FCPClientHello.java

package thaw.fcp;

import java.util.Observable;
import java.util.Observer;

import thaw.core.Logger;

/**
 * http://wiki.freenetproject.org/FreenetFCPSpec2Point0
 * See "ClientHello" and "NodeHello".
 * Note: This query disconnect you if node answer CloseConnectionDuplicateClientName
 *       and start() returns false.
 */
public class FCPClientHello implements FCPQuery, Observer {
	public final static int NODEHELLO_TIMEOUT = 60; /* in seconds */

	private final static String FCP_EXPECTED_VERSION = "2.0";
	private String id;

	private String connectionId;
	private String nodeFCPVersion;
	private String nodeVersion;
	private String nodeName = null;
	private boolean testnet = false; /* Hmm, in fact, we shouldn't have to bother about this one */
	private int nmbCompressionCodecs = -1;
	private String[] codecs;

	private boolean receiveAnswer = false;

	private final FCPQueryManager queryManager;

	/**
	 * Need to know the id of the application (see FCP specs).
	 */
	public FCPClientHello(final FCPQueryManager queryManager, final String id) {
		this.id = id;
		this.queryManager = queryManager;
	}

	public void setID(final String id) {
		this.id = id;
	}

	public String getNodeFCPVersion() {
		return nodeFCPVersion;
	}

	public String getNodeVersion() {
		return nodeVersion;
	}

	public String getNodeName() {
		return nodeName;
	}

	public boolean isOnTestnet() {
		return testnet;
	}

	public int getNmbCompressionCodecs() {
		return nmbCompressionCodecs;
	}


	/**
	 * Warning: This query is blocking (only this one) !
	 * @param queueManager always null
	 */
	public boolean start(final FCPQueueManager queueManager) {

		queryManager.getConnection().registerClientHello(this);

		final FCPMessage message = new FCPMessage();

		message.setMessageName("ClientHello");
		message.setValue("Name", id);
		message.setValue("ExpectedVersion", FCPClientHello.FCP_EXPECTED_VERSION);

		queryManager.addObserver(this);

		if(!queryManager.writeMessage(message)) {
			Logger.warning(this, "Unable to say hello ... ;(");
			return false;
		}


		int count = 0;

		while(!receiveAnswer && count < (NODEHELLO_TIMEOUT*2)) {
			try {
				Thread.sleep(500);
			} catch(final java.lang.InterruptedException e) {
				/* \_o< */
			}
			count++;
		}

		if(nodeName != null) {
			Logger.info(this, "Hello "+nodeName+", I'm Thaw :)");
		} else if (count >= (NODEHELLO_TIMEOUT*2)) {
			Logger.warning(this, "Unable to connect, timeout ...");
			return false;
		} else {
			Logger.warning(this, "ID already used !");
			return false;
		}

		return true;
	}


	public void update(final Observable o, final Object arg) {
		if(arg == null)
			return;

		final FCPMessage answer = (FCPMessage)arg;

		if(o == queryManager) {

			if("NodeHello".equals( answer.getMessageName() )) {
				Logger.info(this, "Received a nodeHello");

				connectionId = answer.getValue("ConnectionIdentifier");

				if (connectionId == null)
					Logger.error(this, "** no connection identifier **");

				nodeFCPVersion = answer.getValue("FCPVersion");
				nodeVersion = answer.getValue("Version");
				nodeName = answer.getValue("Node");
				testnet = Boolean.valueOf(answer.getValue("Testnet")).booleanValue();
				codecs = answer.getValue("CompressionCodecs").split(" ");
				nmbCompressionCodecs = Integer.parseInt(codecs[0]);

				queryManager.deleteObserver(this);

				receiveAnswer = true;
				synchronized(this) {
					notify();
				}
			}

			if("CloseConnectionDuplicateClientName".equals( answer.getMessageName() )) {
				/* Damn ... ! */
				Logger.warning(this, "According to the node, Thaw ID is already used. Please change it in the configuration (in advanced mode)");
				queryManager.deleteObserver(this);
				receiveAnswer = true;
				synchronized(this) {
					notify();
				}
			}
		}

		if(!receiveAnswer) {
			Logger.warning(this, "This message wasn't for us ?! : "+answer.getMessageName());
		}
	}

	/**
	 * Not used.
	 */
	public boolean stop(final FCPQueueManager queueManager) {
		return true;
	}


	public int getQueryType() {
		return 0;
	}


	public String getConnectionId() {
		return connectionId;
	}

	public String getCodec(int i) {
		if(i < nmbCompressionCodecs) {
			return codecs[i+2].split("\\(")[0];
		} else {
			return "";
		}
	}
}