org.prot.manager.zookeeper.jobs.LookupControllers.java Source code

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Here is the source code for org.prot.manager.zookeeper.jobs.LookupControllers.java

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/*******************************************************************************
 * Copyright (c) 2010 Andreas Wolke.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Andreas Wolke - initial API and implementation and initial documentation
 *******************************************************************************/
package org.prot.manager.zookeeper.jobs;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.log4j.Logger;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.data.Stat;
import org.prot.manager.stats.ControllerInfo;
import org.prot.manager.stats.ControllerRegistry;
import org.prot.util.ObjectSerializer;
import org.prot.util.zookeeper.Job;
import org.prot.util.zookeeper.JobState;
import org.prot.util.zookeeper.ZNodes;
import org.prot.util.zookeeper.ZooHelper;
import org.prot.util.zookeeper.data.ControllerEntry;

public class LookupControllers implements Job, Watcher {
    private final static Logger logger = Logger.getLogger(LookupControllers.class);

    private ZooHelper zooHelper;

    private ControllerRegistry registry;

    @Override
    public void process(WatchedEvent event) {
        // Reexecute this job
        zooHelper.getQueue().insert(this);
    }

    @Override
    public JobState execute(ZooHelper zooHelper) throws KeeperException, InterruptedException, IOException {
        // ZooKeeper connection
        ZooKeeper zk = zooHelper.getZooKeeper();

        if (!zooHelper.checkConnection()) {
            registry.update(new ArrayList<ControllerInfo>());
            return JobState.RETRY_LATER;
        }

        // List the controllers directory in ZooKeeper
        logger.debug("Searching Controllers in: " + ZNodes.ZNODE_CONTROLLER);
        List<String> childs = zk.getChildren(ZNodes.ZNODE_CONTROLLER, this);

        // Iterate over all found Controllers
        List<ControllerInfo> infos = new ArrayList<ControllerInfo>();
        for (String child : childs) {
            logger.debug("Found Controller: " + child);

            child = ZNodes.ZNODE_CONTROLLER + "/" + child;
            Stat stat = new Stat();
            byte[] data = zk.getData(child, false, stat);

            ObjectSerializer serializer = new ObjectSerializer();
            ControllerEntry controller = (ControllerEntry) serializer.deserialize(data);

            ControllerInfo info = new ControllerInfo();
            info.setAddress(controller.address);
            info.setServiceAddress(controller.serviceAddress);
            info.setPort(controller.port);
            infos.add(info);
        }

        logger.debug("Updating ControllerRegistry with " + infos.size() + " Controllers");
        registry.update(infos);

        return JobState.OK;
    }

    @Override
    public void init(ZooHelper zooHelper) {
        this.zooHelper = zooHelper;
    }

    @Override
    public boolean isRetryable() {
        return true;
    }

    public void setRegistry(ControllerRegistry registry) {
        this.registry = registry;
    }
}