
 230                                 }
 231
 232                                 if (insertInformation != null) {
 233                                         logger.log(Level.INFO, String.format("Inserting Sone “%s”…", sone.getName()));
 234
 235                                         boolean success = false;
 236                                         try {
 237                                                 sone.setStatus(SoneStatus.inserting);
 238                                                 long insertTime = System.currentTimeMillis();
 239                                                 insertInformation.setTime(insertTime);
 240                                                 eventBus.post(new SoneInsertingEvent(sone));
 241                                                 FreenetURI finalUri = freenetInterface.insertDirectory(insertInformation.getInsertUri(), insertInformation.generateManifestEntries(), "index.html");
 242                                                 eventBus.post(new SoneInsertedEvent(sone, System.currentTimeMillis() - insertTime));
 243                                                 /* at this point we might already be stopped. */
 244                                                 if (shouldStop()) {
 245                                                         /* if so, bail out, don’t change anything. */
 246                                                         break;
 247                                                 }
 248                                                 sone.setTime(insertTime);
 249                                                 sone.setLatestEdition(finalUri.getEdition());
 250                                                 core.touchConfiguration();
 251                                                 success = true;
 252                                                 logger.log(Level.INFO, String.format("Inserted Sone “%s” at %s.", sone.getName(), finalUri));
 253                                         } catch (SoneException se1) {
 254                                                 eventBus.post(new SoneInsertAbortedEvent(sone, se1));
 255                                                 logger.log(Level.WARNING, String.format("Could not insert Sone “%s”!", sone.getName()), se1);
 256                                         } finally {
 257                                                 sone.setStatus(SoneStatus.idle);
 258                                         }
 259
 260                                         /*
 261                                          * reset modification counter if Sone has not been modified
 262                                          * while it was inserted.
 263                                          */
 264                                         if (success) {
 265                                                 synchronized (sone) {
 266                                                         if (lastInsertedFingerprint.equals(sone.getFingerprint())) {
 267                                                                 logger.log(Level.FINE, String.format("Sone “%s” was not modified further, resetting counter…", sone));
 268                                                                 lastModificationTime = 0;
 269                                                                 lastInsertFingerprint = lastInsertedFingerprint;
 270                                                                 core.touchConfiguration();
 271                                                                 modified = false;
 272                                                         }
 273                                                 }
 274                                         }
 275                                 }
 276                         } catch (Throwable t1) {
 277                                 logger.log(Level.SEVERE, "SoneInserter threw an Exception!", t1);
 278                         }
 279                 }
 280         }
 281
 282         /**
 283          * Container for information that are required to insert a Sone. This
 284          * container merely exists to copy all relevant data without holding a lock
 285          * on the {@link Sone} object for too long.
 286          *
 287          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 288          */
 289         private class InsertInformation {
 290
 291                 /** All properties of the Sone, copied for thread safety. */
 292                 private final Map<String, Object> soneProperties = new HashMap<String, Object>();
 293
 294                 /**
 295                  * Creates a new insert information container.
 296                  *
 297                  * @param sone
 298                  *            The sone to insert
 299                  */
 300                 public InsertInformation(Sone sone) {
 301                         soneProperties.put("id", sone.getId());
 302                         soneProperties.put("name", sone.getName());
 303                         soneProperties.put("time", sone.getTime());
 304                         soneProperties.put("requestUri", sone.getRequestUri());
 305                         soneProperties.put("insertUri", sone.getInsertUri());
 306                         soneProperties.put("profile", sone.getProfile());
 307                         soneProperties.put("posts", Ordering.from(Post.TIME_COMPARATOR).sortedCopy(sone.getPosts()));
 308                         soneProperties.put("replies", Ordering.from(Reply.TIME_COMPARATOR).reverse().sortedCopy(sone.getReplies()));
 309                         soneProperties.put("likedPostIds", new HashSet<String>(sone.getLikedPostIds()));
 310                         soneProperties.put("likedReplyIds", new HashSet<String>(sone.getLikedReplyIds()));
 311                         soneProperties.put("albums", FluentIterable.from(sone.getAlbums()).transformAndConcat(Album.FLATTENER).toList());
 312                 }
 313
 314                 //
 315                 // ACCESSORS
 316                 //
 317
 318                 /**
 319                  * Returns the insert URI of the Sone.
 320                  *
 321                  * @return The insert URI of the Sone
 322                  */
 323                 public FreenetURI getInsertUri() {
 324                         return (FreenetURI) soneProperties.get("insertUri");
 325                 }
 326
 327                 /**
 328                  * Sets the time of the Sone at the time of the insert.
 329                  *
 330                  * @param time
 331                  *            The time of the Sone
 332                  */
 333                 public void setTime(long time) {
 334                         soneProperties.put("time", time);
 335                 }
 336
 337                 //
 338                 // ACTIONS
 339                 //
 340
 341                 /**
 342                  * Generates all manifest entries required to insert this Sone.
 343                  *
 344                  * @return The manifest entries for the Sone insert
 345                  */
 346                 public HashMap<String, Object> generateManifestEntries() {
 347                         HashMap<String, Object> manifestEntries = new HashMap<String, Object>();
 348
 349                         /* first, create an index.html. */
 350                         manifestEntries.put("index.html", createManifestElement("index.html", "text/html; charset=utf-8", "/templates/insert/index.html"));
 351
 352                         /* now, store the sone. */
 353                         manifestEntries.put("sone.xml", createManifestElement("sone.xml", "text/xml; charset=utf-8", "/templates/insert/sone.xml"));
 354
 355                         return manifestEntries;
 356                 }
 357
 358                 //
 359                 // PRIVATE METHODS
 360                 //
 361
 362                 /**
 363                  * Creates a new manifest element.
 364                  *
 365                  * @param name
 366                  *            The name of the file
 367                  * @param contentType
 368                  *            The content type of the file
 369                  * @param templateName
 370                  *            The name of the template to render
 371                  * @return The manifest element
 372                  */
 373                 @SuppressWarnings("synthetic-access")
 374                 private ManifestElement createManifestElement(String name, String contentType, String templateName) {
 375                         InputStreamReader templateInputStreamReader = null;
 376                         Template template;
 377                         try {
 378                                 templateInputStreamReader = new InputStreamReader(getClass().getResourceAsStream(templateName), utf8Charset);
 379                                 template = TemplateParser.parse(templateInputStreamReader);
 380                         } catch (TemplateException te1) {
 381                                 logger.log(Level.SEVERE, String.format("Could not parse template “%s”!", templateName), te1);
 382                                 return null;
 383                         } finally {
 384                                 Closer.close(templateInputStreamReader);
 385                         }
 386
 387                         TemplateContext templateContext = templateContextFactory.createTemplateContext();
 388                         templateContext.set("core", core);
 389                         templateContext.set("currentSone", soneProperties);
 390                         templateContext.set("currentEdition", core.getUpdateChecker().getLatestEdition());
 391                         templateContext.set("version", SonePlugin.VERSION);
 392                         StringWriter writer = new StringWriter();
 393                         StringBucket bucket = null;
 394                         try {
 395                                 template.render(templateContext, writer);
 396                                 bucket = new StringBucket(writer.toString(), utf8Charset);
 397                                 return new ManifestElement(name, bucket, contentType, bucket.size());
 398                         } catch (TemplateException te1) {
 399                                 logger.log(Level.SEVERE, String.format("Could not render template “%s”!", templateName), te1);
 400                                 return null;
 401                         } finally {
 402                                 Closer.close(writer);
 403                                 if (bucket != null) {
 404                                         bucket.free();
 405                                 }
 406                         }
 407                 }
 408
 409         }
 410
 411 }