net.tomp2p.peers

Class DefaultMaintenance

java.lang.Object

net.tomp2p.peers.DefaultMaintenance

All Implemented Interfaces:

Maintenance

public class DefaultMaintenance
extends Object
implements Maintenance

The default maintenance implementation.

Author:

Thomas Bocek

Constructor Summary

Constructors

Constructor and Description
DefaultMaintenance(int peerUrgency, int[] intervalSeconds) Constructor that initializes the maps as null references.

Method Summary

Methods

Modifier and Type	Method and Description
Maintenance	init(List<Map<Number160,PeerStatistic>> peerMapVerified, List<Map<Number160,PeerStatistic>> peerMapNonVerified, ConcurrentCacheMap<Number160,PeerAddress> offlineMap, ConcurrentCacheMap<Number160,PeerAddress> shutdownMap, ConcurrentCacheMap<Number160,PeerAddress> exceptionMap) Initializes the maintenance class.
protected boolean	isUrgent(int bagIndex, int bagSize, int peersBefore) Indicates if it is urgent to search for a peer.
static int	log2(int n) As seen in: http://stackoverflow.com/questions/3305059/how-do-you-calculate-log-base-2-in-java-for-integers.
static boolean	needMaintenance(PeerStatistic peerStatatistic, int[] intervalSeconds) Indicates if a peer needs a maintenance check.
PeerStatistic	nextForMaintenance(Collection<PeerAddress> notInterestedAddresses) Finds the next peer that should have a maintenance check.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultMaintenance

public DefaultMaintenance(int peerUrgency,
                  int[] intervalSeconds)

Constructor that initializes the maps as null references. To use this class init must be called that creates a new class with the private constructor.

Parameters:

peerUrgency - The number of peers that should be in the verified map. If the number is lower, urgency is set to yes and we are looking for peers in the non verified map

intervalSeconds - The number of intervals to test a peer. The longer a peer is available the less often we need to check

Method Detail

init

public Maintenance init(List<Map<Number160,PeerStatistic>> peerMapVerified,
               List<Map<Number160,PeerStatistic>> peerMapNonVerified,
               ConcurrentCacheMap<Number160,PeerAddress> offlineMap,
               ConcurrentCacheMap<Number160,PeerAddress> shutdownMap,
               ConcurrentCacheMap<Number160,PeerAddress> exceptionMap)

Description copied from interface: Maintenance

Initializes the maintenance class. This may result in a new class

Specified by:

init in interface Maintenance

Parameters:

peerMapVerified - The map with the bags of verified peers

peerMapNonVerified - The map with the bags of non verified peers

offlineMap - The map with the offline peers

shutdownMap - The map with the peers that friendly quit

exceptionMap - The map with the peers that caused an exception

Returns:

A new or the same maintenance class

nextForMaintenance

public PeerStatistic nextForMaintenance(Collection<PeerAddress> notInterestedAddresses)

Finds the next peer that should have a maintenance check. Returns null if no maintenance is needed at the moment. It will return the most important peers first. Importance is as follows: The most important peers are the close ones in the verified peer map. If a certain threshold in a bag is not reached, the unverified becomes important too.

Specified by:

nextForMaintenance in interface Maintenance

Returns:

The next most important peer to check if its still alive.

isUrgent

protected boolean isUrgent(int bagIndex,
               int bagSize,
               int peersBefore)

Indicates if it is urgent to search for a peer. This means that we have not enough peers in the verified map and we need to get one from the non-verified map.

Parameters:

bagIndex - The number of the bagindex. The smaller the index, the more important the peer

bagSize - The size of the current bag

peersBefore - The number of peers we have that are smaller than in this bag index

Returns:

True, if we need urgently a peer from the non-verified map

needMaintenance

public static boolean needMaintenance(PeerStatistic peerStatatistic,
                      int[] intervalSeconds)

Indicates if a peer needs a maintenance check.

Parameters:

peerStatatistic - The peer with its statistics

Returns:

True if the peer needs a maintenance check

log2

public static int log2(int n)

As seen in: http://stackoverflow.com/questions/3305059/how-do-you-calculate-log-base-2-in-java-for-integers.

Parameters:

n - The number

Returns:

the logarithm base 2