org.red5.server.plugin.PluginRegistry Maven / Gradle / Ivy

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Ant Media Server supports RTMP, RTSP, MP4, HLS, WebRTC, Adaptive Streaming, etc.
There is a newer version: 2.10.0
/*
 * RED5 Open Source Media Server - https://github.com/Red5/
 * 
 * Copyright 2006-2016 by respective authors (see below). 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.red5.server.plugin;

import java.util.Map.Entry;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

import org.red5.logging.Red5LoggerFactory;
import org.red5.server.api.plugin.IRed5Plugin;
import org.slf4j.Logger;

/**
 * Central registry for Red5 plug-ins.
 * 
 * @author Paul Gregoire
 */
public class PluginRegistry {

    private static Logger log = Red5LoggerFactory.getLogger(PluginRegistry.class, "plugins");

    // keeps track of plug-ins, keyed by plug-in name
    private static volatile ConcurrentMap plugins = new ConcurrentHashMap<>(3, 0.9f, 1);

    // locks for guarding plug-ins
    private final static ReadWriteLock pluginLock = new ReentrantReadWriteLock();

    private final static Lock pluginReadLock;

    private final static Lock pluginWriteLock;

    static {
        pluginReadLock = pluginLock.readLock();
        pluginWriteLock = pluginLock.writeLock();
    }

    /**
     * Registers a plug-in.
     * 
     * @param plugin
     *            plugin
     */
    public static void register(IRed5Plugin plugin) {
        log.debug("Register plugin: {}", plugin);
        String pluginName = plugin.getName();
        //get a write lock
        pluginWriteLock.lock();
        try {
            if (plugins.containsKey(pluginName)) {
                //get old plugin
                IRed5Plugin oldPlugin = plugins.get(pluginName);
                //if they are not the same shutdown the older one
                if (!plugin.equals(oldPlugin)) {
                    try {
                        oldPlugin.doStop();
                    } catch (Exception e) {
                        log.warn("Exception caused when stopping old plugin", e);
                    }
                    //replace old one
                    plugins.replace(pluginName, plugin);
                }
            } else {
                plugins.put(pluginName, plugin);
            }
        } finally {
            pluginWriteLock.unlock();
        }
    }

    /**
     * Unregisters a plug-in.
     * 
     * @param plugin
     *            plugin
     */
    public static void unregister(IRed5Plugin plugin) {
        log.debug("Unregister plugin: {}", plugin);
        //get a write lock
        pluginWriteLock.lock();
        try {
            if (plugins.containsValue(plugin)) {
                boolean removed = false;
                for (Entry f : plugins.entrySet()) {
                    if (plugin.equals(f.getValue())) {
                        log.debug("Removing {}", plugin);
                        plugins.remove(f.getKey());
                        removed = true;
                        break;
                    } else {
                        log.debug("Not equal - {} {}", plugin, f.getValue());
                    }
                }
                if (!removed) {
                    log.debug("Last try to remove the plugin");
                    plugins.remove(plugin.getName());
                }
            } else {
                log.warn("Plugin is not registered {}", plugin);
            }
        } finally {
            pluginWriteLock.unlock();
        }
    }

    /**
     * Returns a plug-in.
     * 
     * @param pluginName
     *            plugin name
     * @return requested plug-in matching the name given or null if not found
     */
    public static IRed5Plugin getPlugin(String pluginName) {
        IRed5Plugin plugin = null;
        pluginReadLock.lock();
        try {
            plugin = plugins.get(pluginName);
        } finally {
            pluginReadLock.unlock();
        }
        return plugin;
    }

    /**
     * Shuts down the registry and stops any plug-ins that are found.
     * 
     * @throws Exception
     *             on exception
     */
    public static void shutdown() throws Exception {
        log.info("Destroying and cleaning up {} plugins", plugins.size());
        //loop through the plugins and stop them
        pluginReadLock.lock();
        try {
            for (Entry pluginEntry : plugins.entrySet()) {
                IRed5Plugin plugin = pluginEntry.getValue();
                try {
                    plugin.doStop();
                } catch (Exception ex) {
                    if (plugin != null) {
                        log.warn("Plugin stop failed for: {}", plugin.getName(), ex);
                    } else {
                        log.warn("Plugin stop failed", ex);
                    }
                }
            }
        } finally {
            pluginReadLock.unlock();
        }
        plugins.clear();
    }

}