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

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