/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */ package org.apache.brooklyn.core.internal.storage; /** * A reference to a value, backed by the storage-medium. * * @see BrooklynStorage#getReference(String) * * @author aled */ public interface Reference<T> { // TODO We can add compareAndSet(T,T) as and when required T get(); T set(T val); /** * @return true if the value is null; false otherwise. */ boolean isNull(); /** * Sets the value back to null. Similar to {@code set(null)}. */ void clear(); /** * @return true if the value equals the given parameter; false otherwise */ boolean contains(Object other); }