Package org.jgroups.blocks

Class PartitionedHashMap.ArrayBasedConsistentHashFunction<K>

java.lang.Object

org.jgroups.blocks.MembershipListenerAdapter

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

All Implemented Interfaces:

PartitionedHashMap.HashFunction<K>, MembershipListener

Enclosing class:

PartitionedHashMap<K,V>

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

Uses arrays to store hash values of addresses, plus addresses.

Field Summary

Fields inherited from class org.jgroups.blocks.MembershipListenerAdapter

membershipListeners, membershipListenersCache

Constructor Summary

Constructors

Constructor	Description
ArrayBasedConsistentHashFunction()

Method Summary

Modifier and Type	Method	Description
void	block()	Notify membership listeners to temporarily stop sending messages into a channel.
Address	hash(K key, List<Address> members)	Defines a hash function to pick the right node from the list of cluster nodes.
void	suspect(Address suspected_mbr)	Notify membership listener that some node was suspected.
void	viewAccepted(View new_view)	Notify membership listener that new view was accepted.

Methods inherited from class org.jgroups.blocks.MembershipListenerAdapter

addMembershipListener, removeMembershipListener, unblock

Methods inherited from class java.lang.Object

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

Constructor Details

ArrayBasedConsistentHashFunction

public ArrayBasedConsistentHashFunction()

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

suspect

public void suspect(Address suspected_mbr)

Description copied from class: MembershipListenerAdapter

Notify membership listener that some node was suspected. This method in turn passes suspected member address to all registered membership listeners.

Specified by:

suspect in interface MembershipListener

Overrides:

suspect in class MembershipListenerAdapter

block

public void block()

Description copied from class: MembershipListenerAdapter

Notify membership listeners to temporarily stop sending messages into a channel. This method in turn calls same method of all registered membership listener.

Specified by:

block in interface MembershipListener

Overrides:

block in class MembershipListenerAdapter