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.newestFirst;
  26
  27 import java.io.*;
  28 import java.nio.charset.Charset;
  29 import java.util.HashMap;
  30 import java.util.HashSet;
  31 import java.util.Map;
  32 import java.util.Set;
  33 import java.util.concurrent.atomic.AtomicInteger;
  34 import java.util.logging.Level;
  35 import java.util.logging.Logger;
  36
  37 import com.codahale.metrics.*;
  38 import com.google.common.base.*;
  39 import net.pterodactylus.sone.core.SoneModificationDetector.LockableFingerprintProvider;
  40 import net.pterodactylus.sone.core.event.InsertionDelayChangedEvent;
  41 import net.pterodactylus.sone.core.event.SoneInsertAbortedEvent;
  42 import net.pterodactylus.sone.core.event.SoneInsertedEvent;
  43 import net.pterodactylus.sone.core.event.SoneInsertingEvent;
  44 import net.pterodactylus.sone.data.AlbumKt;
  45 import net.pterodactylus.sone.data.Post;
  46 import net.pterodactylus.sone.data.Reply;
  47 import net.pterodactylus.sone.data.Sone;
  48 import net.pterodactylus.sone.data.Sone.SoneStatus;
  49 import net.pterodactylus.sone.data.SoneKt;
  50 import net.pterodactylus.sone.main.SonePlugin;
  51 import net.pterodactylus.util.service.AbstractService;
  52 import net.pterodactylus.util.template.HtmlFilter;
  53 import net.pterodactylus.util.template.ReflectionAccessor;
  54 import net.pterodactylus.util.template.Template;
  55 import net.pterodactylus.util.template.TemplateContext;
  56 import net.pterodactylus.util.template.TemplateContextFactory;
  57 import net.pterodactylus.util.template.TemplateException;
  58 import net.pterodactylus.util.template.TemplateParser;
  59 import net.pterodactylus.util.template.XmlFilter;
  60
  61 import com.google.common.annotations.VisibleForTesting;
  62 import com.google.common.collect.Ordering;
  63 import com.google.common.eventbus.EventBus;
  64 import com.google.common.eventbus.Subscribe;
  65
  66 import freenet.keys.FreenetURI;
  67 import freenet.support.api.Bucket;
  68 import freenet.support.api.ManifestElement;
  69 import freenet.support.api.RandomAccessBucket;
  70 import freenet.support.io.ArrayBucket;
  71
  72 /**
  73  * A Sone inserter is responsible for inserting a Sone if it has changed.
  74  */
  75 public class SoneInserter extends AbstractService {
  76
  77         /** The logger. */
  78         private static final Logger logger = getLogger(SoneInserter.class.getName());
  79
  80         /** The insertion delay (in seconds). */
  81         private static final AtomicInteger insertionDelay = new AtomicInteger(60);
  82
  83         /** The template factory used to create the templates. */
  84         private static final TemplateContextFactory templateContextFactory = new TemplateContextFactory();
  85
  86         static {
  87                 templateContextFactory.addAccessor(Object.class, new ReflectionAccessor());
  88                 templateContextFactory.addFilter("xml", new XmlFilter());
  89                 templateContextFactory.addFilter("html", new HtmlFilter());
  90         }
  91
  92         /** The UTF-8 charset. */
  93         private static final Charset utf8Charset = Charset.forName("UTF-8");
  94
  95         /** The core. */
  96         private final Core core;
  97
  98         /** The event bus. */
  99         private final EventBus eventBus;
 100
 101         /** The Freenet interface. */
 102         private final FreenetInterface freenetInterface;
 103
 104         private final SoneModificationDetector soneModificationDetector;
 105         private final SoneUriCreator soneUriCreator;
 106         private final long delay;
 107         private final String soneId;
 108         private final Histogram soneInsertDurationHistogram;
 109         private final Meter soneInsertErrorMeter;
 110
 111         /**
 112          * Creates a new Sone inserter.
 113          *
 114          * @param core
 115          *            The core
 116          * @param eventBus
 117          *            The event bus
 118          * @param freenetInterface
 119          *            The freenet interface
 120          * @param soneId
 121          *            The ID of the Sone to insert
 122          */
 123         public SoneInserter(final Core core, EventBus eventBus, FreenetInterface freenetInterface, MetricRegistry metricRegistry, SoneUriCreator soneUriCreator, final String soneId) {
 124                 this(core, eventBus, freenetInterface, metricRegistry, soneUriCreator, soneId, new SoneModificationDetector(new LockableFingerprintProvider() {
 125                         @Override
 126                         public boolean isLocked() {
 127                                 Sone sone = core.getSone(soneId);
 128                                 if (sone == null) {
 129                                         return false;
 130                                 }
 131                                 return core.isLocked(sone);
 132                         }
 133
 134                         @Override
 135                         public String getFingerprint() {
 136                                 Sone sone = core.getSone(soneId);
 137                                 if (sone == null) {
 138                                         return null;
 139                                 }
 140                                 return sone.getFingerprint();
 141                         }
 142                 }, insertionDelay), 1000);
 143         }
 144
 145         @VisibleForTesting
 146         SoneInserter(Core core, EventBus eventBus, FreenetInterface freenetInterface, MetricRegistry metricRegistry, SoneUriCreator soneUriCreator, String soneId, SoneModificationDetector soneModificationDetector, long delay) {
 147                 super("Sone Inserter for “" + soneId + "”", false);
 148                 this.core = core;
 149                 this.eventBus = eventBus;
 150                 this.freenetInterface = freenetInterface;
 151                 this.soneInsertDurationHistogram = metricRegistry.histogram("sone.insert.duration", () -> new Histogram(new ExponentiallyDecayingReservoir(3000, 0)));
 152                 this.soneInsertErrorMeter = metricRegistry.meter("sone.insert.errors");
 153                 this.soneUriCreator = soneUriCreator;
 154                 this.soneId = soneId;
 155                 this.soneModificationDetector = soneModificationDetector;
 156                 this.delay = delay;
 157         }
 158
 159         //
 160         // ACCESSORS
 161         //
 162
 163         @VisibleForTesting
 164         static AtomicInteger getInsertionDelay() {
 165                 return insertionDelay;
 166         }
 167
 168         /**
 169          * Changes the insertion delay, i.e. the time the Sone inserter waits after it
 170          * has noticed a Sone modification before it starts the insert.
 171          *
 172          * @param insertionDelay
 173          *            The insertion delay (in seconds)
 174          */
 175         private static void setInsertionDelay(int insertionDelay) {
 176                 SoneInserter.insertionDelay.set(insertionDelay);
 177         }
 178
 179         /**
 180          * Returns the fingerprint of the last insert.
 181          *
 182          * @return The fingerprint of the last insert
 183          */
 184         public String getLastInsertFingerprint() {
 185                 return soneModificationDetector.getLastInsertFingerprint();
 186         }
 187
 188         /**
 189          * Sets the fingerprint of the last insert.
 190          *
 191          * @param lastInsertFingerprint
 192          *            The fingerprint of the last insert
 193          */
 194         public void setLastInsertFingerprint(String lastInsertFingerprint) {
 195                 soneModificationDetector.setFingerprint(lastInsertFingerprint);
 196         }
 197
 198         /**
 199          * Returns whether the Sone inserter has detected a modification of the
 200          * Sone.
 201          *
 202          * @return {@code true} if the Sone has been modified, {@code false}
 203          *         otherwise
 204          */
 205         public boolean isModified() {
 206                 return soneModificationDetector.isModified();
 207         }
 208
 209         //
 210         // SERVICE METHODS
 211         //
 212
 213         /**
 214          * {@inheritDoc}
 215          */
 216         @Override
 217         protected void serviceRun() {
 218                 while (!shouldStop()) {
 219                         try {
 220                                 /* check every second. */
 221                                 sleep(delay);
 222
 223                                 if (soneModificationDetector.isEligibleForInsert()) {
 224                                         Sone sone = core.getSone(soneId);
 225                                         if (sone == null) {
 226                                                 logger.log(Level.WARNING, format("Sone %s has disappeared, exiting inserter.", soneId));
 227                                                 return;
 228                                         }
 229                                         InsertInformation insertInformation = new InsertInformation(sone);
 230                                         logger.log(Level.INFO, String.format("Inserting Sone “%s”…", sone.getName()));
 231
 232                                         boolean success = false;
 233                                         try {
 234                                                 sone.setStatus(SoneStatus.inserting);
 235                                                 long insertTime = currentTimeMillis();
 236                                                 eventBus.post(new SoneInsertingEvent(sone));
 237                                                 Stopwatch stopwatch = Stopwatch.createStarted();
 238                                                 FreenetURI finalUri = freenetInterface.insertDirectory(soneUriCreator.getInsertUri(sone), insertInformation.generateManifestEntries(), "index.html");
 239                                                 stopwatch.stop();
 240                                                 soneInsertDurationHistogram.update(stopwatch.elapsed(MICROSECONDS));
 241                                                 eventBus.post(new SoneInsertedEvent(sone, stopwatch.elapsed(MILLISECONDS), insertInformation.getFingerprint()));
 242                                                 /* at this point we might already be stopped. */
 243                                                 if (shouldStop()) {
 244                                                         /* if so, bail out, don’t change anything. */
 245                                                         break;
 246                                                 }
 247                                                 sone.setTime(insertTime);
 248                                                 sone.setLatestEdition(finalUri.getEdition());
 249                                                 core.touchConfiguration();
 250                                                 success = true;
 251                                                 logger.log(Level.INFO, String.format("Inserted Sone “%s” at %s.", sone.getName(), finalUri));
 252                                         } catch (SoneException se1) {
 253                                                 soneInsertErrorMeter.mark();
 254                                                 eventBus.post(new SoneInsertAbortedEvent(sone, se1));
 255                                                 logger.log(Level.WARNING, String.format("Could not insert Sone “%s”!", sone.getName()), se1);
 256                                         } finally {
 257                                                 insertInformation.close();
 258                                                 sone.setStatus(SoneStatus.idle);
 259                                         }
 260
 261                                         /*
 262                                          * reset modification counter if Sone has not been modified
 263                                          * while it was inserted.
 264                                          */
 265                                         if (success) {
 266                                                 synchronized (sone) {
 267                                                         if (insertInformation.getFingerprint().equals(sone.getFingerprint())) {
 268                                                                 logger.log(Level.FINE, String.format("Sone “%s” was not modified further, resetting counter…", sone));
 269                                                                 soneModificationDetector.setFingerprint(insertInformation.getFingerprint());
 270                                                                 core.touchConfiguration();
 271                                                         }
 272                                                 }
 273                                         }
 274                                 }
 275                         } catch (Throwable t1) {
 276                                 logger.log(Level.SEVERE, "SoneInserter threw an Exception!", t1);
 277                         }
 278                 }
 279         }
 280
 281         @Subscribe
 282         public void insertionDelayChanged(InsertionDelayChangedEvent insertionDelayChangedEvent) {
 283                 setInsertionDelay(insertionDelayChangedEvent.getInsertionDelay());
 284         }
 285
 286         /**
 287          * Container for information that are required to insert a Sone. This
 288          * container merely exists to copy all relevant data without holding a lock
 289          * on the {@link Sone} object for too long.
 290          */
 291         @VisibleForTesting
 292         class InsertInformation implements Closeable {
 293
 294                 /** All properties of the Sone, copied for thread safety. */
 295                 private final Map<String, Object> soneProperties = new HashMap<>();
 296                 private final String fingerprint;
 297                 private final ManifestCreator manifestCreator;
 298
 299                 /**
 300                  * Creates a new insert information container.
 301                  *
 302                  * @param sone
 303                  *            The sone to insert
 304                  */
 305                 public InsertInformation(Sone sone) {
 306                         this.fingerprint = sone.getFingerprint();
 307                         Map<String, Object> soneProperties = new HashMap<>();
 308                         soneProperties.put("id", sone.getId());
 309                         soneProperties.put("name", sone.getName());
 310                         soneProperties.put("time", currentTimeMillis());
 311                         soneProperties.put("profile", sone.getProfile());
 312                         soneProperties.put("posts", Ordering.from(newestFirst()).sortedCopy(sone.getPosts()));
 313                         soneProperties.put("replies", Ordering.from(Reply.TIME_COMPARATOR).reverse().sortedCopy(sone.getReplies()));
 314                         soneProperties.put("likedPostIds", new HashSet<>(sone.getLikedPostIds()));
 315                         soneProperties.put("likedReplyIds", new HashSet<>(sone.getLikedReplyIds()));
 316                         soneProperties.put("albums", SoneKt.getAllAlbums(sone).stream().filter(AlbumKt.notEmpty()::invoke).collect(toList()));
 317                         manifestCreator = new ManifestCreator(core, soneProperties);
 318                 }
 319
 320                 //
 321                 // ACCESSORS
 322                 //
 323
 324                 @VisibleForTesting
 325                 String getFingerprint() {
 326                         return fingerprint;
 327                 }
 328
 329                 //
 330                 // ACTIONS
 331                 //
 332
 333                 /**
 334                  * Generates all manifest entries required to insert this Sone.
 335                  *
 336                  * @return The manifest entries for the Sone insert
 337                  */
 338                 public HashMap<String, Object> generateManifestEntries() {
 339                         HashMap<String, Object> manifestEntries = new HashMap<>();
 340
 341                         /* first, create an index.html. */
 342                         manifestEntries.put("index.html", manifestCreator.createManifestElement(
 343                                         "index.html", "text/html; charset=utf-8",
 344                                         "/templates/insert/index.html"));
 345
 346                         /* now, store the sone. */
 347                         manifestEntries.put("sone.xml", manifestCreator.createManifestElement(
 348                                         "sone.xml", "text/xml; charset=utf-8",
 349                                         "/templates/insert/sone.xml"));
 350
 351                         return manifestEntries;
 352                 }
 353
 354                 @Override
 355                 public void close() {
 356                         manifestCreator.close();
 357                 }
 358
 359         }
 360
 361         /**
 362          * Creates manifest elements for an insert by rendering a template.
 363          */
 364         @VisibleForTesting
 365         static class ManifestCreator implements Closeable {
 366
 367                 private final Core core;
 368                 private final Map<String, Object> soneProperties;
 369                 private final Set<Bucket> buckets = new HashSet<>();
 370
 371                 ManifestCreator(Core core, Map<String, Object> soneProperties) {
 372                         this.core = core;
 373                         this.soneProperties = soneProperties;
 374                 }
 375
 376                 public ManifestElement createManifestElement(String name, String contentType, String templateName) {
 377                         Template template;
 378                         try (InputStream templateInputStream = getClass().getResourceAsStream(templateName);
 379                                         InputStreamReader templateInputStreamReader = new InputStreamReader(templateInputStream, utf8Charset)) {
 380                                 template = TemplateParser.parse(templateInputStreamReader);
 381                         } catch (IOException | TemplateException e1) {
 382                                 logger.log(Level.SEVERE, String.format("Could not parse template “%s”!", templateName), e1);
 383                                 return null;
 384                         }
 385
 386                         TemplateContext templateContext = templateContextFactory.createTemplateContext();
 387                         templateContext.set("core", core);
 388                         templateContext.set("currentSone", soneProperties);
 389                         templateContext.set("currentEdition", core.getUpdateChecker().getLatestEdition());
 390                         templateContext.set("version", SonePlugin.getPluginVersion());
 391                         try (StringWriter writer = new StringWriter()) {
 392                                 template.render(templateContext, writer);
 393                                 RandomAccessBucket bucket = new ArrayBucket(writer.toString().getBytes(Charsets.UTF_8));
 394                                 buckets.add(bucket);
 395                                 return new ManifestElement(name, bucket, contentType, bucket.size());
 396                         } catch (IOException | TemplateException e1) {
 397                                 logger.log(Level.SEVERE, String.format("Could not render template “%s”!", templateName), e1);
 398                                 return null;
 399                         }
 400                 }
 401
 402                 public void close() {
 403                         for (Bucket bucket : buckets) {
 404                                 bucket.free();
 405                         }
 406                 }
 407
 408         }
 409
 410 }