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.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.base.Charsets;
  54 import com.google.common.collect.FluentIterable;
  55 import com.google.common.collect.Ordering;
  56 import com.google.common.eventbus.EventBus;
  57
  58 import freenet.keys.FreenetURI;
  59 import freenet.support.api.ManifestElement;
  60 import freenet.support.api.RandomAccessBucket;
  61 import freenet.support.io.ArrayBucket;
  62
  63 /**
  64  * A Sone inserter is responsible for inserting a Sone if it has changed.
  65  *
  66  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  67  */
  68 public class SoneInserter extends AbstractService {
  69
  70         /** The logger. */
  71         private static final Logger logger = Logging.getLogger(SoneInserter.class);
  72
  73         /** The insertion delay (in seconds). */
  74         private static volatile int insertionDelay = 60;
  75
  76         /** The template factory used to create the templates. */
  77         private static final TemplateContextFactory templateContextFactory = new TemplateContextFactory();
  78
  79         static {
  80                 templateContextFactory.addAccessor(Object.class, new ReflectionAccessor());
  81                 templateContextFactory.addFilter("xml", new XmlFilter());
  82                 templateContextFactory.addFilter("html", new HtmlFilter());
  83         }
  84
  85         /** The UTF-8 charset. */
  86         private static final Charset utf8Charset = Charset.forName("UTF-8");
  87
  88         /** The core. */
  89         private final Core core;
  90
  91         /** The event bus. */
  92         private final EventBus eventBus;
  93
  94         /** The Freenet interface. */
  95         private final FreenetInterface freenetInterface;
  96
  97         /** The Sone to insert. */
  98         private volatile Sone sone;
  99
 100         /** Whether a modification has been detected. */
 101         private volatile boolean modified = false;
 102
 103         /** The fingerprint of the last insert. */
 104         private volatile String lastInsertFingerprint;
 105
 106         /**
 107          * Creates a new Sone inserter.
 108          *
 109          * @param core
 110          *            The core
 111          * @param eventBus
 112          *            The event bus
 113          * @param freenetInterface
 114          *            The freenet interface
 115          * @param sone
 116          *            The Sone to insert
 117          */
 118         public SoneInserter(Core core, EventBus eventBus, FreenetInterface freenetInterface, Sone sone) {
 119                 super("Sone Inserter for “" + sone.getName() + "”", false);
 120                 this.core = core;
 121                 this.eventBus = eventBus;
 122                 this.freenetInterface = freenetInterface;
 123                 this.sone = sone;
 124         }
 125
 126         //
 127         // ACCESSORS
 128         //
 129
 130         /**
 131          * Sets the Sone to insert.
 132          *
 133          * @param sone
 134          *              The Sone to insert
 135          * @return This Sone inserter
 136          */
 137         public SoneInserter setSone(Sone sone) {
 138                 checkArgument((this.sone == null) || sone.equals(this.sone), "Sone to insert can not be set to a different Sone");
 139                 this.sone = sone;
 140                 return this;
 141         }
 142
 143         /**
 144          * Changes the insertion delay, i.e. the time the Sone inserter waits after it
 145          * has noticed a Sone modification before it starts the insert.
 146          *
 147          * @param insertionDelay
 148          *            The insertion delay (in seconds)
 149          */
 150         public static void setInsertionDelay(int insertionDelay) {
 151                 SoneInserter.insertionDelay = insertionDelay;
 152         }
 153
 154         /**
 155          * Returns the fingerprint of the last insert.
 156          *
 157          * @return The fingerprint of the last insert
 158          */
 159         public String getLastInsertFingerprint() {
 160                 return lastInsertFingerprint;
 161         }
 162
 163         /**
 164          * Sets the fingerprint of the last insert.
 165          *
 166          * @param lastInsertFingerprint
 167          *            The fingerprint of the last insert
 168          */
 169         public void setLastInsertFingerprint(String lastInsertFingerprint) {
 170                 this.lastInsertFingerprint = lastInsertFingerprint;
 171         }
 172
 173         /**
 174          * Returns whether the Sone inserter has detected a modification of the
 175          * Sone.
 176          *
 177          * @return {@code true} if the Sone has been modified, {@code false}
 178          *         otherwise
 179          */
 180         public boolean isModified() {
 181                 return modified;
 182         }
 183
 184         //
 185         // SERVICE METHODS
 186         //
 187
 188         /**
 189          * {@inheritDoc}
 190          */
 191         @Override
 192         protected void serviceRun() {
 193                 long lastModificationTime = 0;
 194                 String lastInsertedFingerprint = lastInsertFingerprint;
 195                 String lastFingerprint = "";
 196                 Sone sone;
 197                 while (!shouldStop()) {
 198                         try {
 199                                 /* check every seconds. */
 200                                 sleep(1000);
 201
 202                                 /* don’t insert locked Sones. */
 203                                 sone = this.sone;
 204                                 if (core.isLocked(sone)) {
 205                                         /* trigger redetection when the Sone is unlocked. */
 206                                         synchronized (sone) {
 207                                                 modified = !sone.getFingerprint().equals(lastInsertedFingerprint);
 208                                         }
 209                                         lastFingerprint = "";
 210                                         lastModificationTime = 0;
 211                                         continue;
 212                                 }
 213
 214                                 InsertInformation insertInformation = null;
 215                                 synchronized (sone) {
 216                                         String fingerprint = sone.getFingerprint();
 217                                         if (!fingerprint.equals(lastFingerprint)) {
 218                                                 if (fingerprint.equals(lastInsertedFingerprint)) {
 219                                                         modified = false;
 220                                                         lastModificationTime = 0;
 221                                                         logger.log(Level.FINE, String.format("Sone %s has been reverted to last insert state.", sone));
 222                                                 } else {
 223                                                         lastModificationTime = System.currentTimeMillis();
 224                                                         modified = true;
 225                                                         logger.log(Level.FINE, String.format("Sone %s has been modified, waiting %d seconds before inserting.", sone.getName(), insertionDelay));
 226                                                 }
 227                                                 lastFingerprint = fingerprint;
 228                                         }
 229                                         if (modified && (lastModificationTime > 0) && ((System.currentTimeMillis() - lastModificationTime) > (insertionDelay * 1000))) {
 230                                                 lastInsertedFingerprint = fingerprint;
 231                                                 insertInformation = new InsertInformation(sone);
 232                                         }
 233                                 }
 234
 235                                 if (insertInformation != null) {
 236                                         logger.log(Level.INFO, String.format("Inserting Sone “%s”…", sone.getName()));
 237
 238                                         boolean success = false;
 239                                         try {
 240                                                 sone.setStatus(SoneStatus.inserting);
 241                                                 long insertTime = System.currentTimeMillis();
 242                                                 insertInformation.setTime(insertTime);
 243                                                 eventBus.post(new SoneInsertingEvent(sone));
 244                                                 FreenetURI finalUri = freenetInterface.insertDirectory(insertInformation.getInsertUri(), insertInformation.generateManifestEntries(), "index.html");
 245                                                 eventBus.post(new SoneInsertedEvent(sone, System.currentTimeMillis() - insertTime));
 246                                                 /* at this point we might already be stopped. */
 247                                                 if (shouldStop()) {
 248                                                         /* if so, bail out, don’t change anything. */
 249                                                         break;
 250                                                 }
 251                                                 sone.setTime(insertTime);
 252                                                 sone.setLatestEdition(finalUri.getEdition());
 253                                                 core.touchConfiguration();
 254                                                 success = true;
 255                                                 logger.log(Level.INFO, String.format("Inserted Sone “%s” at %s.", sone.getName(), finalUri));
 256                                         } catch (SoneException se1) {
 257                                                 eventBus.post(new SoneInsertAbortedEvent(sone, se1));
 258                                                 logger.log(Level.WARNING, String.format("Could not insert Sone “%s”!", sone.getName()), se1);
 259                                         } finally {
 260                                                 sone.setStatus(SoneStatus.idle);
 261                                         }
 262
 263                                         /*
 264                                          * reset modification counter if Sone has not been modified
 265                                          * while it was inserted.
 266                                          */
 267                                         if (success) {
 268                                                 synchronized (sone) {
 269                                                         if (lastInsertedFingerprint.equals(sone.getFingerprint())) {
 270                                                                 logger.log(Level.FINE, String.format("Sone “%s” was not modified further, resetting counter…", sone));
 271                                                                 lastModificationTime = 0;
 272                                                                 lastInsertFingerprint = lastInsertedFingerprint;
 273                                                                 core.touchConfiguration();
 274                                                                 modified = false;
 275                                                         }
 276                                                 }
 277                                         }
 278                                 }
 279                         } catch (Throwable t1) {
 280                                 logger.log(Level.SEVERE, "SoneInserter threw an Exception!", t1);
 281                         }
 282                 }
 283         }
 284
 285         /**
 286          * Container for information that are required to insert a Sone. This
 287          * container merely exists to copy all relevant data without holding a lock
 288          * on the {@link Sone} object for too long.
 289          *
 290          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 291          */
 292         private class InsertInformation {
 293
 294                 /** All properties of the Sone, copied for thread safety. */
 295                 private final Map<String, Object> soneProperties = new HashMap<String, Object>();
 296
 297                 /**
 298                  * Creates a new insert information container.
 299                  *
 300                  * @param sone
 301                  *            The sone to insert
 302                  */
 303                 public InsertInformation(Sone sone) {
 304                         soneProperties.put("id", sone.getId());
 305                         soneProperties.put("name", sone.getName());
 306                         soneProperties.put("time", sone.getTime());
 307                         soneProperties.put("requestUri", sone.getRequestUri());
 308                         soneProperties.put("insertUri", sone.getInsertUri());
 309                         soneProperties.put("profile", sone.getProfile());
 310                         soneProperties.put("posts", Ordering.from(Post.TIME_COMPARATOR).sortedCopy(sone.getPosts()));
 311                         soneProperties.put("replies", Ordering.from(Reply.TIME_COMPARATOR).reverse().sortedCopy(sone.getReplies()));
 312                         soneProperties.put("likedPostIds", new HashSet<String>(sone.getLikedPostIds()));
 313                         soneProperties.put("likedReplyIds", new HashSet<String>(sone.getLikedReplyIds()));
 314                         soneProperties.put("albums", FluentIterable.from(sone.getRootAlbum().getAlbums()).transformAndConcat(Album.FLATTENER).filter(NOT_EMPTY).toList());
 315                 }
 316
 317                 //
 318                 // ACCESSORS
 319                 //
 320
 321                 /**
 322                  * Returns the insert URI of the Sone.
 323                  *
 324                  * @return The insert URI of the Sone
 325                  */
 326                 public FreenetURI getInsertUri() {
 327                         return (FreenetURI) soneProperties.get("insertUri");
 328                 }
 329
 330                 /**
 331                  * Sets the time of the Sone at the time of the insert.
 332                  *
 333                  * @param time
 334                  *            The time of the Sone
 335                  */
 336                 public void setTime(long time) {
 337                         soneProperties.put("time", time);
 338                 }
 339
 340                 //
 341                 // ACTIONS
 342                 //
 343
 344                 /**
 345                  * Generates all manifest entries required to insert this Sone.
 346                  *
 347                  * @return The manifest entries for the Sone insert
 348                  */
 349                 public HashMap<String, Object> generateManifestEntries() {
 350                         HashMap<String, Object> manifestEntries = new HashMap<String, Object>();
 351
 352                         /* first, create an index.html. */
 353                         manifestEntries.put("index.html", createManifestElement("index.html", "text/html; charset=utf-8", "/templates/insert/index.html"));
 354
 355                         /* now, store the sone. */
 356                         manifestEntries.put("sone.xml", createManifestElement("sone.xml", "text/xml; charset=utf-8", "/templates/insert/sone.xml"));
 357
 358                         return manifestEntries;
 359                 }
 360
 361                 //
 362                 // PRIVATE METHODS
 363                 //
 364
 365                 /**
 366                  * Creates a new manifest element.
 367                  *
 368                  * @param name
 369                  *            The name of the file
 370                  * @param contentType
 371                  *            The content type of the file
 372                  * @param templateName
 373                  *            The name of the template to render
 374                  * @return The manifest element
 375                  */
 376                 @SuppressWarnings("synthetic-access")
 377                 private ManifestElement createManifestElement(String name, String contentType, String templateName) {
 378                         InputStreamReader templateInputStreamReader = null;
 379                         Template template;
 380                         try {
 381                                 templateInputStreamReader = new InputStreamReader(getClass().getResourceAsStream(templateName), utf8Charset);
 382                                 template = TemplateParser.parse(templateInputStreamReader);
 383                         } catch (TemplateException te1) {
 384                                 logger.log(Level.SEVERE, String.format("Could not parse template “%s”!", templateName), te1);
 385                                 return null;
 386                         } finally {
 387                                 Closer.close(templateInputStreamReader);
 388                         }
 389
 390                         TemplateContext templateContext = templateContextFactory.createTemplateContext();
 391                         templateContext.set("core", core);
 392                         templateContext.set("currentSone", soneProperties);
 393                         templateContext.set("currentEdition", core.getUpdateChecker().getLatestEdition());
 394                         templateContext.set("version", SonePlugin.VERSION);
 395                         StringWriter writer = new StringWriter();
 396                         RandomAccessBucket bucket = null;
 397                         try {
 398                                 template.render(templateContext, writer);
 399                                 bucket = new ArrayBucket(writer.toString().getBytes(Charsets.UTF_8));
 400                                 return new ManifestElement(name, bucket, contentType, bucket.size());
 401                         } catch (TemplateException te1) {
 402                                 logger.log(Level.SEVERE, String.format("Could not render template “%s”!", templateName), te1);
 403                                 return null;
 404                         } finally {
 405                                 Closer.close(writer);
 406                                 if (bucket != null) {
 407                                         bucket.free();
 408                                 }
 409                         }
 410                 }
 411
 412         }
 413
 414 }