/*

 * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package sun.util.locale.provider;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.HashSet;

import java.util.IllformedLocaleException;

import java.util.List;

import java.util.Locale;

import java.util.Locale.Builder;

import java.util.ResourceBundle.Control;

import java.util.Set;

import java.util.concurrent.ConcurrentHashMap;

import java.util.concurrent.ConcurrentMap;

import java.util.spi.LocaleServiceProvider;

import sun.util.logging.PlatformLogger;

/**

 * An instance of this class holds a set of the third party implementations of a particular

 * locale sensitive service, such as {@link java.util.spi.LocaleNameProvider}.

 *

 * @author Naoto Sato

 * @author Masayoshi Okutsu

 */

public final class LocaleServiceProviderPool {

    /**

     * A Map that holds singleton instances of this class.  Each instance holds a

     * set of provider implementations of a particular locale sensitive service.

     */

    private static ConcurrentMap<Class<? extends LocaleServiceProvider>, LocaleServiceProviderPool> poolOfPools =

        new ConcurrentHashMap<>();

    /**

     * A Map containing locale service providers that implement the

     * specified provider SPI, keyed by a LocaleProviderAdapter.Type

     */

    private ConcurrentMap<LocaleProviderAdapter.Type, LocaleServiceProvider> providers =

        new ConcurrentHashMap<>();

    /**

     * A Map that retains Locale->provider mapping

     */

    private ConcurrentMap<Locale, List<LocaleProviderAdapter.Type>> providersCache =

        new ConcurrentHashMap<>();

    /**

     * Available locales for this locale sensitive service.  This also contains

     * JRE's available locales

     */

    private Set<Locale> availableLocales = null;

    /**

     * Provider class

     */

    private Class<? extends LocaleServiceProvider> providerClass;

    /**

     * Array of all Locale Sensitive SPI classes.

     *

     * We know "spiClasses" contains classes that extends LocaleServiceProvider,

     * but generic array creation is not allowed, thus the "unchecked" warning

     * is suppressed here.

     */

    @SuppressWarnings("unchecked")

    static final Class<LocaleServiceProvider>[] spiClasses =

                (Class<LocaleServiceProvider>[]) new Class<?>[] {

        java.text.spi.BreakIteratorProvider.class,

        java.text.spi.CollatorProvider.class,

        java.text.spi.DateFormatProvider.class,

        java.text.spi.DateFormatSymbolsProvider.class,

        java.text.spi.DecimalFormatSymbolsProvider.class,

        java.text.spi.NumberFormatProvider.class,

        java.util.spi.CurrencyNameProvider.class,

        java.util.spi.LocaleNameProvider.class,

        java.util.spi.TimeZoneNameProvider.class,

        java.util.spi.CalendarDataProvider.class

    };

    /**

     * A factory method that returns a singleton instance

     */

    public static LocaleServiceProviderPool getPool(Class<? extends LocaleServiceProvider> providerClass) {

        LocaleServiceProviderPool pool = poolOfPools.get(providerClass);

        if (pool == null) {

            LocaleServiceProviderPool newPool =

                new LocaleServiceProviderPool(providerClass);

            pool = poolOfPools.putIfAbsent(providerClass, newPool);

            if (pool == null) {

                pool = newPool;

            }

        }

        return pool;

    }

    /**

     * The sole constructor.

     *

     * @param c class of the locale sensitive service

     */

    private LocaleServiceProviderPool (final Class<? extends LocaleServiceProvider> c) {

        providerClass = c;

        for (LocaleProviderAdapter.Type type : LocaleProviderAdapter.getAdapterPreference()) {

            LocaleProviderAdapter lda = LocaleProviderAdapter.forType(type);

            if (lda != null) {

                LocaleServiceProvider provider = lda.getLocaleServiceProvider(c);

                if (provider != null) {

                    providers.putIfAbsent(type, provider);

                }

            }

        }

    }

    static void config(Class<? extends Object> caller, String message) {

        PlatformLogger logger = PlatformLogger.getLogger(caller.getCanonicalName());

        logger.config(message);

    }

    /**

     * Lazy loaded set of available locales.

     * Loading all locales is a very long operation.