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