NumberPriorityQueue.java

/**
 * Copyright 2009 Google Inc.
 *
 * Licensed 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.waveprotocol.wave.model.util;


/**
 * A simple priority queue that using double rather than boxed Double
 * for efficiency.
 *
 * @author zdwang@google.com (David Wang)
 */
public interface NumberPriorityQueue {
  /** Number of items in the queue */
  public int size();

  /** Adds e to the back of the queue */
  public boolean offer(double e);

  /** Peek at the head of queue */
  public double peek();

  /** Removes an item from the beginning of the queue */
  public double poll();
}