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

   1 /*
   2  * Sone - MemoryDatabase.java - Copyright © 2013 David Roden
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.pterodactylus.sone.database.memory;
  19
  20 import static com.google.common.base.Optional.fromNullable;
  21 import static com.google.common.base.Preconditions.checkNotNull;
  22 import static com.google.common.collect.FluentIterable.from;
  23 import static net.pterodactylus.sone.data.Reply.TIME_COMPARATOR;
  24
  25 import java.util.ArrayList;
  26 import java.util.Collection;
  27 import java.util.Collections;
  28 import java.util.Comparator;
  29 import java.util.HashMap;
  30 import java.util.HashSet;
  31 import java.util.List;
  32 import java.util.Map;
  33 import java.util.Set;
  34 import java.util.concurrent.locks.ReadWriteLock;
  35 import java.util.concurrent.locks.ReentrantReadWriteLock;
  36
  37 import net.pterodactylus.sone.data.Album;
  38 import net.pterodactylus.sone.data.Image;
  39 import net.pterodactylus.sone.data.Post;
  40 import net.pterodactylus.sone.data.PostReply;
  41 import net.pterodactylus.sone.data.Sone;
  42 import net.pterodactylus.sone.data.impl.AlbumBuilderImpl;
  43 import net.pterodactylus.sone.data.impl.ImageBuilderImpl;
  44 import net.pterodactylus.sone.database.AlbumBuilder;
  45 import net.pterodactylus.sone.database.Database;
  46 import net.pterodactylus.sone.database.DatabaseException;
  47 import net.pterodactylus.sone.database.ImageBuilder;
  48 import net.pterodactylus.sone.database.PostBuilder;
  49 import net.pterodactylus.sone.database.PostDatabase;
  50 import net.pterodactylus.sone.database.PostReplyBuilder;
  51 import net.pterodactylus.sone.database.SoneProvider;
  52 import net.pterodactylus.util.config.Configuration;
  53 import net.pterodactylus.util.config.ConfigurationException;
  54
  55 import com.google.common.base.Optional;
  56 import com.google.common.base.Predicate;
  57 import com.google.common.collect.HashMultimap;
  58 import com.google.common.collect.Multimap;
  59 import com.google.common.collect.SortedSetMultimap;
  60 import com.google.common.collect.TreeMultimap;
  61 import com.google.common.util.concurrent.AbstractService;
  62 import com.google.inject.Inject;
  63 import com.google.inject.Singleton;
  64
  65 /**
  66  * Memory-based {@link PostDatabase} implementation.
  67  *
  68  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  69  */
  70 @Singleton
  71 public class MemoryDatabase extends AbstractService implements Database {
  72
  73         /** The lock. */
  74         private final ReadWriteLock lock = new ReentrantReadWriteLock();
  75
  76         /** The Sone provider. */
  77         private final SoneProvider soneProvider;
  78
  79         /** The configuration. */
  80         private final Configuration configuration;
  81
  82         /** All posts by their ID. */
  83         private final Map<String, Post> allPosts = new HashMap<String, Post>();
  84
  85         /** All posts by their Sones. */
  86         private final Multimap<String, Post> sonePosts = HashMultimap.create();
  87
  88         /** Whether posts are known. */
  89         private final Set<String> knownPosts = new HashSet<String>();
  90
  91         /** All post replies by their ID. */
  92         private final Map<String, PostReply> allPostReplies = new HashMap<String, PostReply>();
  93
  94         /** Replies sorted by Sone. */
  95         private final SortedSetMultimap<String, PostReply> sonePostReplies = TreeMultimap.create(new Comparator<String>() {
  96
  97                 @Override
  98                 public int compare(String leftString, String rightString) {
  99                         return leftString.compareTo(rightString);
 100                 }
 101         }, TIME_COMPARATOR);
 102
 103         /** 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         private final Multimap<String, Album> soneAlbums = HashMultimap.create();
 108
 109         private final Map<String, Image> allImages = new HashMap<String, Image>();
 110         private final Multimap<String, Image> soneImages = HashMultimap.create();
 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(final String recipientId) {
 189                 lock.readLock().lock();
 190                 try {
 191                         return from(sonePosts.values()).filter(new Predicate<Post>() {
 192                                 @Override
 193                                 public boolean apply(Post post) {
 194                                         return post.getRecipientId().asSet().contains(recipientId);
 195                                 }
 196                         }).toSet();
 197                 } finally {
 198                         lock.readLock().unlock();
 199                 }
 200         }
 201
 202         //
 203         // POSTBUILDERFACTORY METHODS
 204         //
 205
 206         /** {@inheritDocs} */
 207         @Override
 208         public PostBuilder newPostBuilder() {
 209                 return new MemoryPostBuilder(this, soneProvider);
 210         }
 211
 212         //
 213         // POSTSTORE METHODS
 214         //
 215
 216         /** {@inheritDocs} */
 217         @Override
 218         public void storePost(Post post) {
 219                 checkNotNull(post, "post must not be null");
 220                 lock.writeLock().lock();
 221                 try {
 222                         allPosts.put(post.getId(), post);
 223                         getPostsFrom(post.getSone().getId()).add(post);
 224                 } finally {
 225                         lock.writeLock().unlock();
 226                 }
 227         }
 228
 229         /** {@inheritDocs} */
 230         @Override
 231         public void removePost(Post post) {
 232                 checkNotNull(post, "post must not be null");
 233                 lock.writeLock().lock();
 234                 try {
 235                         allPosts.remove(post.getId());
 236                         getPostsFrom(post.getSone().getId()).remove(post);
 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                         Collection<Post> oldPosts = getPostsFrom(sone.getId());
 258                         for (Post post : oldPosts) {
 259                                 allPosts.remove(post.getId());
 260                         }
 261
 262                         /* add new posts. */
 263                         getPostsFrom(sone.getId()).addAll(posts);
 264                         for (Post post : posts) {
 265                                 allPosts.put(post.getId(), post);
 266                         }
 267                 } finally {
 268                         lock.writeLock().unlock();
 269                 }
 270         }
 271
 272         /** {@inheritDocs} */
 273         @Override
 274         public void removePosts(Sone sone) {
 275                 checkNotNull(sone, "sone must not be null");
 276                 lock.writeLock().lock();
 277                 try {
 278                         /* remove all posts by the Sone. */
 279                         getPostsFrom(sone.getId()).clear();
 280                         for (Post post : sone.getPosts()) {
 281                                 allPosts.remove(post.getId());
 282                         }
 283                 } finally {
 284                         lock.writeLock().unlock();
 285                 }
 286         }
 287
 288         //
 289         // POSTREPLYPROVIDER METHODS
 290         //
 291
 292         /** {@inheritDocs} */
 293         @Override
 294         public Optional<PostReply> getPostReply(String id) {
 295                 lock.readLock().lock();
 296                 try {
 297                         return fromNullable(allPostReplies.get(id));
 298                 } finally {
 299                         lock.readLock().unlock();
 300                 }
 301         }
 302
 303         /** {@inheritDocs} */
 304         @Override
 305         public List<PostReply> getReplies(final String postId) {
 306                 lock.readLock().lock();
 307                 try {
 308                         return from(allPostReplies.values())
 309                                         .filter(new Predicate<PostReply>() {
 310                                                 @Override
 311                                                 public boolean apply(PostReply postReply) {
 312                                                         return postReply.getPostId().equals(postId);
 313                                                 }
 314                                         }).toSortedList(TIME_COMPARATOR);
 315                 } finally {
 316                         lock.readLock().unlock();
 317                 }
 318         }
 319
 320         //
 321         // POSTREPLYBUILDERFACTORY METHODS
 322         //
 323
 324         /** {@inheritDocs} */
 325         @Override
 326         public PostReplyBuilder newPostReplyBuilder() {
 327                 return new MemoryPostReplyBuilder(this, soneProvider);
 328         }
 329
 330         //
 331         // POSTREPLYSTORE METHODS
 332         //
 333
 334         /** {@inheritDocs} */
 335         @Override
 336         public void storePostReply(PostReply postReply) {
 337                 lock.writeLock().lock();
 338                 try {
 339                         allPostReplies.put(postReply.getId(), postReply);
 340                 } finally {
 341                         lock.writeLock().unlock();
 342                 }
 343         }
 344
 345         /** {@inheritDocs} */
 346         @Override
 347         public void storePostReplies(Sone sone, Collection<PostReply> postReplies) {
 348                 checkNotNull(sone, "sone must not be null");
 349                 /* verify that all posts are from the same Sone. */
 350                 for (PostReply postReply : postReplies) {
 351                         if (!sone.equals(postReply.getSone())) {
 352                                 throw new IllegalArgumentException(String.format("PostReply from different Sone found: %s", postReply));
 353                         }
 354                 }
 355
 356                 lock.writeLock().lock();
 357                 try {
 358                         /* remove all post replies of the Sone. */
 359                         for (PostReply postReply : getRepliesFrom(sone.getId())) {
 360                                 removePostReply(postReply);
 361                         }
 362                         for (PostReply postReply : postReplies) {
 363                                 allPostReplies.put(postReply.getId(), postReply);
 364                                 sonePostReplies.put(postReply.getSone().getId(), postReply);
 365                         }
 366                 } finally {
 367                         lock.writeLock().unlock();
 368                 }
 369         }
 370
 371         /** {@inheritDocs} */
 372         @Override
 373         public void removePostReply(PostReply postReply) {
 374                 lock.writeLock().lock();
 375                 try {
 376                         allPostReplies.remove(postReply.getId());
 377                 } finally {
 378                         lock.writeLock().unlock();
 379                 }
 380         }
 381
 382         /** {@inheritDocs} */
 383         @Override
 384         public void removePostReplies(Sone sone) {
 385                 checkNotNull(sone, "sone must not be null");
 386
 387                 lock.writeLock().lock();
 388                 try {
 389                         for (PostReply postReply : sone.getReplies()) {
 390                                 removePostReply(postReply);
 391                         }
 392                 } finally {
 393                         lock.writeLock().unlock();
 394                 }
 395         }
 396
 397         //
 398         // ALBUMPROVDER METHODS
 399         //
 400
 401         @Override
 402         public Optional<Album> getAlbum(String albumId) {
 403                 lock.readLock().lock();
 404                 try {
 405                         return fromNullable(allAlbums.get(albumId));
 406                 } finally {
 407                         lock.readLock().unlock();
 408                 }
 409         }
 410
 411         //
 412         // ALBUMBUILDERFACTORY METHODS
 413         //
 414
 415         @Override
 416         public AlbumBuilder newAlbumBuilder() {
 417                 return new AlbumBuilderImpl();
 418         }
 419
 420         //
 421         // ALBUMSTORE METHODS
 422         //
 423
 424         @Override
 425         public void storeAlbum(Album album) {
 426                 lock.writeLock().lock();
 427                 try {
 428                         allAlbums.put(album.getId(), album);
 429                         soneAlbums.put(album.getSone().getId(), album);
 430                 } finally {
 431                         lock.writeLock().unlock();
 432                 }
 433         }
 434
 435         @Override
 436         public void removeAlbum(Album album) {
 437                 lock.writeLock().lock();
 438                 try {
 439                         allAlbums.remove(album.getId());
 440                         soneAlbums.remove(album.getSone().getId(), album);
 441                 } finally {
 442                         lock.writeLock().unlock();
 443                 }
 444         }
 445
 446         //
 447         // IMAGEPROVIDER METHODS
 448         //
 449
 450         @Override
 451         public Optional<Image> getImage(String imageId) {
 452                 lock.readLock().lock();
 453                 try {
 454                         return fromNullable(allImages.get(imageId));
 455                 } finally {
 456                         lock.readLock().unlock();
 457                 }
 458         }
 459
 460         //
 461         // IMAGEBUILDERFACTORY METHODS
 462         //
 463
 464         @Override
 465         public ImageBuilder newImageBuilder() {
 466                 return new ImageBuilderImpl();
 467         }
 468
 469         //
 470         // IMAGESTORE METHODS
 471         //
 472
 473         @Override
 474         public void storeImage(Image image) {
 475                 lock.writeLock().lock();
 476                 try {
 477                         allImages.put(image.getId(), image);
 478                         soneImages.put(image.getSone().getId(), image);
 479                 } finally {
 480                         lock.writeLock().unlock();
 481                 }
 482         }
 483
 484         @Override
 485         public void removeImage(Image image) {
 486                 lock.writeLock().lock();
 487                 try {
 488                         allImages.remove(image.getId());
 489                         soneImages.remove(image.getSone().getId(), image);
 490                 } finally {
 491                         lock.writeLock().unlock();
 492                 }
 493         }
 494
 495         //
 496         // PACKAGE-PRIVATE METHODS
 497         //
 498
 499         /**
 500          * Returns whether the given post is known.
 501          *
 502          * @param post
 503          *              The post
 504          * @return {@code true} if the post is known, {@code false} otherwise
 505          */
 506         boolean isPostKnown(Post post) {
 507                 lock.readLock().lock();
 508                 try {
 509                         return knownPosts.contains(post.getId());
 510                 } finally {
 511                         lock.readLock().unlock();
 512                 }
 513         }
 514
 515         /**
 516          * Sets whether the given post is known.
 517          *
 518          * @param post
 519          *              The post
 520          * @param known
 521          *              {@code true} if the post is known, {@code false} otherwise
 522          */
 523         void setPostKnown(Post post, boolean known) {
 524                 lock.writeLock().lock();
 525                 try {
 526                         if (known) {
 527                                 knownPosts.add(post.getId());
 528                         } else {
 529                                 knownPosts.remove(post.getId());
 530                         }
 531                 } finally {
 532                         lock.writeLock().unlock();
 533                 }
 534         }
 535
 536         /**
 537          * Returns whether the given post reply is known.
 538          *
 539          * @param postReply
 540          *              The post reply
 541          * @return {@code true} if the given post reply is known, {@code false}
 542          *         otherwise
 543          */
 544         boolean isPostReplyKnown(PostReply postReply) {
 545                 lock.readLock().lock();
 546                 try {
 547                         return knownPostReplies.contains(postReply.getId());
 548                 } finally {
 549                         lock.readLock().unlock();
 550                 }
 551         }
 552
 553         /**
 554          * Sets whether the given post reply is known.
 555          *
 556          * @param postReply
 557          *              The post reply
 558          * @param known
 559          *              {@code true} if the post reply is known, {@code false} otherwise
 560          */
 561         void setPostReplyKnown(PostReply postReply, boolean known) {
 562                 lock.writeLock().lock();
 563                 try {
 564                         if (known) {
 565                                 knownPostReplies.add(postReply.getId());
 566                         } else {
 567                                 knownPostReplies.remove(postReply.getId());
 568                         }
 569                 } finally {
 570                         lock.writeLock().unlock();
 571                 }
 572         }
 573
 574         //
 575         // PRIVATE METHODS
 576         //
 577
 578         /**
 579          * Gets all posts for the given Sone, creating a new collection if there is
 580          * none yet.
 581          *
 582          * @param soneId
 583          *              The ID of the Sone to get the posts for
 584          * @return All posts
 585          */
 586         private Collection<Post> getPostsFrom(String soneId) {
 587                 lock.readLock().lock();
 588                 try {
 589                         return sonePosts.get(soneId);
 590                 } finally {
 591                         lock.readLock().unlock();
 592                 }
 593         }
 594
 595         /** Loads the known posts. */
 596         private void loadKnownPosts() {
 597                 lock.writeLock().lock();
 598                 try {
 599                         int postCounter = 0;
 600                         while (true) {
 601                                 String knownPostId = configuration.getStringValue("KnownPosts/" + postCounter++ + "/ID").getValue(null);
 602                                 if (knownPostId == null) {
 603                                         break;
 604                                 }
 605                                 knownPosts.add(knownPostId);
 606                         }
 607                 } finally {
 608                         lock.writeLock().unlock();
 609                 }
 610         }
 611
 612         /**
 613          * Saves the known posts to the configuration.
 614          *
 615          * @throws DatabaseException
 616          *              if a configuration error occurs
 617          */
 618         private void saveKnownPosts() throws DatabaseException {
 619                 lock.readLock().lock();
 620                 try {
 621                         int postCounter = 0;
 622                         for (String knownPostId : knownPosts) {
 623                                 configuration.getStringValue("KnownPosts/" + postCounter++ + "/ID").setValue(knownPostId);
 624                         }
 625                         configuration.getStringValue("KnownPosts/" + postCounter + "/ID").setValue(null);
 626                 } catch (ConfigurationException ce1) {
 627                         throw new DatabaseException("Could not save database.", ce1);
 628                 } finally {
 629                         lock.readLock().unlock();
 630                 }
 631         }
 632
 633         /**
 634          * Returns all replies by the given Sone.
 635          *
 636          * @param id
 637          *              The ID of the Sone
 638          * @return The post replies of the Sone, sorted by time (newest first)
 639          */
 640         private Collection<PostReply> getRepliesFrom(String id) {
 641                 lock.readLock().lock();
 642                 try {
 643                         return Collections.unmodifiableCollection(sonePostReplies.get(id));
 644                 } finally {
 645                         lock.readLock().unlock();
 646                 }
 647         }
 648
 649         /** Loads the known post replies. */
 650         private void loadKnownPostReplies() {
 651                 lock.writeLock().lock();
 652                 try {
 653                         int replyCounter = 0;
 654                         while (true) {
 655                                 String knownReplyId = configuration.getStringValue("KnownReplies/" + replyCounter++ + "/ID").getValue(null);
 656                                 if (knownReplyId == null) {
 657                                         break;
 658                                 }
 659                                 knownPostReplies.add(knownReplyId);
 660                         }
 661                 } finally {
 662                         lock.writeLock().unlock();
 663                 }
 664         }
 665
 666         /**
 667          * Saves the known post replies to the configuration.
 668          *
 669          * @throws DatabaseException
 670          *              if a configuration error occurs
 671          */
 672         private void saveKnownPostReplies() throws DatabaseException {
 673                 lock.readLock().lock();
 674                 try {
 675                         int replyCounter = 0;
 676                         for (String knownReplyId : knownPostReplies) {
 677                                 configuration.getStringValue("KnownReplies/" + replyCounter++ + "/ID").setValue(knownReplyId);
 678                         }
 679                         configuration.getStringValue("KnownReplies/" + replyCounter + "/ID").setValue(null);
 680                 } catch (ConfigurationException ce1) {
 681                         throw new DatabaseException("Could not save database.", ce1);
 682                 } finally {
 683                         lock.readLock().unlock();
 684                 }
 685         }
 686
 687 }