NodeReader.java

/*******************************************************************************
 *  Copyright (c)2010 REMAIN B.V. The Netherlands. (http://www.remainsoftware.com).
 *  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:
 *     Wim Jongman - initial API and implementation 
 *     Ahmed Aadel - initial API and implementation     
 *******************************************************************************/
package org.eclipse.ecf.provider.zookeeper.node.internal;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.util.Map;

import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.Watcher.Event.EventType;
import org.apache.zookeeper.Watcher.Event.KeeperState;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.data.Stat;
import org.eclipse.core.runtime.Assert;
import org.eclipse.ecf.provider.zookeeper.core.DiscoverdService;
import org.eclipse.ecf.provider.zookeeper.core.internal.Localizer;
import org.eclipse.ecf.provider.zookeeper.core.internal.Notification;
import org.eclipse.ecf.provider.zookeeper.util.Logger;
import org.eclipse.ecf.provider.zookeeper.util.PrettyPrinter;
import org.osgi.service.log.LogService;

public class NodeReader implements Watcher,
		org.apache.zookeeper.AsyncCallback.DataCallback {

	private String path;
	private DiscoverdService discovered;
	private ZooKeeper zookeeper;
	private String ip;
	boolean isNodePublished;
	private boolean isDisposed;
	private ReadRoot readRoot;

	public NodeReader(String path, ReadRoot readRoot) {
		Assert.isNotNull(path);
		Assert.isNotNull(readRoot);
		this.readRoot = readRoot;
		this.path = path;
		this.zookeeper = readRoot.getReadKeeper();
		this.ip = readRoot.getIp();
		this.zookeeper.getData(getAbsolutePath(), this, this, null);
		this.zookeeper.exists(getAbsolutePath(), this, null, null);
	}

	public void setPath(String path) {
		this.path = path;
	}

	public String getPath() {
		return this.path;
	}

	public String getAbsolutePath() {
		return INode.ROOT_SLASH + getPath();
	}

	public synchronized void processResult(int rc, String p, Object ctx,
			byte[] data, Stat stat) {
		if (p == null || !p.equals(getAbsolutePath()) || data == null) {
			return;
		}
		ObjectInputStream objin = null;
		ByteArrayInputStream bain = null;
		Map<String, Object> serviceData = null;
		try {
			bain = new ByteArrayInputStream(data);
			objin = new ObjectInputStream(bain);
			try {
				serviceData = (Map<String, Object>) objin.readObject();
			} catch (ClassNotFoundException e) {
				Logger.log(LogService.LOG_ERROR, "NodeReader.processResult: "
						+ e.getMessage(), e);
			}
			if (serviceData == null || serviceData.isEmpty()) {
				return;
			}
			this.discovered = new DiscoverdService(getPath(), serviceData);
			readRoot.getDiscoverdServices()
					.put(this.discovered.getServiceID().getServiceTypeID()
							.getName(), this.discovered);
			Logger.log(LogService.LOG_DEBUG, PrettyPrinter.prompt(PrettyPrinter.REMOTE_AVAILABLE, this.discovered), null);
			Localizer.getSingleton().localize(
					new Notification(this.discovered, Notification.AVAILABLE));

		} catch (IOException e) {
			Logger.log(LogService.LOG_DEBUG, e.getMessage(), e);
		} finally {
			if (objin != null) {
				try {
					objin.close();
				} catch (IOException e) {
					// ignore
				}
			}
			if (bain != null) {
				try {
					bain.close();
				} catch (IOException e) {
					// ignore
				}
			}
		}
	}

	public void setIp(String ip) {
		this.ip = ip;
	}

	public String getIp() {
		return this.ip;
	}

	public void process(WatchedEvent event) {

		if (this.isDisposed) {
			// Already disposed
			return;
		}
		if (event.getState() == KeeperState.Disconnected
				|| event.getState() == KeeperState.Expired
				|| event.getType() == EventType.NodeDeleted) {
			/*
			 * This node is deleted or the connection with the server we're
			 * reading from is down. This discovered service wrapped by this
			 * node is no more available.
			 */
			dispose();
		}

	}

	public synchronized void dispose() {
		if (isDisposed || discovered == null)
			return;
		if (null != readRoot.getDiscoverdServices().remove(
				this.discovered.getServiceID().getServiceTypeID().getName())) {
			this.discovered.dispose();
			isDisposed = true;

		}
	}

}