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.database.Database;
  44 import net.pterodactylus.sone.database.DatabaseException;
  45 import net.pterodactylus.sone.database.PostBuilder;
  46 import net.pterodactylus.sone.database.PostDatabase;
  47 import net.pterodactylus.sone.database.PostReplyBuilder;
  48 import net.pterodactylus.sone.database.SoneProvider;
  49 import net.pterodactylus.util.config.Configuration;
  50 import net.pterodactylus.util.config.ConfigurationException;
  51
  52 import com.google.common.base.Optional;
  53 import com.google.common.collect.ArrayListMultimap;
  54 import com.google.common.collect.ListMultimap;
  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 ListMultimap<String, String> albumImages = ArrayListMultimap.create();
 109
 110         private final Map<String, Image> allImages = new HashMap<String, Image>();
 111
 112         /**
 113          * Creates a new memory database.
 114          *
 115          * @param soneProvider
 116          *              The Sone provider
 117          * @param configuration
 118          *              The configuration for loading and saving elements
 119          */
 120         @Inject
 121         public MemoryDatabase(SoneProvider soneProvider, Configuration configuration) {
 122                 this.soneProvider = soneProvider;
 123                 this.configuration = configuration;
 124         }
 125
 126         //
 127         // DATABASE METHODS
 128         //
 129
 130         /**
 131          * Saves the database.
 132          *
 133          * @throws DatabaseException
 134          *              if an error occurs while saving
 135          */
 136         @Override
 137         public void save() throws DatabaseException {
 138                 saveKnownPosts();
 139                 saveKnownPostReplies();
 140         }
 141
 142         //
 143         // SERVICE METHODS
 144         //
 145
 146         /** {@inheritDocs} */
 147         @Override
 148         protected void doStart() {
 149                 loadKnownPosts();
 150                 loadKnownPostReplies();
 151                 notifyStarted();
 152         }
 153
 154         /** {@inheritDocs} */
 155         @Override
 156         protected void doStop() {
 157                 try {
 158                         save();
 159                         notifyStopped();
 160                 } catch (DatabaseException de1) {
 161                         notifyFailed(de1);
 162                 }
 163         }
 164
 165         //
 166         // POSTPROVIDER METHODS
 167         //
 168
 169         /** {@inheritDocs} */
 170         @Override
 171         public Optional<Post> getPost(String postId) {
 172                 lock.readLock().lock();
 173                 try {
 174                         return fromNullable(allPosts.get(postId));
 175                 } finally {
 176                         lock.readLock().unlock();
 177                 }
 178         }
 179
 180         /** {@inheritDocs} */
 181         @Override
 182         public Collection<Post> getPosts(String soneId) {
 183                 return new HashSet<Post>(getPostsFrom(soneId));
 184         }
 185
 186         /** {@inheritDocs} */
 187         @Override
 188         public Collection<Post> getDirectedPosts(String recipientId) {
 189                 lock.readLock().lock();
 190                 try {
 191                         Collection<Post> posts = recipientPosts.get(recipientId);
 192                         return (posts == null) ? Collections.<Post>emptySet() : new HashSet<Post>(posts);
 193                 } finally {
 194                         lock.readLock().unlock();
 195                 }
 196         }
 197
 198         //
 199         // POSTBUILDERFACTORY METHODS
 200         //
 201
 202         /** {@inheritDocs} */
 203         @Override
 204         public PostBuilder newPostBuilder() {
 205                 return new MemoryPostBuilder(this, soneProvider);
 206         }
 207
 208         //
 209         // POSTSTORE METHODS
 210         //
 211
 212         /** {@inheritDocs} */
 213         @Override
 214         public void storePost(Post post) {
 215                 checkNotNull(post, "post must not be null");
 216                 lock.writeLock().lock();
 217                 try {
 218                         allPosts.put(post.getId(), post);
 219                         getPostsFrom(post.getSone().getId()).add(post);
 220                         if (post.getRecipientId().isPresent()) {
 221                                 getPostsTo(post.getRecipientId().get()).add(post);
 222                         }
 223                 } finally {
 224                         lock.writeLock().unlock();
 225                 }
 226         }
 227
 228         /** {@inheritDocs} */
 229         @Override
 230         public void removePost(Post post) {
 231                 checkNotNull(post, "post must not be null");
 232                 lock.writeLock().lock();
 233                 try {
 234                         allPosts.remove(post.getId());
 235                         getPostsFrom(post.getSone().getId()).remove(post);
 236                         if (post.getRecipientId().isPresent()) {
 237                                 getPostsTo(post.getRecipientId().get()).remove(post);
 238                         }
 239                         post.getSone().removePost(post);
 240                 } finally {
 241                         lock.writeLock().unlock();
 242                 }
 243         }
 244
 245         /** {@inheritDocs} */
 246         @Override
 247         public void storePosts(Sone sone, Collection<Post> posts) throws IllegalArgumentException {
 248                 checkNotNull(sone, "sone must not be null");
 249                 /* verify that all posts are from the same Sone. */
 250                 for (Post post : posts) {
 251                         if (!sone.equals(post.getSone())) {
 252                                 throw new IllegalArgumentException(String.format("Post from different Sone found: %s", post));
 253                         }
 254                 }
 255
 256                 lock.writeLock().lock();
 257                 try {
 258                         /* remove all posts by the Sone. */
 259                         getPostsFrom(sone.getId()).clear();
 260                         for (Post post : posts) {
 261                                 allPosts.remove(post.getId());
 262                                 if (post.getRecipientId().isPresent()) {
 263                                         getPostsTo(post.getRecipientId().get()).remove(post);
 264                                 }
 265                         }
 266
 267                         /* add new posts. */
 268                         getPostsFrom(sone.getId()).addAll(posts);
 269                         for (Post post : posts) {
 270                                 allPosts.put(post.getId(), post);
 271                                 if (post.getRecipientId().isPresent()) {
 272                                         getPostsTo(post.getRecipientId().get()).add(post);
 273                                 }
 274                         }
 275                 } finally {
 276                         lock.writeLock().unlock();
 277                 }
 278         }
 279
 280         /** {@inheritDocs} */
 281         @Override
 282         public void removePosts(Sone sone) {
 283                 checkNotNull(sone, "sone must not be null");
 284                 lock.writeLock().lock();
 285                 try {
 286                         /* remove all posts by the Sone. */
 287                         getPostsFrom(sone.getId()).clear();
 288                         for (Post post : sone.getPosts()) {
 289                                 allPosts.remove(post.getId());
 290                                 if (post.getRecipientId().isPresent()) {
 291                                         getPostsTo(post.getRecipientId().get()).remove(post);
 292                                 }
 293                         }
 294                 } finally {
 295                         lock.writeLock().unlock();
 296                 }
 297         }
 298
 299         //
 300         // POSTREPLYPROVIDER METHODS
 301         //
 302
 303         /** {@inheritDocs} */
 304         @Override
 305         public Optional<PostReply> getPostReply(String id) {
 306                 lock.readLock().lock();
 307                 try {
 308                         return fromNullable(allPostReplies.get(id));
 309                 } finally {
 310                         lock.readLock().unlock();
 311                 }
 312         }
 313
 314         /** {@inheritDocs} */
 315         @Override
 316         public List<PostReply> getReplies(String postId) {
 317                 lock.readLock().lock();
 318                 try {
 319                         if (!postReplies.containsKey(postId)) {
 320                                 return Collections.emptyList();
 321                         }
 322                         return new ArrayList<PostReply>(postReplies.get(postId));
 323                 } finally {
 324                         lock.readLock().unlock();
 325                 }
 326         }
 327
 328         //
 329         // POSTREPLYBUILDERFACTORY METHODS
 330         //
 331
 332         /** {@inheritDocs} */
 333         @Override
 334         public PostReplyBuilder newPostReplyBuilder() {
 335                 return new MemoryPostReplyBuilder(this, soneProvider);
 336         }
 337
 338         //
 339         // POSTREPLYSTORE METHODS
 340         //
 341
 342         /** {@inheritDocs} */
 343         @Override
 344         public void storePostReply(PostReply postReply) {
 345                 lock.writeLock().lock();
 346                 try {
 347                         allPostReplies.put(postReply.getId(), postReply);
 348                         if (postReplies.containsKey(postReply.getPostId())) {
 349                                 postReplies.get(postReply.getPostId()).add(postReply);
 350                         } else {
 351                                 TreeSet<PostReply> replies = new TreeSet<PostReply>(Reply.TIME_COMPARATOR);
 352                                 replies.add(postReply);
 353                                 postReplies.put(postReply.getPostId(), replies);
 354                         }
 355                 } finally {
 356                         lock.writeLock().unlock();
 357                 }
 358         }
 359
 360         /** {@inheritDocs} */
 361         @Override
 362         public void storePostReplies(Sone sone, Collection<PostReply> postReplies) {
 363                 checkNotNull(sone, "sone must not be null");
 364                 /* verify that all posts are from the same Sone. */
 365                 for (PostReply postReply : postReplies) {
 366                         if (!sone.equals(postReply.getSone())) {
 367                                 throw new IllegalArgumentException(String.format("PostReply from different Sone found: %s", postReply));
 368                         }
 369                 }
 370
 371                 lock.writeLock().lock();
 372                 try {
 373                         /* remove all post replies of the Sone. */
 374                         for (PostReply postReply : getRepliesFrom(sone.getId())) {
 375                                 removePostReply(postReply);
 376                         }
 377                         for (PostReply postReply : postReplies) {
 378                                 allPostReplies.put(postReply.getId(), postReply);
 379                                 sonePostReplies.put(postReply.getSone().getId(), postReply);
 380                                 if (this.postReplies.containsKey(postReply.getPostId())) {
 381                                         this.postReplies.get(postReply.getPostId()).add(postReply);
 382                                 } else {
 383                                         TreeSet<PostReply> replies = new TreeSet<PostReply>(Reply.TIME_COMPARATOR);
 384                                         replies.add(postReply);
 385                                         this.postReplies.put(postReply.getPostId(), replies);
 386                                 }
 387                         }
 388                 } finally {
 389                         lock.writeLock().unlock();
 390                 }
 391         }
 392
 393         /** {@inheritDocs} */
 394         @Override
 395         public void removePostReply(PostReply postReply) {
 396                 lock.writeLock().lock();
 397                 try {
 398                         allPostReplies.remove(postReply.getId());
 399                         if (postReplies.containsKey(postReply.getPostId())) {
 400                                 postReplies.get(postReply.getPostId()).remove(postReply);
 401                                 if (postReplies.get(postReply.getPostId()).isEmpty()) {
 402                                         postReplies.remove(postReply.getPostId());
 403                                 }
 404                         }
 405                 } finally {
 406                         lock.writeLock().unlock();
 407                 }
 408         }
 409
 410         /** {@inheritDocs} */
 411         @Override
 412         public void removePostReplies(Sone sone) {
 413                 checkNotNull(sone, "sone must not be null");
 414
 415                 lock.writeLock().lock();
 416                 try {
 417                         for (PostReply postReply : sone.getReplies()) {
 418                                 removePostReply(postReply);
 419                         }
 420                 } finally {
 421                         lock.writeLock().unlock();
 422                 }
 423         }
 424
 425         //
 426         // ALBUMPROVDER METHODS
 427         //
 428
 429         @Override
 430         public Optional<Album> getAlbum(String albumId) {
 431                 lock.readLock().lock();
 432                 try {
 433                         return fromNullable(allAlbums.get(albumId));
 434                 } finally {
 435                         lock.readLock().unlock();
 436                 }
 437         }
 438
 439         //
 440         // ALBUMSTORE METHODS
 441         //
 442
 443         @Override
 444         public void storeAlbum(Album album) {
 445                 lock.writeLock().lock();
 446                 try {
 447                         allAlbums.put(album.getId(), album);
 448                 } finally {
 449                         lock.writeLock().unlock();
 450                 }
 451         }
 452
 453         @Override
 454         public void removeAlbum(Album album) {
 455                 lock.writeLock().lock();
 456                 try {
 457                         allAlbums.remove(album.getId());
 458                 } finally {
 459                         lock.writeLock().unlock();
 460                 }
 461         }
 462
 463         //
 464         // IMAGEPROVIDER METHODS
 465         //
 466
 467         @Override
 468         public Optional<Image> getImage(String imageId) {
 469                 lock.readLock().lock();
 470                 try {
 471                         return fromNullable(allImages.get(imageId));
 472                 } finally {
 473                         lock.readLock().unlock();
 474                 }
 475         }
 476
 477         //
 478         // IMAGESTORE METHODS
 479         //
 480
 481         @Override
 482         public void storeImage(Image image) {
 483                 lock.writeLock().lock();
 484                 try {
 485                         allImages.put(image.getId(), image);
 486                         albumImages.put(image.getAlbum().getId(), image.getId());
 487                 } finally {
 488                         lock.writeLock().unlock();
 489                 }
 490         }
 491
 492         @Override
 493         public void removeImage(Image image) {
 494                 lock.writeLock().lock();
 495                 try {
 496                         allImages.remove(image.getId());
 497                         albumImages.remove(image.getAlbum().getId(), image.getId());
 498                 } finally {
 499                         lock.writeLock().unlock();
 500                 }
 501         }
 502
 503         //
 504         // PACKAGE-PRIVATE METHODS
 505         //
 506
 507         /**
 508          * Returns whether the given post is known.
 509          *
 510          * @param post
 511          *              The post
 512          * @return {@code true} if the post is known, {@code false} otherwise
 513          */
 514         boolean isPostKnown(Post post) {
 515                 lock.readLock().lock();
 516                 try {
 517                         return knownPosts.contains(post.getId());
 518                 } finally {
 519                         lock.readLock().unlock();
 520                 }
 521         }
 522
 523         /**
 524          * Sets whether the given post is known.
 525          *
 526          * @param post
 527          *              The post
 528          * @param known
 529          *              {@code true} if the post is known, {@code false} otherwise
 530          */
 531         void setPostKnown(Post post, boolean known) {
 532                 lock.writeLock().lock();
 533                 try {
 534                         if (known) {
 535                                 knownPosts.add(post.getId());
 536                         } else {
 537                                 knownPosts.remove(post.getId());
 538                         }
 539                 } finally {
 540                         lock.writeLock().unlock();
 541                 }
 542         }
 543
 544         /**
 545          * Returns whether the given post reply is known.
 546          *
 547          * @param postReply
 548          *              The post reply
 549          * @return {@code true} if the given post reply is known, {@code false}
 550          *         otherwise
 551          */
 552         boolean isPostReplyKnown(PostReply postReply) {
 553                 lock.readLock().lock();
 554                 try {
 555                         return knownPostReplies.contains(postReply.getId());
 556                 } finally {
 557                         lock.readLock().unlock();
 558                 }
 559         }
 560
 561         /**
 562          * Sets whether the given post reply is known.
 563          *
 564          * @param postReply
 565          *              The post reply
 566          * @param known
 567          *              {@code true} if the post reply is known, {@code false} otherwise
 568          */
 569         void setPostReplyKnown(PostReply postReply, boolean known) {
 570                 lock.writeLock().lock();
 571                 try {
 572                         if (known) {
 573                                 knownPostReplies.add(postReply.getId());
 574                         } else {
 575                                 knownPostReplies.remove(postReply.getId());
 576                         }
 577                 } finally {
 578                         lock.writeLock().unlock();
 579                 }
 580         }
 581
 582         //
 583         // PRIVATE METHODS
 584         //
 585
 586         /**
 587          * Gets all posts for the given Sone, creating a new collection if there is
 588          * none yet.
 589          *
 590          * @param soneId
 591          *              The ID of the Sone to get the posts for
 592          * @return All posts
 593          */
 594         private Collection<Post> getPostsFrom(String soneId) {
 595                 Collection<Post> posts = null;
 596                 lock.readLock().lock();
 597                 try {
 598                         posts = sonePosts.get(soneId);
 599                 } finally {
 600                         lock.readLock().unlock();
 601                 }
 602                 if (posts != null) {
 603                         return posts;
 604                 }
 605
 606                 posts = new HashSet<Post>();
 607                 lock.writeLock().lock();
 608                 try {
 609                         sonePosts.put(soneId, posts);
 610                 } finally {
 611                         lock.writeLock().unlock();
 612                 }
 613
 614                 return posts;
 615         }
 616
 617         /**
 618          * Gets all posts that are directed the given Sone, creating a new collection
 619          * if there is none yet.
 620          *
 621          * @param recipientId
 622          *              The ID of the Sone to get the posts for
 623          * @return All posts
 624          */
 625         private Collection<Post> getPostsTo(String recipientId) {
 626                 Collection<Post> posts = null;
 627                 lock.readLock().lock();
 628                 try {
 629                         posts = recipientPosts.get(recipientId);
 630                 } finally {
 631                         lock.readLock().unlock();
 632                 }
 633                 if (posts != null) {
 634                         return posts;
 635                 }
 636
 637                 posts = new HashSet<Post>();
 638                 lock.writeLock().lock();
 639                 try {
 640                         recipientPosts.put(recipientId, posts);
 641                 } finally {
 642                         lock.writeLock().unlock();
 643                 }
 644
 645                 return posts;
 646         }
 647
 648         /** Loads the known posts. */
 649         private void loadKnownPosts() {
 650                 lock.writeLock().lock();
 651                 try {
 652                         int postCounter = 0;
 653                         while (true) {
 654                                 String knownPostId = configuration.getStringValue("KnownPosts/" + postCounter++ + "/ID").getValue(null);
 655                                 if (knownPostId == null) {
 656                                         break;
 657                                 }
 658                                 knownPosts.add(knownPostId);
 659                         }
 660                 } finally {
 661                         lock.writeLock().unlock();
 662                 }
 663         }
 664
 665         /**
 666          * Saves the known posts to the configuration.
 667          *
 668          * @throws DatabaseException
 669          *              if a configuration error occurs
 670          */
 671         private void saveKnownPosts() throws DatabaseException {
 672                 lock.readLock().lock();
 673                 try {
 674                         int postCounter = 0;
 675                         for (String knownPostId : knownPosts) {
 676                                 configuration.getStringValue("KnownPosts/" + postCounter++ + "/ID").setValue(knownPostId);
 677                         }
 678                         configuration.getStringValue("KnownPosts/" + postCounter + "/ID").setValue(null);
 679                 } catch (ConfigurationException ce1) {
 680                         throw new DatabaseException("Could not save database.", ce1);
 681                 } finally {
 682                         lock.readLock().unlock();
 683                 }
 684         }
 685
 686         /**
 687          * Returns all replies by the given Sone.
 688          *
 689          * @param id
 690          *              The ID of the Sone
 691          * @return The post replies of the Sone, sorted by time (newest first)
 692          */
 693         private Collection<PostReply> getRepliesFrom(String id) {
 694                 lock.readLock().lock();
 695                 try {
 696                         if (sonePostReplies.containsKey(id)) {
 697                                 return Collections.unmodifiableCollection(sonePostReplies.get(id));
 698                         }
 699                         return Collections.emptySet();
 700                 } finally {
 701                         lock.readLock().unlock();
 702                 }
 703         }
 704
 705         /** Loads the known post replies. */
 706         private void loadKnownPostReplies() {
 707                 lock.writeLock().lock();
 708                 try {
 709                         int replyCounter = 0;
 710                         while (true) {
 711                                 String knownReplyId = configuration.getStringValue("KnownReplies/" + replyCounter++ + "/ID").getValue(null);
 712                                 if (knownReplyId == null) {
 713                                         break;
 714                                 }
 715                                 knownPostReplies.add(knownReplyId);
 716                         }
 717                 } finally {
 718                         lock.writeLock().unlock();
 719                 }
 720         }
 721
 722         /**
 723          * Saves the known post replies to the configuration.
 724          *
 725          * @throws DatabaseException
 726          *              if a configuration error occurs
 727          */
 728         private void saveKnownPostReplies() throws DatabaseException {
 729                 lock.readLock().lock();
 730                 try {
 731                         int replyCounter = 0;
 732                         for (String knownReplyId : knownPostReplies) {
 733                                 configuration.getStringValue("KnownReplies/" + replyCounter++ + "/ID").setValue(knownReplyId);
 734                         }
 735                         configuration.getStringValue("KnownReplies/" + replyCounter + "/ID").setValue(null);
 736                 } catch (ConfigurationException ce1) {
 737                         throw new DatabaseException("Could not save database.", ce1);
 738                 } finally {
 739                         lock.readLock().unlock();
 740                 }
 741         }
 742
 743 }