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Java-based middleware for in-memory processing of big data in a distributed environment.

There is a newer version: 6.2.1-p1

/* 
 Copyright (C) GridGain Systems. All Rights Reserved.
 
 Licensed 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.gridgain.grid.util;

import java.util.*;
import java.util.concurrent.*;

/**
 *
 */
public final class GridUuidCache {
    /** Maximum cache size. */
    private static final int MAX = 1024;

    /** Cache. */
    private static final ConcurrentMap cache =
        new GridBoundedConcurrentLinkedHashMap<>(MAX, 1024, 0.75f, 64);

    /**
     * Gets cached UUID to preserve memory.
     *
     * @param id Read UUID.
     * @return Cached UUID equivalent to the read one.
     */
    public static UUID onGridUuidRead(UUID id) {
        UUID cached = cache.get(id);

        if (cached == null) {
            UUID old = cache.putIfAbsent(id, cached = id);

            if (old != null)
                cached = old;
        }

        return cached;
    }

    /**
     * Ensure singleton.
     */
    private GridUuidCache() {
        // No-op.
    }
}