OF-1125: StreamID should be Cacheable.

src/java/org/jivesoftware/openfire/spi/BasicStreamIDFactory.java

@@ -23,6 +23,9 @@ package org.jivesoftware.openfire.spi;
 import org.apache.commons.lang.StringEscapeUtils;
 import org.jivesoftware.openfire.StreamID;
 import org.jivesoftware.openfire.StreamIDFactory;
+import org.jivesoftware.util.cache.CacheSizes;
+import org.jivesoftware.util.cache.Cacheable;
+import org.jivesoftware.util.cache.CannotCalculateSizeException;
 
 import java.math.BigInteger;
 import java.security.SecureRandom;
@@ -54,7 +57,7 @@ public class BasicStreamIDFactory implements StreamIDFactory {
         return new BasicStreamID(name);
     }
 
-    private static class BasicStreamID implements StreamID {
+    private static class BasicStreamID implements StreamID, Cacheable {
         String id;
 
         public BasicStreamID(String id) {
@@ -86,5 +89,15 @@ public class BasicStreamIDFactory implements StreamIDFactory {
             if ( o == null || getClass() != o.getClass() ) return false;
             return id.equals( ((BasicStreamID) o).id );
         }
+
+        @Override
+        public int getCachedSize() throws CannotCalculateSizeException
+        {
+            // Approximate the size of the object in bytes by calculating the size of each field.
+            int size = 0;
+            size += CacheSizes.sizeOfObject();   // overhead of object
+            size += CacheSizes.sizeOfString(id); // id
+            return size;
+        }
     }
 }