package kademlia;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.InetAddress;
import java.util.NoSuchElementException;
import java.util.Timer;
import java.util.TimerTask;
import kademlia.dht.GetParameter;
import kademlia.dht.DHT;
import kademlia.dht.KadContent;
import kademlia.dht.KademliaDHT;
import kademlia.dht.KademliaStorageEntry;
import kademlia.dht.JKademliaStorageEntry;
import kademlia.exceptions.ContentNotFoundException;
import kademlia.exceptions.RoutingException;
import kademlia.message.MessageFactory;
import kademlia.node.Node;
import kademlia.node.KademliaId;
import kademlia.operation.ConnectOperation;
import kademlia.operation.ContentLookupOperation;
import kademlia.operation.Operation;
import kademlia.operation.KadRefreshOperation;
import kademlia.operation.StoreOperation;
import kademlia.routing.JKademliaRoutingTable;
import kademlia.routing.KademliaRoutingTable;
import kademlia.util.serializer.JsonDHTSerializer;
import kademlia.util.serializer.JsonRoutingTableSerializer;
import kademlia.util.serializer.JsonSerializer;
/**
* The main Kademlia Node on the network, this node manages everything for this local system.
*
* @author Joshua Kissoon
* @since 20140215
*
* @todo When we receive a store message - if we have a newer version of the content, re-send this newer version to that node so as to update their version
* @todo Handle IPv6 Addresses
*
*/
public class JKademliaNode implements KademliaNode
{
/* Kademlia Attributes */
private final String ownerId;
/* Objects to be used */
private final transient Node localNode;
private final transient KadServer server;
private final transient KademliaDHT dht;
private transient KademliaRoutingTable routingTable;
private final int udpPort;
private transient KadConfiguration config;
/* Timer used to execute refresh operations */
private transient Timer refreshOperationTimer;
private transient TimerTask refreshOperationTTask;
/* Factories */
private final transient MessageFactory messageFactory;
/* Statistics */
private final transient KadStatistician statistician;
{
statistician = new Statistician();
}
/**
* Creates a Kademlia DistributedMap using the specified name as filename base.
* If the id cannot be read from disk the specified defaultId is used.
* The instance is bootstraped to an existing network by specifying the
* address of a bootstrap node in the network.
*
* @param ownerId The Name of this node used for storage
* @param localNode The Local Node for this Kad instance
* @param udpPort The UDP port to use for routing messages
* @param dht The DHT for this instance
* @param config
* @param routingTable
*
* @throws IOException If an error occurred while reading id or local map
* from disk <i>or</i> a network error occurred while
* attempting to bootstrap to the network
* */
public JKademliaNode(String ownerId, Node localNode, int udpPort, KademliaDHT dht, KademliaRoutingTable routingTable, KadConfiguration config) throws IOException
{
this.ownerId = ownerId;
this.udpPort = udpPort;
this.localNode = localNode;
this.dht = dht;
this.config = config;
this.routingTable = routingTable;
this.messageFactory = new MessageFactory(this, this.dht, this.config);
this.server = new KadServer(udpPort, this.messageFactory, this.localNode, this.config, this.statistician);
this.startRefreshOperation();
}
@Override
public final void startRefreshOperation()
{
this.refreshOperationTimer = new Timer(true);
refreshOperationTTask = new TimerTask()
{
@Override
public void run()
{
try
{
/* Runs a DHT RefreshOperation */
JKademliaNode.this.refresh();
}
catch (IOException e)
{
System.err.println("KademliaNode: Refresh Operation Failed; Message: " + e.getMessage());
}
}
};
refreshOperationTimer.schedule(refreshOperationTTask, this.config.restoreInterval(), this.config.restoreInterval());
}
@Override
public final void stopRefreshOperation()
{
/* Close off the timer tasks */
this.refreshOperationTTask.cancel();
this.refreshOperationTimer.cancel();
this.refreshOperationTimer.purge();
}
public JKademliaNode(String ownerId, Node node, int udpPort, KademliaRoutingTable routingTable, KadConfiguration config) throws IOException
{
this(
ownerId,
node,
udpPort,
new DHT(ownerId, config),
routingTable,
config
);
}
public JKademliaNode(String ownerId, Node node, int udpPort, KadConfiguration config) throws IOException
{
this(
ownerId,
node,
udpPort,
new JKademliaRoutingTable(node, config),
config
);
}
public JKademliaNode(String ownerId, KademliaId defaultId, int udpPort) throws IOException
{
this(
ownerId,
new Node(defaultId, InetAddress.getLocalHost(), udpPort),
udpPort,
new DefaultConfiguration()
);
}
/**
* Load Stored state using default configuration
*
* @param ownerId The ID of the owner for the stored state
*
* @return A Kademlia instance loaded from a stored state in a file
*
* @throws java.io.FileNotFoundException
* @throws java.lang.ClassNotFoundException
*/
public static JKademliaNode loadFromFile(String ownerId) throws FileNotFoundException, IOException, ClassNotFoundException
{
return JKademliaNode.loadFromFile(ownerId, new DefaultConfiguration());
}
/**
* Load Stored state
*
* @param ownerId The ID of the owner for the stored state
* @param iconfig Configuration information to work with
*
* @return A Kademlia instance loaded from a stored state in a file
*
* @throws java.io.FileNotFoundException
* @throws java.lang.ClassNotFoundException
*/
public static JKademliaNode loadFromFile(String ownerId, KadConfiguration iconfig) throws FileNotFoundException, IOException, ClassNotFoundException
{
DataInputStream din;
/**
* @section Read Basic Kad data
*/
din = new DataInputStream(new FileInputStream(getStateStorageFolderName(ownerId, iconfig) + File.separator + "kad.kns"));
JKademliaNode ikad = new JsonSerializer<JKademliaNode>().read(din);
/**
* @section Read the routing table
*/
din = new DataInputStream(new FileInputStream(getStateStorageFolderName(ownerId, iconfig) + File.separator + "routingtable.kns"));
KademliaRoutingTable irtbl = new JsonRoutingTableSerializer(iconfig).read(din);
/**
* @section Read the node state
*/
din = new DataInputStream(new FileInputStream(getStateStorageFolderName(ownerId, iconfig) + File.separator + "node.kns"));
Node inode = new JsonSerializer<Node>().read(din);
/**
* @section Read the DHT
*/
din = new DataInputStream(new FileInputStream(getStateStorageFolderName(ownerId, iconfig) + File.separator + "dht.kns"));
KademliaDHT idht = new JsonDHTSerializer().read(din);
idht.setConfiguration(iconfig);
return new JKademliaNode(ownerId, inode, ikad.getPort(), idht, irtbl, iconfig);
}
@Override
public Node getNode()
{
return this.localNode;
}
@Override
public KadServer getServer()
{
return this.server;
}
@Override
public KademliaDHT getDHT()
{
return this.dht;
}
@Override
public KadConfiguration getCurrentConfiguration()
{
return this.config;
}
@Override
public synchronized final void bootstrap(Node n) throws IOException, RoutingException
{
long startTime = System.nanoTime();
Operation op = new ConnectOperation(this.server, this, n, this.config);
op.execute();
long endTime = System.nanoTime();
this.statistician.setBootstrapTime(endTime - startTime);
}
@Override
public int put(KadContent content) throws IOException
{
return this.put(new JKademliaStorageEntry(content));
}
@Override
public int put(JKademliaStorageEntry entry) throws IOException
{
StoreOperation sop = new StoreOperation(this.server, this, entry, this.dht, this.config);
sop.execute();
/* Return how many nodes the content was stored on */
return sop.numNodesStoredAt();
}
@Override
public void putLocally(KadContent content) throws IOException
{
this.dht.store(new JKademliaStorageEntry(content));
}
@Override
public JKademliaStorageEntry get(GetParameter param) throws NoSuchElementException, IOException, ContentNotFoundException
{
if (this.dht.contains(param))
{
/* If the content exist in our own DHT, then return it. */
return this.dht.get(param);
}
/* Seems like it doesn't exist in our DHT, get it from other Nodes */
long startTime = System.nanoTime();
ContentLookupOperation clo = new ContentLookupOperation(server, this, param, this.config);
clo.execute();
long endTime = System.nanoTime();
this.statistician.addContentLookup(endTime - startTime, clo.routeLength(), clo.isContentFound());
return clo.getContentFound();
}
@Override
public void refresh() throws IOException
{
new KadRefreshOperation(this.server, this, this.dht, this.config).execute();
}
@Override
public String getOwnerId()
{
return this.ownerId;
}
@Override
public int getPort()
{
return this.udpPort;
}
@Override
public void shutdown(final boolean saveState) throws IOException
{
/* Shut down the server */
this.server.shutdown();
this.stopRefreshOperation();
/* Save this Kademlia instance's state if required */
if (saveState)
{
/* Save the system state */
this.saveKadState();
}
}
@Override
public void saveKadState() throws IOException
{
DataOutputStream dout;
/**
* @section Store Basic Kad data
*/
dout = new DataOutputStream(new FileOutputStream(getStateStorageFolderName(this.ownerId, this.config) + File.separator + "kad.kns"));
new JsonSerializer<JKademliaNode>().write(this, dout);
/**
* @section Save the node state
*/
dout = new DataOutputStream(new FileOutputStream(getStateStorageFolderName(this.ownerId, this.config) + File.separator + "node.kns"));
new JsonSerializer<Node>().write(this.localNode, dout);
/**
* @section Save the routing table
* We need to save the routing table separate from the node since the routing table will contain the node and the node will contain the routing table
* This will cause a serialization recursion, and in turn a Stack Overflow
*/
dout = new DataOutputStream(new FileOutputStream(getStateStorageFolderName(this.ownerId, this.config) + File.separator + "routingtable.kns"));
new JsonRoutingTableSerializer(this.config).write(this.getRoutingTable(), dout);
/**
* @section Save the DHT
*/
dout = new DataOutputStream(new FileOutputStream(getStateStorageFolderName(this.ownerId, this.config) + File.separator + "dht.kns"));
new JsonDHTSerializer().write(this.dht, dout);
}
/**
* Get the name of the folder for which a content should be stored
*
* @return String The name of the folder to store node states
*/
private static String getStateStorageFolderName(String ownerId, KadConfiguration iconfig)
{
/* Setup the nodes storage folder if it doesn't exist */
String path = iconfig.getNodeDataFolder(ownerId) + File.separator + "nodeState";
File nodeStateFolder = new File(path);
if (!nodeStateFolder.isDirectory())
{
nodeStateFolder.mkdir();
}
return nodeStateFolder.toString();
}
@Override
public KademliaRoutingTable getRoutingTable()
{
return this.routingTable;
}
@Override
public KadStatistician getStatistician()
{
return this.statistician;
}
/**
* Creates a string containing all data about this Kademlia instance
*
* @return The string representation of this Kad instance
*/
@Override
public String toString()
{
StringBuilder sb = new StringBuilder("\n\nPrinting Kad State for instance with owner: ");
sb.append(this.ownerId);
sb.append("\n\n");
sb.append("\n");
sb.append("Local Node");
sb.append(this.localNode);
sb.append("\n");
sb.append("\n");
sb.append("Routing Table: ");
sb.append(this.getRoutingTable());
sb.append("\n");
sb.append("\n");
sb.append("DHT: ");
sb.append(this.dht);
sb.append("\n");
sb.append("\n\n\n");
return sb.toString();
}
}