Class DefaultConsistentHash

java.lang.Object

org.infinispan.distribution.ch.impl.AbstractConsistentHash

org.infinispan.distribution.ch.impl.DefaultConsistentHash

All Implemented Interfaces:

ConsistentHash

@Immutable
@ProtoTypeId(1067)
public class DefaultConsistentHash
extends AbstractConsistentHash

Default ConsistentHash implementation. This object is immutable. Every segment must have a primary owner.

Since:

5.2

Author:

Dan Berindei, anistor@redhat.com

Field Summary

Fields inherited from class org.infinispan.distribution.ch.impl.AbstractConsistentHash

capacityFactors, members, STATE_CAPACITY_FACTOR, STATE_CAPACITY_FACTORS, STATE_NUM_SEGMENTS

Method Summary

Modifier and Type	Method	Description
static DefaultConsistentHash	create(int numOwners, int numSegments, List<Address> members, Map<Address,Float> capacityFactors, List<Address>[] segmentOwners)
boolean	equals(Object o)
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	isSegmentLocalToNode(Address nodeAddress, int segmentId)	Check if a segment is local to a given member.
List<Address>	locateOwnersForSegment(int segmentId)
Address	locatePrimaryOwnerForSegment(int segmentId)
void	toScopedState(ScopedPersistentState state, Function<Address,UUID> addressMapper)	Writes this ConsistentHash to the specified scoped persistent state.
String	toString()
DefaultConsistentHash	union(DefaultConsistentHash dch2)	Merges two consistent hash objects that have the same number of segments, numOwners and hash function.

Methods inherited from class org.infinispan.distribution.ch.impl.AbstractConsistentHash

checkSameHashAndSegments, getCapacityFactors, getMemberIndexMap, getMembers, mergeLists, parseMembers, parseNumSegments, unionCapacityFactors, writeAddressToState

Methods inherited from class java.lang.Object

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

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

isReplicated

Method Details

create

public static DefaultConsistentHash create(int numOwners,
 int numSegments,
 List<Address> members,
 Map<Address,Float> capacityFactors,
 List<Address>[] segmentOwners)

getNumOwners

@ProtoField(3)
public int getNumOwners()

getNumSegments

public int getNumSegments()

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.

getSegmentsForOwner

public Set<Integer> getSegmentsForOwner(Address owner)

Description copied from interface: ConsistentHash

Returns the segments owned by a cache member.

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. The set is empty if owner is not a member of the consistent hash.

getPrimarySegmentsForOwner

public Set<Integer> getPrimarySegmentsForOwner(Address owner)

Description copied from interface: ConsistentHash

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

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. The set is empty if owner is not a member of the consistent hash.

locateOwnersForSegment

public List<Address> locateOwnersForSegment(int segmentId)

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)

Returns:

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

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.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object

getRoutingTableAsString

public String getRoutingTableAsString()

Description copied from interface: ConsistentHash

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

union

public DefaultConsistentHash union(DefaultConsistentHash dch2)

Merges two consistent hash objects that have the same number of segments, numOwners and hash function. For each segment, the primary owner of the first CH has priority, the other primary owners become backups.

toScopedState

public void toScopedState(ScopedPersistentState state,
 Function<Address,UUID> addressMapper)

Description copied from interface: ConsistentHash

Writes this ConsistentHash to the specified scoped persistent state.

Specified by:

toScopedState in interface ConsistentHash

Overrides:

toScopedState in class AbstractConsistentHash

Parameters:

state - The state to which this ConsistentHash will be written.

addressMapper - The mapper Function to convert the Address to the UUID used to persist the address within the state.