src/main/java/net/pterodactylus/sone/core/SoneInserter.java

   1 /*
   2  * Sone - SoneInserter.java - Copyright © 2010–2020 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 java.lang.String.format;
  21 import static java.lang.System.currentTimeMillis;
  22 import static java.util.concurrent.TimeUnit.*;
  23 import static java.util.logging.Logger.getLogger;
  24 import static java.util.stream.Collectors.toList;
  25 import static net.pterodactylus.sone.data.PostKt.newestPostFirst;
  26 import static net.pterodactylus.sone.data.ReplyKt.newestReplyFirst;
  27
  28 import java.io.*;
  29 import java.nio.charset.Charset;
  30 import java.util.HashMap;
  31 import java.util.HashSet;
  32 import java.util.Map;
  33 import java.util.Set;
  34 import java.util.concurrent.atomic.AtomicInteger;
  35 import java.util.logging.Level;
  36 import java.util.logging.Logger;
  37
  38 import com.codahale.metrics.*;
  39 import com.google.common.base.*;
  40 import net.pterodactylus.sone.core.SoneModificationDetector.LockableFingerprintProvider;
  41 import net.pterodactylus.sone.core.event.InsertionDelayChangedEvent;
  42 import net.pterodactylus.sone.core.event.SoneInsertAbortedEvent;
  43 import net.pterodactylus.sone.core.event.SoneInsertedEvent;
  44 import net.pterodactylus.sone.core.event.SoneInsertingEvent;
  45 import net.pterodactylus.sone.data.AlbumKt;
  46 import net.pterodactylus.sone.data.Post;
  47 import net.pterodactylus.sone.data.Reply;
  48 import net.pterodactylus.sone.data.Sone;
  49 import net.pterodactylus.sone.data.Sone.SoneStatus;
  50 import net.pterodactylus.sone.data.SoneKt;
  51 import net.pterodactylus.sone.main.SonePlugin;
  52 import net.pterodactylus.util.service.AbstractService;
  53 import net.pterodactylus.util.template.HtmlFilter;
  54 import net.pterodactylus.util.template.ReflectionAccessor;
  55 import net.pterodactylus.util.template.Template;
  56 import net.pterodactylus.util.template.TemplateContext;
  57 import net.pterodactylus.util.template.TemplateContextFactory;
  58 import net.pterodactylus.util.template.TemplateException;
  59 import net.pterodactylus.util.template.TemplateParser;
  60 import net.pterodactylus.util.template.XmlFilter;
  61
  62 import com.google.common.annotations.VisibleForTesting;
  63 import com.google.common.collect.Ordering;
  64 import com.google.common.eventbus.EventBus;
  65 import com.google.common.eventbus.Subscribe;
  66
  67 import freenet.keys.FreenetURI;
  68 import freenet.support.api.Bucket;
  69 import freenet.support.api.ManifestElement;
  70 import freenet.support.api.RandomAccessBucket;
  71 import freenet.support.io.ArrayBucket;
  72
  73 /**
  74  * A Sone inserter is responsible for inserting a Sone if it has changed.
  75  */
  76 public class SoneInserter extends AbstractService {
  77
  78         /** The logger. */
  79         private static final Logger logger = getLogger(SoneInserter.class.getName());
  80
  81         /** The insertion delay (in seconds). */
  82         private static final AtomicInteger insertionDelay = new AtomicInteger(60);
  83
  84         /** The template factory used to create the templates. */
  85         private static final TemplateContextFactory templateContextFactory = new TemplateContextFactory();
  86
  87         static {
  88                 templateContextFactory.addAccessor(Object.class, new ReflectionAccessor());
  89                 templateContextFactory.addFilter("xml", new XmlFilter());
  90                 templateContextFactory.addFilter("html", new HtmlFilter());
  91         }
  92
  93         /** The UTF-8 charset. */
  94         private static final Charset utf8Charset = Charset.forName("UTF-8");
  95
  96         /** The core. */
  97         private final Core core;
  98
  99         /** The event bus. */
 100         private final EventBus eventBus;
 101
 102         /** The Freenet interface. */
 103         private final FreenetInterface freenetInterface;
 104
 105         private final SoneModificationDetector soneModificationDetector;
 106         private final SoneUriCreator soneUriCreator;
 107         private final long delay;
 108         private final String soneId;
 109         private final Histogram soneInsertDurationHistogram;
 110         private final Meter soneInsertErrorMeter;
 111
 112         /**
 113          * Creates a new Sone inserter.
 114          *
 115          * @param core
 116          *            The core
 117          * @param eventBus
 118          *            The event bus
 119          * @param freenetInterface
 120          *            The freenet interface
 121          * @param soneId
 122          *            The ID of the Sone to insert
 123          */
 124         public SoneInserter(final Core core, EventBus eventBus, FreenetInterface freenetInterface, MetricRegistry metricRegistry, SoneUriCreator soneUriCreator, final String soneId) {
 125                 this(core, eventBus, freenetInterface, metricRegistry, soneUriCreator, soneId, new SoneModificationDetector(new LockableFingerprintProvider() {
 126                         @Override
 127                         public boolean isLocked() {
 128                                 Sone sone = core.getSone(soneId);
 129                                 if (sone == null) {
 130                                         return false;
 131                                 }
 132                                 return core.isLocked(sone);
 133                         }
 134
 135                         @Override
 136                         public String getFingerprint() {
 137                                 Sone sone = core.getSone(soneId);
 138                                 if (sone == null) {
 139                                         return null;
 140                                 }
 141                                 return sone.getFingerprint();
 142                         }
 143                 }, insertionDelay), 1000);
 144         }
 145
 146         @VisibleForTesting
 147         SoneInserter(Core core, EventBus eventBus, FreenetInterface freenetInterface, MetricRegistry metricRegistry, SoneUriCreator soneUriCreator, String soneId, SoneModificationDetector soneModificationDetector, long delay) {
 148                 super("Sone Inserter for “" + soneId + "”", false);
 149                 this.core = core;
 150                 this.eventBus = eventBus;
 151                 this.freenetInterface = freenetInterface;
 152                 this.soneInsertDurationHistogram = metricRegistry.histogram("sone.insert.duration", () -> new Histogram(new ExponentiallyDecayingReservoir(3000, 0)));
 153                 this.soneInsertErrorMeter = metricRegistry.meter("sone.insert.errors");
 154                 this.soneUriCreator = soneUriCreator;
 155                 this.soneId = soneId;
 156                 this.soneModificationDetector = soneModificationDetector;
 157                 this.delay = delay;
 158         }
 159
 160         //
 161         // ACCESSORS
 162         //
 163
 164         @VisibleForTesting
 165         static AtomicInteger getInsertionDelay() {
 166                 return insertionDelay;
 167         }
 168
 169         /**
 170          * Changes the insertion delay, i.e. the time the Sone inserter waits after it
 171          * has noticed a Sone modification before it starts the insert.
 172          *
 173          * @param insertionDelay
 174          *            The insertion delay (in seconds)
 175          */
 176         private static void setInsertionDelay(int insertionDelay) {
 177                 SoneInserter.insertionDelay.set(insertionDelay);
 178         }
 179
 180         /**
 181          * Returns the fingerprint of the last insert.
 182          *
 183          * @return The fingerprint of the last insert
 184          */
 185         public String getLastInsertFingerprint() {
 186                 return soneModificationDetector.getLastInsertFingerprint();
 187         }
 188
 189         /**
 190          * Sets the fingerprint of the last insert.
 191          *
 192          * @param lastInsertFingerprint
 193          *            The fingerprint of the last insert
 194          */
 195         public void setLastInsertFingerprint(String lastInsertFingerprint) {
 196                 soneModificationDetector.setFingerprint(lastInsertFingerprint);
 197         }
 198
 199         /**
 200          * Returns whether the Sone inserter has detected a modification of the
 201          * Sone.
 202          *
 203          * @return {@code true} if the Sone has been modified, {@code false}
 204          *         otherwise
 205          */
 206         public boolean isModified() {
 207                 return soneModificationDetector.isModified();
 208         }
 209
 210         //
 211         // SERVICE METHODS
 212         //
 213
 214         /**
 215          * {@inheritDoc}
 216          */
 217         @Override
 218         protected void serviceRun() {
 219                 while (!shouldStop()) {
 220                         try {
 221                                 /* check every second. */
 222                                 sleep(delay);
 223
 224                                 if (soneModificationDetector.isEligibleForInsert()) {
 225                                         Sone sone = core.getSone(soneId);
 226                                         if (sone == null) {
 227                                                 logger.log(Level.WARNING, format("Sone %s has disappeared, exiting inserter.", soneId));
 228                                                 return;
 229                                         }
 230                                         InsertInformation insertInformation = new InsertInformation(sone);
 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 = currentTimeMillis();
 237                                                 eventBus.post(new SoneInsertingEvent(sone));
 238                                                 Stopwatch stopwatch = Stopwatch.createStarted();
 239                                                 FreenetURI finalUri = freenetInterface.insertDirectory(soneUriCreator.getInsertUri(sone), insertInformation.generateManifestEntries(), "index.html");
 240                                                 stopwatch.stop();
 241                                                 soneInsertDurationHistogram.update(stopwatch.elapsed(MICROSECONDS));
 242                                                 eventBus.post(new SoneInsertedEvent(sone, stopwatch.elapsed(MILLISECONDS), insertInformation.getFingerprint()));
 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                                                 soneInsertErrorMeter.mark();
 255                                                 eventBus.post(new SoneInsertAbortedEvent(sone, se1));
 256                                                 logger.log(Level.WARNING, String.format("Could not insert Sone “%s”!", sone.getName()), se1);
 257                                         } finally {
 258                                                 insertInformation.close();
 259                                                 sone.setStatus(SoneStatus.idle);
 260                                         }
 261
 262                                         /*
 263                                          * reset modification counter if Sone has not been modified
 264                                          * while it was inserted.
 265                                          */
 266                                         if (success) {
 267                                                 synchronized (sone) {
 268                                                         if (insertInformation.getFingerprint().equals(sone.getFingerprint())) {
 269                                                                 logger.log(Level.FINE, String.format("Sone “%s” was not modified further, resetting counter…", sone));
 270                                                                 soneModificationDetector.setFingerprint(insertInformation.getFingerprint());
 271                                                                 core.touchConfiguration();
 272                                                         }
 273                                                 }
 274                                         }
 275                                 }
 276                         } catch (Throwable t1) {
 277                                 logger.log(Level.SEVERE, "SoneInserter threw an Exception!", t1);
 278                         }
 279                 }
 280         }
 281
 282         @Subscribe
 283         public void insertionDelayChanged(InsertionDelayChangedEvent insertionDelayChangedEvent) {
 284                 setInsertionDelay(insertionDelayChangedEvent.getInsertionDelay());
 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         @VisibleForTesting
 293         class InsertInformation implements Closeable {
 294
 295                 /** All properties of the Sone, copied for thread safety. */
 296                 private final Map<String, Object> soneProperties = new HashMap<>();
 297                 private final String fingerprint;
 298                 private final ManifestCreator manifestCreator;
 299
 300                 /**
 301                  * Creates a new insert information container.
 302                  *
 303                  * @param sone
 304                  *            The sone to insert
 305                  */
 306                 public InsertInformation(Sone sone) {
 307                         this.fingerprint = sone.getFingerprint();
 308                         Map<String, Object> soneProperties = new HashMap<>();
 309                         soneProperties.put("id", sone.getId());
 310                         soneProperties.put("name", sone.getName());
 311                         soneProperties.put("time", currentTimeMillis());
 312                         soneProperties.put("profile", sone.getProfile());
 313                         soneProperties.put("posts", Ordering.from(newestPostFirst()).sortedCopy(sone.getPosts()));
 314                         soneProperties.put("replies", Ordering.from(newestReplyFirst()).sortedCopy(sone.getReplies()));
 315                         soneProperties.put("likedPostIds", new HashSet<>(sone.getLikedPostIds()));
 316                         soneProperties.put("likedReplyIds", new HashSet<>(sone.getLikedReplyIds()));
 317                         soneProperties.put("albums", SoneKt.getAllAlbums(sone).stream().filter(AlbumKt.notEmpty()::invoke).collect(toList()));
 318                         manifestCreator = new ManifestCreator(core, soneProperties);
 319                 }
 320
 321                 //
 322                 // ACCESSORS
 323                 //
 324
 325                 @VisibleForTesting
 326                 String getFingerprint() {
 327                         return fingerprint;
 328                 }
 329
 330                 //
 331                 // ACTIONS
 332                 //
 333
 334                 /**
 335                  * Generates all manifest entries required to insert this Sone.
 336                  *
 337                  * @return The manifest entries for the Sone insert
 338                  */
 339                 public HashMap<String, Object> generateManifestEntries() {
 340                         HashMap<String, Object> manifestEntries = new HashMap<>();
 341
 342                         /* first, create an index.html. */
 343                         manifestEntries.put("index.html", manifestCreator.createManifestElement(
 344                                         "index.html", "text/html; charset=utf-8",
 345                                         "/templates/insert/index.html"));
 346
 347                         /* now, store the sone. */
 348                         manifestEntries.put("sone.xml", manifestCreator.createManifestElement(
 349                                         "sone.xml", "text/xml; charset=utf-8",
 350                                         "/templates/insert/sone.xml"));
 351
 352                         return manifestEntries;
 353                 }
 354
 355                 @Override
 356                 public void close() {
 357                         manifestCreator.close();
 358                 }
 359
 360         }
 361
 362         /**
 363          * Creates manifest elements for an insert by rendering a template.
 364          */
 365         @VisibleForTesting
 366         static class ManifestCreator implements Closeable {
 367
 368                 private final Core core;
 369                 private final Map<String, Object> soneProperties;
 370                 private final Set<Bucket> buckets = new HashSet<>();
 371
 372                 ManifestCreator(Core core, Map<String, Object> soneProperties) {
 373                         this.core = core;
 374                         this.soneProperties = soneProperties;
 375                 }
 376
 377                 public ManifestElement createManifestElement(String name, String contentType, String templateName) {
 378                         Template template;
 379                         try (InputStream templateInputStream = getClass().getResourceAsStream(templateName);
 380                                         InputStreamReader templateInputStreamReader = new InputStreamReader(templateInputStream, utf8Charset)) {
 381                                 template = TemplateParser.parse(templateInputStreamReader);
 382                         } catch (IOException | TemplateException e1) {
 383                                 logger.log(Level.SEVERE, String.format("Could not parse template “%s”!", templateName), e1);
 384                                 return null;
 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.getPluginVersion());
 392                         try (StringWriter writer = new StringWriter()) {
 393                                 template.render(templateContext, writer);
 394                                 RandomAccessBucket bucket = new ArrayBucket(writer.toString().getBytes(Charsets.UTF_8));
 395                                 buckets.add(bucket);
 396                                 return new ManifestElement(name, bucket, contentType, bucket.size());
 397                         } catch (IOException | TemplateException e1) {
 398                                 logger.log(Level.SEVERE, String.format("Could not render template “%s”!", templateName), e1);
 399                                 return null;
 400                         }
 401                 }
 402
 403                 public void close() {
 404                         for (Bucket bucket : buckets) {
 405                                 bucket.free();
 406                         }
 407                 }
 408
 409         }
 410
 411 }