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.atomic.AtomicInteger;
  36 import java.util.logging.Level;
  37 import java.util.logging.Logger;
  38
  39 import com.codahale.metrics.*;
  40 import com.google.common.base.*;
  41 import net.pterodactylus.sone.core.SoneModificationDetector.LockableFingerprintProvider;
  42 import net.pterodactylus.sone.core.event.InsertionDelayChangedEvent;
  43 import net.pterodactylus.sone.core.event.SoneInsertAbortedEvent;
  44 import net.pterodactylus.sone.core.event.SoneInsertedEvent;
  45 import net.pterodactylus.sone.core.event.SoneInsertingEvent;
  46 import net.pterodactylus.sone.data.Album;
  47 import net.pterodactylus.sone.data.Post;
  48 import net.pterodactylus.sone.data.Reply;
  49 import net.pterodactylus.sone.data.Sone;
  50 import net.pterodactylus.sone.data.Sone.SoneStatus;
  51 import net.pterodactylus.sone.main.SonePlugin;
  52 import net.pterodactylus.util.io.Closer;
  53 import net.pterodactylus.util.service.AbstractService;
  54 import net.pterodactylus.util.template.HtmlFilter;
  55 import net.pterodactylus.util.template.ReflectionAccessor;
  56 import net.pterodactylus.util.template.Template;
  57 import net.pterodactylus.util.template.TemplateContext;
  58 import net.pterodactylus.util.template.TemplateContextFactory;
  59 import net.pterodactylus.util.template.TemplateException;
  60 import net.pterodactylus.util.template.TemplateParser;
  61 import net.pterodactylus.util.template.XmlFilter;
  62
  63 import com.google.common.annotations.VisibleForTesting;
  64 import com.google.common.collect.FluentIterable;
  65 import com.google.common.collect.Ordering;
  66 import com.google.common.eventbus.EventBus;
  67 import com.google.common.eventbus.Subscribe;
  68
  69 import freenet.keys.FreenetURI;
  70 import freenet.support.api.Bucket;
  71 import freenet.support.api.ManifestElement;
  72 import freenet.support.api.RandomAccessBucket;
  73 import freenet.support.io.ArrayBucket;
  74
  75 /**
  76  * A Sone inserter is responsible for inserting a Sone if it has changed.
  77  */
  78 public class SoneInserter extends AbstractService {
  79
  80         /** The logger. */
  81         private static final Logger logger = getLogger(SoneInserter.class.getName());
  82
  83         /** The insertion delay (in seconds). */
  84         private static final AtomicInteger insertionDelay = new AtomicInteger(60);
  85
  86         /** The template factory used to create the templates. */
  87         private static final TemplateContextFactory templateContextFactory = new TemplateContextFactory();
  88
  89         static {
  90                 templateContextFactory.addAccessor(Object.class, new ReflectionAccessor());
  91                 templateContextFactory.addFilter("xml", new XmlFilter());
  92                 templateContextFactory.addFilter("html", new HtmlFilter());
  93         }
  94
  95         /** The UTF-8 charset. */
  96         private static final Charset utf8Charset = Charset.forName("UTF-8");
  97
  98         /** The core. */
  99         private final Core core;
 100
 101         /** The event bus. */
 102         private final EventBus eventBus;
 103
 104         /** The Freenet interface. */
 105         private final FreenetInterface freenetInterface;
 106
 107         private final SoneModificationDetector soneModificationDetector;
 108         private final SoneUriCreator soneUriCreator;
 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, SoneUriCreator soneUriCreator, final String soneId) {
 127                 this(core, eventBus, freenetInterface, metricRegistry, soneUriCreator, 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, SoneUriCreator soneUriCreator, 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.soneUriCreator = soneUriCreator;
 157                 this.soneId = soneId;
 158                 this.soneModificationDetector = soneModificationDetector;
 159                 this.delay = delay;
 160         }
 161
 162         //
 163         // ACCESSORS
 164         //
 165
 166         @VisibleForTesting
 167         static AtomicInteger getInsertionDelay() {
 168                 return insertionDelay;
 169         }
 170
 171         /**
 172          * Changes the insertion delay, i.e. the time the Sone inserter waits after it
 173          * has noticed a Sone modification before it starts the insert.
 174          *
 175          * @param insertionDelay
 176          *            The insertion delay (in seconds)
 177          */
 178         private static void setInsertionDelay(int insertionDelay) {
 179                 SoneInserter.insertionDelay.set(insertionDelay);
 180         }
 181
 182         /**
 183          * Returns the fingerprint of the last insert.
 184          *
 185          * @return The fingerprint of the last insert
 186          */
 187         public String getLastInsertFingerprint() {
 188                 return soneModificationDetector.getLastInsertFingerprint();
 189         }
 190
 191         /**
 192          * Sets the fingerprint of the last insert.
 193          *
 194          * @param lastInsertFingerprint
 195          *            The fingerprint of the last insert
 196          */
 197         public void setLastInsertFingerprint(String lastInsertFingerprint) {
 198                 soneModificationDetector.setFingerprint(lastInsertFingerprint);
 199         }
 200
 201         /**
 202          * Returns whether the Sone inserter has detected a modification of the
 203          * Sone.
 204          *
 205          * @return {@code true} if the Sone has been modified, {@code false}
 206          *         otherwise
 207          */
 208         public boolean isModified() {
 209                 return soneModificationDetector.isModified();
 210         }
 211
 212         //
 213         // SERVICE METHODS
 214         //
 215
 216         /**
 217          * {@inheritDoc}
 218          */
 219         @Override
 220         protected void serviceRun() {
 221                 while (!shouldStop()) {
 222                         try {
 223                                 /* check every second. */
 224                                 sleep(delay);
 225
 226                                 if (soneModificationDetector.isEligibleForInsert()) {
 227                                         Sone sone = core.getSone(soneId);
 228                                         if (sone == null) {
 229                                                 logger.log(Level.WARNING, format("Sone %s has disappeared, exiting inserter.", soneId));
 230                                                 return;
 231                                         }
 232                                         InsertInformation insertInformation = new InsertInformation(sone);
 233                                         logger.log(Level.INFO, String.format("Inserting Sone “%s”…", sone.getName()));
 234
 235                                         boolean success = false;
 236                                         try {
 237                                                 sone.setStatus(SoneStatus.inserting);
 238                                                 long insertTime = currentTimeMillis();
 239                                                 eventBus.post(new SoneInsertingEvent(sone));
 240                                                 Stopwatch stopwatch = Stopwatch.createStarted();
 241                                                 FreenetURI finalUri = freenetInterface.insertDirectory(soneUriCreator.getInsertUri(sone), insertInformation.generateManifestEntries(), "index.html");
 242                                                 stopwatch.stop();
 243                                                 soneInsertDurationHistogram.update(stopwatch.elapsed(MICROSECONDS));
 244                                                 eventBus.post(new SoneInsertedEvent(sone, stopwatch.elapsed(MILLISECONDS), insertInformation.getFingerprint()));
 245                                                 /* at this point we might already be stopped. */
 246                                                 if (shouldStop()) {
 247                                                         /* if so, bail out, don’t change anything. */
 248                                                         break;
 249                                                 }
 250                                                 sone.setTime(insertTime);
 251                                                 sone.setLatestEdition(finalUri.getEdition());
 252                                                 core.touchConfiguration();
 253                                                 success = true;
 254                                                 logger.log(Level.INFO, String.format("Inserted Sone “%s” at %s.", sone.getName(), finalUri));
 255                                         } catch (SoneException se1) {
 256                                                 soneInsertErrorMeter.mark();
 257                                                 eventBus.post(new SoneInsertAbortedEvent(sone, se1));
 258                                                 logger.log(Level.WARNING, String.format("Could not insert Sone “%s”!", sone.getName()), se1);
 259                                         } finally {
 260                                                 insertInformation.close();
 261                                                 sone.setStatus(SoneStatus.idle);
 262                                         }
 263
 264                                         /*
 265                                          * reset modification counter if Sone has not been modified
 266                                          * while it was inserted.
 267                                          */
 268                                         if (success) {
 269                                                 synchronized (sone) {
 270                                                         if (insertInformation.getFingerprint().equals(sone.getFingerprint())) {
 271                                                                 logger.log(Level.FINE, String.format("Sone “%s” was not modified further, resetting counter…", sone));
 272                                                                 soneModificationDetector.setFingerprint(insertInformation.getFingerprint());
 273                                                                 core.touchConfiguration();
 274                                                         }
 275                                                 }
 276                                         }
 277                                 }
 278                         } catch (Throwable t1) {
 279                                 logger.log(Level.SEVERE, "SoneInserter threw an Exception!", t1);
 280                         }
 281                 }
 282         }
 283
 284         @Subscribe
 285         public void insertionDelayChanged(InsertionDelayChangedEvent insertionDelayChangedEvent) {
 286                 setInsertionDelay(insertionDelayChangedEvent.getInsertionDelay());
 287         }
 288
 289         /**
 290          * Container for information that are required to insert a Sone. This
 291          * container merely exists to copy all relevant data without holding a lock
 292          * on the {@link Sone} object for too long.
 293          */
 294         @VisibleForTesting
 295         class InsertInformation implements Closeable {
 296
 297                 /** All properties of the Sone, copied for thread safety. */
 298                 private final Map<String, Object> soneProperties = new HashMap<>();
 299                 private final String fingerprint;
 300                 private final ManifestCreator manifestCreator;
 301
 302                 /**
 303                  * Creates a new insert information container.
 304                  *
 305                  * @param sone
 306                  *            The sone to insert
 307                  */
 308                 public InsertInformation(Sone sone) {
 309                         this.fingerprint = sone.getFingerprint();
 310                         Map<String, Object> soneProperties = new HashMap<>();
 311                         soneProperties.put("id", sone.getId());
 312                         soneProperties.put("name", sone.getName());
 313                         soneProperties.put("time", currentTimeMillis());
 314                         soneProperties.put("requestUri", sone.getRequestUri());
 315                         soneProperties.put("profile", sone.getProfile());
 316                         soneProperties.put("posts", Ordering.from(Post.NEWEST_FIRST).sortedCopy(sone.getPosts()));
 317                         soneProperties.put("replies", Ordering.from(Reply.TIME_COMPARATOR).reverse().sortedCopy(sone.getReplies()));
 318                         soneProperties.put("likedPostIds", new HashSet<>(sone.getLikedPostIds()));
 319                         soneProperties.put("likedReplyIds", new HashSet<>(sone.getLikedReplyIds()));
 320                         soneProperties.put("albums", FluentIterable.from(sone.getRootAlbum().getAlbums()).transformAndConcat(Album.FLATTENER).filter(NOT_EMPTY).toList());
 321                         manifestCreator = new ManifestCreator(core, soneProperties);
 322                 }
 323
 324                 //
 325                 // ACCESSORS
 326                 //
 327
 328                 @VisibleForTesting
 329                 String getFingerprint() {
 330                         return fingerprint;
 331                 }
 332
 333                 //
 334                 // ACTIONS
 335                 //
 336
 337                 /**
 338                  * Generates all manifest entries required to insert this Sone.
 339                  *
 340                  * @return The manifest entries for the Sone insert
 341                  */
 342                 public HashMap<String, Object> generateManifestEntries() {
 343                         HashMap<String, Object> manifestEntries = new HashMap<>();
 344
 345                         /* first, create an index.html. */
 346                         manifestEntries.put("index.html", manifestCreator.createManifestElement(
 347                                         "index.html", "text/html; charset=utf-8",
 348                                         "/templates/insert/index.html"));
 349
 350                         /* now, store the sone. */
 351                         manifestEntries.put("sone.xml", manifestCreator.createManifestElement(
 352                                         "sone.xml", "text/xml; charset=utf-8",
 353                                         "/templates/insert/sone.xml"));
 354
 355                         return manifestEntries;
 356                 }
 357
 358                 @Override
 359                 public void close() {
 360                         manifestCreator.close();
 361                 }
 362
 363         }
 364
 365         /**
 366          * Creates manifest elements for an insert by rendering a template.
 367          */
 368         @VisibleForTesting
 369         static class ManifestCreator implements Closeable {
 370
 371                 private final Core core;
 372                 private final Map<String, Object> soneProperties;
 373                 private final Set<Bucket> buckets = new HashSet<>();
 374
 375                 ManifestCreator(Core core, Map<String, Object> soneProperties) {
 376                         this.core = core;
 377                         this.soneProperties = soneProperties;
 378                 }
 379
 380                 public ManifestElement createManifestElement(String name, String contentType, String templateName) {
 381                         InputStreamReader templateInputStreamReader = null;
 382                         InputStream templateInputStream = null;
 383                         Template template;
 384                         try {
 385                                 templateInputStream = getClass().getResourceAsStream(templateName);
 386                                 templateInputStreamReader = new InputStreamReader(templateInputStream, utf8Charset);
 387                                 template = TemplateParser.parse(templateInputStreamReader);
 388                         } catch (TemplateException te1) {
 389                                 logger.log(Level.SEVERE, String.format("Could not parse template “%s”!", templateName), te1);
 390                                 return null;
 391                         } finally {
 392                                 Closer.close(templateInputStreamReader);
 393                                 Closer.close(templateInputStream);
 394                         }
 395
 396                         TemplateContext templateContext = templateContextFactory.createTemplateContext();
 397                         templateContext.set("core", core);
 398                         templateContext.set("currentSone", soneProperties);
 399                         templateContext.set("currentEdition", core.getUpdateChecker().getLatestEdition());
 400                         templateContext.set("version", SonePlugin.getPluginVersion());
 401                         StringWriter writer = new StringWriter();
 402                         try {
 403                                 template.render(templateContext, writer);
 404                                 RandomAccessBucket bucket = new ArrayBucket(writer.toString().getBytes(Charsets.UTF_8));
 405                                 buckets.add(bucket);
 406                                 return new ManifestElement(name, bucket, contentType, bucket.size());
 407                         } catch (TemplateException te1) {
 408                                 logger.log(Level.SEVERE, String.format("Could not render template “%s”!", templateName), te1);
 409                                 return null;
 410                         } finally {
 411                                 Closer.close(writer);
 412                         }
 413                 }
 414
 415                 public void close() {
 416                         for (Bucket bucket : buckets) {
 417                                 bucket.free();
 418                         }
 419                 }
 420
 421         }
 422
 423 }