/*
 * Copyright 2021 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.buffer.api.tests;

import java.util.function.Supplier;

final class Memoize<T> implements Supplier<T> {
    private final Supplier<T> supplier;
    private volatile T memo;

    Memoize(Supplier<T> supplier) {
        this.supplier = supplier;
    }

    @Override
    public T get() {
        T val = memo;
        if (val == null) {
            memo = val = supplier.get();
        }
        return val;
    }
}