org.elasticsearch.common.collect.BoundedArrayList Maven / Gradle / Ivy

/*
 * Licensed to Elastic Search and Shay Banon under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. Elastic Search 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.elasticsearch.common.collect;

import java.util.AbstractList;
import java.util.RandomAccess;

/**
 * An array list that is based on an array and a size, only using the first size elements in the array.
 */
public class BoundedArrayList extends AbstractList implements RandomAccess {

    private final E[] a;
    private final int size;

    public BoundedArrayList(E[] array, int size) {
        if (array == null)
            throw new NullPointerException();
        a = array;
        this.size = size;
    }

    public int size() {
        return size;
    }

    public Object[] toArray() {
        throw new UnsupportedOperationException();
    }

    public  T[] toArray(T[] a) {
        throw new UnsupportedOperationException();
    }

    public E get(int index) {
        return a[index];
    }

    public E set(int index, E element) {
        E oldValue = a[index];
        a[index] = element;
        return oldValue;
    }

    public int indexOf(Object o) {
        if (o == null) {
            for (int i = 0; i < a.length; i++)
                if (a[i] == null)
                    return i;
        } else {
            for (int i = 0; i < a.length; i++)
                if (o.equals(a[i]))
                    return i;
        }
        return -1;
    }

    public boolean contains(Object o) {
        return indexOf(o) != -1;
    }
}