| /* |
| * 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.qpid.util; |
| |
| import java.util.Queue; |
| |
| /** |
| * Defines a queue that has a push operation to add an element to the head of the queue. |
| * |
| * @todo Seems like this may be pointless, the implementation uses this method to increment the message count |
| * then calls offer. Why not simply override offer and drop this interface? |
| */ |
| public interface MessageQueue<E> extends Queue<E> |
| { |
| /** |
| * Inserts the specified element into this queue, if possible. When using queues that may impose insertion |
| * restrictions (for example capacity bounds), method offer is generally preferable to method Collection.add(E), |
| * which can fail to insert an element only by throwing an exception. |
| * |
| * @param o The element to insert. |
| * |
| * @return <tt>true</tt> if it was possible to add the element to this queue, else <tt>false</tt> |
| */ |
| boolean pushHead(E o); |
| } |