Package org.jgroups.blocks

Class PartitionedHashMap.ConsistentHashFunction<K>

java.lang.Object

org.jgroups.blocks.MembershipListenerAdapter

org.jgroups.blocks.PartitionedHashMap.ConsistentHashFunction<K>

All Implemented Interfaces:

PartitionedHashMap.HashFunction<K>, MembershipListener

Enclosing class:

PartitionedHashMap<K,V>

public static class PartitionedHashMap.ConsistentHashFunction<K>
extends MembershipListenerAdapter
implements PartitionedHashMap.HashFunction<K>

Field Summary

Fields inherited from class org.jgroups.blocks.MembershipListenerAdapter

membershipListeners, membershipListenersCache

Constructor Summary

Constructors

Constructor	Description
ConsistentHashFunction()

Method Summary

Modifier and Type	Method	Description
Address	hash(K key, List<Address> members)	Defines a hash function to pick the right node from the list of cluster nodes.
void	viewAccepted(View new_view)	Notify membership listener that new view was accepted.

Methods inherited from class org.jgroups.blocks.MembershipListenerAdapter

addMembershipListener, block, removeMembershipListener, suspect, unblock

Methods inherited from class java.lang.Object

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

Constructor Details

ConsistentHashFunction

public ConsistentHashFunction()

Method Details

hash

public Address hash(K key,
 List<Address> members)

Description copied from interface: PartitionedHashMap.HashFunction

Defines a hash function to pick the right node from the list of cluster nodes. Ideally, this function uses consistent hashing, so that the same key maps to the same node despite cluster view changes. If a view change causes all keys to hash to different nodes, then PartitionedHashMap will redirect requests to different nodes and this causes unnecessary overhead.

Specified by:

hash in interface PartitionedHashMap.HashFunction<K>

Parameters:

key - The object to be hashed

members - The membership. This value can be ignored for example if the hash function keeps track of the membership itself, e.g. by registering as a membership listener (PartitionedHashMap.addMembershipListener(org.jgroups.MembershipListener) )

Returns:

viewAccepted

public void viewAccepted(View new_view)

Description copied from class: MembershipListenerAdapter

Notify membership listener that new view was accepted. This method in turn passes new view to all registered membership listeners.

Specified by:

viewAccepted in interface MembershipListener

Overrides:

viewAccepted in class MembershipListenerAdapter