/*

 * Copyright (c) 2015, 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

 * or visit www.oracle.com if you need additional information or have any

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 */

package jdk.internal.loader;

import java.lang.module.Configuration;

import java.lang.module.ResolvedModule;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.stream.Stream;

/**

 * A pool of class loaders.

 *

 * @see ModuleLayer#defineModulesWithManyLoaders

 */

public final class LoaderPool {

    // maps module names to class loaders

    private final Map<String, Loader> loaders;

    /**

     * Creates a pool of class loaders. Each module in the given configuration

     * will be loaded its own class loader in the pool. The class loader is

     * created with the given parent class loader as its parent.

     */

    public LoaderPool(Configuration cf,

                      List<ModuleLayer> parentLayers,

                      ClassLoader parentLoader)

    {

        Map<String, Loader> loaders = new HashMap<>();

        for (ResolvedModule resolvedModule : cf.modules()) {

            Loader loader = new Loader(resolvedModule, this, parentLoader);

            String mn = resolvedModule.name();

            loaders.put(mn, loader);

        }

        this.loaders = loaders;

        // complete the initialization

        loaders.values().forEach(l -> l.initRemotePackageMap(cf, parentLayers));

    }

    /**

     * Returns the class loader for the named module

     */

    public Loader loaderFor(String name) {

        Loader loader = loaders.get(name);

        assert loader != null;

        return loader;

    }

    /**

     * Returns a stream of the loaders in this pool.

     */

    public Stream<Loader> loaders() {

        return loaders.values().stream();

    }

}