de.hpi.fgis.hdrs.node.AntiEntropyThread.java Source code

Introduction

Here is the source code for de.hpi.fgis.hdrs.node.AntiEntropyThread.java

Source

/**
 * Copyright 2011 Daniel Hefenbrock
 *
 * 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 de.hpi.fgis.hdrs.node;

import java.io.IOException;
import java.net.ConnectException;
import java.net.UnknownHostException;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.TimeUnit;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import de.hpi.fgis.hdrs.Peer;
import de.hpi.fgis.hdrs.routing.Router;

public class AntiEntropyThread extends Thread {

    static final Log LOG = LogFactory.getLog(AntiEntropyThread.class);

    private final Router router;
    private volatile boolean quit = false;

    LinkedBlockingQueue<Peer> queue = new LinkedBlockingQueue<Peer>();

    AntiEntropyThread(Router router) {
        this.router = router;
        setName("Anti-Entropy Thread");
    }

    @Override
    public void run() {

        while (!quit) {

            // wait for some ae request, or 10 seconds
            Peer peer = null;
            try {
                peer = queue.poll(10, TimeUnit.SECONDS);
            } catch (InterruptedException e) {
                // ignore
            }

            try {
                router.update(peer);
            } catch (UnknownHostException ex) {
                // this node can't be reached.  might be a temporary network failure,
                // log a warning
                LOG.warn("Cannot run anti-entropy with peer " + peer + ": unkown host");
            } catch (ConnectException ex) {
                LOG.warn("Cannot run anti-entropy with peer " + peer + ": cannot connect");
            } catch (IOException ex) {
                LOG.warn("Anti-entropy error.", ex);
            } catch (Throwable ex) {
                LOG.fatal("Anti-entropy failure.", ex);
                quit();
            }

        }

    }

    public void quit() {
        quit = true;
        interrupt();
    }

    public void quitJoin() {
        quit();
        try {
            join();
        } catch (InterruptedException e) {
            // ignore
        }
    }

    public void run(Peer peer) {
        queue.offer(peer);
    }

}