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

   1 /*
   2  * Sone - MemoryPostDatabase.java - Copyright © 2014 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 com.google.common.collect.HashMultimap.create;
  24
  25 import java.util.Collection;
  26 import java.util.Collections;
  27 import java.util.HashMap;
  28 import java.util.HashSet;
  29 import java.util.Map;
  30 import java.util.Set;
  31 import java.util.concurrent.locks.ReadWriteLock;
  32
  33 import net.pterodactylus.sone.data.Post;
  34 import net.pterodactylus.sone.data.Sone;
  35 import net.pterodactylus.sone.database.DatabaseException;
  36 import net.pterodactylus.sone.database.PostDatabase;
  37 import net.pterodactylus.util.config.Configuration;
  38 import net.pterodactylus.util.config.ConfigurationException;
  39
  40 import com.google.common.base.Function;
  41 import com.google.common.base.Optional;
  42 import com.google.common.collect.Multimap;
  43 import com.google.common.collect.SetMultimap;
  44
  45 /**
  46  * Memory-based {@link PostDatabase} implementation.
  47  *
  48  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  49  */
  50 public class MemoryPostDatabase implements PostDatabase {
  51
  52         private final MemoryDatabase memoryDatabase;
  53         private final ReadWriteLock readWriteLock;
  54         private final Configuration configuration;
  55         private final Map<String, Post> allPosts = new HashMap<String, Post>();
  56         private final Multimap<String, Post> sonePosts = create();
  57         private final SetMultimap<String, String> likedPostsBySone = create();
  58         private final SetMultimap<String, String> postLikingSones = create();
  59         private final Multimap<String, Post> recipientPosts = create();
  60         private final Set<String> knownPosts = new HashSet<String>();
  61
  62         public MemoryPostDatabase(MemoryDatabase memoryDatabase, ReadWriteLock readWriteLock, Configuration configuration) {
  63                 this.memoryDatabase = memoryDatabase;
  64                 this.readWriteLock = readWriteLock;
  65                 this.configuration = configuration;
  66         }
  67
  68         @Override
  69         public Function<String, Optional<Post>> getPost() {
  70                 return new Function<String, Optional<Post>>() {
  71                         @Override
  72                         public Optional<Post> apply(String postId) {
  73                                 return (postId == null) ? Optional.<Post>absent() : getPost(postId);
  74                         }
  75                 };
  76         }
  77
  78         @Override
  79         public Optional<Post> getPost(String postId) {
  80                 readWriteLock.readLock().lock();
  81                 try {
  82                         return fromNullable(allPosts.get(postId));
  83                 } finally {
  84                         readWriteLock.readLock().unlock();
  85                 }
  86         }
  87
  88         @Override
  89         public Collection<Post> getPosts(String soneId) {
  90                 readWriteLock.readLock().lock();
  91                 try {
  92                         return new HashSet<Post>(sonePosts.get(soneId));
  93                 } finally {
  94                         readWriteLock.readLock().unlock();
  95                 }
  96         }
  97
  98         @Override
  99         public Collection<Post> getDirectedPosts(String recipientId) {
 100                 readWriteLock.readLock().lock();
 101                 try {
 102                         Collection<Post> posts = recipientPosts.get(recipientId);
 103                         return (posts == null) ? Collections.<Post>emptySet() : new HashSet<Post>(posts);
 104                 } finally {
 105                         readWriteLock.readLock().unlock();
 106                 }
 107         }
 108
 109         /**
 110          * Returns whether the given post is known.
 111          *
 112          * @param post
 113          *              The post
 114          * @return {@code true} if the post is known, {@code false} otherwise
 115          */
 116         @Override
 117         public boolean isPostKnown(Post post) {
 118                 readWriteLock.readLock().lock();
 119                 try {
 120                         return knownPosts.contains(post.getId());
 121                 } finally {
 122                         readWriteLock.readLock().unlock();
 123                 }
 124         }
 125
 126         /**
 127          * Sets whether the given post is known.
 128          *
 129          * @param post
 130          *              The post
 131          */
 132         @Override
 133         public void setPostKnown(Post post) {
 134                 readWriteLock.writeLock().lock();
 135                 try {
 136                         knownPosts.add(post.getId());
 137                 } finally {
 138                         readWriteLock.writeLock().unlock();
 139                 }
 140         }
 141
 142         @Override
 143         public void likePost(Post post, Sone localSone) {
 144                 readWriteLock.writeLock().lock();
 145                 try {
 146                         likedPostsBySone.put(localSone.getId(), post.getId());
 147                         postLikingSones.put(post.getId(), localSone.getId());
 148                 } finally {
 149                         readWriteLock.writeLock().unlock();
 150                 }
 151         }
 152
 153         @Override
 154         public void unlikePost(Post post, Sone localSone) {
 155                 readWriteLock.writeLock().lock();
 156                 try {
 157                         likedPostsBySone.remove(localSone.getId(), post.getId());
 158                         postLikingSones.remove(post.getId(), localSone.getId());
 159                 } finally {
 160                         readWriteLock.writeLock().unlock();
 161                 }
 162         }
 163
 164         public boolean isLiked(Post post, Sone sone) {
 165                 readWriteLock.readLock().lock();
 166                 try {
 167                         return likedPostsBySone.containsEntry(sone.getId(), post.getId());
 168                 } finally {
 169                         readWriteLock.readLock().unlock();
 170                 }
 171         }
 172
 173         @Override
 174         public Set<Sone> getLikes(Post post) {
 175                 readWriteLock.readLock().lock();
 176                 try {
 177                         return from(postLikingSones.get(post.getId())).transform(memoryDatabase.getSone()).transformAndConcat(MemoryDatabase.<Sone>unwrap()).toSet();
 178                 } finally {
 179                         readWriteLock.readLock().unlock();
 180                 }
 181         }
 182
 183         @Override
 184         public void storePost(Post post) {
 185                 checkNotNull(post, "post must not be null");
 186                 readWriteLock.writeLock().lock();
 187                 try {
 188                         allPosts.put(post.getId(), post);
 189                         sonePosts.put(post.getSone().getId(), post);
 190                         if (post.getRecipientId().isPresent()) {
 191                                 recipientPosts.put(post.getRecipientId().get(), post);
 192                         }
 193                 } finally {
 194                         readWriteLock.writeLock().unlock();
 195                 }
 196         }
 197
 198         @Override
 199         public void removePost(Post post) {
 200                 checkNotNull(post, "post must not be null");
 201                 readWriteLock.writeLock().lock();
 202                 try {
 203                         allPosts.remove(post.getId());
 204                         sonePosts.remove(post.getSone().getId(), post);
 205                         if (post.getRecipientId().isPresent()) {
 206                                 recipientPosts.remove(post.getRecipientId().get(), post);
 207                         }
 208                         post.getSone().removePost(post);
 209                 } finally {
 210                         readWriteLock.writeLock().unlock();
 211                 }
 212         }
 213
 214         @Override
 215         public void storePosts(Sone sone, Collection<Post> posts) throws IllegalArgumentException {
 216                 checkNotNull(sone, "sone must not be null");
 217                 /* verify that all posts are from the same Sone. */
 218                 for (Post post : posts) {
 219                         if (!sone.equals(post.getSone())) {
 220                                 throw new IllegalArgumentException(String.format("Post from different Sone found: %s", post));
 221                         }
 222                 }
 223
 224                 readWriteLock.writeLock().lock();
 225                 try {
 226                         /* remove all posts by the Sone. */
 227                         sonePosts.removeAll(sone.getId());
 228                         for (Post post : posts) {
 229                                 allPosts.remove(post.getId());
 230                                 if (post.getRecipientId().isPresent()) {
 231                                         recipientPosts.remove(post.getRecipientId().get(), post);
 232                                 }
 233                         }
 234
 235                         /* add new posts. */
 236                         sonePosts.putAll(sone.getId(), posts);
 237                         for (Post post : posts) {
 238                                 allPosts.put(post.getId(), post);
 239                                 if (post.getRecipientId().isPresent()) {
 240                                         recipientPosts.put(post.getRecipientId().get(), post);
 241                                 }
 242                         }
 243                 } finally {
 244                         readWriteLock.writeLock().unlock();
 245                 }
 246         }
 247
 248         @Override
 249         public void removePosts(Sone sone) {
 250                 checkNotNull(sone, "sone must not be null");
 251                 readWriteLock.writeLock().lock();
 252                 try {
 253                         /* remove all posts by the Sone. */
 254                         sonePosts.removeAll(sone.getId());
 255                         for (Post post : sone.getPosts()) {
 256                                 allPosts.remove(post.getId());
 257                                 if (post.getRecipientId().isPresent()) {
 258                                         recipientPosts.remove(post.getRecipientId().get(), post);
 259                                 }
 260                         }
 261                 } finally {
 262                         readWriteLock.writeLock().unlock();
 263                 }
 264         }
 265
 266         public void start() {
 267                 readWriteLock.writeLock().lock();
 268                 try {
 269                         int postCounter = 0;
 270                         while (true) {
 271                                 String knownPostId = configuration.getStringValue("KnownPosts/" + postCounter++ + "/ID").getValue(null);
 272                                 if (knownPostId == null) {
 273                                         break;
 274                                 }
 275                                 knownPosts.add(knownPostId);
 276                         }
 277                 } finally {
 278                         readWriteLock.writeLock().unlock();
 279                 }
 280         }
 281
 282         public void stop() throws DatabaseException {
 283                 save();
 284         }
 285
 286         public void save() throws DatabaseException {
 287                 readWriteLock.readLock().lock();
 288                 try {
 289                         int postCounter = 0;
 290                         for (String knownPostId : knownPosts) {
 291                                 configuration.getStringValue("KnownPosts/" + postCounter++ + "/ID").setValue(knownPostId);
 292                         }
 293                         configuration.getStringValue("KnownPosts/" + postCounter + "/ID").setValue(null);
 294                 } catch (ConfigurationException ce1) {
 295                         throw new DatabaseException("Could not save database.", ce1);
 296                 } finally {
 297                         readWriteLock.readLock().unlock();
 298                 }
 299         }
 300
 301 }