org.infinispan.distribution.ch.impl

Class ReplicatedConsistentHash

java.lang.Object

org.infinispan.distribution.ch.impl.ReplicatedConsistentHash

All Implemented Interfaces:

ConsistentHash

public class ReplicatedConsistentHash
extends Object
implements ConsistentHash

Special implementation of ConsistentHash for replicated caches. The hash-space has several segments owned by all members and the primary ownership of each segment is evenly spread between members.

Since:

5.2

Author:

Dan Berindei, anistor@redhat.com

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ReplicatedConsistentHash.Externalizer

Constructor Summary

Constructors

Constructor and Description
ReplicatedConsistentHash(List<Address> members, int[] primaryOwners)

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object obj)
List<Address>	getMembers() Should return the addresses of the nodes used to create this consistent hash.
int	getNumOwners()
int	getNumSegments()
Set<Integer>	getPrimarySegmentsForOwner(Address owner) Returns the segments that this cache member is the primary owner for.
String	getRoutingTableAsString() Returns a string containing all the segments and their associated addresses.
Set<Integer>	getSegmentsForOwner(Address owner) Returns the segments owned by a cache member.
int	hashCode()
boolean	isReplicated()
boolean	isSegmentLocalToNode(Address nodeAddress, int segmentId) Check if a segment is local to a given member.
List<Address>	locateOwnersForSegment(int segmentId)
Address	locatePrimaryOwnerForSegment(int segmentId)
ConsistentHash	remapAddresses(UnaryOperator<Address> remapper) Returns a new ConsistentHash with the addresses remapped according to the provided UnaryOperator.
void	toScopedState(ScopedPersistentState state) Writes this ConsistentHash to the specified scoped state.
String	toString()
ReplicatedConsistentHash	union(ReplicatedConsistentHash ch2)

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.infinispan.distribution.ch.ConsistentHash

getCapacityFactors

Constructor Detail

ReplicatedConsistentHash

public ReplicatedConsistentHash(List<Address> members,
                                int[] primaryOwners)

Method Detail

union

public ReplicatedConsistentHash union(ReplicatedConsistentHash ch2)

getNumSegments

public int getNumSegments()

Specified by:

getNumSegments in interface ConsistentHash

Returns:

The actual number of hash space segments. Note that it may not be the same as the number of segments passed in at creation time.

getNumOwners

public int getNumOwners()

getMembers

public List<Address> getMembers()

Description copied from interface: ConsistentHash

Should return the addresses of the nodes used to create this consistent hash.

Specified by:

getMembers in interface ConsistentHash

Returns:

set of node addresses.

locateOwnersForSegment

public List<Address> locateOwnersForSegment(int segmentId)

Specified by:

locateOwnersForSegment in interface ConsistentHash

Returns:

All the nodes that own a given hash space segment, first address is the primary owner. The returned list is unmodifiable.

locatePrimaryOwnerForSegment

public Address locatePrimaryOwnerForSegment(int segmentId)

Specified by:

locatePrimaryOwnerForSegment in interface ConsistentHash

Returns:

The primary owner of a given hash space segment. This is equivalent to locateOwnersForSegment(segmentId).get(0) but is more efficient

getSegmentsForOwner

public Set<Integer> getSegmentsForOwner(Address owner)

Description copied from interface: ConsistentHash

Returns the segments owned by a cache member.

Specified by:

getSegmentsForOwner in interface ConsistentHash

Parameters:

owner - the address of the member

Returns:

a non-null set of segment IDs, may or may not be unmodifiable, which shouldn't be modified by caller

getPrimarySegmentsForOwner

public Set<Integer> getPrimarySegmentsForOwner(Address owner)

Description copied from interface: ConsistentHash

Returns the segments that this cache member is the primary owner for.

Specified by:

getPrimarySegmentsForOwner in interface ConsistentHash

Parameters:

owner - the address of the member

Returns:

a non-null set of segment IDs, may or may not be unmodifiable, which shouldn't be modified by caller

getRoutingTableAsString

public String getRoutingTableAsString()

Description copied from interface: ConsistentHash

Returns a string containing all the segments and their associated addresses.

Specified by:

getRoutingTableAsString in interface ConsistentHash

isSegmentLocalToNode

public boolean isSegmentLocalToNode(Address nodeAddress,
                                    int segmentId)

Description copied from interface: ConsistentHash

Check if a segment is local to a given member.

Implementation note: normally key-based method are implemented based on segment-based methods. Here, however, we need a default implementation for the segment-based method for backwards-compatibility reasons.

Specified by:

isSegmentLocalToNode in interface ConsistentHash

isReplicated

public boolean isReplicated()

Specified by:

isReplicated in interface ConsistentHash

Returns:

true if every member owns every segment. This allows callers to skip computing the segment of a key in some cases.

toScopedState

public void toScopedState(ScopedPersistentState state)

Description copied from interface: ConsistentHash

Writes this ConsistentHash to the specified scoped state. Before invoking this method, the ConsistentHash addresses will have to be replaced with their corresponding PersistentUUIDs

Specified by:

toScopedState in interface ConsistentHash

Parameters:

state - the state to which this ConsistentHash will be written

remapAddresses

public ConsistentHash remapAddresses(UnaryOperator<Address> remapper)

Description copied from interface: ConsistentHash

Returns a new ConsistentHash with the addresses remapped according to the provided UnaryOperator. If an address cannot me remapped (i.e. the remapper returns null) this method should return null.

Specified by:

remapAddresses in interface ConsistentHash

Parameters:

remapper - the remapper which given an address replaces it with another one

Returns:

the remapped ConsistentHash or null if one of the remapped addresses is null

toString

public String toString()

Overrides:

toString in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object