Move friend-related functionality into the database.

[Sone.git] / src / main / java / net / pterodactylus / sone / database / memory / MemoryFriendDatabase.java

diff --git a/src/main/java/net/pterodactylus/sone/database/memory/MemoryFriendDatabase.java b/src/main/java/net/pterodactylus/sone/database/memory/MemoryFriendDatabase.java
new file mode 100644 (file)
index 0000000..1802843
--- /dev/null
+++ b/src/main/java/net/pterodactylus/sone/database/memory/MemoryFriendDatabase.java
@@ -0,0 +1,79 @@
+package net.pterodactylus.sone.database.memory;
+
+import java.util.Collection;
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.Multimap;
+
+/**
+ * In-memory implementation of friend-related functionality.
+ *
+ * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+ */
+class MemoryFriendDatabase {
+
+       private final ReadWriteLock lock = new ReentrantReadWriteLock();
+       private final ConfigurationLoader configurationLoader;
+       private final Multimap<String, String> soneFriends = HashMultimap.create();
+
+       MemoryFriendDatabase(ConfigurationLoader configurationLoader) {
+               this.configurationLoader = configurationLoader;
+       }
+
+       Collection<String> getFriends(String localSoneId) {
+               loadFriends(localSoneId);
+               lock.readLock().lock();
+               try {
+                       return soneFriends.get(localSoneId);
+               } finally {
+                       lock.readLock().unlock();
+               }
+       }
+
+       boolean isFriend(String localSoneId, String friendSoneId) {
+               loadFriends(localSoneId);
+               lock.readLock().lock();
+               try {
+                       return soneFriends.containsEntry(localSoneId, friendSoneId);
+               } finally {
+                       lock.readLock().unlock();
+               }
+       }
+
+       void addFriend(String localSoneId, String friendSoneId) {
+               lock.writeLock().lock();
+               try {
+                       if (soneFriends.put(localSoneId, friendSoneId)) {
+                               configurationLoader.saveFriends(localSoneId, soneFriends.get(localSoneId));
+                       }
+               } finally {
+                       lock.writeLock().unlock();
+               }
+       }
+
+       void removeFriend(String localSoneId, String friendSoneId) {
+               lock.writeLock().lock();
+               try {
+                       if (soneFriends.remove(localSoneId, friendSoneId)) {
+                               configurationLoader.saveFriends(localSoneId, soneFriends.get(localSoneId));
+                       }
+               } finally {
+                       lock.writeLock().unlock();
+               }
+       }
+
+       private void loadFriends(String localSoneId) {
+               lock.writeLock().lock();
+               try {
+                       if (soneFriends.containsKey(localSoneId)) {
+                               return;
+                       }
+                       soneFriends.putAll(localSoneId, configurationLoader.loadFriends(localSoneId));
+               } finally {
+                       lock.writeLock().unlock();
+               }
+       }
+
+}