DefaultPriorityQueue.java — netty Source File

Source Code

/*
 * Copyright 2015 The Netty Project
 *
 * The Netty Project 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:
 *
 *   https://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 io.netty.util.internal;

import java.util.AbstractQueue;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Iterator;
import java.util.NoSuchElementException;

import static io.netty.util.internal.PriorityQueueNode.INDEX_NOT_IN_QUEUE;

/**
 * A priority queue which uses natural ordering of elements. Elements are also required to be of type
 * {@link PriorityQueueNode} for the purpose of maintaining the index in the priority queue.
 * @param <T> The object that is maintained in the queue.
 */
public final class DefaultPriorityQueue<T extends PriorityQueueNode> extends AbstractQueue<T>
                                                                     implements PriorityQueue<T> {
    private static final PriorityQueueNode[] EMPTY_ARRAY = new PriorityQueueNode[0];
    private final Comparator<T> comparator;
    private T[] queue;
    private int size;

    @SuppressWarnings("unchecked")
    public DefaultPriorityQueue(Comparator<T> comparator, int initialSize) {
        this.comparator = ObjectUtil.checkNotNull(comparator, "comparator");
        queue = (T[]) (initialSize != 0 ? new PriorityQueueNode[initialSize] : EMPTY_ARRAY);
    }

    @Override
    public int size() {
        return size;
    }

    @Override
    public boolean isEmpty() {
        return size == 0;
    }

    @Override
    public boolean contains(Object o) {
        if (!(o instanceof PriorityQueueNode)) {
            return false;
        }
        PriorityQueueNode node = (PriorityQueueNode) o;
        return contains(node, node.priorityQueueIndex(this));
// ... (237 more lines)