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 net.pterodactylus.sone.data.Reply.TIME_COMPARATOR;
  23
  24 import java.util.ArrayList;
  25 import java.util.Collection;
  26 import java.util.Collections;
  27 import java.util.Comparator;
  28 import java.util.HashMap;
  29 import java.util.HashSet;
  30 import java.util.List;
  31 import java.util.Map;
  32 import java.util.Set;
  33 import java.util.concurrent.locks.ReadWriteLock;
  34 import java.util.concurrent.locks.ReentrantReadWriteLock;
  35
  36 import net.pterodactylus.sone.data.Album;
  37 import net.pterodactylus.sone.data.Image;
  38 import net.pterodactylus.sone.data.Post;
  39 import net.pterodactylus.sone.data.PostReply;
  40 import net.pterodactylus.sone.data.Sone;
  41 import net.pterodactylus.sone.data.impl.AlbumBuilderImpl;
  42 import net.pterodactylus.sone.data.impl.ImageBuilderImpl;
  43 import net.pterodactylus.sone.database.AlbumBuilder;
  44 import net.pterodactylus.sone.database.Database;
  45 import net.pterodactylus.sone.database.DatabaseException;
  46 import net.pterodactylus.sone.database.ImageBuilder;
  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.HashMultimap;
  56 import com.google.common.collect.Multimap;
  57 import com.google.common.collect.SortedSetMultimap;
  58 import com.google.common.collect.TreeMultimap;
  59 import com.google.common.util.concurrent.AbstractService;
  60 import com.google.inject.Inject;
  61 import com.google.inject.Singleton;
  62
  63 /**
  64  * Memory-based {@link PostDatabase} implementation.
  65  *
  66  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  67  */
  68 @Singleton
  69 public class MemoryDatabase extends AbstractService implements Database {
  70
  71         /** The lock. */
  72         private final ReadWriteLock lock = new ReentrantReadWriteLock();
  73
  74         /** The Sone provider. */
  75         private final SoneProvider soneProvider;
  76
  77         /** The configuration. */
  78         private final Configuration configuration;
  79
  80         /** All posts by their ID. */
  81         private final Map<String, Post> allPosts = new HashMap<String, Post>();
  82
  83         /** All posts by their Sones. */
  84         private final Multimap<String, Post> sonePosts = HashMultimap.create();
  85
  86         /** All posts by their recipient. */
  87         private final Multimap<String, Post> recipientPosts = HashMultimap.create();
  88
  89         /** Whether posts are known. */
  90         private final Set<String> knownPosts = new HashSet<String>();
  91
  92         /** All post replies by their ID. */
  93         private final Map<String, PostReply> allPostReplies = new HashMap<String, PostReply>();
  94
  95         /** Replies sorted by Sone. */
  96         private final SortedSetMultimap<String, PostReply> sonePostReplies = TreeMultimap.create(new Comparator<String>() {
  97
  98                 @Override
  99                 public int compare(String leftString, String rightString) {
 100                         return leftString.compareTo(rightString);
 101                 }
 102         }, TIME_COMPARATOR);
 103
 104         /** Replies by post. */
 105         private final SortedSetMultimap<String, PostReply> postReplies = TreeMultimap.create(new Comparator<String>() {
 106
 107                 @Override
 108                 public int compare(String leftString, String rightString) {
 109                         return leftString.compareTo(rightString);
 110                 }
 111         }, TIME_COMPARATOR);
 112
 113         /** Whether post replies are known. */
 114         private final Set<String> knownPostReplies = new HashSet<String>();
 115
 116         private final Map<String, Album> allAlbums = new HashMap<String, Album>();
 117         private final Multimap<String, Album> soneAlbums = HashMultimap.create();
 118
 119         private final Map<String, Image> allImages = new HashMap<String, Image>();
 120         private final Multimap<String, Image> soneImages = HashMultimap.create();
 121
 122         /**
 123          * Creates a new memory database.
 124          *
 125          * @param soneProvider
 126          *              The Sone provider
 127          * @param configuration
 128          *              The configuration for loading and saving elements
 129          */
 130         @Inject
 131         public MemoryDatabase(SoneProvider soneProvider, Configuration configuration) {
 132                 this.soneProvider = soneProvider;
 133                 this.configuration = configuration;
 134         }
 135
 136         //
 137         // DATABASE METHODS
 138         //
 139
 140         /**
 141          * Saves the database.
 142          *
 143          * @throws DatabaseException
 144          *              if an error occurs while saving
 145          */
 146         @Override
 147         public void save() throws DatabaseException {
 148                 saveKnownPosts();
 149                 saveKnownPostReplies();
 150         }
 151
 152         //
 153         // SERVICE METHODS
 154         //
 155
 156         /** {@inheritDocs} */
 157         @Override
 158         protected void doStart() {
 159                 loadKnownPosts();
 160                 loadKnownPostReplies();
 161                 notifyStarted();
 162         }
 163
 164         /** {@inheritDocs} */
 165         @Override
 166         protected void doStop() {
 167                 try {
 168                         save();
 169                         notifyStopped();
 170                 } catch (DatabaseException de1) {
 171                         notifyFailed(de1);
 172                 }
 173         }
 174
 175         //
 176         // POSTPROVIDER METHODS
 177         //
 178
 179         /** {@inheritDocs} */
 180         @Override
 181         public Optional<Post> getPost(String postId) {
 182                 lock.readLock().lock();
 183                 try {
 184                         return fromNullable(allPosts.get(postId));
 185                 } finally {
 186                         lock.readLock().unlock();
 187                 }
 188         }
 189
 190         /** {@inheritDocs} */
 191         @Override
 192         public Collection<Post> getPosts(String soneId) {
 193                 return new HashSet<Post>(getPostsFrom(soneId));
 194         }
 195
 196         /** {@inheritDocs} */
 197         @Override
 198         public Collection<Post> getDirectedPosts(String recipientId) {
 199                 lock.readLock().lock();
 200                 try {
 201                         Collection<Post> posts = recipientPosts.get(recipientId);
 202                         return (posts == null) ? Collections.<Post>emptySet() : new HashSet<Post>(posts);
 203                 } finally {
 204                         lock.readLock().unlock();
 205                 }
 206         }
 207
 208         //
 209         // POSTBUILDERFACTORY METHODS
 210         //
 211
 212         /** {@inheritDocs} */
 213         @Override
 214         public PostBuilder newPostBuilder() {
 215                 return new MemoryPostBuilder(this, soneProvider);
 216         }
 217
 218         //
 219         // POSTSTORE METHODS
 220         //
 221
 222         /** {@inheritDocs} */
 223         @Override
 224         public void storePost(Post post) {
 225                 checkNotNull(post, "post must not be null");
 226                 lock.writeLock().lock();
 227                 try {
 228                         allPosts.put(post.getId(), post);
 229                         getPostsFrom(post.getSone().getId()).add(post);
 230                         if (post.getRecipientId().isPresent()) {
 231                                 getPostsTo(post.getRecipientId().get()).add(post);
 232                         }
 233                 } finally {
 234                         lock.writeLock().unlock();
 235                 }
 236         }
 237
 238         /** {@inheritDocs} */
 239         @Override
 240         public void removePost(Post post) {
 241                 checkNotNull(post, "post must not be null");
 242                 lock.writeLock().lock();
 243                 try {
 244                         allPosts.remove(post.getId());
 245                         getPostsFrom(post.getSone().getId()).remove(post);
 246                         if (post.getRecipientId().isPresent()) {
 247                                 getPostsTo(post.getRecipientId().get()).remove(post);
 248                         }
 249                         post.getSone().removePost(post);
 250                 } finally {
 251                         lock.writeLock().unlock();
 252                 }
 253         }
 254
 255         /** {@inheritDocs} */
 256         @Override
 257         public void storePosts(Sone sone, Collection<Post> posts) throws IllegalArgumentException {
 258                 checkNotNull(sone, "sone must not be null");
 259                 /* verify that all posts are from the same Sone. */
 260                 for (Post post : posts) {
 261                         if (!sone.equals(post.getSone())) {
 262                                 throw new IllegalArgumentException(String.format("Post from different Sone found: %s", post));
 263                         }
 264                 }
 265
 266                 lock.writeLock().lock();
 267                 try {
 268                         /* remove all posts by the Sone. */
 269                         Collection<Post> oldPosts = getPostsFrom(sone.getId());
 270                         for (Post post : oldPosts) {
 271                                 allPosts.remove(post.getId());
 272                                 if (post.getRecipientId().isPresent()) {
 273                                         getPostsTo(post.getRecipientId().get()).remove(post);
 274                                 }
 275                         }
 276
 277                         /* add new posts. */
 278                         getPostsFrom(sone.getId()).addAll(posts);
 279                         for (Post post : posts) {
 280                                 allPosts.put(post.getId(), post);
 281                                 if (post.getRecipientId().isPresent()) {
 282                                         getPostsTo(post.getRecipientId().get()).add(post);
 283                                 }
 284                         }
 285                 } finally {
 286                         lock.writeLock().unlock();
 287                 }
 288         }
 289
 290         /** {@inheritDocs} */
 291         @Override
 292         public void removePosts(Sone sone) {
 293                 checkNotNull(sone, "sone must not be null");
 294                 lock.writeLock().lock();
 295                 try {
 296                         /* remove all posts by the Sone. */
 297                         getPostsFrom(sone.getId()).clear();
 298                         for (Post post : sone.getPosts()) {
 299                                 allPosts.remove(post.getId());
 300                                 if (post.getRecipientId().isPresent()) {
 301                                         getPostsTo(post.getRecipientId().get()).remove(post);
 302                                 }
 303                         }
 304                 } finally {
 305                         lock.writeLock().unlock();
 306                 }
 307         }
 308
 309         //
 310         // POSTREPLYPROVIDER METHODS
 311         //
 312
 313         /** {@inheritDocs} */
 314         @Override
 315         public Optional<PostReply> getPostReply(String id) {
 316                 lock.readLock().lock();
 317                 try {
 318                         return fromNullable(allPostReplies.get(id));
 319                 } finally {
 320                         lock.readLock().unlock();
 321                 }
 322         }
 323
 324         /** {@inheritDocs} */
 325         @Override
 326         public List<PostReply> getReplies(String postId) {
 327                 lock.readLock().lock();
 328                 try {
 329                         if (!postReplies.containsKey(postId)) {
 330                                 return Collections.emptyList();
 331                         }
 332                         return new ArrayList<PostReply>(postReplies.get(postId));
 333                 } finally {
 334                         lock.readLock().unlock();
 335                 }
 336         }
 337
 338         //
 339         // POSTREPLYBUILDERFACTORY METHODS
 340         //
 341
 342         /** {@inheritDocs} */
 343         @Override
 344         public PostReplyBuilder newPostReplyBuilder() {
 345                 return new MemoryPostReplyBuilder(this, soneProvider);
 346         }
 347
 348         //
 349         // POSTREPLYSTORE METHODS
 350         //
 351
 352         /** {@inheritDocs} */
 353         @Override
 354         public void storePostReply(PostReply postReply) {
 355                 lock.writeLock().lock();
 356                 try {
 357                         allPostReplies.put(postReply.getId(), postReply);
 358                         postReplies.put(postReply.getPostId(), postReply);
 359                 } finally {
 360                         lock.writeLock().unlock();
 361                 }
 362         }
 363
 364         /** {@inheritDocs} */
 365         @Override
 366         public void storePostReplies(Sone sone, Collection<PostReply> postReplies) {
 367                 checkNotNull(sone, "sone must not be null");
 368                 /* verify that all posts are from the same Sone. */
 369                 for (PostReply postReply : postReplies) {
 370                         if (!sone.equals(postReply.getSone())) {
 371                                 throw new IllegalArgumentException(String.format("PostReply from different Sone found: %s", postReply));
 372                         }
 373                 }
 374
 375                 lock.writeLock().lock();
 376                 try {
 377                         /* remove all post replies of the Sone. */
 378                         for (PostReply postReply : getRepliesFrom(sone.getId())) {
 379                                 removePostReply(postReply);
 380                         }
 381                         for (PostReply postReply : postReplies) {
 382                                 allPostReplies.put(postReply.getId(), postReply);
 383                                 sonePostReplies.put(postReply.getSone().getId(), postReply);
 384                                 this.postReplies.put(postReply.getPostId(), postReply);
 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                         }
 400                 } finally {
 401                         lock.writeLock().unlock();
 402                 }
 403         }
 404
 405         /** {@inheritDocs} */
 406         @Override
 407         public void removePostReplies(Sone sone) {
 408                 checkNotNull(sone, "sone must not be null");
 409
 410                 lock.writeLock().lock();
 411                 try {
 412                         for (PostReply postReply : sone.getReplies()) {
 413                                 removePostReply(postReply);
 414                         }
 415                 } finally {
 416                         lock.writeLock().unlock();
 417                 }
 418         }
 419
 420         //
 421         // ALBUMPROVDER METHODS
 422         //
 423
 424         @Override
 425         public Optional<Album> getAlbum(String albumId) {
 426                 lock.readLock().lock();
 427                 try {
 428                         return fromNullable(allAlbums.get(albumId));
 429                 } finally {
 430                         lock.readLock().unlock();
 431                 }
 432         }
 433
 434         //
 435         // ALBUMBUILDERFACTORY METHODS
 436         //
 437
 438         @Override
 439         public AlbumBuilder newAlbumBuilder() {
 440                 return new AlbumBuilderImpl();
 441         }
 442
 443         //
 444         // ALBUMSTORE METHODS
 445         //
 446
 447         @Override
 448         public void storeAlbum(Album album) {
 449                 lock.writeLock().lock();
 450                 try {
 451                         allAlbums.put(album.getId(), album);
 452                         soneAlbums.put(album.getSone().getId(), album);
 453                 } finally {
 454                         lock.writeLock().unlock();
 455                 }
 456         }
 457
 458         @Override
 459         public void removeAlbum(Album album) {
 460                 lock.writeLock().lock();
 461                 try {
 462                         allAlbums.remove(album.getId());
 463                         soneAlbums.remove(album.getSone().getId(), album);
 464                 } finally {
 465                         lock.writeLock().unlock();
 466                 }
 467         }
 468
 469         //
 470         // IMAGEPROVIDER METHODS
 471         //
 472
 473         @Override
 474         public Optional<Image> getImage(String imageId) {
 475                 lock.readLock().lock();
 476                 try {
 477                         return fromNullable(allImages.get(imageId));
 478                 } finally {
 479                         lock.readLock().unlock();
 480                 }
 481         }
 482
 483         //
 484         // IMAGEBUILDERFACTORY METHODS
 485         //
 486
 487         @Override
 488         public ImageBuilder newImageBuilder() {
 489                 return new ImageBuilderImpl();
 490         }
 491
 492         //
 493         // IMAGESTORE METHODS
 494         //
 495
 496         @Override
 497         public void storeImage(Image image) {
 498                 lock.writeLock().lock();
 499                 try {
 500                         allImages.put(image.getId(), image);
 501                         soneImages.put(image.getSone().getId(), image);
 502                 } finally {
 503                         lock.writeLock().unlock();
 504                 }
 505         }
 506
 507         @Override
 508         public void removeImage(Image image) {
 509                 lock.writeLock().lock();
 510                 try {
 511                         allImages.remove(image.getId());
 512                         soneImages.remove(image.getSone().getId(), image);
 513                 } finally {
 514                         lock.writeLock().unlock();
 515                 }
 516         }
 517
 518         //
 519         // PACKAGE-PRIVATE METHODS
 520         //
 521
 522         /**
 523          * Returns whether the given post is known.
 524          *
 525          * @param post
 526          *              The post
 527          * @return {@code true} if the post is known, {@code false} otherwise
 528          */
 529         boolean isPostKnown(Post post) {
 530                 lock.readLock().lock();
 531                 try {
 532                         return knownPosts.contains(post.getId());
 533                 } finally {
 534                         lock.readLock().unlock();
 535                 }
 536         }
 537
 538         /**
 539          * Sets whether the given post is known.
 540          *
 541          * @param post
 542          *              The post
 543          * @param known
 544          *              {@code true} if the post is known, {@code false} otherwise
 545          */
 546         void setPostKnown(Post post, boolean known) {
 547                 lock.writeLock().lock();
 548                 try {
 549                         if (known) {
 550                                 knownPosts.add(post.getId());
 551                         } else {
 552                                 knownPosts.remove(post.getId());
 553                         }
 554                 } finally {
 555                         lock.writeLock().unlock();
 556                 }
 557         }
 558
 559         /**
 560          * Returns whether the given post reply is known.
 561          *
 562          * @param postReply
 563          *              The post reply
 564          * @return {@code true} if the given post reply is known, {@code false}
 565          *         otherwise
 566          */
 567         boolean isPostReplyKnown(PostReply postReply) {
 568                 lock.readLock().lock();
 569                 try {
 570                         return knownPostReplies.contains(postReply.getId());
 571                 } finally {
 572                         lock.readLock().unlock();
 573                 }
 574         }
 575
 576         /**
 577          * Sets whether the given post reply is known.
 578          *
 579          * @param postReply
 580          *              The post reply
 581          * @param known
 582          *              {@code true} if the post reply is known, {@code false} otherwise
 583          */
 584         void setPostReplyKnown(PostReply postReply, boolean known) {
 585                 lock.writeLock().lock();
 586                 try {
 587                         if (known) {
 588                                 knownPostReplies.add(postReply.getId());
 589                         } else {
 590                                 knownPostReplies.remove(postReply.getId());
 591                         }
 592                 } finally {
 593                         lock.writeLock().unlock();
 594                 }
 595         }
 596
 597         //
 598         // PRIVATE METHODS
 599         //
 600
 601         /**
 602          * Gets all posts for the given Sone, creating a new collection if there is
 603          * none yet.
 604          *
 605          * @param soneId
 606          *              The ID of the Sone to get the posts for
 607          * @return All posts
 608          */
 609         private Collection<Post> getPostsFrom(String soneId) {
 610                 lock.readLock().lock();
 611                 try {
 612                         return sonePosts.get(soneId);
 613                 } finally {
 614                         lock.readLock().unlock();
 615                 }
 616         }
 617
 618         /**
 619          * Gets all posts that are directed the given Sone, creating a new collection
 620          * if there is none yet.
 621          *
 622          * @param recipientId
 623          *              The ID of the Sone to get the posts for
 624          * @return All posts
 625          */
 626         private Collection<Post> getPostsTo(String recipientId) {
 627                 lock.readLock().lock();
 628                 try {
 629                         return recipientPosts.get(recipientId);
 630                 } finally {
 631                         lock.readLock().unlock();
 632                 }
 633         }
 634
 635         /** Loads the known posts. */
 636         private void loadKnownPosts() {
 637                 lock.writeLock().lock();
 638                 try {
 639                         int postCounter = 0;
 640                         while (true) {
 641                                 String knownPostId = configuration.getStringValue("KnownPosts/" + postCounter++ + "/ID").getValue(null);
 642                                 if (knownPostId == null) {
 643                                         break;
 644                                 }
 645                                 knownPosts.add(knownPostId);
 646                         }
 647                 } finally {
 648                         lock.writeLock().unlock();
 649                 }
 650         }
 651
 652         /**
 653          * Saves the known posts to the configuration.
 654          *
 655          * @throws DatabaseException
 656          *              if a configuration error occurs
 657          */
 658         private void saveKnownPosts() throws DatabaseException {
 659                 lock.readLock().lock();
 660                 try {
 661                         int postCounter = 0;
 662                         for (String knownPostId : knownPosts) {
 663                                 configuration.getStringValue("KnownPosts/" + postCounter++ + "/ID").setValue(knownPostId);
 664                         }
 665                         configuration.getStringValue("KnownPosts/" + postCounter + "/ID").setValue(null);
 666                 } catch (ConfigurationException ce1) {
 667                         throw new DatabaseException("Could not save database.", ce1);
 668                 } finally {
 669                         lock.readLock().unlock();
 670                 }
 671         }
 672
 673         /**
 674          * Returns all replies by the given Sone.
 675          *
 676          * @param id
 677          *              The ID of the Sone
 678          * @return The post replies of the Sone, sorted by time (newest first)
 679          */
 680         private Collection<PostReply> getRepliesFrom(String id) {
 681                 lock.readLock().lock();
 682                 try {
 683                         return Collections.unmodifiableCollection(sonePostReplies.get(id));
 684                 } finally {
 685                         lock.readLock().unlock();
 686                 }
 687         }
 688
 689         /** Loads the known post replies. */
 690         private void loadKnownPostReplies() {
 691                 lock.writeLock().lock();
 692                 try {
 693                         int replyCounter = 0;
 694                         while (true) {
 695                                 String knownReplyId = configuration.getStringValue("KnownReplies/" + replyCounter++ + "/ID").getValue(null);
 696                                 if (knownReplyId == null) {
 697                                         break;
 698                                 }
 699                                 knownPostReplies.add(knownReplyId);
 700                         }
 701                 } finally {
 702                         lock.writeLock().unlock();
 703                 }
 704         }
 705
 706         /**
 707          * Saves the known post replies to the configuration.
 708          *
 709          * @throws DatabaseException
 710          *              if a configuration error occurs
 711          */
 712         private void saveKnownPostReplies() throws DatabaseException {
 713                 lock.readLock().lock();
 714                 try {
 715                         int replyCounter = 0;
 716                         for (String knownReplyId : knownPostReplies) {
 717                                 configuration.getStringValue("KnownReplies/" + replyCounter++ + "/ID").setValue(knownReplyId);
 718                         }
 719                         configuration.getStringValue("KnownReplies/" + replyCounter + "/ID").setValue(null);
 720                 } catch (ConfigurationException ce1) {
 721                         throw new DatabaseException("Could not save database.", ce1);
 722                 } finally {
 723                         lock.readLock().unlock();
 724                 }
 725         }
 726
 727 }