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.Preconditions.checkNotNull;
  21
  22 import java.util.ArrayList;
  23 import java.util.Collection;
  24 import java.util.Collections;
  25 import java.util.HashMap;
  26 import java.util.HashSet;
  27 import java.util.List;
  28 import java.util.Map;
  29 import java.util.Set;
  30 import java.util.SortedSet;
  31 import java.util.TreeSet;
  32 import java.util.concurrent.locks.ReadWriteLock;
  33 import java.util.concurrent.locks.ReentrantReadWriteLock;
  34
  35 import net.pterodactylus.sone.data.Post;
  36 import net.pterodactylus.sone.data.PostReply;
  37 import net.pterodactylus.sone.data.Reply;
  38 import net.pterodactylus.sone.data.Sone;
  39 import net.pterodactylus.sone.database.Database;
  40 import net.pterodactylus.sone.database.DatabaseException;
  41 import net.pterodactylus.sone.database.PostBuilder;
  42 import net.pterodactylus.sone.database.PostDatabase;
  43 import net.pterodactylus.sone.database.PostReplyBuilder;
  44 import net.pterodactylus.sone.database.SoneProvider;
  45 import net.pterodactylus.util.config.Configuration;
  46 import net.pterodactylus.util.config.ConfigurationException;
  47
  48 import com.google.common.base.Optional;
  49 import com.google.common.util.concurrent.AbstractService;
  50 import com.google.inject.Inject;
  51
  52 /**
  53  * Memory-based {@link PostDatabase} implementation.
  54  *
  55  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  56  */
  57 public class MemoryDatabase extends AbstractService implements Database {
  58
  59         /** The lock. */
  60         private final ReadWriteLock lock = new ReentrantReadWriteLock();
  61
  62         /** The Sone provider. */
  63         private final SoneProvider soneProvider;
  64
  65         /** The configuration. */
  66         private final Configuration configuration;
  67
  68         /** All posts by their ID. */
  69         private final Map<String, Post> allPosts = new HashMap<String, Post>();
  70
  71         /** All posts by their Sones. */
  72         private final Map<String, Collection<Post>> sonePosts = new HashMap<String, Collection<Post>>();
  73
  74         /** All posts by their recipient. */
  75         private final Map<String, Collection<Post>> recipientPosts = new HashMap<String, Collection<Post>>();
  76
  77         /** Whether posts are known. */
  78         private final Set<String> knownPosts = new HashSet<String>();
  79
  80         /** All post replies by their ID. */
  81         private final Map<String, PostReply> allPostReplies = new HashMap<String, PostReply>();
  82
  83         /** Replies by post. */
  84         private final Map<String, SortedSet<PostReply>> postReplies = new HashMap<String, SortedSet<PostReply>>();
  85
  86         /** Whether post replies are known. */
  87         private final Set<String> knownPostReplies = new HashSet<String>();
  88
  89         /**
  90          * Creates a new memory database.
  91          *
  92          * @param soneProvider
  93          *            The Sone provider
  94          * @param configuration
  95          *            The configuration for loading and saving elements
  96          */
  97         @Inject
  98         public MemoryDatabase(SoneProvider soneProvider, Configuration configuration) {
  99                 this.soneProvider = soneProvider;
 100                 this.configuration = configuration;
 101         }
 102
 103         //
 104         // DATABASE METHODS
 105         //
 106
 107         /**
 108          * Saves the database.
 109          *
 110          * @throws DatabaseException
 111          *             if an error occurs while saving
 112          */
 113         @Override
 114         public void save() throws DatabaseException {
 115                 saveKnownPosts();
 116                 saveKnownPostReplies();
 117         }
 118
 119         //
 120         // SERVICE METHODS
 121         //
 122
 123         /**
 124          * {@inheritDocs}
 125          */
 126         @Override
 127         protected void doStart() {
 128                 loadKnownPosts();
 129                 loadKnownPostReplies();
 130                 notifyStarted();
 131         }
 132
 133         /**
 134          * {@inheritDocs}
 135          */
 136         @Override
 137         protected void doStop() {
 138                 try {
 139                         save();
 140                         notifyStopped();
 141                 } catch (DatabaseException de1) {
 142                         notifyFailed(de1);
 143                 }
 144         }
 145
 146         //
 147         // POSTPROVIDER METHODS
 148         //
 149
 150         /**
 151          * {@inheritDocs}
 152          */
 153         @Override
 154         public Optional<Post> getPost(String postId) {
 155                 lock.readLock().lock();
 156                 try {
 157                         return Optional.fromNullable(allPosts.get(postId));
 158                 } finally {
 159                         lock.readLock().unlock();
 160                 }
 161         }
 162
 163         /**
 164          * {@inheritDocs}
 165          */
 166         @Override
 167         public Collection<Post> getPosts(String soneId) {
 168                 return new HashSet<Post>(getPostsFrom(soneId));
 169         }
 170
 171         /**
 172          * {@inheritDocs}
 173          */
 174         @Override
 175         public Collection<Post> getDirectedPosts(String recipientId) {
 176                 lock.readLock().lock();
 177                 try {
 178                         Collection<Post> posts = recipientPosts.get(recipientId);
 179                         return (posts == null) ? Collections.<Post> emptySet() : new HashSet<Post>(posts);
 180                 } finally {
 181                         lock.readLock().unlock();
 182                 }
 183         }
 184
 185         //
 186         // POSTBUILDERFACTORY METHODS
 187         //
 188
 189         /**
 190          * {@inheritDocs}
 191          */
 192         @Override
 193         public PostBuilder newPostBuilder() {
 194                 return new MemoryPostBuilder(this, soneProvider);
 195         }
 196
 197         //
 198         // POSTSTORE METHODS
 199         //
 200
 201         /**
 202          * {@inheritDocs}
 203          */
 204         @Override
 205         public void storePost(Post post) {
 206                 checkNotNull(post, "post must not be null");
 207                 lock.writeLock().lock();
 208                 try {
 209                         allPosts.put(post.getId(), post);
 210                         getPostsFrom(post.getSone().getId()).add(post);
 211                         if (post.getRecipientId().isPresent()) {
 212                                 getPostsTo(post.getRecipientId().get()).add(post);
 213                         }
 214                 } finally {
 215                         lock.writeLock().unlock();
 216                 }
 217         }
 218
 219         /**
 220          * {@inheritDocs}
 221          */
 222         @Override
 223         public void removePost(Post post) {
 224                 checkNotNull(post, "post must not be null");
 225                 lock.writeLock().lock();
 226                 try {
 227                         allPosts.remove(post.getId());
 228                         getPostsFrom(post.getSone().getId()).remove(post);
 229                         if (post.getRecipientId().isPresent()) {
 230                                 getPostsTo(post.getRecipientId().get()).remove(post);
 231                         }
 232                         post.getSone().removePost(post);
 233                 } finally {
 234                         lock.writeLock().unlock();
 235                 }
 236         }
 237
 238         /**
 239          * {@inheritDocs}
 240          */
 241         @Override
 242         public void storePosts(Sone sone, Collection<Post> posts) throws IllegalArgumentException {
 243                 checkNotNull(sone, "sone must not be null");
 244                 /* verify that all posts are from the same Sone. */
 245                 for (Post post : posts) {
 246                         if (!sone.equals(post.getSone())) {
 247                                 throw new IllegalArgumentException(String.format("Post from different Sone found: %s", post));
 248                         }
 249                 }
 250
 251                 lock.writeLock().lock();
 252                 try {
 253                         /* remove all posts by the Sone. */
 254                         getPostsFrom(sone.getId()).clear();
 255                         for (Post post : posts) {
 256                                 allPosts.remove(post.getId());
 257                                 if (post.getRecipientId().isPresent()) {
 258                                         getPostsTo(post.getRecipientId().get()).remove(post);
 259                                 }
 260                         }
 261
 262                         /* add new posts. */
 263                         getPostsFrom(sone.getId()).addAll(posts);
 264                         for (Post post : posts) {
 265                                 allPosts.put(post.getId(), post);
 266                                 if (post.getRecipientId().isPresent()) {
 267                                         getPostsTo(post.getRecipientId().get()).add(post);
 268                                 }
 269                         }
 270                 } finally {
 271                         lock.writeLock().unlock();
 272                 }
 273         }
 274
 275         /**
 276          * {@inheritDocs}
 277          */
 278         @Override
 279         public void removePosts(Sone sone) {
 280                 checkNotNull(sone, "sone must not be null");
 281                 lock.writeLock().lock();
 282                 try {
 283                         /* remove all posts by the Sone. */
 284                         getPostsFrom(sone.getId()).clear();
 285                         for (Post post : sone.getPosts()) {
 286                                 allPosts.remove(post.getId());
 287                                 if (post.getRecipientId().isPresent()) {
 288                                         getPostsTo(post.getRecipientId().get()).remove(post);
 289                                 }
 290                         }
 291                 } finally {
 292                         lock.writeLock().unlock();
 293                 }
 294         }
 295
 296         //
 297         // POSTREPLYPROVIDER METHODS
 298         //
 299
 300         /**
 301          * {@inheritDocs}
 302          */
 303         @Override
 304         public Optional<PostReply> getPostReply(String id) {
 305                 lock.readLock().lock();
 306                 try {
 307                         return Optional.fromNullable(allPostReplies.get(id));
 308                 } finally {
 309                         lock.readLock().unlock();
 310                 }
 311         }
 312
 313         /**
 314          * {@inheritDocs}
 315          */
 316         @Override
 317         public List<PostReply> getReplies(String postId) {
 318                 lock.readLock().lock();
 319                 try {
 320                         if (!postReplies.containsKey(postId)) {
 321                                 return Collections.emptyList();
 322                         }
 323                         return new ArrayList<PostReply>(postReplies.get(postId));
 324                 } finally {
 325                         lock.readLock().unlock();
 326                 }
 327         }
 328
 329         //
 330         // POSTREPLYBUILDERFACTORY METHODS
 331         //
 332
 333         /**
 334          * {@inheritDocs}
 335          */
 336         @Override
 337         public PostReplyBuilder newPostReplyBuilder() {
 338                 return new MemoryPostReplyBuilder(this, soneProvider);
 339         }
 340
 341         //
 342         // POSTREPLYSTORE METHODS
 343         //
 344
 345         /**
 346          * {@inheritDocs}
 347          */
 348         @Override
 349         public void storePostReply(PostReply postReply) {
 350                 lock.writeLock().lock();
 351                 try {
 352                         allPostReplies.put(postReply.getId(), postReply);
 353                         if (postReplies.containsKey(postReply.getPostId())) {
 354                                 postReplies.get(postReply.getPostId()).add(postReply);
 355                         } else {
 356                                 TreeSet<PostReply> replies = new TreeSet<PostReply>(Reply.TIME_COMPARATOR);
 357                                 replies.add(postReply);
 358                                 postReplies.put(postReply.getPostId(), replies);
 359                         }
 360                 } finally {
 361                         lock.writeLock().unlock();
 362                 }
 363         }
 364
 365         /**
 366          * {@inheritDocs}
 367          */
 368         @Override
 369         public void storePostReplies(Sone sone, Collection<PostReply> postReplies) {
 370                 checkNotNull(sone, "sone must not be null");
 371                 /* verify that all posts are from the same Sone. */
 372                 for (PostReply postReply : postReplies) {
 373                         if (!sone.equals(postReply.getSone())) {
 374                                 throw new IllegalArgumentException(String.format("PostReply from different Sone found: %s", postReply));
 375                         }
 376                 }
 377
 378                 lock.writeLock().lock();
 379                 try {
 380                         /* remove all post replies of the Sone. */
 381                         for (PostReply postReply : getRepliesFrom(sone.getId())) {
 382                                 removePostReply(postReply);
 383                         }
 384                         for (PostReply postReply : postReplies) {
 385                                 allPostReplies.put(postReply.getId(), postReply);
 386                                 if (this.postReplies.containsKey(postReply.getPostId())) {
 387                                         this.postReplies.get(postReply.getPostId()).add(postReply);
 388                                 } else {
 389                                         TreeSet<PostReply> replies = new TreeSet<PostReply>(Reply.TIME_COMPARATOR);
 390                                         replies.add(postReply);
 391                                         this.postReplies.put(postReply.getPostId(), replies);
 392                                 }
 393                         }
 394                 } finally {
 395                         lock.writeLock().unlock();
 396                 }
 397         }
 398
 399         /**
 400          * {@inheritDocs}
 401          */
 402         @Override
 403         public void removePostReply(PostReply postReply) {
 404                 lock.writeLock().lock();
 405                 try {
 406                         allPostReplies.remove(postReply.getId());
 407                         if (postReplies.containsKey(postReply.getPostId())) {
 408                                 postReplies.get(postReply.getPostId()).remove(postReply);
 409                                 if (postReplies.get(postReply.getPostId()).isEmpty()) {
 410                                         postReplies.remove(postReply.getPostId());
 411                                 }
 412                         }
 413                 } finally {
 414                         lock.writeLock().unlock();
 415                 }
 416         }
 417
 418         /**
 419          * {@inheritDocs}
 420          */
 421         @Override
 422         public void removePostReplies(Sone sone) {
 423                 checkNotNull(sone, "sone must not be null");
 424
 425                 lock.writeLock().lock();
 426                 try {
 427                         for (PostReply postReply : sone.getReplies()) {
 428                                 removePostReply(postReply);
 429                         }
 430                 } finally {
 431                         lock.writeLock().unlock();
 432                 }
 433         }
 434
 435         //
 436         // PACKAGE-PRIVATE METHODS
 437         //
 438
 439         /**
 440          * Returns whether the given post is known.
 441          *
 442          * @param post
 443          *            The post
 444          * @return {@code true} if the post is known, {@code false} otherwise
 445          */
 446         boolean isPostKnown(Post post) {
 447                 lock.readLock().lock();
 448                 try {
 449                         return knownPosts.contains(post.getId());
 450                 } finally {
 451                         lock.readLock().unlock();
 452                 }
 453         }
 454
 455         /**
 456          * Sets whether the given post is known.
 457          *
 458          * @param post
 459          *            The post
 460          * @param known
 461          *            {@code true} if the post is known, {@code false} otherwise
 462          */
 463         void setPostKnown(Post post, boolean known) {
 464                 lock.writeLock().lock();
 465                 try {
 466                         if (known) {
 467                                 knownPosts.add(post.getId());
 468                         } else {
 469                                 knownPosts.remove(post.getId());
 470                         }
 471                 } finally {
 472                         lock.writeLock().unlock();
 473                 }
 474         }
 475
 476         /**
 477          * Returns whether the given post reply is known.
 478          *
 479          * @param postReply
 480          *            The post reply
 481          * @return {@code true} if the given post reply is known, {@code false}
 482          *         otherwise
 483          */
 484         boolean isPostReplyKnown(PostReply postReply) {
 485                 lock.readLock().lock();
 486                 try {
 487                         return knownPostReplies.contains(postReply.getId());
 488                 } finally {
 489                         lock.readLock().unlock();
 490                 }
 491         }
 492
 493         /**
 494          * Sets whether the given post reply is known.
 495          *
 496          * @param postReply
 497          *            The post reply
 498          * @param known
 499          *            {@code true} if the post reply is known, {@code false}
 500          *            otherwise
 501          */
 502         void setPostReplyKnown(PostReply postReply, boolean known) {
 503                 lock.writeLock().lock();
 504                 try {
 505                         if (known) {
 506                                 knownPostReplies.add(postReply.getId());
 507                         } else {
 508                                 knownPostReplies.remove(postReply.getId());
 509                         }
 510                 } finally {
 511                         lock.writeLock().unlock();
 512                 }
 513         }
 514
 515         //
 516         // PRIVATE METHODS
 517         //
 518
 519         /**
 520          * Gets all posts for the given Sone, creating a new collection if there is
 521          * none yet.
 522          *
 523          * @param soneId
 524          *            The ID of the Sone to get the posts for
 525          * @return All posts
 526          */
 527         private Collection<Post> getPostsFrom(String soneId) {
 528                 Collection<Post> posts = null;
 529                 lock.readLock().lock();
 530                 try {
 531                         posts = sonePosts.get(soneId);
 532                 } finally {
 533                         lock.readLock().unlock();
 534                 }
 535                 if (posts != null) {
 536                         return posts;
 537                 }
 538
 539                 posts = new HashSet<Post>();
 540                 lock.writeLock().lock();
 541                 try {
 542                         sonePosts.put(soneId, posts);
 543                 } finally {
 544                         lock.writeLock().unlock();
 545                 }
 546
 547                 return posts;
 548         }
 549
 550         /**
 551          * Gets all posts that are directed the given Sone, creating a new
 552          * collection if there is none yet.
 553          *
 554          * @param recipientId
 555          *            The ID of the Sone to get the posts for
 556          * @return All posts
 557          */
 558         private Collection<Post> getPostsTo(String recipientId) {
 559                 Collection<Post> posts = null;
 560                 lock.readLock().lock();
 561                 try {
 562                         posts = recipientPosts.get(recipientId);
 563                 } finally {
 564                         lock.readLock().unlock();
 565                 }
 566                 if (posts != null) {
 567                         return posts;
 568                 }
 569
 570                 posts = new HashSet<Post>();
 571                 lock.writeLock().lock();
 572                 try {
 573                         recipientPosts.put(recipientId, posts);
 574                 } finally {
 575                         lock.writeLock().unlock();
 576                 }
 577
 578                 return posts;
 579         }
 580
 581         /**
 582          * Loads the known posts.
 583          */
 584         private void loadKnownPosts() {
 585                 lock.writeLock().lock();
 586                 try {
 587                         int postCounter = 0;
 588                         while (true) {
 589                                 String knownPostId = configuration.getStringValue("KnownPosts/" + postCounter++ + "/ID").getValue(null);
 590                                 if (knownPostId == null) {
 591                                         break;
 592                                 }
 593                                 knownPosts.add(knownPostId);
 594                         }
 595                 } finally {
 596                         lock.writeLock().unlock();
 597                 }
 598         }
 599
 600         /**
 601          * Saves the known posts to the configuration.
 602          *
 603          * @throws DatabaseException
 604          *             if a configuration error occurs
 605          */
 606         private void saveKnownPosts() throws DatabaseException {
 607                 lock.readLock().lock();
 608                 try {
 609                         int postCounter = 0;
 610                         for (String knownPostId : knownPosts) {
 611                                 configuration.getStringValue("KnownPosts/" + postCounter++ + "/ID").setValue(knownPostId);
 612                         }
 613                         configuration.getStringValue("KnownPosts/" + postCounter + "/ID").setValue(null);
 614                 } catch (ConfigurationException ce1) {
 615                         throw new DatabaseException("Could not save database.", ce1);
 616                 } finally {
 617                         lock.readLock().unlock();
 618                 }
 619         }
 620
 621         /**
 622          * Loads the known post replies.
 623          */
 624         private void loadKnownPostReplies() {
 625                 lock.writeLock().lock();
 626                 try {
 627                         int replyCounter = 0;
 628                         while (true) {
 629                                 String knownReplyId = configuration.getStringValue("KnownReplies/" + replyCounter++ + "/ID").getValue(null);
 630                                 if (knownReplyId == null) {
 631                                         break;
 632                                 }
 633                                 knownPostReplies.add(knownReplyId);
 634                         }
 635                 } finally {
 636                         lock.writeLock().unlock();
 637                 }
 638         }
 639
 640         /**
 641          * Saves the known post replies to the configuration.
 642          *
 643          * @throws DatabaseException
 644          *             if a configuration error occurs
 645          */
 646         private void saveKnownPostReplies() throws DatabaseException {
 647                 lock.readLock().lock();
 648                 try {
 649                         int replyCounter = 0;
 650                         for (String knownReplyId : knownPostReplies) {
 651                                 configuration.getStringValue("KnownReplies/" + replyCounter++ + "/ID").setValue(knownReplyId);
 652                         }
 653                         configuration.getStringValue("KnownReplies/" + replyCounter + "/ID").setValue(null);
 654                 } catch (ConfigurationException ce1) {
 655                         throw new DatabaseException("Could not save database.", ce1);
 656                 } finally {
 657                         lock.readLock().unlock();
 658                 }
 659         }
 660
 661 }