Router.java

/*
 * Copyright: Almende B.V. (2014), Rotterdam, The Netherlands
 * License: The Apache Software License, Version 2.0
 */
package com.almende.eve.transport;

import java.io.IOException;
import java.net.URI;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;

import com.almende.eve.capabilities.handler.Handler;
import com.almende.util.callback.AsyncCallback;
import com.almende.util.jackson.JOM;
import com.almende.util.threads.ThreadPool;
import com.fasterxml.jackson.databind.node.ArrayNode;
import com.fasterxml.jackson.databind.node.ObjectNode;

/**
 * The Class Router, outbound transport selection based on protocol scheme.
 */
public class Router implements Transport {
	private static final Logger				LOG			= Logger.getLogger(Router.class
																.getName());
	private final Map<String, Transport>	transports	= new HashMap<String, Transport>(2);

	/**
	 * Register new transport. If a given protocol is already known, this will
	 * overwrite the reference.
	 * 
	 * @param transport
	 *            the transport
	 */
	public void register(final Transport transport) {
		if (transport == null) {
			LOG.warning("Not registering a null transport.");
			return;
		}
		for (final String protocol : transport.getProtocols()) {
			transports.put(protocol, transport);
		}
	}

	/*
	 * (non-Javadoc)
	 * @see com.almende.eve.transport.Transport#send(java.net.URI, byte[],
	 * java.lang.String)
	 */
	@Override
	public <T> void send(final URI receiverUri, final String message,
			final String tag, final AsyncCallback<T> callback) throws IOException {
		final Transport transport = transports.get(receiverUri.getScheme()
				.toLowerCase());
		if (transport != null) {
			transport.send(receiverUri, message, tag, callback);
		} else {
			throw new IOException("No transport known for scheme:"
					+ receiverUri.getScheme());
		}
	}

	/*
	 * (non-Javadoc)
	 * @see com.almende.eve.transport.Transport#send(java.net.URI, byte[],
	 * java.lang.String)
	 */
	@Override
	public <T> void send(final URI receiverUri, final byte[] message,
			final String tag, final AsyncCallback<T> callback) throws IOException {
		final Transport transport = transports.get(receiverUri.getScheme()
				.toLowerCase());
		if (transport != null) {
			transport.send(receiverUri, message, tag, callback);
		} else {
			throw new IOException("No transport known for scheme:"
					+ receiverUri.getScheme());
		}
	}

	/*
	 * (non-Javadoc)
	 * @see com.almende.eve.transport.Transport#send(java.net.URI, byte[],
	 * java.lang.String)
	 */
	@Override
	public <T> void send(final URI receiverUri, final Object message,
			final String tag, final AsyncCallback<T> callback) throws IOException {
	        final Transport transport = transports.get(receiverUri.getScheme()
	                                                   .toLowerCase(Locale.ENGLISH));
    		if (transport != null) {
    			transport.send(receiverUri, message, tag, callback);
    		} else {
    			throw new IOException("No transport known for scheme:"
    					+ receiverUri.getScheme());
    		}
	}

	/*
	 * (non-Javadoc)
	 * @see com.almende.eve.transport.Transport#connect()
	 */
	@Override
	public void connect() throws IOException {
		final Set<Transport> result = new HashSet<Transport>(transports.size());
		for (final Transport transport : transports.values()) {
			result.add(transport);
		}
		for (final Transport transport : result) {
			final long[] sleep = new long[1];
			sleep[0] = 1000L;
			final double rnd = Math.random();
			final ScheduledThreadPoolExecutor STE = ThreadPool
					.getScheduledPool();
			STE.schedule(new Runnable() {
				@Override
				public void run() {
					try {
						transport.connect();
					} catch (IOException e) {
						LOG.log(Level.WARNING,
								"Failed to reconnect agent on new transport.",
								e);
						if (sleep[0] <= 80000) {
							sleep[0] *= 2;
							STE.schedule(this, (long) (sleep[0] * rnd),
									TimeUnit.MILLISECONDS);
						}
					}
				}

			}, (long) (sleep[0] * rnd), TimeUnit.MILLISECONDS);
		}
	}

	/*
	 * (non-Javadoc)
	 * @see com.almende.eve.transport.Transport#disconnect()
	 */
	@Override
	public void disconnect() {
		final Set<Transport> result = new HashSet<Transport>(transports.size());
		for (final Transport transport : transports.values()) {
			result.add(transport);
		}
		for (final Transport transport : result) {
			transport.disconnect();
		}
	}

	/*
	 * (non-Javadoc)
	 * @see com.almende.eve.transport.Transport#delete()
	 */
	@Override
	public void delete() {
		final Set<Transport> result = new HashSet<Transport>(transports.size());
		for (final Transport transport : transports.values()) {
			result.add(transport);
		}
		for (final Transport transport : result) {
			transport.delete();
		}
		transports.clear();
	}

	/*
	 * (non-Javadoc)
	 * @see com.almende.eve.transport.Transport#getHandle()
	 */
	@Override
	public Handler<Receiver> getHandle() {
		return null;
	}

	/*
	 * (non-Javadoc)
	 * @see com.almende.eve.transport.Transport#getAddress()
	 */
	@Override
	public URI getAddress() {
		return null;
	}

	/**
	 * Gets the addresses.
	 * 
	 * @return the addresses
	 */
	public List<URI> getAddresses() {
		final Set<URI> result = new HashSet<URI>(transports.size());
		for (final Transport transport : transports.values()) {
			result.add(transport.getAddress());
		}
		return new ArrayList<URI>(result);
	}

	/**
	 * Gets the addresses by scheme.
	 *
	 * @param scheme
	 *            the scheme
	 * @return the addresses by scheme
	 */
	public URI getAddressByScheme(String scheme) {
		return transports.get(scheme).getAddress();
	}
	
	/*
	 * (non-Javadoc)
	 * @see com.almende.eve.transport.Transport#getProtocols()
	 */
	@Override
	public List<String> getProtocols() {
		return new ArrayList<String>(transports.keySet());
	}

	/*
	 * (non-Javadoc)
	 * @see com.almende.eve.capabilities.Capability#getParams()
	 */
	@Override
	public ObjectNode getParams() {
		final ArrayNode transportConfs = JOM.createArrayNode();
		for (final Transport transport : transports.values()) {
			transportConfs.add(transport.getParams());
		}
		final ObjectNode result = JOM.createObjectNode();
		result.set("transports", transportConfs);
		return result;
	}

}