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 java.lang.System.currentTimeMillis;
  22 import static net.pterodactylus.sone.data.Album.NOT_EMPTY;
  23
  24 import java.io.InputStream;
  25 import java.io.InputStreamReader;
  26 import java.io.StringWriter;
  27 import java.nio.charset.Charset;
  28 import java.util.HashMap;
  29 import java.util.HashSet;
  30 import java.util.Map;
  31 import java.util.concurrent.atomic.AtomicInteger;
  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.collect.FluentIterable;
  58 import com.google.common.collect.Ordering;
  59 import com.google.common.eventbus.EventBus;
  60
  61 import freenet.client.async.ManifestElement;
  62 import freenet.keys.FreenetURI;
  63
  64 /**
  65  * A Sone inserter is responsible for inserting a Sone if it has changed.
  66  *
  67  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  68  */
  69 public class SoneInserter extends AbstractService {
  70
  71         /** The logger. */
  72         private static final Logger logger = Logging.getLogger(SoneInserter.class);
  73
  74         /** The insertion delay (in seconds). */
  75         private static final AtomicInteger insertionDelay = new AtomicInteger(60);
  76
  77         /** The template factory used to create the templates. */
  78         private static final TemplateContextFactory templateContextFactory = new TemplateContextFactory();
  79
  80         static {
  81                 templateContextFactory.addAccessor(Object.class, new ReflectionAccessor());
  82                 templateContextFactory.addFilter("xml", new XmlFilter());
  83                 templateContextFactory.addFilter("html", new HtmlFilter());
  84         }
  85
  86         /** The UTF-8 charset. */
  87         private static final Charset utf8Charset = Charset.forName("UTF-8");
  88
  89         /** The core. */
  90         private final Core core;
  91
  92         /** The event bus. */
  93         private final EventBus eventBus;
  94
  95         /** The Freenet interface. */
  96         private final FreenetInterface freenetInterface;
  97
  98         private final SoneModificationDetector soneModificationDetector;
  99
 100         /** The Sone to insert. */
 101         private volatile Sone sone;
 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                 this.soneModificationDetector = new SoneModificationDetector(core, sone, insertionDelay);
 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.set(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 soneModificationDetector.getOriginalFingerprint();
 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                 soneModificationDetector.setFingerprint(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 soneModificationDetector.isModified();
 180         }
 181
 182         //
 183         // SERVICE METHODS
 184         //
 185
 186         /**
 187          * {@inheritDoc}
 188          */
 189         @Override
 190         protected void serviceRun() {
 191                 while (!shouldStop()) {
 192                         try {
 193                                 /* check every second. */
 194                                 sleep(1000);
 195
 196                                 if (soneModificationDetector.isEligibleForInsert()) {
 197                                         InsertInformation insertInformation = new InsertInformation(sone);
 198                                         logger.log(Level.INFO, String.format("Inserting Sone “%s”…", sone.getName()));
 199
 200                                         boolean success = false;
 201                                         try {
 202                                                 sone.setStatus(SoneStatus.inserting);
 203                                                 long insertTime = currentTimeMillis();
 204                                                 eventBus.post(new SoneInsertingEvent(sone));
 205                                                 FreenetURI finalUri = freenetInterface.insertDirectory(insertInformation.getInsertUri(), insertInformation.generateManifestEntries(), "index.html");
 206                                                 eventBus.post(new SoneInsertedEvent(sone, currentTimeMillis() - insertTime));
 207                                                 /* at this point we might already be stopped. */
 208                                                 if (shouldStop()) {
 209                                                         /* if so, bail out, don’t change anything. */
 210                                                         break;
 211                                                 }
 212                                                 sone.setTime(insertTime);
 213                                                 sone.setLatestEdition(finalUri.getEdition());
 214                                                 core.touchConfiguration();
 215                                                 success = true;
 216                                                 logger.log(Level.INFO, String.format("Inserted Sone “%s” at %s.", sone.getName(), finalUri));
 217                                         } catch (SoneException se1) {
 218                                                 eventBus.post(new SoneInsertAbortedEvent(sone, se1));
 219                                                 logger.log(Level.WARNING, String.format("Could not insert Sone “%s”!", sone.getName()), se1);
 220                                         } finally {
 221                                                 sone.setStatus(SoneStatus.idle);
 222                                         }
 223
 224                                         /*
 225                                          * reset modification counter if Sone has not been modified
 226                                          * while it was inserted.
 227                                          */
 228                                         if (success) {
 229                                                 synchronized (sone) {
 230                                                         if (insertInformation.getFingerprint().equals(sone.getFingerprint())) {
 231                                                                 logger.log(Level.FINE, String.format("Sone “%s” was not modified further, resetting counter…", sone));
 232                                                                 soneModificationDetector.setFingerprint(insertInformation.getFingerprint());
 233                                                                 core.touchConfiguration();
 234                                                         }
 235                                                 }
 236                                         }
 237                                 }
 238                         } catch (Throwable t1) {
 239                                 logger.log(Level.SEVERE, "SoneInserter threw an Exception!", t1);
 240                         }
 241                 }
 242         }
 243
 244         /**
 245          * Container for information that are required to insert a Sone. This
 246          * container merely exists to copy all relevant data without holding a lock
 247          * on the {@link Sone} object for too long.
 248          *
 249          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 250          */
 251         private class InsertInformation {
 252
 253                 private final String fingerprint;
 254
 255                 /** All properties of the Sone, copied for thread safety. */
 256                 private final Map<String, Object> soneProperties = new HashMap<String, Object>();
 257
 258                 /**
 259                  * Creates a new insert information container.
 260                  *
 261                  * @param sone
 262                  *            The sone to insert
 263                  */
 264                 public InsertInformation(Sone sone) {
 265                         this.fingerprint = sone.getFingerprint();
 266                         soneProperties.put("id", sone.getId());
 267                         soneProperties.put("name", sone.getName());
 268                         soneProperties.put("time", currentTimeMillis());
 269                         soneProperties.put("requestUri", sone.getRequestUri());
 270                         soneProperties.put("insertUri", sone.getInsertUri());
 271                         soneProperties.put("profile", sone.getProfile());
 272                         soneProperties.put("posts", Ordering.from(Post.TIME_COMPARATOR).sortedCopy(sone.getPosts()));
 273                         soneProperties.put("replies", Ordering.from(Reply.TIME_COMPARATOR).reverse().sortedCopy(sone.getReplies()));
 274                         soneProperties.put("likedPostIds", new HashSet<String>(sone.getLikedPostIds()));
 275                         soneProperties.put("likedReplyIds", new HashSet<String>(sone.getLikedReplyIds()));
 276                         soneProperties.put("albums", FluentIterable.from(sone.getRootAlbum().getAlbums()).transformAndConcat(Album.FLATTENER).filter(NOT_EMPTY).toList());
 277                 }
 278
 279                 //
 280                 // ACCESSORS
 281                 //
 282
 283                 private String getFingerprint() {
 284                         return fingerprint;
 285                 }
 286
 287                 /**
 288                  * Returns the insert URI of the Sone.
 289                  *
 290                  * @return The insert URI of the Sone
 291                  */
 292                 public FreenetURI getInsertUri() {
 293                         return (FreenetURI) soneProperties.get("insertUri");
 294                 }
 295
 296                 //
 297                 // ACTIONS
 298                 //
 299
 300                 /**
 301                  * Generates all manifest entries required to insert this Sone.
 302                  *
 303                  * @return The manifest entries for the Sone insert
 304                  */
 305                 public HashMap<String, Object> generateManifestEntries() {
 306                         HashMap<String, Object> manifestEntries = new HashMap<String, Object>();
 307
 308                         /* first, create an index.html. */
 309                         manifestEntries.put("index.html", createManifestElement("index.html", "text/html; charset=utf-8", "/templates/insert/index.html"));
 310
 311                         /* now, store the sone. */
 312                         manifestEntries.put("sone.xml", createManifestElement("sone.xml", "text/xml; charset=utf-8", "/templates/insert/sone.xml"));
 313
 314                         return manifestEntries;
 315                 }
 316
 317                 //
 318                 // PRIVATE METHODS
 319                 //
 320
 321                 /**
 322                  * Creates a new manifest element.
 323                  *
 324                  * @param name
 325                  *            The name of the file
 326                  * @param contentType
 327                  *            The content type of the file
 328                  * @param templateName
 329                  *            The name of the template to render
 330                  * @return The manifest element
 331                  */
 332                 @SuppressWarnings("synthetic-access")
 333                 private ManifestElement createManifestElement(String name, String contentType, String templateName) {
 334                         InputStreamReader templateInputStreamReader = null;
 335                         InputStream templateInputStream = null;
 336                         Template template;
 337                         try {
 338                                 templateInputStream = getClass().getResourceAsStream(templateName);
 339                                 templateInputStreamReader = new InputStreamReader(templateInputStream, utf8Charset);
 340                                 template = TemplateParser.parse(templateInputStreamReader);
 341                         } catch (TemplateException te1) {
 342                                 logger.log(Level.SEVERE, String.format("Could not parse template “%s”!", templateName), te1);
 343                                 return null;
 344                         } finally {
 345                                 Closer.close(templateInputStreamReader);
 346                                 Closer.close(templateInputStream);
 347                         }
 348
 349                         TemplateContext templateContext = templateContextFactory.createTemplateContext();
 350                         templateContext.set("core", core);
 351                         templateContext.set("currentSone", soneProperties);
 352                         templateContext.set("currentEdition", core.getUpdateChecker().getLatestEdition());
 353                         templateContext.set("version", SonePlugin.VERSION);
 354                         StringWriter writer = new StringWriter();
 355                         StringBucket bucket = null;
 356                         try {
 357                                 template.render(templateContext, writer);
 358                                 bucket = new StringBucket(writer.toString(), utf8Charset);
 359                                 return new ManifestElement(name, bucket, contentType, bucket.size());
 360                         } catch (TemplateException te1) {
 361                                 logger.log(Level.SEVERE, String.format("Could not render template “%s”!", templateName), te1);
 362                                 return null;
 363                         } finally {
 364                                 Closer.close(writer);
 365                                 if (bucket != null) {
 366                                         bucket.free();
 367                                 }
 368                         }
 369                 }
 370
 371         }
 372
 373 }