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 net.pterodactylus.sone.data.Album.NOT_EMPTY;
  25
  26 import java.io.Closeable;
  27 import java.io.InputStream;
  28 import java.io.InputStreamReader;
  29 import java.io.StringWriter;
  30 import java.nio.charset.Charset;
  31 import java.util.HashMap;
  32 import java.util.HashSet;
  33 import java.util.Map;
  34 import java.util.Set;
  35 import java.util.concurrent.*;
  36 import java.util.concurrent.atomic.AtomicInteger;
  37 import java.util.logging.Level;
  38 import java.util.logging.Logger;
  39
  40 import com.codahale.metrics.*;
  41 import com.google.common.base.*;
  42 import net.pterodactylus.sone.core.SoneModificationDetector.LockableFingerprintProvider;
  43 import net.pterodactylus.sone.core.event.InsertionDelayChangedEvent;
  44 import net.pterodactylus.sone.core.event.SoneInsertAbortedEvent;
  45 import net.pterodactylus.sone.core.event.SoneInsertedEvent;
  46 import net.pterodactylus.sone.core.event.SoneInsertingEvent;
  47 import net.pterodactylus.sone.data.Album;
  48 import net.pterodactylus.sone.data.Post;
  49 import net.pterodactylus.sone.data.Reply;
  50 import net.pterodactylus.sone.data.Sone;
  51 import net.pterodactylus.sone.data.Sone.SoneStatus;
  52 import net.pterodactylus.sone.main.SonePlugin;
  53 import net.pterodactylus.util.io.Closer;
  54 import net.pterodactylus.util.service.AbstractService;
  55 import net.pterodactylus.util.template.HtmlFilter;
  56 import net.pterodactylus.util.template.ReflectionAccessor;
  57 import net.pterodactylus.util.template.Template;
  58 import net.pterodactylus.util.template.TemplateContext;
  59 import net.pterodactylus.util.template.TemplateContextFactory;
  60 import net.pterodactylus.util.template.TemplateException;
  61 import net.pterodactylus.util.template.TemplateParser;
  62 import net.pterodactylus.util.template.XmlFilter;
  63
  64 import com.google.common.annotations.VisibleForTesting;
  65 import com.google.common.collect.FluentIterable;
  66 import com.google.common.collect.Ordering;
  67 import com.google.common.eventbus.EventBus;
  68 import com.google.common.eventbus.Subscribe;
  69
  70 import freenet.keys.FreenetURI;
  71 import freenet.support.api.Bucket;
  72 import freenet.support.api.ManifestElement;
  73 import freenet.support.api.RandomAccessBucket;
  74 import freenet.support.io.ArrayBucket;
  75
  76 /**
  77  * A Sone inserter is responsible for inserting a Sone if it has changed.
  78  */
  79 public class SoneInserter extends AbstractService {
  80
  81         /** The logger. */
  82         private static final Logger logger = getLogger(SoneInserter.class.getName());
  83
  84         /** The insertion delay (in seconds). */
  85         private static final AtomicInteger insertionDelay = new AtomicInteger(60);
  86
  87         /** The template factory used to create the templates. */
  88         private static final TemplateContextFactory templateContextFactory = new TemplateContextFactory();
  89
  90         static {
  91                 templateContextFactory.addAccessor(Object.class, new ReflectionAccessor());
  92                 templateContextFactory.addFilter("xml", new XmlFilter());
  93                 templateContextFactory.addFilter("html", new HtmlFilter());
  94         }
  95
  96         /** The UTF-8 charset. */
  97         private static final Charset utf8Charset = Charset.forName("UTF-8");
  98
  99         /** The core. */
 100         private final Core core;
 101
 102         /** The event bus. */
 103         private final EventBus eventBus;
 104
 105         /** The Freenet interface. */
 106         private final FreenetInterface freenetInterface;
 107
 108         private final SoneModificationDetector soneModificationDetector;
 109         private final long delay;
 110         private final String soneId;
 111         private final Histogram soneInsertDurationHistogram;
 112         private final Meter soneInsertErrorMeter;
 113
 114         /**
 115          * Creates a new Sone inserter.
 116          *
 117          * @param core
 118          *            The core
 119          * @param eventBus
 120          *            The event bus
 121          * @param freenetInterface
 122          *            The freenet interface
 123          * @param soneId
 124          *            The ID of the Sone to insert
 125          */
 126         public SoneInserter(final Core core, EventBus eventBus, FreenetInterface freenetInterface, MetricRegistry metricRegistry, final String soneId) {
 127                 this(core, eventBus, freenetInterface, metricRegistry, soneId, new SoneModificationDetector(new LockableFingerprintProvider() {
 128                         @Override
 129                         public boolean isLocked() {
 130                                 Sone sone = core.getSone(soneId);
 131                                 if (sone == null) {
 132                                         return false;
 133                                 }
 134                                 return core.isLocked(sone);
 135                         }
 136
 137                         @Override
 138                         public String getFingerprint() {
 139                                 Sone sone = core.getSone(soneId);
 140                                 if (sone == null) {
 141                                         return null;
 142                                 }
 143                                 return sone.getFingerprint();
 144                         }
 145                 }, insertionDelay), 1000);
 146         }
 147
 148         @VisibleForTesting
 149         SoneInserter(Core core, EventBus eventBus, FreenetInterface freenetInterface, MetricRegistry metricRegistry, String soneId, SoneModificationDetector soneModificationDetector, long delay) {
 150                 super("Sone Inserter for “" + soneId + "”", false);
 151                 this.core = core;
 152                 this.eventBus = eventBus;
 153                 this.freenetInterface = freenetInterface;
 154                 this.soneInsertDurationHistogram = metricRegistry.histogram("sone.insert.duration", () -> new Histogram(new ExponentiallyDecayingReservoir(3000, 0)));
 155                 this.soneInsertErrorMeter = metricRegistry.meter("sone.insert.errors");
 156                 this.soneId = soneId;
 157                 this.soneModificationDetector = soneModificationDetector;
 158                 this.delay = delay;
 159         }
 160
 161         //
 162         // ACCESSORS
 163         //
 164
 165         @VisibleForTesting
 166         static AtomicInteger getInsertionDelay() {
 167                 return insertionDelay;
 168         }
 169
 170         /**
 171          * Changes the insertion delay, i.e. the time the Sone inserter waits after it
 172          * has noticed a Sone modification before it starts the insert.
 173          *
 174          * @param insertionDelay
 175          *            The insertion delay (in seconds)
 176          */
 177         private static void setInsertionDelay(int insertionDelay) {
 178                 SoneInserter.insertionDelay.set(insertionDelay);
 179         }
 180
 181         /**
 182          * Returns the fingerprint of the last insert.
 183          *
 184          * @return The fingerprint of the last insert
 185          */
 186         public String getLastInsertFingerprint() {
 187                 return soneModificationDetector.getLastInsertFingerprint();
 188         }
 189
 190         /**
 191          * Sets the fingerprint of the last insert.
 192          *
 193          * @param lastInsertFingerprint
 194          *            The fingerprint of the last insert
 195          */
 196         public void setLastInsertFingerprint(String lastInsertFingerprint) {
 197                 soneModificationDetector.setFingerprint(lastInsertFingerprint);
 198         }
 199
 200         /**
 201          * Returns whether the Sone inserter has detected a modification of the
 202          * Sone.
 203          *
 204          * @return {@code true} if the Sone has been modified, {@code false}
 205          *         otherwise
 206          */
 207         public boolean isModified() {
 208                 return soneModificationDetector.isModified();
 209         }
 210
 211         //
 212         // SERVICE METHODS
 213         //
 214
 215         /**
 216          * {@inheritDoc}
 217          */
 218         @Override
 219         protected void serviceRun() {
 220                 while (!shouldStop()) {
 221                         try {
 222                                 /* check every second. */
 223                                 sleep(delay);
 224
 225                                 if (soneModificationDetector.isEligibleForInsert()) {
 226                                         Sone sone = core.getSone(soneId);
 227                                         if (sone == null) {
 228                                                 logger.log(Level.WARNING, format("Sone %s has disappeared, exiting inserter.", soneId));
 229                                                 return;
 230                                         }
 231                                         InsertInformation insertInformation = new InsertInformation(sone);
 232                                         logger.log(Level.INFO, String.format("Inserting Sone “%s”…", sone.getName()));
 233
 234                                         boolean success = false;
 235                                         try {
 236                                                 sone.setStatus(SoneStatus.inserting);
 237                                                 long insertTime = currentTimeMillis();
 238                                                 eventBus.post(new SoneInsertingEvent(sone));
 239                                                 Stopwatch stopwatch = Stopwatch.createStarted();
 240                                                 FreenetURI finalUri = freenetInterface.insertDirectory(sone.getInsertUri(), insertInformation.generateManifestEntries(), "index.html");
 241                                                 stopwatch.stop();
 242                                                 soneInsertDurationHistogram.update(stopwatch.elapsed(MICROSECONDS));
 243                                                 eventBus.post(new SoneInsertedEvent(sone, stopwatch.elapsed(MILLISECONDS), insertInformation.getFingerprint()));
 244                                                 /* at this point we might already be stopped. */
 245                                                 if (shouldStop()) {
 246                                                         /* if so, bail out, don’t change anything. */
 247                                                         break;
 248                                                 }
 249                                                 sone.setTime(insertTime);
 250                                                 sone.setLatestEdition(finalUri.getEdition());
 251                                                 core.touchConfiguration();
 252                                                 success = true;
 253                                                 logger.log(Level.INFO, String.format("Inserted Sone “%s” at %s.", sone.getName(), finalUri));
 254                                         } catch (SoneException se1) {
 255                                                 soneInsertErrorMeter.mark();
 256                                                 eventBus.post(new SoneInsertAbortedEvent(sone, se1));
 257                                                 logger.log(Level.WARNING, String.format("Could not insert Sone “%s”!", sone.getName()), se1);
 258                                         } finally {
 259                                                 insertInformation.close();
 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 (insertInformation.getFingerprint().equals(sone.getFingerprint())) {
 270                                                                 logger.log(Level.FINE, String.format("Sone “%s” was not modified further, resetting counter…", sone));
 271                                                                 soneModificationDetector.setFingerprint(insertInformation.getFingerprint());
 272                                                                 core.touchConfiguration();
 273                                                         }
 274                                                 }
 275                                         }
 276                                 }
 277                         } catch (Throwable t1) {
 278                                 logger.log(Level.SEVERE, "SoneInserter threw an Exception!", t1);
 279                         }
 280                 }
 281         }
 282
 283         @Subscribe
 284         public void insertionDelayChanged(InsertionDelayChangedEvent insertionDelayChangedEvent) {
 285                 setInsertionDelay(insertionDelayChangedEvent.getInsertionDelay());
 286         }
 287
 288         /**
 289          * Container for information that are required to insert a Sone. This
 290          * container merely exists to copy all relevant data without holding a lock
 291          * on the {@link Sone} object for too long.
 292          */
 293         @VisibleForTesting
 294         class InsertInformation implements Closeable {
 295
 296                 /** All properties of the Sone, copied for thread safety. */
 297                 private final Map<String, Object> soneProperties = new HashMap<>();
 298                 private final String fingerprint;
 299                 private final ManifestCreator manifestCreator;
 300
 301                 /**
 302                  * Creates a new insert information container.
 303                  *
 304                  * @param sone
 305                  *            The sone to insert
 306                  */
 307                 public InsertInformation(Sone sone) {
 308                         this.fingerprint = sone.getFingerprint();
 309                         Map<String, Object> soneProperties = new HashMap<>();
 310                         soneProperties.put("id", sone.getId());
 311                         soneProperties.put("name", sone.getName());
 312                         soneProperties.put("time", currentTimeMillis());
 313                         soneProperties.put("requestUri", sone.getRequestUri());
 314                         soneProperties.put("profile", sone.getProfile());
 315                         soneProperties.put("posts", Ordering.from(Post.NEWEST_FIRST).sortedCopy(sone.getPosts()));
 316                         soneProperties.put("replies", Ordering.from(Reply.TIME_COMPARATOR).reverse().sortedCopy(sone.getReplies()));
 317                         soneProperties.put("likedPostIds", new HashSet<>(sone.getLikedPostIds()));
 318                         soneProperties.put("likedReplyIds", new HashSet<>(sone.getLikedReplyIds()));
 319                         soneProperties.put("albums", FluentIterable.from(sone.getRootAlbum().getAlbums()).transformAndConcat(Album.FLATTENER).filter(NOT_EMPTY).toList());
 320                         manifestCreator = new ManifestCreator(core, soneProperties);
 321                 }
 322
 323                 //
 324                 // ACCESSORS
 325                 //
 326
 327                 @VisibleForTesting
 328                 String getFingerprint() {
 329                         return fingerprint;
 330                 }
 331
 332                 //
 333                 // ACTIONS
 334                 //
 335
 336                 /**
 337                  * Generates all manifest entries required to insert this Sone.
 338                  *
 339                  * @return The manifest entries for the Sone insert
 340                  */
 341                 public HashMap<String, Object> generateManifestEntries() {
 342                         HashMap<String, Object> manifestEntries = new HashMap<>();
 343
 344                         /* first, create an index.html. */
 345                         manifestEntries.put("index.html", manifestCreator.createManifestElement(
 346                                         "index.html", "text/html; charset=utf-8",
 347                                         "/templates/insert/index.html"));
 348
 349                         /* now, store the sone. */
 350                         manifestEntries.put("sone.xml", manifestCreator.createManifestElement(
 351                                         "sone.xml", "text/xml; charset=utf-8",
 352                                         "/templates/insert/sone.xml"));
 353
 354                         return manifestEntries;
 355                 }
 356
 357                 @Override
 358                 public void close() {
 359                         manifestCreator.close();
 360                 }
 361
 362         }
 363
 364         /**
 365          * Creates manifest elements for an insert by rendering a template.
 366          */
 367         @VisibleForTesting
 368         static class ManifestCreator implements Closeable {
 369
 370                 private final Core core;
 371                 private final Map<String, Object> soneProperties;
 372                 private final Set<Bucket> buckets = new HashSet<>();
 373
 374                 ManifestCreator(Core core, Map<String, Object> soneProperties) {
 375                         this.core = core;
 376                         this.soneProperties = soneProperties;
 377                 }
 378
 379                 public ManifestElement createManifestElement(String name, String contentType, String templateName) {
 380                         InputStreamReader templateInputStreamReader = null;
 381                         InputStream templateInputStream = null;
 382                         Template template;
 383                         try {
 384                                 templateInputStream = getClass().getResourceAsStream(templateName);
 385                                 templateInputStreamReader = new InputStreamReader(templateInputStream, utf8Charset);
 386                                 template = TemplateParser.parse(templateInputStreamReader);
 387                         } catch (TemplateException te1) {
 388                                 logger.log(Level.SEVERE, String.format("Could not parse template “%s”!", templateName), te1);
 389                                 return null;
 390                         } finally {
 391                                 Closer.close(templateInputStreamReader);
 392                                 Closer.close(templateInputStream);
 393                         }
 394
 395                         TemplateContext templateContext = templateContextFactory.createTemplateContext();
 396                         templateContext.set("core", core);
 397                         templateContext.set("currentSone", soneProperties);
 398                         templateContext.set("currentEdition", core.getUpdateChecker().getLatestEdition());
 399                         templateContext.set("version", SonePlugin.getPluginVersion());
 400                         StringWriter writer = new StringWriter();
 401                         try {
 402                                 template.render(templateContext, writer);
 403                                 RandomAccessBucket bucket = new ArrayBucket(writer.toString().getBytes(Charsets.UTF_8));
 404                                 buckets.add(bucket);
 405                                 return new ManifestElement(name, bucket, contentType, bucket.size());
 406                         } catch (TemplateException te1) {
 407                                 logger.log(Level.SEVERE, String.format("Could not render template “%s”!", templateName), te1);
 408                                 return null;
 409                         } finally {
 410                                 Closer.close(writer);
 411                         }
 412                 }
 413
 414                 public void close() {
 415                         for (Bucket bucket : buckets) {
 416                                 bucket.free();
 417                         }
 418                 }
 419
 420         }
 421
 422 }