RedisUtil.java

/*
 * Copyright 2017 Async-IO.org
 *
 * 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.atmosphere.plugin.redis;

import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
import org.atmosphere.cpr.AtmosphereConfig;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPubSub;
import redis.clients.jedis.exceptions.JedisException;

import java.net.URI;
import java.util.concurrent.atomic.AtomicBoolean;

public class RedisUtil {
    private static final Logger logger = LoggerFactory.getLogger(RedisBroadcaster.class);

    private static final String REDIS_AUTH = RedisBroadcaster.class.getName() + ".authorization";
    private static final String REDIS_SERVER = RedisBroadcaster.class.getName() + ".server";
    private static final String REDIS_SHARED_POOL = RedisBroadcaster.class.getName() + ".sharedPool";

    private Jedis jedisSubscriber;
    private Jedis jedisPublisher;
    private String authToken = null;

    private boolean sharedPool = false;
    private JedisPool jedisPool;
    private final AtmosphereConfig config;
    private URI uri;
    private final AtomicBoolean destroyed = new AtomicBoolean();
    private final Callback callback;

    public RedisUtil(URI uri, AtmosphereConfig config, Callback callback) {
        this.config = config;
        this.callback = callback;
        this.uri = uri;
    }

    public String getAuth() {
        return authToken;
    }

    public void setAuth(String auth) {
        authToken = auth;
    }

    public void configure() {

        if (config.getServletConfig().getInitParameter(REDIS_AUTH) != null) {
            authToken = config.getServletConfig().getInitParameter(REDIS_AUTH);
        }

        if (config.getServletConfig().getInitParameter(REDIS_SERVER) != null) {
            uri = URI.create(config.getServletConfig().getInitParameter(REDIS_SERVER));
        } else if (uri == null) {
            throw new NullPointerException("uri cannot be null");
        }

        if (config.getServletConfig().getInitParameter(REDIS_SHARED_POOL) != null) {
            sharedPool = Boolean.parseBoolean(config.getServletConfig().getInitParameter(REDIS_SHARED_POOL));
        }

        logger.info("{} shared connection pool {}", getClass().getName(), sharedPool);

        if (sharedPool) {
            if (config.properties().get(REDIS_SHARED_POOL) != null) {
                jedisPool = (JedisPool) config.properties().get(REDIS_SHARED_POOL);
            }

            // setup is synchronized, no need to sync here as well.
            if (jedisPool == null) {
                GenericObjectPoolConfig gConfig = new GenericObjectPoolConfig();
                gConfig.setTestOnBorrow(true);
                gConfig.setTestWhileIdle(true);

                jedisPool = new JedisPool(gConfig, uri.getHost(), uri.getPort());

                config.properties().put(REDIS_SHARED_POOL, jedisPool);
            } else {
                disconnectSubscriber();
            }
        }

        // We use the pool only for publishing
        jedisSubscriber = new Jedis(uri.getHost(), uri.getPort());
        try {
            jedisSubscriber.connect();
            auth(jedisSubscriber);
        } catch (JedisException e) {
            logger.error("failed to connect subscriber", e);
            disconnectSubscriber();
        }

        jedisPublisher = sharedPool ? null : new Jedis(uri.getHost(), uri.getPort());
        if (!sharedPool) {
            try {
                jedisPublisher.connect();
                auth(jedisPublisher);
            } catch (JedisException e) {
                logger.error("failed to connect publisher", e);
                disconnectPublisher();
            }
        }
    }

    public synchronized void setID(String id) {
        disconnectPublisher();
        disconnectSubscriber();
    }

    /**
     * {@inheritDoc}
     */
    public void destroy() {
        if (!sharedPool) {
            Object lockingObject = getLockingObject();
            synchronized (lockingObject) {
                try {
                    disconnectPublisher();
                    disconnectSubscriber();
                    if (jedisPool != null) {
                        jedisPool.destroy();
                    }
                } catch (Throwable t) {
                    logger.warn("Jedis error on close", t);
                } finally {
                    config.properties().put(REDIS_SHARED_POOL, null);
                }
            }
        }
    }

    public boolean isShared(){
        return sharedPool;
    }

    /**
     * {@inheritDoc}
     */
    public void incomingBroadcast() {
        logger.info("Subscribing to: {}", callback.getID());

        jedisSubscriber.subscribe(new JedisPubSub() {

            public void onMessage(String channel, String message) {
                callback.broadcastReceivedMessage(message);
            }

            public void onSubscribe(String channel, int subscribedChannels) {
                logger.debug("onSubscribe: {}", channel);
            }

            public void onUnsubscribe(String channel, int subscribedChannels) {
                logger.debug("onUnsubscribe: {}", channel);
            }

            public void onPSubscribe(String pattern, int subscribedChannels) {
                logger.debug("onPSubscribe: {}", pattern);
            }

            public void onPUnsubscribe(String pattern, int subscribedChannels) {
                logger.debug("onPUnsubscribe: {}", pattern);
            }

            public void onPMessage(String pattern, String channel, String message) {
                logger.debug("onPMessage: pattern: {}, channel: {}, message: {}",
                        new Object[]{pattern, channel, message});
            }
        }, callback.getID());
    }

    public void outgoingBroadcast(Object message) {
        // Marshal the message outside of the sync block.
        String contents = message.toString();

        Object lockingObject = getLockingObject();
        synchronized (lockingObject) {
            if (destroyed.get()) {
                logger.debug("JedisPool closed. Re-opening");
                setID(callback.getID());
            }

            if (sharedPool) {
                for (int i = 0; i < 10; ++i) {
                    boolean valid = true;
                    Jedis jedis = jedisPool.getResource();

                    try {
                        auth(jedis);
                        jedis.publish(callback.getID(), contents);
                    } catch (JedisException e) {
                        valid = false;
                        logger.warn("outgoingBroadcast exception", e);
                    } finally {
                        if (valid) {
                            jedisPool.returnResource(jedis);
                        } else {
                            jedisPool.returnBrokenResource(jedis);
                        }
                    }

                    if (valid) {
                        break;
                    }
                }
            } else {
                try {
                    jedisPublisher.publish(callback.getID(), contents);
                } catch (JedisException e) {
                    logger.warn("outgoingBroadcast exception", e);
                }
            }
        }
    }

    private void auth(Jedis jedis) {
        if (authToken != null) {
            jedis.auth(authToken);
        }
    }

    private void disconnectSubscriber() {
        if (jedisSubscriber == null) return;

        synchronized (jedisSubscriber) {
            try {
                jedisSubscriber.disconnect();
            } catch (JedisException e) {
                logger.error("failed to disconnect subscriber", e);
            }
        }
    }

    private void disconnectPublisher() {
        if (jedisPublisher == null) return;

        synchronized (jedisPublisher) {
            try {
                jedisPublisher.disconnect();
            } catch (JedisException e) {
                logger.error("failed to disconnect publisher", e);
            }
        }
    }

    private Object getLockingObject() {
        return sharedPool ? jedisPool : jedisPublisher;
    }

    public static interface Callback {

        String getID();

        void broadcastReceivedMessage(String message);

    }
}