com.force.i18n.grammar.parser.ConcurrentUniquefy Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of grammaticus Show documentation

Localization Framework that allows grammatically correct renaming of nouns

There is a newer version: 1.2.30

/*
 * Copyright (c) 2017, salesforce.com, inc.
 * All rights reserved.
 * Licensed under the BSD 3-Clause license.
 * For full license text, see LICENSE.txt file in the repo root  or https://opensource.org/licenses/BSD-3-Clause
 */

package com.force.i18n.grammar.parser;

import java.io.Serializable;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

/**
 * A version of uniquefy that works in a "concurrent" fashion, so that it's not actually
 * "unique", but close enough to prevent leakage.  Use this for fixed-set caches.
 * @author stamm
 */
public class ConcurrentUniquefy implements Serializable {

    private final ConcurrentMap pool;

    /**
     * Create a new string pool.
     */
    public ConcurrentUniquefy() {
        this.pool = new ConcurrentHashMap(128, .75f, 2);
    }

    /**
     * Look to see if the given value is already in the given string pool.
     * If so, return the one already in the pool.  Otherwise, add it to the pool.
     * @param value the value to make unique
     * @return the value or an equivalent already in the pool.
     */
    public T unique(T value) {
        if (value == null) return null;

        T result = this.pool.get(value);
        if (result != null) return result;

        result = this.pool.putIfAbsent(value, value);
        assert result == null || result.equals(value) : "There's a flaw in the equals logic associated with " + value.getClass();
        return result == null ? value : result;
    }
}