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

   1 package net.pterodactylus.sone.database.memory;
   2
   3 import static com.google.common.base.Optional.fromNullable;
   4 import static com.google.common.collect.FluentIterable.from;
   5
   6 import java.util.HashSet;
   7 import java.util.Set;
   8 import java.util.concurrent.locks.ReadWriteLock;
   9 import java.util.concurrent.locks.ReentrantReadWriteLock;
  10
  11 import net.pterodactylus.sone.data.Post;
  12 import net.pterodactylus.sone.data.Post.EmptyPost;
  13 import net.pterodactylus.sone.database.BookmarkDatabase;
  14
  15 import com.google.common.base.Function;
  16
  17 /**
  18  * Memory-based {@link BookmarkDatabase} implementation.
  19  *
  20  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  21  */
  22 public class MemoryBookmarkDatabase implements BookmarkDatabase {
  23
  24         private final ReadWriteLock lock = new ReentrantReadWriteLock();
  25         private final MemoryDatabase memoryDatabase;
  26         private final ConfigurationLoader configurationLoader;
  27         private final Set<String> bookmarkedPosts = new HashSet<String>();
  28
  29         public MemoryBookmarkDatabase(MemoryDatabase memoryDatabase,
  30                         ConfigurationLoader configurationLoader) {
  31                 this.memoryDatabase = memoryDatabase;
  32                 this.configurationLoader = configurationLoader;
  33         }
  34
  35         public void start() {
  36                 loadBookmarkedPosts();
  37         }
  38
  39         private void loadBookmarkedPosts() {
  40                 Set<String> bookmarkedPosts = configurationLoader.loadBookmarkedPosts();
  41                 lock.writeLock().lock();
  42                 try {
  43                         this.bookmarkedPosts.clear();
  44                         this.bookmarkedPosts.addAll(bookmarkedPosts);
  45                 } finally {
  46                         lock.writeLock().unlock();
  47                 }
  48         }
  49
  50         public void stop() {
  51                 saveBookmarkedPosts();
  52         }
  53
  54         private void saveBookmarkedPosts() {
  55                 lock.readLock().lock();
  56                 try {
  57                         configurationLoader.saveBookmarkedPosts(this.bookmarkedPosts);
  58                 } finally {
  59                         lock.readLock().unlock();
  60                 }
  61         }
  62
  63         @Override
  64         public void bookmarkPost(Post post) {
  65                 lock.writeLock().lock();
  66                 try {
  67                         bookmarkedPosts.add(post.getId());
  68                         saveBookmarkedPosts();
  69                 } finally {
  70                         lock.writeLock().unlock();
  71                 }
  72         }
  73
  74         @Override
  75         public void unbookmarkPost(Post post) {
  76                 lock.writeLock().lock();
  77                 try {
  78                         bookmarkedPosts.remove(post.getId());
  79                         saveBookmarkedPosts();
  80                 } finally {
  81                         lock.writeLock().unlock();
  82                 }
  83         }
  84
  85         @Override
  86         public boolean isPostBookmarked(Post post) {
  87                 lock.readLock().lock();
  88                 try {
  89                         return bookmarkedPosts.contains(post.getId());
  90                 } finally {
  91                         lock.readLock().unlock();
  92                 }
  93         }
  94
  95         @Override
  96         public Set<Post> getBookmarkedPosts() {
  97                 lock.readLock().lock();
  98                 try {
  99                         return from(bookmarkedPosts).transform(
 100                                         new Function<String, Post>() {
 101                                                 @Override
 102                                                 public Post apply(String postId) {
 103                                                         return fromNullable(memoryDatabase.getPost(postId))
 104                                                                         .or(new EmptyPost(postId));
 105                                                 }
 106                                         }).toSet();
 107                 } finally {
 108                         lock.readLock().unlock();
 109                 }
 110         }
 111
 112 }