Add synchronization note.

[Sone.git] / src / main / java / net / pterodactylus / sone / data / Sone.java

diff --git a/src/main/java/net/pterodactylus/sone/data/Sone.java b/src/main/java/net/pterodactylus/sone/data/Sone.java
index 4a73470..8b2367b 100644 (file)
--- a/src/main/java/net/pterodactylus/sone/data/Sone.java
+++ b/src/main/java/net/pterodactylus/sone/data/Sone.java
@@ -27,6 +27,8 @@ import freenet.keys.FreenetURI;
 /**
  * A Sone defines everything about a user: the {@link User} itself, her profile,
  * her status updates.
+ * <p>
+ * Operations that modify the Sone need to synchronize on the Sone in question.
  *
  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  */
@@ -48,6 +50,9 @@ public class Sone {
        /** All friend Sones. */
        private final Set<Sone> friendSones = new HashSet<Sone>();
 
+       /** Modification count. */
+       private volatile long modificationCounter = 0;
+
        /**
         * Creates a new Sone.
         *
@@ -149,8 +154,10 @@ public class Sone {
         *            The friend Sone to add
         * @return This Sone (for method chaining)
         */
-       public Sone addFriendSone(Sone friendSone) {
-               friendSones.add(friendSone);
+       public synchronized Sone addFriendSone(Sone friendSone) {
+               if (friendSones.add(friendSone)) {
+                       modificationCounter++;
+               }
                return this;
        }
 
@@ -161,11 +168,32 @@ public class Sone {
         *            The friend Sone to remove
         * @return This Sone (for method chaining)
         */
-       public Sone removeFriendSone(Sone friendSone) {
-               friendSones.remove(friendSone);
+       public synchronized Sone removeFriendSone(Sone friendSone) {
+               if (friendSones.remove(friendSone)) {
+                       modificationCounter++;
+               }
                return this;
        }
 
+       /**
+        * Returns the modification counter.
+        *
+        * @return The modification counter
+        */
+       public synchronized long getModificationCounter() {
+               return modificationCounter;
+       }
+
+       /**
+        * Sets the modification counter.
+        *
+        * @param modificationCounter
+        *            The new modification counter
+        */
+       public synchronized void setModificationCounter(long modificationCounter) {
+               this.modificationCounter = modificationCounter;
+       }
+
        //
        // OBJECT METHODS
        //
@@ -178,4 +206,15 @@ public class Sone {
                return id.hashCode();
        }
 
+       /**
+        * {@inheritDoc}
+        */
+       @Override
+       public boolean equals(Object object) {
+               if (!(object instanceof Sone)) {
+                       return false;
+               }
+               return ((Sone) object).id.equals(id);
+       }
+
 }