| /* |
| * 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.ignite.internal.util; |
| |
| import java.util.Comparator; |
| import java.util.PriorityQueue; |
| import org.apache.ignite.internal.util.typedef.internal.A; |
| |
| /** |
| * Bounded variant of {@link PriorityQueue}. |
| * |
| * @param <E> Type of the queue element. |
| */ |
| public class GridBoundedPriorityQueue<E> extends PriorityQueue<E> { |
| /** */ |
| private static final long serialVersionUID = 0L; |
| |
| /** Queue max capacity. */ |
| private final int maxCap; |
| |
| /** Comparator. */ |
| private final Comparator<? super E> cmp; |
| |
| /** |
| * Creates a bounded priority queue with the specified maximum size. |
| * At most {@code maxCap} elements would be kept in the queue. |
| * |
| * @param maxCap Maximum size of the queue. |
| * @param cmp Comparator that orders the elements. |
| */ |
| public GridBoundedPriorityQueue(int maxCap, Comparator<? super E> cmp) { |
| super(maxCap, cmp); |
| |
| A.notNull(cmp, "comparator not null"); |
| |
| this.maxCap = maxCap; |
| this.cmp = cmp; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override public boolean offer(E e) { |
| if (size() >= maxCap) { |
| E head = peek(); |
| |
| if (cmp.compare(e, head) <= 0) |
| return false; |
| |
| poll(); |
| } |
| |
| return super.offer(e); |
| } |
| } |