vxquery-core/src/main/java/org/apache/vxquery/datamodel/accessors/PointableCache.java

/*
 * 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.vxquery.datamodel.accessors;

import java.util.ArrayList;
import java.util.List;

import org.apache.hyracks.data.std.api.IPointable;

public class PointableCache<T extends IPointable> {
    private final List<T> list;

    public PointableCache() {
        list = new ArrayList<T>();
    }

    public T takeOne() {
        if (list.isEmpty()) {
            return null;
        }
        return list.remove(list.size() - 1);
    }

    public void giveBack(T pointable) {
        list.add(pointable);
    }
}