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
  23 import java.util.ArrayList;
  24 import java.util.Collection;
  25 import java.util.Collections;
  26 import java.util.Comparator;
  27 import java.util.HashMap;
  28 import java.util.HashSet;
  29 import java.util.List;
  30 import java.util.Map;
  31 import java.util.Set;
  32 import java.util.SortedSet;
  33 import java.util.TreeSet;
  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.Reply;
  42 import net.pterodactylus.sone.data.Sone;
  43 import net.pterodactylus.sone.data.impl.AlbumBuilderImpl;
  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.PostBuilder;
  48 import net.pterodactylus.sone.database.PostDatabase;
  49 import net.pterodactylus.sone.database.PostReplyBuilder;
  50 import net.pterodactylus.sone.database.SoneProvider;
  51 import net.pterodactylus.util.config.Configuration;
  52 import net.pterodactylus.util.config.ConfigurationException;
  53
  54 import com.google.common.base.Optional;
  55 import com.google.common.collect.SortedSetMultimap;
  56 import com.google.common.collect.TreeMultimap;
  57 import com.google.common.util.concurrent.AbstractService;
  58 import com.google.inject.Inject;
  59
  60 /**
  61  * Memory-based {@link PostDatabase} implementation.
  62  *
  63  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  64  */
  65 public class MemoryDatabase extends AbstractService implements Database {
  66
  67         /** The lock. */
  68         private final ReadWriteLock lock = new ReentrantReadWriteLock();
  69
  70         /** The Sone provider. */
  71         private final SoneProvider soneProvider;
  72
  73         /** The configuration. */
  74         private final Configuration configuration;
  75
  76         /** All posts by their ID. */
  77         private final Map<String, Post> allPosts = new HashMap<String, Post>();
  78
  79         /** All posts by their Sones. */
  80         private final Map<String, Collection<Post>> sonePosts = new HashMap<String, Collection<Post>>();
  81
  82         /** All posts by their recipient. */
  83         private final Map<String, Collection<Post>> recipientPosts = new HashMap<String, Collection<Post>>();
  84
  85         /** Whether posts are known. */
  86         private final Set<String> knownPosts = new HashSet<String>();
  87
  88         /** All post replies by their ID. */
  89         private final Map<String, PostReply> allPostReplies = new HashMap<String, PostReply>();
  90
  91         /** Replies sorted by Sone. */
  92         private final SortedSetMultimap<String, PostReply> sonePostReplies = TreeMultimap.create(new Comparator<String>() {
  93
  94                 @Override
  95                 public int compare(String leftString, String rightString) {
  96                         return leftString.compareTo(rightString);
  97                 }
  98         }, PostReply.TIME_COMPARATOR);
  99
 100         /** Replies by post. */
 101         private final Map<String, SortedSet<PostReply>> postReplies = new HashMap<String, SortedSet<PostReply>>();
 102
 103         /** Whether post replies are known. */
 104         private final Set<String> knownPostReplies = new HashSet<String>();
 105
 106         private final Map<String, Album> allAlbums = new HashMap<String, Album>();
 107
 108         private final Map<String, Image> allImages = new HashMap<String, Image>();
 109
 110         /**
 111          * Creates a new memory database.
 112          *
 113          * @param soneProvider
 114          *              The Sone provider
 115          * @param configuration
 116          *              The configuration for loading and saving elements
 117          */
 118         @Inject
 119         public MemoryDatabase(SoneProvider soneProvider, Configuration configuration) {
 120                 this.soneProvider = soneProvider;
 121                 this.configuration = configuration;
 122         }
 123
 124         //
 125         // DATABASE METHODS
 126         //
 127
 128         /**
 129          * Saves the database.
 130          *
 131          * @throws DatabaseException
 132          *              if an error occurs while saving
 133          */
 134         @Override
 135         public void save() throws DatabaseException {
 136                 saveKnownPosts();
 137                 saveKnownPostReplies();
 138         }
 139
 140         //
 141         // SERVICE METHODS
 142         //
 143
 144         /** {@inheritDocs} */
 145         @Override
 146         protected void doStart() {
 147                 loadKnownPosts();
 148                 loadKnownPostReplies();
 149                 notifyStarted();
 150         }
 151
 152         /** {@inheritDocs} */
 153         @Override
 154         protected void doStop() {
 155                 try {
 156                         save();
 157                         notifyStopped();
 158                 } catch (DatabaseException de1) {
 159                         notifyFailed(de1);
 160                 }
 161         }
 162
 163         //
 164         // POSTPROVIDER METHODS
 165         //
 166
 167         /** {@inheritDocs} */
 168         @Override
 169         public Optional<Post> getPost(String postId) {
 170                 lock.readLock().lock();
 171                 try {
 172                         return fromNullable(allPosts.get(postId));
 173                 } finally {
 174                         lock.readLock().unlock();
 175                 }
 176         }
 177
 178         /** {@inheritDocs} */
 179         @Override
 180         public Collection<Post> getPosts(String soneId) {
 181                 return new HashSet<Post>(getPostsFrom(soneId));
 182         }
 183
 184         /** {@inheritDocs} */
 185         @Override
 186         public Collection<Post> getDirectedPosts(String recipientId) {
 187                 lock.readLock().lock();
 188                 try {
 189                         Collection<Post> posts = recipientPosts.get(recipientId);
 190                         return (posts == null) ? Collections.<Post>emptySet() : new HashSet<Post>(posts);
 191                 } finally {
 192                         lock.readLock().unlock();
 193                 }
 194         }
 195
 196         //
 197         // POSTBUILDERFACTORY METHODS
 198         //
 199
 200         /** {@inheritDocs} */
 201         @Override
 202         public PostBuilder newPostBuilder() {
 203                 return new MemoryPostBuilder(this, soneProvider);
 204         }
 205
 206         //
 207         // POSTSTORE METHODS
 208         //
 209
 210         /** {@inheritDocs} */
 211         @Override
 212         public void storePost(Post post) {
 213                 checkNotNull(post, "post must not be null");
 214                 lock.writeLock().lock();
 215                 try {
 216                         allPosts.put(post.getId(), post);
 217                         getPostsFrom(post.getSone().getId()).add(post);
 218                         if (post.getRecipientId().isPresent()) {
 219                                 getPostsTo(post.getRecipientId().get()).add(post);
 220                         }
 221                 } finally {
 222                         lock.writeLock().unlock();
 223                 }
 224         }
 225
 226         /** {@inheritDocs} */
 227         @Override
 228         public void removePost(Post post) {
 229                 checkNotNull(post, "post must not be null");
 230                 lock.writeLock().lock();
 231                 try {
 232                         allPosts.remove(post.getId());
 233                         getPostsFrom(post.getSone().getId()).remove(post);
 234                         if (post.getRecipientId().isPresent()) {
 235                                 getPostsTo(post.getRecipientId().get()).remove(post);
 236                         }
 237                         post.getSone().removePost(post);
 238                 } finally {
 239                         lock.writeLock().unlock();
 240                 }
 241         }
 242
 243         /** {@inheritDocs} */
 244         @Override
 245         public void storePosts(Sone sone, Collection<Post> posts) throws IllegalArgumentException {
 246                 checkNotNull(sone, "sone must not be null");
 247                 /* verify that all posts are from the same Sone. */
 248                 for (Post post : posts) {
 249                         if (!sone.equals(post.getSone())) {
 250                                 throw new IllegalArgumentException(String.format("Post from different Sone found: %s", post));
 251                         }
 252                 }
 253
 254                 lock.writeLock().lock();
 255                 try {
 256                         /* remove all posts by the Sone. */
 257                         getPostsFrom(sone.getId()).clear();
 258                         for (Post post : posts) {
 259                                 allPosts.remove(post.getId());
 260                                 if (post.getRecipientId().isPresent()) {
 261                                         getPostsTo(post.getRecipientId().get()).remove(post);
 262                                 }
 263                         }
 264
 265                         /* add new posts. */
 266                         getPostsFrom(sone.getId()).addAll(posts);
 267                         for (Post post : posts) {
 268                                 allPosts.put(post.getId(), post);
 269                                 if (post.getRecipientId().isPresent()) {
 270                                         getPostsTo(post.getRecipientId().get()).add(post);
 271                                 }
 272                         }
 273                 } finally {
 274                         lock.writeLock().unlock();
 275                 }
 276         }
 277
 278         /** {@inheritDocs} */
 279         @Override
 280         public void removePosts(Sone sone) {
 281                 checkNotNull(sone, "sone must not be null");
 282                 lock.writeLock().lock();
 283                 try {
 284                         /* remove all posts by the Sone. */
 285                         getPostsFrom(sone.getId()).clear();
 286                         for (Post post : sone.getPosts()) {
 287                                 allPosts.remove(post.getId());
 288                                 if (post.getRecipientId().isPresent()) {
 289                                         getPostsTo(post.getRecipientId().get()).remove(post);
 290                                 }
 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                         if (postReplies.containsKey(postReply.getPostId())) {
 347                                 postReplies.get(postReply.getPostId()).add(postReply);
 348                         } else {
 349                                 TreeSet<PostReply> replies = new TreeSet<PostReply>(Reply.TIME_COMPARATOR);
 350                                 replies.add(postReply);
 351                                 postReplies.put(postReply.getPostId(), replies);
 352                         }
 353                 } finally {
 354                         lock.writeLock().unlock();
 355                 }
 356         }
 357
 358         /** {@inheritDocs} */
 359         @Override
 360         public void storePostReplies(Sone sone, Collection<PostReply> postReplies) {
 361                 checkNotNull(sone, "sone must not be null");
 362                 /* verify that all posts are from the same Sone. */
 363                 for (PostReply postReply : postReplies) {
 364                         if (!sone.equals(postReply.getSone())) {
 365                                 throw new IllegalArgumentException(String.format("PostReply from different Sone found: %s", postReply));
 366                         }
 367                 }
 368
 369                 lock.writeLock().lock();
 370                 try {
 371                         /* remove all post replies of the Sone. */
 372                         for (PostReply postReply : getRepliesFrom(sone.getId())) {
 373                                 removePostReply(postReply);
 374                         }
 375                         for (PostReply postReply : postReplies) {
 376                                 allPostReplies.put(postReply.getId(), postReply);
 377                                 sonePostReplies.put(postReply.getSone().getId(), postReply);
 378                                 if (this.postReplies.containsKey(postReply.getPostId())) {
 379                                         this.postReplies.get(postReply.getPostId()).add(postReply);
 380                                 } else {
 381                                         TreeSet<PostReply> replies = new TreeSet<PostReply>(Reply.TIME_COMPARATOR);
 382                                         replies.add(postReply);
 383                                         this.postReplies.put(postReply.getPostId(), replies);
 384                                 }
 385                         }
 386                 } finally {
 387                         lock.writeLock().unlock();
 388                 }
 389         }
 390
 391         /** {@inheritDocs} */
 392         @Override
 393         public void removePostReply(PostReply postReply) {
 394                 lock.writeLock().lock();
 395                 try {
 396                         allPostReplies.remove(postReply.getId());
 397                         if (postReplies.containsKey(postReply.getPostId())) {
 398                                 postReplies.get(postReply.getPostId()).remove(postReply);
 399                                 if (postReplies.get(postReply.getPostId()).isEmpty()) {
 400                                         postReplies.remove(postReply.getPostId());
 401                                 }
 402                         }
 403                 } finally {
 404                         lock.writeLock().unlock();
 405                 }
 406         }
 407
 408         /** {@inheritDocs} */
 409         @Override
 410         public void removePostReplies(Sone sone) {
 411                 checkNotNull(sone, "sone must not be null");
 412
 413                 lock.writeLock().lock();
 414                 try {
 415                         for (PostReply postReply : sone.getReplies()) {
 416                                 removePostReply(postReply);
 417                         }
 418                 } finally {
 419                         lock.writeLock().unlock();
 420                 }
 421         }
 422
 423         //
 424         // ALBUMPROVDER METHODS
 425         //
 426
 427         @Override
 428         public Optional<Album> getAlbum(String albumId) {
 429                 lock.readLock().lock();
 430                 try {
 431                         return fromNullable(allAlbums.get(albumId));
 432                 } finally {
 433                         lock.readLock().unlock();
 434                 }
 435         }
 436
 437         //
 438         // ALBUMBUILDERFACTORY METHODS
 439         //
 440
 441         @Override
 442         public AlbumBuilder newAlbumBuilder() {
 443                 return new AlbumBuilderImpl();
 444         }
 445
 446         //
 447         // ALBUMSTORE METHODS
 448         //
 449
 450         @Override
 451         public void storeAlbum(Album album) {
 452                 lock.writeLock().lock();
 453                 try {
 454                         allAlbums.put(album.getId(), album);
 455                 } finally {
 456                         lock.writeLock().unlock();
 457                 }
 458         }
 459
 460         @Override
 461         public void removeAlbum(Album album) {
 462                 lock.writeLock().lock();
 463                 try {
 464                         allAlbums.remove(album.getId());
 465                 } finally {
 466                         lock.writeLock().unlock();
 467                 }
 468         }
 469
 470         //
 471         // IMAGEPROVIDER METHODS
 472         //
 473
 474         @Override
 475         public Optional<Image> getImage(String imageId) {
 476                 lock.readLock().lock();
 477                 try {
 478                         return fromNullable(allImages.get(imageId));
 479                 } finally {
 480                         lock.readLock().unlock();
 481                 }
 482         }
 483
 484         //
 485         // IMAGESTORE METHODS
 486         //
 487
 488         @Override
 489         public void storeImage(Image image) {
 490                 lock.writeLock().lock();
 491                 try {
 492                         allImages.put(image.getId(), image);
 493                 } finally {
 494                         lock.writeLock().unlock();
 495                 }
 496         }
 497
 498         @Override
 499         public void removeImage(Image image) {
 500                 lock.writeLock().lock();
 501                 try {
 502                         allImages.remove(image.getId());
 503                 } finally {
 504                         lock.writeLock().unlock();
 505                 }
 506         }
 507
 508         //
 509         // PACKAGE-PRIVATE METHODS
 510         //
 511
 512         /**
 513          * Returns whether the given post is known.
 514          *
 515          * @param post
 516          *              The post
 517          * @return {@code true} if the post is known, {@code false} otherwise
 518          */
 519         boolean isPostKnown(Post post) {
 520                 lock.readLock().lock();
 521                 try {
 522                         return knownPosts.contains(post.getId());
 523                 } finally {
 524                         lock.readLock().unlock();
 525                 }
 526         }
 527
 528         /**
 529          * Sets whether the given post is known.
 530          *
 531          * @param post
 532          *              The post
 533          * @param known
 534          *              {@code true} if the post is known, {@code false} otherwise
 535          */
 536         void setPostKnown(Post post, boolean known) {
 537                 lock.writeLock().lock();
 538                 try {
 539                         if (known) {
 540                                 knownPosts.add(post.getId());
 541                         } else {
 542                                 knownPosts.remove(post.getId());
 543                         }
 544                 } finally {
 545                         lock.writeLock().unlock();
 546                 }
 547         }
 548
 549         /**
 550          * Returns whether the given post reply is known.
 551          *
 552          * @param postReply
 553          *              The post reply
 554          * @return {@code true} if the given post reply is known, {@code false}
 555          *         otherwise
 556          */
 557         boolean isPostReplyKnown(PostReply postReply) {
 558                 lock.readLock().lock();
 559                 try {
 560                         return knownPostReplies.contains(postReply.getId());
 561                 } finally {
 562                         lock.readLock().unlock();
 563                 }
 564         }
 565
 566         /**
 567          * Sets whether the given post reply is known.
 568          *
 569          * @param postReply
 570          *              The post reply
 571          * @param known
 572          *              {@code true} if the post reply is known, {@code false} otherwise
 573          */
 574         void setPostReplyKnown(PostReply postReply, boolean known) {
 575                 lock.writeLock().lock();
 576                 try {
 577                         if (known) {
 578                                 knownPostReplies.add(postReply.getId());
 579                         } else {
 580                                 knownPostReplies.remove(postReply.getId());
 581                         }
 582                 } finally {
 583                         lock.writeLock().unlock();
 584                 }
 585         }
 586
 587         //
 588         // PRIVATE METHODS
 589         //
 590
 591         /**
 592          * Gets all posts for the given Sone, creating a new collection if there is
 593          * none yet.
 594          *
 595          * @param soneId
 596          *              The ID of the Sone to get the posts for
 597          * @return All posts
 598          */
 599         private Collection<Post> getPostsFrom(String soneId) {
 600                 Collection<Post> posts = null;
 601                 lock.readLock().lock();
 602                 try {
 603                         posts = sonePosts.get(soneId);
 604                 } finally {
 605                         lock.readLock().unlock();
 606                 }
 607                 if (posts != null) {
 608                         return posts;
 609                 }
 610
 611                 posts = new HashSet<Post>();
 612                 lock.writeLock().lock();
 613                 try {
 614                         sonePosts.put(soneId, posts);
 615                 } finally {
 616                         lock.writeLock().unlock();
 617                 }
 618
 619                 return posts;
 620         }
 621
 622         /**
 623          * Gets all posts that are directed the given Sone, creating a new collection
 624          * if there is none yet.
 625          *
 626          * @param recipientId
 627          *              The ID of the Sone to get the posts for
 628          * @return All posts
 629          */
 630         private Collection<Post> getPostsTo(String recipientId) {
 631                 Collection<Post> posts = null;
 632                 lock.readLock().lock();
 633                 try {
 634                         posts = recipientPosts.get(recipientId);
 635                 } finally {
 636                         lock.readLock().unlock();
 637                 }
 638                 if (posts != null) {
 639                         return posts;
 640                 }
 641
 642                 posts = new HashSet<Post>();
 643                 lock.writeLock().lock();
 644                 try {
 645                         recipientPosts.put(recipientId, posts);
 646                 } finally {
 647                         lock.writeLock().unlock();
 648                 }
 649
 650                 return posts;
 651         }
 652
 653         /** Loads the known posts. */
 654         private void loadKnownPosts() {
 655                 lock.writeLock().lock();
 656                 try {
 657                         int postCounter = 0;
 658                         while (true) {
 659                                 String knownPostId = configuration.getStringValue("KnownPosts/" + postCounter++ + "/ID").getValue(null);
 660                                 if (knownPostId == null) {
 661                                         break;
 662                                 }
 663                                 knownPosts.add(knownPostId);
 664                         }
 665                 } finally {
 666                         lock.writeLock().unlock();
 667                 }
 668         }
 669
 670         /**
 671          * Saves the known posts to the configuration.
 672          *
 673          * @throws DatabaseException
 674          *              if a configuration error occurs
 675          */
 676         private void saveKnownPosts() throws DatabaseException {
 677                 lock.readLock().lock();
 678                 try {
 679                         int postCounter = 0;
 680                         for (String knownPostId : knownPosts) {
 681                                 configuration.getStringValue("KnownPosts/" + postCounter++ + "/ID").setValue(knownPostId);
 682                         }
 683                         configuration.getStringValue("KnownPosts/" + postCounter + "/ID").setValue(null);
 684                 } catch (ConfigurationException ce1) {
 685                         throw new DatabaseException("Could not save database.", ce1);
 686                 } finally {
 687                         lock.readLock().unlock();
 688                 }
 689         }
 690
 691         /**
 692          * Returns all replies by the given Sone.
 693          *
 694          * @param id
 695          *              The ID of the Sone
 696          * @return The post replies of the Sone, sorted by time (newest first)
 697          */
 698         private Collection<PostReply> getRepliesFrom(String id) {
 699                 lock.readLock().lock();
 700                 try {
 701                         if (sonePostReplies.containsKey(id)) {
 702                                 return Collections.unmodifiableCollection(sonePostReplies.get(id));
 703                         }
 704                         return Collections.emptySet();
 705                 } finally {
 706                         lock.readLock().unlock();
 707                 }
 708         }
 709
 710         /** Loads the known post replies. */
 711         private void loadKnownPostReplies() {
 712                 lock.writeLock().lock();
 713                 try {
 714                         int replyCounter = 0;
 715                         while (true) {
 716                                 String knownReplyId = configuration.getStringValue("KnownReplies/" + replyCounter++ + "/ID").getValue(null);
 717                                 if (knownReplyId == null) {
 718                                         break;
 719                                 }
 720                                 knownPostReplies.add(knownReplyId);
 721                         }
 722                 } finally {
 723                         lock.writeLock().unlock();
 724                 }
 725         }
 726
 727         /**
 728          * Saves the known post replies to the configuration.
 729          *
 730          * @throws DatabaseException
 731          *              if a configuration error occurs
 732          */
 733         private void saveKnownPostReplies() throws DatabaseException {
 734                 lock.readLock().lock();
 735                 try {
 736                         int replyCounter = 0;
 737                         for (String knownReplyId : knownPostReplies) {
 738                                 configuration.getStringValue("KnownReplies/" + replyCounter++ + "/ID").setValue(knownReplyId);
 739                         }
 740                         configuration.getStringValue("KnownReplies/" + replyCounter + "/ID").setValue(null);
 741                 } catch (ConfigurationException ce1) {
 742                         throw new DatabaseException("Could not save database.", ce1);
 743                 } finally {
 744                         lock.readLock().unlock();
 745                 }
 746         }
 747
 748 }