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 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<>();
  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                         saveBookmarkedPosts();
  67                 } finally {
  68                         lock.writeLock().unlock();
  69                 }
  70         }
  71
  72         @Override
  73         public void unbookmarkPost(Post post) {
  74                 lock.writeLock().lock();
  75                 try {
  76                         bookmarkedPosts.remove(post.getId());
  77                         saveBookmarkedPosts();
  78                 } finally {
  79                         lock.writeLock().unlock();
  80                 }
  81         }
  82
  83         @Override
  84         public boolean isPostBookmarked(Post post) {
  85                 lock.readLock().lock();
  86                 try {
  87                         return bookmarkedPosts.contains(post.getId());
  88                 } finally {
  89                         lock.readLock().unlock();
  90                 }
  91         }
  92
  93         @Override
  94         public Set<Post> getBookmarkedPosts() {
  95                 lock.readLock().lock();
  96                 try {
  97                         return from(bookmarkedPosts).transform(
  98                                         new Function<String, Post>() {
  99                                                 @Override
 100                                                 public Post apply(String postId) {
 101                                                         return fromNullable(memoryDatabase.getPost(postId))
 102                                                                         .or(new EmptyPost(postId));
 103                                                 }
 104                                         }).toSet();
 105                 } finally {
 106                         lock.readLock().unlock();
 107                 }
 108         }
 109
 110 }