private static String getDefaultNodeConfigurationCacheKey( PubSubService.UniqueIdentifier serviceIdentifier, boolean isLeafType )
    {
        return serviceIdentifier.getServiceId() + "|" + isLeafType;
    }
Cache that holds all published items (mapped by node ID).
xmppserver/src/main/java/org/jivesoftware/openfire/pubsub/InMemoryPubSubPersistenceProvider.java