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
  25 import java.io.*;
  26 import java.nio.charset.Charset;
  27 import java.util.HashMap;
  28 import java.util.HashSet;
  29 import java.util.Map;
  30 import java.util.Set;
  31 import java.util.concurrent.atomic.AtomicInteger;
  32 import java.util.logging.Level;
  33 import java.util.logging.Logger;
  34
  35 import com.codahale.metrics.*;
  36 import com.google.common.base.*;
  37 import net.pterodactylus.sone.core.SoneModificationDetector.LockableFingerprintProvider;
  38 import net.pterodactylus.sone.core.event.InsertionDelayChangedEvent;
  39 import net.pterodactylus.sone.core.event.SoneInsertAbortedEvent;
  40 import net.pterodactylus.sone.core.event.SoneInsertedEvent;
  41 import net.pterodactylus.sone.core.event.SoneInsertingEvent;
  42 import net.pterodactylus.sone.data.Album;
  43 import net.pterodactylus.sone.data.AlbumsKt;
  44 import net.pterodactylus.sone.data.Post;
  45 import net.pterodactylus.sone.data.Reply;
  46 import net.pterodactylus.sone.data.Sone;
  47 import net.pterodactylus.sone.data.Sone.SoneStatus;
  48 import net.pterodactylus.sone.main.SonePlugin;
  49 import net.pterodactylus.util.service.AbstractService;
  50 import net.pterodactylus.util.template.HtmlFilter;
  51 import net.pterodactylus.util.template.ReflectionAccessor;
  52 import net.pterodactylus.util.template.Template;
  53 import net.pterodactylus.util.template.TemplateContext;
  54 import net.pterodactylus.util.template.TemplateContextFactory;
  55 import net.pterodactylus.util.template.TemplateException;
  56 import net.pterodactylus.util.template.TemplateParser;
  57 import net.pterodactylus.util.template.XmlFilter;
  58
  59 import com.google.common.annotations.VisibleForTesting;
  60 import com.google.common.collect.FluentIterable;
  61 import com.google.common.collect.Ordering;
  62 import com.google.common.eventbus.EventBus;
  63 import com.google.common.eventbus.Subscribe;
  64
  65 import freenet.keys.FreenetURI;
  66 import freenet.support.api.Bucket;
  67 import freenet.support.api.ManifestElement;
  68 import freenet.support.api.RandomAccessBucket;
  69 import freenet.support.io.ArrayBucket;
  70
  71 /**
  72  * A Sone inserter is responsible for inserting a Sone if it has changed.
  73  */
  74 public class SoneInserter extends AbstractService {
  75
  76         /** The logger. */
  77         private static final Logger logger = getLogger(SoneInserter.class.getName());
  78
  79         /** The insertion delay (in seconds). */
  80         private static final AtomicInteger insertionDelay = new AtomicInteger(60);
  81
  82         /** The template factory used to create the templates. */
  83         private static final TemplateContextFactory templateContextFactory = new TemplateContextFactory();
  84
  85         static {
  86                 templateContextFactory.addAccessor(Object.class, new ReflectionAccessor());
  87                 templateContextFactory.addFilter("xml", new XmlFilter());
  88                 templateContextFactory.addFilter("html", new HtmlFilter());
  89         }
  90
  91         /** The UTF-8 charset. */
  92         private static final Charset utf8Charset = Charset.forName("UTF-8");
  93
  94         /** The core. */
  95         private final Core core;
  96
  97         /** The event bus. */
  98         private final EventBus eventBus;
  99
 100         /** The Freenet interface. */
 101         private final FreenetInterface freenetInterface;
 102
 103         private final SoneModificationDetector soneModificationDetector;
 104         private final SoneUriCreator soneUriCreator;
 105         private final long delay;
 106         private final String soneId;
 107         private final Histogram soneInsertDurationHistogram;
 108         private final Meter soneInsertErrorMeter;
 109
 110         /**
 111          * Creates a new Sone inserter.
 112          *
 113          * @param core
 114          *            The core
 115          * @param eventBus
 116          *            The event bus
 117          * @param freenetInterface
 118          *            The freenet interface
 119          * @param soneId
 120          *            The ID of the Sone to insert
 121          */
 122         public SoneInserter(final Core core, EventBus eventBus, FreenetInterface freenetInterface, MetricRegistry metricRegistry, SoneUriCreator soneUriCreator, final String soneId) {
 123                 this(core, eventBus, freenetInterface, metricRegistry, soneUriCreator, soneId, new SoneModificationDetector(new LockableFingerprintProvider() {
 124                         @Override
 125                         public boolean isLocked() {
 126                                 Sone sone = core.getSone(soneId);
 127                                 if (sone == null) {
 128                                         return false;
 129                                 }
 130                                 return core.isLocked(sone);
 131                         }
 132
 133                         @Override
 134                         public String getFingerprint() {
 135                                 Sone sone = core.getSone(soneId);
 136                                 if (sone == null) {
 137                                         return null;
 138                                 }
 139                                 return sone.getFingerprint();
 140                         }
 141                 }, insertionDelay), 1000);
 142         }
 143
 144         @VisibleForTesting
 145         SoneInserter(Core core, EventBus eventBus, FreenetInterface freenetInterface, MetricRegistry metricRegistry, SoneUriCreator soneUriCreator, String soneId, SoneModificationDetector soneModificationDetector, long delay) {
 146                 super("Sone Inserter for “" + soneId + "”", false);
 147                 this.core = core;
 148                 this.eventBus = eventBus;
 149                 this.freenetInterface = freenetInterface;
 150                 this.soneInsertDurationHistogram = metricRegistry.histogram("sone.insert.duration", () -> new Histogram(new ExponentiallyDecayingReservoir(3000, 0)));
 151                 this.soneInsertErrorMeter = metricRegistry.meter("sone.insert.errors");
 152                 this.soneUriCreator = soneUriCreator;
 153                 this.soneId = soneId;
 154                 this.soneModificationDetector = soneModificationDetector;
 155                 this.delay = delay;
 156         }
 157
 158         //
 159         // ACCESSORS
 160         //
 161
 162         @VisibleForTesting
 163         static AtomicInteger getInsertionDelay() {
 164                 return insertionDelay;
 165         }
 166
 167         /**
 168          * Changes the insertion delay, i.e. the time the Sone inserter waits after it
 169          * has noticed a Sone modification before it starts the insert.
 170          *
 171          * @param insertionDelay
 172          *            The insertion delay (in seconds)
 173          */
 174         private static void setInsertionDelay(int insertionDelay) {
 175                 SoneInserter.insertionDelay.set(insertionDelay);
 176         }
 177
 178         /**
 179          * Returns the fingerprint of the last insert.
 180          *
 181          * @return The fingerprint of the last insert
 182          */
 183         public String getLastInsertFingerprint() {
 184                 return soneModificationDetector.getLastInsertFingerprint();
 185         }
 186
 187         /**
 188          * Sets the fingerprint of the last insert.
 189          *
 190          * @param lastInsertFingerprint
 191          *            The fingerprint of the last insert
 192          */
 193         public void setLastInsertFingerprint(String lastInsertFingerprint) {
 194                 soneModificationDetector.setFingerprint(lastInsertFingerprint);
 195         }
 196
 197         /**
 198          * Returns whether the Sone inserter has detected a modification of the
 199          * Sone.
 200          *
 201          * @return {@code true} if the Sone has been modified, {@code false}
 202          *         otherwise
 203          */
 204         public boolean isModified() {
 205                 return soneModificationDetector.isModified();
 206         }
 207
 208         //
 209         // SERVICE METHODS
 210         //
 211
 212         /**
 213          * {@inheritDoc}
 214          */
 215         @Override
 216         protected void serviceRun() {
 217                 while (!shouldStop()) {
 218                         try {
 219                                 /* check every second. */
 220                                 sleep(delay);
 221
 222                                 if (soneModificationDetector.isEligibleForInsert()) {
 223                                         Sone sone = core.getSone(soneId);
 224                                         if (sone == null) {
 225                                                 logger.log(Level.WARNING, format("Sone %s has disappeared, exiting inserter.", soneId));
 226                                                 return;
 227                                         }
 228                                         InsertInformation insertInformation = new InsertInformation(sone);
 229                                         logger.log(Level.INFO, String.format("Inserting Sone “%s”…", sone.getName()));
 230
 231                                         boolean success = false;
 232                                         try {
 233                                                 sone.setStatus(SoneStatus.inserting);
 234                                                 long insertTime = currentTimeMillis();
 235                                                 eventBus.post(new SoneInsertingEvent(sone));
 236                                                 Stopwatch stopwatch = Stopwatch.createStarted();
 237                                                 FreenetURI finalUri = freenetInterface.insertDirectory(soneUriCreator.getInsertUri(sone), insertInformation.generateManifestEntries(), "index.html");
 238                                                 stopwatch.stop();
 239                                                 soneInsertDurationHistogram.update(stopwatch.elapsed(MICROSECONDS));
 240                                                 eventBus.post(new SoneInsertedEvent(sone, stopwatch.elapsed(MILLISECONDS), insertInformation.getFingerprint()));
 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                                                 soneInsertErrorMeter.mark();
 253                                                 eventBus.post(new SoneInsertAbortedEvent(sone, se1));
 254                                                 logger.log(Level.WARNING, String.format("Could not insert Sone “%s”!", sone.getName()), se1);
 255                                         } finally {
 256                                                 insertInformation.close();
 257                                                 sone.setStatus(SoneStatus.idle);
 258                                         }
 259
 260                                         /*
 261                                          * reset modification counter if Sone has not been modified
 262                                          * while it was inserted.
 263                                          */
 264                                         if (success) {
 265                                                 synchronized (sone) {
 266                                                         if (insertInformation.getFingerprint().equals(sone.getFingerprint())) {
 267                                                                 logger.log(Level.FINE, String.format("Sone “%s” was not modified further, resetting counter…", sone));
 268                                                                 soneModificationDetector.setFingerprint(insertInformation.getFingerprint());
 269                                                                 core.touchConfiguration();
 270                                                         }
 271                                                 }
 272                                         }
 273                                 }
 274                         } catch (Throwable t1) {
 275                                 logger.log(Level.SEVERE, "SoneInserter threw an Exception!", t1);
 276                         }
 277                 }
 278         }
 279
 280         @Subscribe
 281         public void insertionDelayChanged(InsertionDelayChangedEvent insertionDelayChangedEvent) {
 282                 setInsertionDelay(insertionDelayChangedEvent.getInsertionDelay());
 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         @VisibleForTesting
 291         class InsertInformation implements Closeable {
 292
 293                 /** All properties of the Sone, copied for thread safety. */
 294                 private final Map<String, Object> soneProperties = new HashMap<>();
 295                 private final String fingerprint;
 296                 private final ManifestCreator manifestCreator;
 297
 298                 /**
 299                  * Creates a new insert information container.
 300                  *
 301                  * @param sone
 302                  *            The sone to insert
 303                  */
 304                 public InsertInformation(Sone sone) {
 305                         this.fingerprint = sone.getFingerprint();
 306                         Map<String, Object> soneProperties = new HashMap<>();
 307                         soneProperties.put("id", sone.getId());
 308                         soneProperties.put("name", sone.getName());
 309                         soneProperties.put("time", currentTimeMillis());
 310                         soneProperties.put("profile", sone.getProfile());
 311                         soneProperties.put("posts", Ordering.from(Post.NEWEST_FIRST).sortedCopy(sone.getPosts()));
 312                         soneProperties.put("replies", Ordering.from(Reply.TIME_COMPARATOR).reverse().sortedCopy(sone.getReplies()));
 313                         soneProperties.put("likedPostIds", new HashSet<>(sone.getLikedPostIds()));
 314                         soneProperties.put("likedReplyIds", new HashSet<>(sone.getLikedReplyIds()));
 315                         soneProperties.put("albums", FluentIterable.from(sone.getRootAlbum().getAlbums()).transformAndConcat(Album.FLATTENER).filter(AlbumsKt.notEmpty()::invoke).toList());
 316                         manifestCreator = new ManifestCreator(core, soneProperties);
 317                 }
 318
 319                 //
 320                 // ACCESSORS
 321                 //
 322
 323                 @VisibleForTesting
 324                 String getFingerprint() {
 325                         return fingerprint;
 326                 }
 327
 328                 //
 329                 // ACTIONS
 330                 //
 331
 332                 /**
 333                  * Generates all manifest entries required to insert this Sone.
 334                  *
 335                  * @return The manifest entries for the Sone insert
 336                  */
 337                 public HashMap<String, Object> generateManifestEntries() {
 338                         HashMap<String, Object> manifestEntries = new HashMap<>();
 339
 340                         /* first, create an index.html. */
 341                         manifestEntries.put("index.html", manifestCreator.createManifestElement(
 342                                         "index.html", "text/html; charset=utf-8",
 343                                         "/templates/insert/index.html"));
 344
 345                         /* now, store the sone. */
 346                         manifestEntries.put("sone.xml", manifestCreator.createManifestElement(
 347                                         "sone.xml", "text/xml; charset=utf-8",
 348                                         "/templates/insert/sone.xml"));
 349
 350                         return manifestEntries;
 351                 }
 352
 353                 @Override
 354                 public void close() {
 355                         manifestCreator.close();
 356                 }
 357
 358         }
 359
 360         /**
 361          * Creates manifest elements for an insert by rendering a template.
 362          */
 363         @VisibleForTesting
 364         static class ManifestCreator implements Closeable {
 365
 366                 private final Core core;
 367                 private final Map<String, Object> soneProperties;
 368                 private final Set<Bucket> buckets = new HashSet<>();
 369
 370                 ManifestCreator(Core core, Map<String, Object> soneProperties) {
 371                         this.core = core;
 372                         this.soneProperties = soneProperties;
 373                 }
 374
 375                 public ManifestElement createManifestElement(String name, String contentType, String templateName) {
 376                         Template template;
 377                         try (InputStream templateInputStream = getClass().getResourceAsStream(templateName);
 378                                         InputStreamReader templateInputStreamReader = new InputStreamReader(templateInputStream, utf8Charset)) {
 379                                 template = TemplateParser.parse(templateInputStreamReader);
 380                         } catch (IOException | TemplateException e1) {
 381                                 logger.log(Level.SEVERE, String.format("Could not parse template “%s”!", templateName), e1);
 382                                 return null;
 383                         }
 384
 385                         TemplateContext templateContext = templateContextFactory.createTemplateContext();
 386                         templateContext.set("core", core);
 387                         templateContext.set("currentSone", soneProperties);
 388                         templateContext.set("currentEdition", core.getUpdateChecker().getLatestEdition());
 389                         templateContext.set("version", SonePlugin.getPluginVersion());
 390                         try (StringWriter writer = new StringWriter()) {
 391                                 template.render(templateContext, writer);
 392                                 RandomAccessBucket bucket = new ArrayBucket(writer.toString().getBytes(Charsets.UTF_8));
 393                                 buckets.add(bucket);
 394                                 return new ManifestElement(name, bucket, contentType, bucket.size());
 395                         } catch (IOException | TemplateException e1) {
 396                                 logger.log(Level.SEVERE, String.format("Could not render template “%s”!", templateName), e1);
 397                                 return null;
 398                         }
 399                 }
 400
 401                 public void close() {
 402                         for (Bucket bucket : buckets) {
 403                                 bucket.free();
 404                         }
 405                 }
 406
 407         }
 408
 409 }