/*
 * 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.pulsar.common.util;

import java.util.function.Supplier;

/***
 * Used to lazy load a value, only calculate it when used. Not thread-safety.
 */
public class LazyLoadableValue<T> {

    private Supplier<T> loader;

    private T value;

    public LazyLoadableValue(Supplier<T> loader) {
        this.loader = loader;
    }

    public T getValue() {
        if (value == null) {
            value = loader.get();
        }
        return value;
    }
}
