src/main/java/net/pterodactylus/sone/database/memory/MemoryDatabase.java

   1 /*
   2  * Sone - MemoryDatabase.java - Copyright © 2013 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.database.memory;
  19
  20 import static com.google.common.base.Optional.fromNullable;
  21 import static com.google.common.base.Preconditions.checkNotNull;
  22 import static com.google.common.collect.FluentIterable.from;
  23 import static net.pterodactylus.sone.data.Reply.TIME_COMPARATOR;
  24
  25 import java.util.ArrayList;
  26 import java.util.Collection;
  27 import java.util.Collections;
  28 import java.util.Comparator;
  29 import java.util.HashMap;
  30 import java.util.HashSet;
  31 import java.util.List;
  32 import java.util.Map;
  33 import java.util.Set;
  34 import java.util.concurrent.locks.ReadWriteLock;
  35 import java.util.concurrent.locks.ReentrantReadWriteLock;
  36
  37 import net.pterodactylus.sone.data.Album;
  38 import net.pterodactylus.sone.data.Image;
  39 import net.pterodactylus.sone.data.Post;
  40 import net.pterodactylus.sone.data.PostReply;
  41 import net.pterodactylus.sone.data.Sone;
  42 import net.pterodactylus.sone.data.impl.AlbumBuilderImpl;
  43 import net.pterodactylus.sone.data.impl.ImageBuilderImpl;
  44 import net.pterodactylus.sone.database.AlbumBuilder;
  45 import net.pterodactylus.sone.database.Database;
  46 import net.pterodactylus.sone.database.DatabaseException;
  47 import net.pterodactylus.sone.database.ImageBuilder;
  48 import net.pterodactylus.sone.database.PostBuilder;
  49 import net.pterodactylus.sone.database.PostDatabase;
  50 import net.pterodactylus.sone.database.PostReplyBuilder;
  51 import net.pterodactylus.sone.database.SoneProvider;
  52 import net.pterodactylus.util.config.Configuration;
  53 import net.pterodactylus.util.config.ConfigurationException;
  54
  55 import com.google.common.base.Optional;
  56 import com.google.common.base.Predicate;
  57 import com.google.common.collect.HashMultimap;
  58 import com.google.common.collect.Multimap;
  59 import com.google.common.collect.SortedSetMultimap;
  60 import com.google.common.collect.TreeMultimap;
  61 import com.google.common.util.concurrent.AbstractService;
  62 import com.google.inject.Inject;
  63 import com.google.inject.Singleton;
  64
  65 /**
  66  * Memory-based {@link PostDatabase} implementation.
  67  *
  68  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  69  */
  70 @Singleton
  71 public class MemoryDatabase extends AbstractService implements Database {
  72
  73         /** The lock. */
  74         private final ReadWriteLock lock = new ReentrantReadWriteLock();
  75
  76         /** The Sone provider. */
  77         private final SoneProvider soneProvider;
  78
  79         /** The configuration. */
  80         private final Configuration configuration;
  81
  82         /** All posts by their ID. */
  83         private final Map<String, Post> allPosts = new HashMap<String, Post>();
  84
  85         /** All posts by their Sones. */
  86         private final Multimap<String, Post> sonePosts = HashMultimap.create();
  87
  88         /** Whether posts are known. */
  89         private final Set<String> knownPosts = new HashSet<String>();
  90
  91         /** All post replies by their ID. */
  92         private final Map<String, PostReply> allPostReplies = new HashMap<String, PostReply>();
  93
  94         /** Replies sorted by Sone. */
  95         private final SortedSetMultimap<String, PostReply> sonePostReplies = TreeMultimap.create(new Comparator<String>() {
  96
  97                 @Override
  98                 public int compare(String leftString, String rightString) {
  99                         return leftString.compareTo(rightString);
 100                 }
 101         }, TIME_COMPARATOR);
 102
 103         /** Replies by post. */
 104         private final SortedSetMultimap<String, PostReply> postReplies = TreeMultimap.create(new Comparator<String>() {
 105
 106                 @Override
 107                 public int compare(String leftString, String rightString) {
 108                         return leftString.compareTo(rightString);
 109                 }
 110         }, TIME_COMPARATOR);
 111
 112         /** Whether post replies are known. */
 113         private final Set<String> knownPostReplies = new HashSet<String>();
 114
 115         private final Map<String, Album> allAlbums = new HashMap<String, Album>();
 116         private final Multimap<String, Album> soneAlbums = HashMultimap.create();
 117
 118         private final Map<String, Image> allImages = new HashMap<String, Image>();
 119         private final Multimap<String, Image> soneImages = HashMultimap.create();
 120
 121         /**
 122          * Creates a new memory database.
 123          *
 124          * @param soneProvider
 125          *              The Sone provider
 126          * @param configuration
 127          *              The configuration for loading and saving elements
 128          */
 129         @Inject
 130         public MemoryDatabase(SoneProvider soneProvider, Configuration configuration) {
 131                 this.soneProvider = soneProvider;
 132                 this.configuration = configuration;
 133         }
 134
 135         //
 136         // DATABASE METHODS
 137         //
 138
 139         /**
 140          * Saves the database.
 141          *
 142          * @throws DatabaseException
 143          *              if an error occurs while saving
 144          */
 145         @Override
 146         public void save() throws DatabaseException {
 147                 saveKnownPosts();
 148                 saveKnownPostReplies();
 149         }
 150
 151         //
 152         // SERVICE METHODS
 153         //
 154
 155         /** {@inheritDocs} */
 156         @Override
 157         protected void doStart() {
 158                 loadKnownPosts();
 159                 loadKnownPostReplies();
 160                 notifyStarted();
 161         }
 162
 163         /** {@inheritDocs} */
 164         @Override
 165         protected void doStop() {
 166                 try {
 167                         save();
 168                         notifyStopped();
 169                 } catch (DatabaseException de1) {
 170                         notifyFailed(de1);
 171                 }
 172         }
 173
 174         //
 175         // POSTPROVIDER METHODS
 176         //
 177
 178         /** {@inheritDocs} */
 179         @Override
 180         public Optional<Post> getPost(String postId) {
 181                 lock.readLock().lock();
 182                 try {
 183                         return fromNullable(allPosts.get(postId));
 184                 } finally {
 185                         lock.readLock().unlock();
 186                 }
 187         }
 188
 189         /** {@inheritDocs} */
 190         @Override
 191         public Collection<Post> getPosts(String soneId) {
 192                 return new HashSet<Post>(getPostsFrom(soneId));
 193         }
 194
 195         /** {@inheritDocs} */
 196         @Override
 197         public Collection<Post> getDirectedPosts(final String recipientId) {
 198                 lock.readLock().lock();
 199                 try {
 200                         return from(sonePosts.values()).filter(new Predicate<Post>() {
 201                                 @Override
 202                                 public boolean apply(Post post) {
 203                                         return post.getRecipientId().asSet().contains(recipientId);
 204                                 }
 205                         }).toSet();
 206                 } finally {
 207                         lock.readLock().unlock();
 208                 }
 209         }
 210
 211         //
 212         // POSTBUILDERFACTORY METHODS
 213         //
 214
 215         /** {@inheritDocs} */
 216         @Override
 217         public PostBuilder newPostBuilder() {
 218                 return new MemoryPostBuilder(this, soneProvider);
 219         }
 220
 221         //
 222         // POSTSTORE METHODS
 223         //
 224
 225         /** {@inheritDocs} */
 226         @Override
 227         public void storePost(Post post) {
 228                 checkNotNull(post, "post must not be null");
 229                 lock.writeLock().lock();
 230                 try {
 231                         allPosts.put(post.getId(), post);
 232                         getPostsFrom(post.getSone().getId()).add(post);
 233                 } finally {
 234                         lock.writeLock().unlock();
 235                 }
 236         }
 237
 238         /** {@inheritDocs} */
 239         @Override
 240         public void removePost(Post post) {
 241                 checkNotNull(post, "post must not be null");
 242                 lock.writeLock().lock();
 243                 try {
 244                         allPosts.remove(post.getId());
 245                         getPostsFrom(post.getSone().getId()).remove(post);
 246                         post.getSone().removePost(post);
 247                 } finally {
 248                         lock.writeLock().unlock();
 249                 }
 250         }
 251
 252         /** {@inheritDocs} */
 253         @Override
 254         public void storePosts(Sone sone, Collection<Post> posts) throws IllegalArgumentException {
 255                 checkNotNull(sone, "sone must not be null");
 256                 /* verify that all posts are from the same Sone. */
 257                 for (Post post : posts) {
 258                         if (!sone.equals(post.getSone())) {
 259                                 throw new IllegalArgumentException(String.format("Post from different Sone found: %s", post));
 260                         }
 261                 }
 262
 263                 lock.writeLock().lock();
 264                 try {
 265                         /* remove all posts by the Sone. */
 266                         Collection<Post> oldPosts = getPostsFrom(sone.getId());
 267                         for (Post post : oldPosts) {
 268                                 allPosts.remove(post.getId());
 269                         }
 270
 271                         /* add new posts. */
 272                         getPostsFrom(sone.getId()).addAll(posts);
 273                         for (Post post : posts) {
 274                                 allPosts.put(post.getId(), post);
 275                         }
 276                 } finally {
 277                         lock.writeLock().unlock();
 278                 }
 279         }
 280
 281         /** {@inheritDocs} */
 282         @Override
 283         public void removePosts(Sone sone) {
 284                 checkNotNull(sone, "sone must not be null");
 285                 lock.writeLock().lock();
 286                 try {
 287                         /* remove all posts by the Sone. */
 288                         getPostsFrom(sone.getId()).clear();
 289                         for (Post post : sone.getPosts()) {
 290                                 allPosts.remove(post.getId());
 291                         }
 292                 } finally {
 293                         lock.writeLock().unlock();
 294                 }
 295         }
 296
 297         //
 298         // POSTREPLYPROVIDER METHODS
 299         //
 300
 301         /** {@inheritDocs} */
 302         @Override
 303         public Optional<PostReply> getPostReply(String id) {
 304                 lock.readLock().lock();
 305                 try {
 306                         return fromNullable(allPostReplies.get(id));
 307                 } finally {
 308                         lock.readLock().unlock();
 309                 }
 310         }
 311
 312         /** {@inheritDocs} */
 313         @Override
 314         public List<PostReply> getReplies(String postId) {
 315                 lock.readLock().lock();
 316                 try {
 317                         if (!postReplies.containsKey(postId)) {
 318                                 return Collections.emptyList();
 319                         }
 320                         return new ArrayList<PostReply>(postReplies.get(postId));
 321                 } finally {
 322                         lock.readLock().unlock();
 323                 }
 324         }
 325
 326         //
 327         // POSTREPLYBUILDERFACTORY METHODS
 328         //
 329
 330         /** {@inheritDocs} */
 331         @Override
 332         public PostReplyBuilder newPostReplyBuilder() {
 333                 return new MemoryPostReplyBuilder(this, soneProvider);
 334         }
 335
 336         //
 337         // POSTREPLYSTORE METHODS
 338         //
 339
 340         /** {@inheritDocs} */
 341         @Override
 342         public void storePostReply(PostReply postReply) {
 343                 lock.writeLock().lock();
 344                 try {
 345                         allPostReplies.put(postReply.getId(), postReply);
 346                         postReplies.put(postReply.getPostId(), postReply);
 347                 } finally {
 348                         lock.writeLock().unlock();
 349                 }
 350         }
 351
 352         /** {@inheritDocs} */
 353         @Override
 354         public void storePostReplies(Sone sone, Collection<PostReply> postReplies) {
 355                 checkNotNull(sone, "sone must not be null");
 356                 /* verify that all posts are from the same Sone. */
 357                 for (PostReply postReply : postReplies) {
 358                         if (!sone.equals(postReply.getSone())) {
 359                                 throw new IllegalArgumentException(String.format("PostReply from different Sone found: %s", postReply));
 360                         }
 361                 }
 362
 363                 lock.writeLock().lock();
 364                 try {
 365                         /* remove all post replies of the Sone. */
 366                         for (PostReply postReply : getRepliesFrom(sone.getId())) {
 367                                 removePostReply(postReply);
 368                         }
 369                         for (PostReply postReply : postReplies) {
 370                                 allPostReplies.put(postReply.getId(), postReply);
 371                                 sonePostReplies.put(postReply.getSone().getId(), postReply);
 372                                 this.postReplies.put(postReply.getPostId(), postReply);
 373                         }
 374                 } finally {
 375                         lock.writeLock().unlock();
 376                 }
 377         }
 378
 379         /** {@inheritDocs} */
 380         @Override
 381         public void removePostReply(PostReply postReply) {
 382                 lock.writeLock().lock();
 383                 try {
 384                         allPostReplies.remove(postReply.getId());
 385                         if (postReplies.containsKey(postReply.getPostId())) {
 386                                 postReplies.get(postReply.getPostId()).remove(postReply);
 387                         }
 388                 } finally {
 389                         lock.writeLock().unlock();
 390                 }
 391         }
 392
 393         /** {@inheritDocs} */
 394         @Override
 395         public void removePostReplies(Sone sone) {
 396                 checkNotNull(sone, "sone must not be null");
 397
 398                 lock.writeLock().lock();
 399                 try {
 400                         for (PostReply postReply : sone.getReplies()) {
 401                                 removePostReply(postReply);
 402                         }
 403                 } finally {
 404                         lock.writeLock().unlock();
 405                 }
 406         }
 407
 408         //
 409         // ALBUMPROVDER METHODS
 410         //
 411
 412         @Override
 413         public Optional<Album> getAlbum(String albumId) {
 414                 lock.readLock().lock();
 415                 try {
 416                         return fromNullable(allAlbums.get(albumId));
 417                 } finally {
 418                         lock.readLock().unlock();
 419                 }
 420         }
 421
 422         //
 423         // ALBUMBUILDERFACTORY METHODS
 424         //
 425
 426         @Override
 427         public AlbumBuilder newAlbumBuilder() {
 428                 return new AlbumBuilderImpl();
 429         }
 430
 431         //
 432         // ALBUMSTORE METHODS
 433         //
 434
 435         @Override
 436         public void storeAlbum(Album album) {
 437                 lock.writeLock().lock();
 438                 try {
 439                         allAlbums.put(album.getId(), album);
 440                         soneAlbums.put(album.getSone().getId(), album);
 441                 } finally {
 442                         lock.writeLock().unlock();
 443                 }
 444         }
 445
 446         @Override
 447         public void removeAlbum(Album album) {
 448                 lock.writeLock().lock();
 449                 try {
 450                         allAlbums.remove(album.getId());
 451                         soneAlbums.remove(album.getSone().getId(), album);
 452                 } finally {
 453                         lock.writeLock().unlock();
 454                 }
 455         }
 456
 457         //
 458         // IMAGEPROVIDER METHODS
 459         //
 460
 461         @Override
 462         public Optional<Image> getImage(String imageId) {
 463                 lock.readLock().lock();
 464                 try {
 465                         return fromNullable(allImages.get(imageId));
 466                 } finally {
 467                         lock.readLock().unlock();
 468                 }
 469         }
 470
 471         //
 472         // IMAGEBUILDERFACTORY METHODS
 473         //
 474
 475         @Override
 476         public ImageBuilder newImageBuilder() {
 477                 return new ImageBuilderImpl();
 478         }
 479
 480         //
 481         // IMAGESTORE METHODS
 482         //
 483
 484         @Override
 485         public void storeImage(Image image) {
 486                 lock.writeLock().lock();
 487                 try {
 488                         allImages.put(image.getId(), image);
 489                         soneImages.put(image.getSone().getId(), image);
 490                 } finally {
 491                         lock.writeLock().unlock();
 492                 }
 493         }
 494
 495         @Override
 496         public void removeImage(Image image) {
 497                 lock.writeLock().lock();
 498                 try {
 499                         allImages.remove(image.getId());
 500                         soneImages.remove(image.getSone().getId(), image);
 501                 } finally {
 502                         lock.writeLock().unlock();
 503                 }
 504         }
 505
 506         //
 507         // PACKAGE-PRIVATE METHODS
 508         //
 509
 510         /**
 511          * Returns whether the given post is known.
 512          *
 513          * @param post
 514          *              The post
 515          * @return {@code true} if the post is known, {@code false} otherwise
 516          */
 517         boolean isPostKnown(Post post) {
 518                 lock.readLock().lock();
 519                 try {
 520                         return knownPosts.contains(post.getId());
 521                 } finally {
 522                         lock.readLock().unlock();
 523                 }
 524         }
 525
 526         /**
 527          * Sets whether the given post is known.
 528          *
 529          * @param post
 530          *              The post
 531          * @param known
 532          *              {@code true} if the post is known, {@code false} otherwise
 533          */
 534         void setPostKnown(Post post, boolean known) {
 535                 lock.writeLock().lock();
 536                 try {
 537                         if (known) {
 538                                 knownPosts.add(post.getId());
 539                         } else {
 540                                 knownPosts.remove(post.getId());
 541                         }
 542                 } finally {
 543                         lock.writeLock().unlock();
 544                 }
 545         }
 546
 547         /**
 548          * Returns whether the given post reply is known.
 549          *
 550          * @param postReply
 551          *              The post reply
 552          * @return {@code true} if the given post reply is known, {@code false}
 553          *         otherwise
 554          */
 555         boolean isPostReplyKnown(PostReply postReply) {
 556                 lock.readLock().lock();
 557                 try {
 558                         return knownPostReplies.contains(postReply.getId());
 559                 } finally {
 560                         lock.readLock().unlock();
 561                 }
 562         }
 563
 564         /**
 565          * Sets whether the given post reply is known.
 566          *
 567          * @param postReply
 568          *              The post reply
 569          * @param known
 570          *              {@code true} if the post reply is known, {@code false} otherwise
 571          */
 572         void setPostReplyKnown(PostReply postReply, boolean known) {
 573                 lock.writeLock().lock();
 574                 try {
 575                         if (known) {
 576                                 knownPostReplies.add(postReply.getId());
 577                         } else {
 578                                 knownPostReplies.remove(postReply.getId());
 579                         }
 580                 } finally {
 581                         lock.writeLock().unlock();
 582                 }
 583         }
 584
 585         //
 586         // PRIVATE METHODS
 587         //
 588
 589         /**
 590          * Gets all posts for the given Sone, creating a new collection if there is
 591          * none yet.
 592          *
 593          * @param soneId
 594          *              The ID of the Sone to get the posts for
 595          * @return All posts
 596          */
 597         private Collection<Post> getPostsFrom(String soneId) {
 598                 lock.readLock().lock();
 599                 try {
 600                         return sonePosts.get(soneId);
 601                 } finally {
 602                         lock.readLock().unlock();
 603                 }
 604         }
 605
 606         /** Loads the known posts. */
 607         private void loadKnownPosts() {
 608                 lock.writeLock().lock();
 609                 try {
 610                         int postCounter = 0;
 611                         while (true) {
 612                                 String knownPostId = configuration.getStringValue("KnownPosts/" + postCounter++ + "/ID").getValue(null);
 613                                 if (knownPostId == null) {
 614                                         break;
 615                                 }
 616                                 knownPosts.add(knownPostId);
 617                         }
 618                 } finally {
 619                         lock.writeLock().unlock();
 620                 }
 621         }
 622
 623         /**
 624          * Saves the known posts to the configuration.
 625          *
 626          * @throws DatabaseException
 627          *              if a configuration error occurs
 628          */
 629         private void saveKnownPosts() throws DatabaseException {
 630                 lock.readLock().lock();
 631                 try {
 632                         int postCounter = 0;
 633                         for (String knownPostId : knownPosts) {
 634                                 configuration.getStringValue("KnownPosts/" + postCounter++ + "/ID").setValue(knownPostId);
 635                         }
 636                         configuration.getStringValue("KnownPosts/" + postCounter + "/ID").setValue(null);
 637                 } catch (ConfigurationException ce1) {
 638                         throw new DatabaseException("Could not save database.", ce1);
 639                 } finally {
 640                         lock.readLock().unlock();
 641                 }
 642         }
 643
 644         /**
 645          * Returns all replies by the given Sone.
 646          *
 647          * @param id
 648          *              The ID of the Sone
 649          * @return The post replies of the Sone, sorted by time (newest first)
 650          */
 651         private Collection<PostReply> getRepliesFrom(String id) {
 652                 lock.readLock().lock();
 653                 try {
 654                         return Collections.unmodifiableCollection(sonePostReplies.get(id));
 655                 } finally {
 656                         lock.readLock().unlock();
 657                 }
 658         }
 659
 660         /** Loads the known post replies. */
 661         private void loadKnownPostReplies() {
 662                 lock.writeLock().lock();
 663                 try {
 664                         int replyCounter = 0;
 665                         while (true) {
 666                                 String knownReplyId = configuration.getStringValue("KnownReplies/" + replyCounter++ + "/ID").getValue(null);
 667                                 if (knownReplyId == null) {
 668                                         break;
 669                                 }
 670                                 knownPostReplies.add(knownReplyId);
 671                         }
 672                 } finally {
 673                         lock.writeLock().unlock();
 674                 }
 675         }
 676
 677         /**
 678          * Saves the known post replies to the configuration.
 679          *
 680          * @throws DatabaseException
 681          *              if a configuration error occurs
 682          */
 683         private void saveKnownPostReplies() throws DatabaseException {
 684                 lock.readLock().lock();
 685                 try {
 686                         int replyCounter = 0;
 687                         for (String knownReplyId : knownPostReplies) {
 688                                 configuration.getStringValue("KnownReplies/" + replyCounter++ + "/ID").setValue(knownReplyId);
 689                         }
 690                         configuration.getStringValue("KnownReplies/" + replyCounter + "/ID").setValue(null);
 691                 } catch (ConfigurationException ce1) {
 692                         throw new DatabaseException("Could not save database.", ce1);
 693                 } finally {
 694                         lock.readLock().unlock();
 695                 }
 696         }
 697
 698 }