org.jpos.util.Recyclable Maven / Gradle / Ivy

/*
 * jPOS Project [http://jpos.org]
 * Copyright (C) 2000-2023 jPOS Software SRL
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see .
 */

package org.jpos.util;

import java.util.concurrent.atomic.AtomicLong;
import java.util.function.Supplier;

/**
 * Caches a supplier's result up to approximately maxCycles.
 *
 * After approximately maxCycles calls to its get() operation,
 * Recyclable fetches a new result from its underlying Supplier.
 * 
 *
 * @param  the type of results supplied by this supplier
 * @since 2.1.3
 */
public class Recyclable implements Supplier {
    private Supplier supplier;
    private long maxCycles;
    private AtomicLong cycles = new AtomicLong();
    private volatile T obj;

    public Recyclable(Supplier supplier, long maxCycles) {
        this.supplier = supplier;
        this.maxCycles = maxCycles;
    }

    @Override
    public T get() {
        if (cycles.getAndIncrement() == maxCycles || obj == null) {
            obj = supplier.get();
            cycles.set(0);
        }
        return obj;
    }
}