@Override
    public void purgeNode( LeafNode leafNode )
    {
        Node.UniqueIdentifier uid = leafNode.getUniqueIdentifier();
        log.debug( "Purging node {}", uid );

        final Lock lock = itemsCache.getLock( leafNode.getUniqueIdentifier() );
        lock.lock();
        try {
            itemsCache.remove( leafNode.getUniqueIdentifier() );
        } finally {
            lock.unlock();
        }

        CacheUtil.removeValueFromMultiValuedCache( serviceIdToNodesCache, leafNode );
    }
Cache that holds all published items (mapped by node ID).
xmppserver/src/main/java/org/jivesoftware/openfire/pubsub/InMemoryPubSubPersistenceProvider.java