net.tomp2p.peers
Class PeerMapKadImpl

java.lang.Object
  net.tomp2p.peers.PeerMapKadImpl

All Implemented Interfaces:

PeerMap

public class PeerMapKadImpl
extends Object
implements PeerMap

This routing implementation uses is based on Kademlia. However, many changes have been applied to make it faster and more flexible. This class is partially thread-safe.

Author:

Thomas Bocek

Constructor Summary

PeerMapKadImpl(Number160 self, int bagSize, int cacheSize, int cacheTimeout, int maxFail, int[] maintenanceTimeoutsSeconds)
Creates a bag of peers

Method Summary

void	addAddressFilter(InetAddress address)
void	addPeerMapChangeListener(PeerMapChangeListener peerMapChangeListener)
void	addPeerOfflineListener(PeerOfflineListener peerListener)
SortedSet<PeerAddress>	closePeers(Number160 id, int atLeast) Returns close peer from the set to a given key.
boolean	contains(PeerAddress peerAddress)
Comparator<PeerAddress>	createPeerComparator()
Comparator<PeerAddress>	createPeerComparator(Number160 id) Creates a comparator that orders to peers according to their distance to the specified id.
Collection<PeerAddress>	getAll() Return all addresses from the neighbor list.
Statistics	getStatistics()
int	isCloser(Number160 id, Number160 rn, Number160 rn2) Returns -1 if the first key is closer to the key, if the second is closer, then 1 is returned.
int	isCloser(Number160 id, PeerAddress rn, PeerAddress rn2) Returns -1 if the first remote node is closer to the key, if the second is closer, then 1 is returned.
boolean	isPeerRemovedTemporarly(PeerAddress remoteNode) Checks if this peer has been removed.
boolean	peerOffline(PeerAddress remotePeer, boolean force) Remove a peer from the list.
boolean	peerOnline(PeerAddress remotePeer, PeerAddress referrer) Adds a neighbor to the neighbor list.
Collection<PeerAddress>	peersForMaintenance()
void	removePeerMapChangeListener(PeerMapChangeListener peerMapChangeListener)
void	removePeerOfflineListener(PeerOfflineListener peerListener)
Number160	self() Each node that has a bag has an ID itself to define what is close.
int	size() The peerCount keeps track of the total number of peer in the system.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

PeerMapKadImpl

public PeerMapKadImpl(Number160 self,
                      int bagSize,
                      int cacheSize,
                      int cacheTimeout,
                      int maxFail,
                      int[] maintenanceTimeoutsSeconds)

Creates a bag of peers

Parameters:

self - The id of this peer

bagSize - The size of a bag. The original Kademlia suggests 20, but we can go much lower, as we dont have a fixed limit for a bag. The bagSize is a suggestion and if maxpeers has not been reached, the peer is added even though it exceeds the bag limit.

cacheSize - The size of the cache of removed peers

cacheTimeout - The time that a removed peer will be in the cache in milliseconds.

peerMapChangeListener - Listeners that will be called if a peer is added or removed.

Method Detail

addPeerMapChangeListener

public void addPeerMapChangeListener(PeerMapChangeListener peerMapChangeListener)

Specified by:

addPeerMapChangeListener in interface PeerMap

removePeerMapChangeListener

public void removePeerMapChangeListener(PeerMapChangeListener peerMapChangeListener)

Specified by:

removePeerMapChangeListener in interface PeerMap

addPeerOfflineListener

public void addPeerOfflineListener(PeerOfflineListener peerListener)

Specified by:

addPeerOfflineListener in interface PeerMap

removePeerOfflineListener

public void removePeerOfflineListener(PeerOfflineListener peerListener)

Specified by:

removePeerOfflineListener in interface PeerMap

getStatistics

public Statistics getStatistics()

Specified by:

getStatistics in interface PeerMap

size

public int size()

The peerCount keeps track of the total number of peer in the system.

Specified by:

size in interface PeerMap

Returns:

the total number of peers

self

public Number160 self()

Description copied from interface: PeerMap

Each node that has a bag has an ID itself to define what is close. This method returns this ID.

Specified by:

self in interface PeerMap

Returns:

The id of this node

peerOnline

public boolean peerOnline(PeerAddress remotePeer,
                          PeerAddress referrer)

Description copied from interface: PeerMap

Adds a neighbor to the neighbor list. If the bag is full, the id zero or the same as our id, the neighbor is not added. This method is tread-safe

Specified by:

peerOnline in interface PeerMap

Parameters:

remotePeer - The node that should be added

Returns:

True if the neighbor could be added, otherwise false.

peerOffline

public boolean peerOffline(PeerAddress remotePeer,
                           boolean force)

Description copied from interface: PeerMap

Remove a peer from the list. In order to not reappear, the node is put for a certain time in a cache list to keep the node removed. This method is thread-safe.

Specified by:

peerOffline in interface PeerMap

Parameters:

remotePeer - The node that should be removed

Returns:

True if the neighbor was removed and added to a cache list. False if peer has not been removed or is already in the peer removed temporarly list.

peersForMaintenance

public Collection<PeerAddress> peersForMaintenance()

Specified by:

peersForMaintenance in interface PeerMap

isPeerRemovedTemporarly

public boolean isPeerRemovedTemporarly(PeerAddress remoteNode)

Description copied from interface: PeerMap

Checks if this peer has been removed. A peer that has been removed will be stored in a cache list for a certain time. This method is tread-safe

Specified by:

isPeerRemovedTemporarly in interface PeerMap

Parameters:

remoteNode - The node to check

Returns:

True if the peer has been removed recently

contains

public boolean contains(PeerAddress peerAddress)

Specified by:

contains in interface PeerMap

closePeers

public SortedSet<PeerAddress> closePeers(Number160 id,
                                         int atLeast)

Description copied from interface: PeerMap

Returns close peer from the set to a given key. This method is tread-safe. You can use the returned set as its a copy of the actual PeerMap and changes in the return set do not affect PeerMap.

Specified by:

closePeers in interface PeerMap

Parameters:

id - The key that should be close to the keys in the map

atLeast - The number we want to find at least

Returns:

A navigable set with close peers first in this set.

isCloser

public int isCloser(Number160 id,
                    PeerAddress rn,
                    PeerAddress rn2)

Description copied from interface: PeerMap

Returns -1 if the first remote node is closer to the key, if the second is closer, then 1 is returned. If both are equal, 0 is returned

Specified by:

isCloser in interface PeerMap

Parameters:

id - The key to search for

rn - The remote node on the routing path to node close to key

rn2 - An other remote node on the routing path to node close to key

Returns:

-1 if nodeAddress1 is closer to the key than nodeAddress2, otherwise 1. 0 is returned if both are equal.

isCloser

public int isCloser(Number160 id,
                    Number160 rn,
                    Number160 rn2)

Description copied from interface: PeerMap

Returns -1 if the first key is closer to the key, if the second is closer, then 1 is returned. If both are equal, 0 is returned

Specified by:

isCloser in interface PeerMap

Parameters:

id - The key to search for

rn - The first key

rn2 - The second key

Returns:

-1 if key1 is closer to key, otherwise 1. 0 is returned if both are equal.

toString

public String toString()

Overrides:

toString in class Object

createPeerComparator

public Comparator<PeerAddress> createPeerComparator(Number160 id)

Description copied from interface: PeerMap

Creates a comparator that orders to peers according to their distance to the specified id.

Specified by:

createPeerComparator in interface PeerMap

Parameters:

id - The id that defines the metric

Returns:

The comparator to be used with the collection framework

createPeerComparator

public Comparator<PeerAddress> createPeerComparator()

Specified by:

createPeerComparator in interface PeerMap

getAll

public Collection<PeerAddress> getAll()

Description copied from interface: PeerMap

Return all addresses from the neighbor list. The collection is partially sorted.

Specified by:

getAll in interface PeerMap

Returns:

All neighbors

addAddressFilter

public void addAddressFilter(InetAddress address)

Specified by:

addAddressFilter in interface PeerMap