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.base.Predicates.not;
  23 import static com.google.common.collect.FluentIterable.from;
  24 import static java.util.Collections.emptyList;
  25 import static net.pterodactylus.sone.data.Sone.LOCAL_SONE_FILTER;
  26
  27 import java.util.ArrayList;
  28 import java.util.Collection;
  29 import java.util.Collections;
  30 import java.util.Comparator;
  31 import java.util.HashMap;
  32 import java.util.HashSet;
  33 import java.util.List;
  34 import java.util.Map;
  35 import java.util.Set;
  36 import java.util.concurrent.locks.ReadWriteLock;
  37 import java.util.concurrent.locks.ReentrantReadWriteLock;
  38
  39 import net.pterodactylus.sone.data.Album;
  40 import net.pterodactylus.sone.data.Image;
  41 import net.pterodactylus.sone.data.Post;
  42 import net.pterodactylus.sone.data.PostReply;
  43 import net.pterodactylus.sone.data.Sone;
  44 import net.pterodactylus.sone.data.impl.DefaultSoneBuilder;
  45 import net.pterodactylus.sone.database.Database;
  46 import net.pterodactylus.sone.database.DatabaseException;
  47 import net.pterodactylus.sone.database.PostDatabase;
  48 import net.pterodactylus.sone.database.SoneBuilder;
  49 import net.pterodactylus.sone.freenet.wot.Identity;
  50 import net.pterodactylus.util.config.Configuration;
  51 import net.pterodactylus.util.config.ConfigurationException;
  52
  53 import com.google.common.base.Function;
  54 import com.google.common.base.Optional;
  55 import com.google.common.collect.ArrayListMultimap;
  56 import com.google.common.collect.HashMultimap;
  57 import com.google.common.collect.ListMultimap;
  58 import com.google.common.collect.Maps;
  59 import com.google.common.collect.Multimap;
  60 import com.google.common.collect.SetMultimap;
  61 import com.google.common.collect.SortedSetMultimap;
  62 import com.google.common.collect.TreeMultimap;
  63 import com.google.common.util.concurrent.AbstractService;
  64 import com.google.inject.Inject;
  65
  66 /**
  67  * Memory-based {@link PostDatabase} implementation.
  68  *
  69  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  70  */
  71 public class MemoryDatabase extends AbstractService implements Database {
  72
  73         /** The lock. */
  74         private final ReadWriteLock lock = new ReentrantReadWriteLock();
  75
  76         /** The configuration. */
  77         private final Configuration configuration;
  78
  79         private final Map<String, Identity> identities = Maps.newHashMap();
  80         private final Map<String, Sone> sones = new HashMap<String, Sone>();
  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         private final SetMultimap<String, String> likedPostsBySone = HashMultimap.create();
  88         private final SetMultimap<String, String> postLikingSones = HashMultimap.create();
  89
  90         /** All posts by their recipient. */
  91         private final Multimap<String, Post> recipientPosts = HashMultimap.create();
  92
  93         /** Whether posts are known. */
  94         private final Set<String> knownPosts = new HashSet<String>();
  95
  96         /** All post replies by their ID. */
  97         private final Map<String, PostReply> allPostReplies = new HashMap<String, PostReply>();
  98         private final SetMultimap<String, String> likedPostRepliesBySone = HashMultimap.create();
  99         private final SetMultimap<String, String> postReplyLikingSones = HashMultimap.create();
 100
 101         /** Replies sorted by Sone. */
 102         private final SortedSetMultimap<String, PostReply> sonePostReplies = TreeMultimap.create(new Comparator<String>() {
 103
 104                 @Override
 105                 public int compare(String leftString, String rightString) {
 106                         return leftString.compareTo(rightString);
 107                 }
 108         }, PostReply.TIME_COMPARATOR);
 109
 110         /** Replies by post. */
 111         private final SortedSetMultimap<String, PostReply> postReplies = TreeMultimap.create(new Comparator<String>() {
 112
 113                 @Override
 114                 public int compare(String leftString, String rightString) {
 115                         return leftString.compareTo(rightString);
 116                 }
 117         }, PostReply.TIME_COMPARATOR);
 118
 119         /** Whether post replies are known. */
 120         private final Set<String> knownPostReplies = new HashSet<String>();
 121
 122         private final Map<String, Album> allAlbums = new HashMap<String, Album>();
 123         private final ListMultimap<String, String> albumChildren = ArrayListMultimap.create();
 124         private final ListMultimap<String, String> albumImages = ArrayListMultimap.create();
 125
 126         private final Map<String, Image> allImages = new HashMap<String, Image>();
 127
 128         /**
 129          * Creates a new memory database.
 130          *
 131          * @param configuration
 132          *              The configuration for loading and saving elements
 133          */
 134         @Inject
 135         public MemoryDatabase(Configuration configuration) {
 136                 this.configuration = configuration;
 137         }
 138
 139         //
 140         // DATABASE METHODS
 141         //
 142
 143         @Override
 144         public void save() throws DatabaseException {
 145                 saveKnownPosts();
 146                 saveKnownPostReplies();
 147         }
 148
 149         //
 150         // SERVICE METHODS
 151         //
 152
 153         @Override
 154         protected void doStart() {
 155                 loadKnownPosts();
 156                 loadKnownPostReplies();
 157                 notifyStarted();
 158         }
 159
 160         @Override
 161         protected void doStop() {
 162                 try {
 163                         save();
 164                         notifyStopped();
 165                 } catch (DatabaseException de1) {
 166                         notifyFailed(de1);
 167                 }
 168         }
 169
 170         @Override
 171         public Optional<Identity> getIdentity(String identityId) {
 172                 lock.readLock().lock();
 173                 try {
 174                         return fromNullable(identities.get(identityId));
 175                 } finally {
 176                         lock.readLock().unlock();
 177                 }
 178         }
 179
 180         @Override
 181         public void storeIdentity(Identity identitiy) {
 182                 lock.writeLock().lock();
 183                 try {
 184                         identities.put(identitiy.getId(), identitiy);
 185                 } finally {
 186                         lock.writeLock().unlock();
 187                 }
 188         }
 189
 190         @Override
 191         public Function<String, Optional<Sone>> getSone() {
 192                 return new Function<String, Optional<Sone>>() {
 193                         @Override
 194                         public Optional<Sone> apply(String soneId) {
 195                                 return (soneId == null) ? Optional.<Sone>absent() : getSone(soneId);
 196                         }
 197                 };
 198         }
 199
 200         @Override
 201         public Optional<Sone> getSone(String soneId) {
 202                 lock.readLock().lock();
 203                 try {
 204                         return fromNullable(sones.get(soneId));
 205                 } finally {
 206                         lock.readLock().unlock();
 207                 }
 208         }
 209
 210         @Override
 211         public Collection<Sone> getSones() {
 212                 lock.readLock().lock();
 213                 try {
 214                         return Collections.unmodifiableCollection(sones.values());
 215                 } finally {
 216                         lock.readLock().unlock();
 217                 }
 218         }
 219
 220         @Override
 221         public Collection<Sone> getLocalSones() {
 222                 lock.readLock().lock();
 223                 try {
 224                         return from(getSones()).filter(LOCAL_SONE_FILTER).toSet();
 225                 } finally {
 226                         lock.readLock().unlock();
 227                 }
 228         }
 229
 230         @Override
 231         public Collection<Sone> getRemoteSones() {
 232                 lock.readLock().lock();
 233                 try {
 234                         return from(getSones()).filter(not(LOCAL_SONE_FILTER)).toSet();
 235                 } finally {
 236                         lock.readLock().unlock();
 237                 }
 238         }
 239
 240         @Override
 241         public void storeSone(Sone sone) {
 242                 lock.writeLock().lock();
 243                 try {
 244                         sones.put(sone.getId(), sone);
 245                 } finally {
 246                         lock.writeLock().unlock();
 247                 }
 248         }
 249
 250         @Override
 251         public SoneBuilder newSoneBuilder() {
 252                 return new DefaultSoneBuilder(this) {
 253                         @Override
 254                         public Sone build(Optional<SoneCreated> soneCreated) throws IllegalStateException {
 255                                 Sone sone = super.build(soneCreated);
 256                                 lock.writeLock().lock();
 257                                 try {
 258                                         sones.put(sone.getId(), sone);
 259                                 } finally {
 260                                         lock.writeLock().unlock();
 261                                 }
 262                                 return sone;
 263                         }
 264                 };
 265         }
 266
 267         //
 268         // POSTPROVIDER METHODS
 269         //
 270
 271         @Override
 272         public Function<String, Optional<Post>> getPost() {
 273                 return new Function<String, Optional<Post>>() {
 274                         @Override
 275                         public Optional<Post> apply(String postId) {
 276                                 return (postId == null) ? Optional.<Post>absent() : getPost(postId);
 277                         }
 278                 };
 279         }
 280
 281         @Override
 282         public Optional<Post> getPost(String postId) {
 283                 lock.readLock().lock();
 284                 try {
 285                         return fromNullable(allPosts.get(postId));
 286                 } finally {
 287                         lock.readLock().unlock();
 288                 }
 289         }
 290
 291         @Override
 292         public Collection<Post> getPosts(String soneId) {
 293                 lock.readLock().lock();
 294                 try {
 295                         return new HashSet<Post>(sonePosts.get(soneId));
 296                 } finally {
 297                         lock.readLock().unlock();
 298                 }
 299         }
 300
 301         @Override
 302         public Collection<Post> getDirectedPosts(String recipientId) {
 303                 lock.readLock().lock();
 304                 try {
 305                         Collection<Post> posts = recipientPosts.get(recipientId);
 306                         return (posts == null) ? Collections.<Post>emptySet() : new HashSet<Post>(posts);
 307                 } finally {
 308                         lock.readLock().unlock();
 309                 }
 310         }
 311
 312         @Override
 313         public void likePost(Post post, Sone localSone) {
 314                 lock.writeLock().lock();
 315                 try {
 316                         likedPostsBySone.put(localSone.getId(), post.getId());
 317                         postLikingSones.put(post.getId(), localSone.getId());
 318                 } finally {
 319                         lock.writeLock().unlock();
 320                 }
 321         }
 322
 323         @Override
 324         public void unlikePost(Post post, Sone localSone) {
 325                 lock.writeLock().lock();
 326                 try {
 327                         likedPostsBySone.remove(localSone.getId(), post.getId());
 328                         postLikingSones.remove(post.getId(), localSone.getId());
 329                 } finally {
 330                         lock.writeLock().unlock();
 331                 }
 332         }
 333
 334         public boolean isLiked(Post post, Sone sone) {
 335                 lock.readLock().lock();
 336                 try {
 337                         return likedPostsBySone.containsEntry(sone.getId(), post.getId());
 338                 } finally {
 339                         lock.readLock().unlock();
 340                 }
 341         }
 342
 343         @Override
 344         public Set<Sone> getLikes(Post post) {
 345                 lock.readLock().lock();
 346                 try {
 347                         return from(postLikingSones.get(post.getId())).transform(getSone()).transformAndConcat(this.<Sone>unwrap()).toSet();
 348                 } finally {
 349                         lock.readLock().unlock();
 350                 }
 351         }
 352
 353         //
 354         // POSTSTORE METHODS
 355         //
 356
 357         @Override
 358         public void storePost(Post post) {
 359                 checkNotNull(post, "post must not be null");
 360                 lock.writeLock().lock();
 361                 try {
 362                         allPosts.put(post.getId(), post);
 363                         sonePosts.put(post.getSone().getId(), post);
 364                         if (post.getRecipientId().isPresent()) {
 365                                 recipientPosts.put(post.getRecipientId().get(), post);
 366                         }
 367                 } finally {
 368                         lock.writeLock().unlock();
 369                 }
 370         }
 371
 372         @Override
 373         public void removePost(Post post) {
 374                 checkNotNull(post, "post must not be null");
 375                 lock.writeLock().lock();
 376                 try {
 377                         allPosts.remove(post.getId());
 378                         sonePosts.remove(post.getSone().getId(), post);
 379                         if (post.getRecipientId().isPresent()) {
 380                                 recipientPosts.remove(post.getRecipientId().get(), post);
 381                         }
 382                         post.getSone().removePost(post);
 383                 } finally {
 384                         lock.writeLock().unlock();
 385                 }
 386         }
 387
 388         @Override
 389         public void storePosts(Sone sone, Collection<Post> posts) throws IllegalArgumentException {
 390                 checkNotNull(sone, "sone must not be null");
 391                 /* verify that all posts are from the same Sone. */
 392                 for (Post post : posts) {
 393                         if (!sone.equals(post.getSone())) {
 394                                 throw new IllegalArgumentException(String.format("Post from different Sone found: %s", post));
 395                         }
 396                 }
 397
 398                 lock.writeLock().lock();
 399                 try {
 400                         /* remove all posts by the Sone. */
 401                         sonePosts.removeAll(sone.getId());
 402                         for (Post post : posts) {
 403                                 allPosts.remove(post.getId());
 404                                 if (post.getRecipientId().isPresent()) {
 405                                         recipientPosts.remove(post.getRecipientId().get(), post);
 406                                 }
 407                         }
 408
 409                         /* add new posts. */
 410                         sonePosts.putAll(sone.getId(), posts);
 411                         for (Post post : posts) {
 412                                 allPosts.put(post.getId(), post);
 413                                 if (post.getRecipientId().isPresent()) {
 414                                         recipientPosts.put(post.getRecipientId().get(), post);
 415                                 }
 416                         }
 417                 } finally {
 418                         lock.writeLock().unlock();
 419                 }
 420         }
 421
 422         @Override
 423         public void removePosts(Sone sone) {
 424                 checkNotNull(sone, "sone must not be null");
 425                 lock.writeLock().lock();
 426                 try {
 427                         /* remove all posts by the Sone. */
 428                         sonePosts.removeAll(sone.getId());
 429                         for (Post post : sone.getPosts()) {
 430                                 allPosts.remove(post.getId());
 431                                 if (post.getRecipientId().isPresent()) {
 432                                         recipientPosts.remove(post.getRecipientId().get(), post);
 433                                 }
 434                         }
 435                 } finally {
 436                         lock.writeLock().unlock();
 437                 }
 438         }
 439
 440         //
 441         // POSTREPLYPROVIDER METHODS
 442         //
 443
 444         @Override
 445         public Optional<PostReply> getPostReply(String id) {
 446                 lock.readLock().lock();
 447                 try {
 448                         return fromNullable(allPostReplies.get(id));
 449                 } finally {
 450                         lock.readLock().unlock();
 451                 }
 452         }
 453
 454         @Override
 455         public List<PostReply> getReplies(String postId) {
 456                 lock.readLock().lock();
 457                 try {
 458                         if (!postReplies.containsKey(postId)) {
 459                                 return emptyList();
 460                         }
 461                         return new ArrayList<PostReply>(postReplies.get(postId));
 462                 } finally {
 463                         lock.readLock().unlock();
 464                 }
 465         }
 466
 467         @Override
 468         public void likePostReply(PostReply postReply, Sone localSone) {
 469                 lock.writeLock().lock();
 470                 try {
 471                         likedPostRepliesBySone.put(localSone.getId(), postReply.getId());
 472                         postReplyLikingSones.put(postReply.getId(), localSone.getId());
 473                 } finally {
 474                         lock.writeLock().unlock();
 475                 }
 476         }
 477
 478         @Override
 479         public void unlikePostReply(PostReply postReply, Sone localSone) {
 480                 lock.writeLock().lock();
 481                 try {
 482                         likedPostRepliesBySone.remove(localSone.getId(), postReply.getId());
 483                         postReplyLikingSones.remove(postReply.getId(), localSone.getId());
 484                 } finally {
 485                         lock.writeLock().unlock();
 486                 }
 487         }
 488
 489         @Override
 490         public boolean isLiked(PostReply postReply, Sone sone) {
 491                 lock.readLock().lock();
 492                 try {
 493                         return postReplyLikingSones.containsEntry(postReply.getId(), sone.getId());
 494                 } finally {
 495                         lock.readLock().unlock();
 496                 }
 497         }
 498
 499         @Override
 500         public Set<Sone> getLikes(PostReply postReply) {
 501                 lock.readLock().lock();
 502                 try {
 503                         return from(postReplyLikingSones.get(postReply.getId())).transform(getSone()).transformAndConcat(this.<Sone>unwrap()).toSet();
 504                 } finally {
 505                         lock.readLock().unlock();
 506                 }
 507         }
 508
 509         //
 510         // POSTREPLYSTORE METHODS
 511         //
 512
 513         /**
 514          * Returns whether the given post reply is known.
 515          *
 516          * @param postReply
 517          *              The post reply
 518          * @return {@code true} if the given post reply is known, {@code false}
 519          *         otherwise
 520          */
 521         public boolean isPostReplyKnown(PostReply postReply) {
 522                 lock.readLock().lock();
 523                 try {
 524                         return knownPostReplies.contains(postReply.getId());
 525                 } finally {
 526                         lock.readLock().unlock();
 527                 }
 528         }
 529
 530         @Override
 531         public void setPostReplyKnown(PostReply postReply) {
 532                 lock.writeLock().lock();
 533                 try {
 534                         knownPostReplies.add(postReply.getId());
 535                 } finally {
 536                         lock.writeLock().unlock();
 537                 }
 538         }
 539
 540         @Override
 541         public void storePostReply(PostReply postReply) {
 542                 lock.writeLock().lock();
 543                 try {
 544                         allPostReplies.put(postReply.getId(), postReply);
 545                         postReplies.put(postReply.getPostId(), postReply);
 546                 } finally {
 547                         lock.writeLock().unlock();
 548                 }
 549         }
 550
 551         @Override
 552         public void storePostReplies(Sone sone, Collection<PostReply> postReplies) {
 553                 checkNotNull(sone, "sone must not be null");
 554                 /* verify that all posts are from the same Sone. */
 555                 for (PostReply postReply : postReplies) {
 556                         if (!sone.equals(postReply.getSone())) {
 557                                 throw new IllegalArgumentException(String.format("PostReply from different Sone found: %s", postReply));
 558                         }
 559                 }
 560
 561                 lock.writeLock().lock();
 562                 try {
 563                         /* remove all post replies of the Sone. */
 564                         for (PostReply postReply : getRepliesFrom(sone.getId())) {
 565                                 removePostReply(postReply);
 566                         }
 567                         for (PostReply postReply : postReplies) {
 568                                 allPostReplies.put(postReply.getId(), postReply);
 569                                 sonePostReplies.put(postReply.getSone().getId(), postReply);
 570                                 this.postReplies.put(postReply.getPostId(), postReply);
 571                         }
 572                 } finally {
 573                         lock.writeLock().unlock();
 574                 }
 575         }
 576
 577         @Override
 578         public void removePostReply(PostReply postReply) {
 579                 lock.writeLock().lock();
 580                 try {
 581                         allPostReplies.remove(postReply.getId());
 582                         postReplies.remove(postReply.getPostId(), postReply);
 583                 } finally {
 584                         lock.writeLock().unlock();
 585                 }
 586         }
 587
 588         @Override
 589         public void removePostReplies(Sone sone) {
 590                 checkNotNull(sone, "sone must not be null");
 591
 592                 lock.writeLock().lock();
 593                 try {
 594                         for (PostReply postReply : sone.getReplies()) {
 595                                 removePostReply(postReply);
 596                         }
 597                 } finally {
 598                         lock.writeLock().unlock();
 599                 }
 600         }
 601
 602         //
 603         // ALBUMPROVDER METHODS
 604         //
 605
 606         @Override
 607         public Optional<Album> getAlbum(String albumId) {
 608                 lock.readLock().lock();
 609                 try {
 610                         return fromNullable(allAlbums.get(albumId));
 611                 } finally {
 612                         lock.readLock().unlock();
 613                 }
 614         }
 615
 616         @Override
 617         public List<Album> getAlbums(Album parent) {
 618                 lock.readLock().lock();
 619                 try {
 620                         return from(albumChildren.get(parent.getId())).transformAndConcat(getAlbum()).toList();
 621                 } finally {
 622                         lock.readLock().unlock();
 623                 }
 624         }
 625
 626         @Override
 627         public void moveUp(Album album) {
 628                 lock.writeLock().lock();
 629                 try {
 630                         List<String> albums = albumChildren.get(album.getParent().getId());
 631                         int currentIndex = albums.indexOf(album.getId());
 632                         if (currentIndex == 0) {
 633                                 return;
 634                         }
 635                         albums.remove(album.getId());
 636                         albums.add(currentIndex - 1, album.getId());
 637                 } finally {
 638                         lock.writeLock().unlock();
 639                 }
 640         }
 641
 642         @Override
 643         public void moveDown(Album album) {
 644                 lock.writeLock().lock();
 645                 try {
 646                         List<String> albums = albumChildren.get(album.getParent().getId());
 647                         int currentIndex = albums.indexOf(album.getId());
 648                         if (currentIndex == (albums.size() - 1)) {
 649                                 return;
 650                         }
 651                         albums.remove(album.getId());
 652                         albums.add(currentIndex + 1, album.getId());
 653                 } finally {
 654                         lock.writeLock().unlock();
 655                 }
 656         }
 657
 658         //
 659         // ALBUMSTORE METHODS
 660         //
 661
 662         @Override
 663         public void storeAlbum(Album album) {
 664                 lock.writeLock().lock();
 665                 try {
 666                         allAlbums.put(album.getId(), album);
 667                         if (!album.isRoot()) {
 668                                 albumChildren.put(album.getParent().getId(), album.getId());
 669                         }
 670                 } finally {
 671                         lock.writeLock().unlock();
 672                 }
 673         }
 674
 675         @Override
 676         public void removeAlbum(Album album) {
 677                 lock.writeLock().lock();
 678                 try {
 679                         allAlbums.remove(album.getId());
 680                         albumChildren.remove(album.getParent().getId(), album.getId());
 681                 } finally {
 682                         lock.writeLock().unlock();
 683                 }
 684         }
 685
 686         //
 687         // IMAGEPROVIDER METHODS
 688         //
 689
 690         @Override
 691         public Optional<Image> getImage(String imageId) {
 692                 lock.readLock().lock();
 693                 try {
 694                         return fromNullable(allImages.get(imageId));
 695                 } finally {
 696                         lock.readLock().unlock();
 697                 }
 698         }
 699
 700         @Override
 701         public List<Image> getImages(Album parent) {
 702                 lock.readLock().lock();
 703                 try {
 704                         return from(albumImages.get(parent.getId())).transformAndConcat(getImage()).toList();
 705                 } finally {
 706                         lock.readLock().unlock();
 707                 }
 708         }
 709
 710         @Override
 711         public void moveUp(Image image) {
 712                 lock.writeLock().lock();
 713                 try {
 714                         List<String> images = albumImages.get(image.getAlbum().getId());
 715                         int currentIndex = images.indexOf(image.getId());
 716                         if (currentIndex == 0) {
 717                                 return;
 718                         }
 719                         images.remove(image.getId());
 720                         images.add(currentIndex - 1, image.getId());
 721                 } finally {
 722                         lock.writeLock().unlock();
 723                 }
 724         }
 725
 726         @Override
 727         public void moveDown(Image image) {
 728                 lock.writeLock().lock();
 729                 try {
 730                         List<String> images = albumChildren.get(image.getAlbum().getId());
 731                         int currentIndex = images.indexOf(image.getId());
 732                         if (currentIndex == (images.size() - 1)) {
 733                                 return;
 734                         }
 735                         images.remove(image.getId());
 736                         images.add(currentIndex + 1, image.getId());
 737                 } finally {
 738                         lock.writeLock().unlock();
 739                 }
 740         }
 741
 742         //
 743         // IMAGESTORE METHODS
 744         //
 745
 746         @Override
 747         public void storeImage(Image image) {
 748                 lock.writeLock().lock();
 749                 try {
 750                         allImages.put(image.getId(), image);
 751                         albumImages.put(image.getAlbum().getId(), image.getId());
 752                 } finally {
 753                         lock.writeLock().unlock();
 754                 }
 755         }
 756
 757         @Override
 758         public void removeImage(Image image) {
 759                 lock.writeLock().lock();
 760                 try {
 761                         allImages.remove(image.getId());
 762                         albumImages.remove(image.getAlbum().getId(), image.getId());
 763                 } finally {
 764                         lock.writeLock().unlock();
 765                 }
 766         }
 767
 768         //
 769         // PACKAGE-PRIVATE METHODS
 770         //
 771
 772         /**
 773          * Returns whether the given post is known.
 774          *
 775          * @param post
 776          *              The post
 777          * @return {@code true} if the post is known, {@code false} otherwise
 778          */
 779         boolean isPostKnown(Post post) {
 780                 lock.readLock().lock();
 781                 try {
 782                         return knownPosts.contains(post.getId());
 783                 } finally {
 784                         lock.readLock().unlock();
 785                 }
 786         }
 787
 788         /**
 789          * Sets whether the given post is known.
 790          *
 791          * @param post
 792          *              The post
 793          * @param known
 794          *              {@code true} if the post is known, {@code false} otherwise
 795          */
 796         void setPostKnown(Post post, boolean known) {
 797                 lock.writeLock().lock();
 798                 try {
 799                         if (known) {
 800                                 knownPosts.add(post.getId());
 801                         } else {
 802                                 knownPosts.remove(post.getId());
 803                         }
 804                 } finally {
 805                         lock.writeLock().unlock();
 806                 }
 807         }
 808
 809         //
 810         // PRIVATE METHODS
 811         //
 812
 813         /** Loads the known posts. */
 814         private void loadKnownPosts() {
 815                 lock.writeLock().lock();
 816                 try {
 817                         int postCounter = 0;
 818                         while (true) {
 819                                 String knownPostId = configuration.getStringValue("KnownPosts/" + postCounter++ + "/ID").getValue(null);
 820                                 if (knownPostId == null) {
 821                                         break;
 822                                 }
 823                                 knownPosts.add(knownPostId);
 824                         }
 825                 } finally {
 826                         lock.writeLock().unlock();
 827                 }
 828         }
 829
 830         /**
 831          * Saves the known posts to the configuration.
 832          *
 833          * @throws DatabaseException
 834          *              if a configuration error occurs
 835          */
 836         private void saveKnownPosts() throws DatabaseException {
 837                 lock.readLock().lock();
 838                 try {
 839                         int postCounter = 0;
 840                         for (String knownPostId : knownPosts) {
 841                                 configuration.getStringValue("KnownPosts/" + postCounter++ + "/ID").setValue(knownPostId);
 842                         }
 843                         configuration.getStringValue("KnownPosts/" + postCounter + "/ID").setValue(null);
 844                 } catch (ConfigurationException ce1) {
 845                         throw new DatabaseException("Could not save database.", ce1);
 846                 } finally {
 847                         lock.readLock().unlock();
 848                 }
 849         }
 850
 851         /**
 852          * Returns all replies by the given Sone.
 853          *
 854          * @param id
 855          *              The ID of the Sone
 856          * @return The post replies of the Sone, sorted by time (newest first)
 857          */
 858         private Collection<PostReply> getRepliesFrom(String id) {
 859                 lock.readLock().lock();
 860                 try {
 861                         if (sonePostReplies.containsKey(id)) {
 862                                 return Collections.unmodifiableCollection(sonePostReplies.get(id));
 863                         }
 864                         return Collections.emptySet();
 865                 } finally {
 866                         lock.readLock().unlock();
 867                 }
 868         }
 869
 870         /** Loads the known post replies. */
 871         private void loadKnownPostReplies() {
 872                 lock.writeLock().lock();
 873                 try {
 874                         int replyCounter = 0;
 875                         while (true) {
 876                                 String knownReplyId = configuration.getStringValue("KnownReplies/" + replyCounter++ + "/ID").getValue(null);
 877                                 if (knownReplyId == null) {
 878                                         break;
 879                                 }
 880                                 knownPostReplies.add(knownReplyId);
 881                         }
 882                 } finally {
 883                         lock.writeLock().unlock();
 884                 }
 885         }
 886
 887         /**
 888          * Saves the known post replies to the configuration.
 889          *
 890          * @throws DatabaseException
 891          *              if a configuration error occurs
 892          */
 893         private void saveKnownPostReplies() throws DatabaseException {
 894                 lock.readLock().lock();
 895                 try {
 896                         int replyCounter = 0;
 897                         for (String knownReplyId : knownPostReplies) {
 898                                 configuration.getStringValue("KnownReplies/" + replyCounter++ + "/ID").setValue(knownReplyId);
 899                         }
 900                         configuration.getStringValue("KnownReplies/" + replyCounter + "/ID").setValue(null);
 901                 } catch (ConfigurationException ce1) {
 902                         throw new DatabaseException("Could not save database.", ce1);
 903                 } finally {
 904                         lock.readLock().unlock();
 905                 }
 906         }
 907
 908         private Function<String, Iterable<Album>> getAlbum() {
 909                 return new Function<String, Iterable<Album>>() {
 910                         @Override
 911                         public Iterable<Album> apply(String input) {
 912                                 return (input == null) ? Collections.<Album>emptyList() : getAlbum(input).asSet();
 913                         }
 914                 };
 915         }
 916
 917         private Function<String, Iterable<Image>> getImage() {
 918                 return new Function<String, Iterable<Image>>() {
 919                         @Override
 920                         public Iterable<Image> apply(String input) {
 921                                 return (input == null) ? Collections.<Image>emptyList() : getImage(input).asSet();
 922                         }
 923                 };
 924         }
 925
 926         private static <T> Function<Optional<T>, Iterable<T>> unwrap() {
 927                 return new Function<Optional<T>, Iterable<T>>() {
 928                         @Override
 929                         public Iterable<T> apply(Optional<T> input) {
 930                                 return (input == null) ? Collections.<T>emptyList() : input.asSet();
 931                         }
 932                 };
 933         }
 934
 935 }