Package akka.cluster.ddata

Class ORSet.FullStateDeltaOp<A>

java.lang.Object

akka.cluster.ddata.ORSet.AtomicDeltaOp<A>

akka.cluster.ddata.ORSet.FullStateDeltaOp<A>

All Implemented Interfaces:

ORSet.DeltaOp, ReplicatedData, ReplicatedDataSerialization, ReplicatedDelta, ReplicatedDeltaSize, RequiresCausalDeliveryOfDeltas, java.io.Serializable, scala.Equals, scala.Product, scala.Serializable

Enclosing class:

ORSet<A>

public static final class ORSet.FullStateDeltaOp<A>
extends ORSet.AtomicDeltaOp<A>
implements scala.Product, scala.Serializable

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
FullStateDeltaOp(ORSet<A> underlying)

Method Summary

Modifier and Type	Method	Description
boolean	canEqual(java.lang.Object x$1)
<A> ORSet.FullStateDeltaOp<A>	copy(ORSet<A> underlying)
<A> ORSet<A>	copy$default$1()
boolean	equals(java.lang.Object x$1)
int	hashCode()
ORSet.DeltaOp	merge(ORSet.DeltaOp that)
int	productArity()
java.lang.Object	productElement(int x$1)
scala.collection.Iterator<java.lang.Object>	productIterator()
java.lang.String	productPrefix()
java.lang.String	toString()
ORSet<A>	underlying()	Implements a 'Observed Remove Set' CRDT, also called a 'OR-Set'.

Methods inherited from class akka.cluster.ddata.ORSet.AtomicDeltaOp

deltaSize, zero

Methods inherited from class java.lang.Object

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

Methods inherited from interface akka.cluster.ddata.ReplicatedData

merge

Constructor Detail

FullStateDeltaOp

public FullStateDeltaOp(ORSet<A> underlying)

Method Detail

underlying

public ORSet<A> underlying()

Implements a 'Observed Remove Set' CRDT, also called a 'OR-Set'. Elements can be added and removed any number of times. Concurrent add wins over remove.

It is not implemented as in the paper A comprehensive study of Convergent and Commutative Replicated Data Types. This is more space efficient and doesn't accumulate garbage for removed elements. It is described in the paper An optimized conflict-free replicated set The implementation is inspired by the Riak DT riak_dt_orswot.

The ORSet has a version vector that is incremented when an element is added to the set. The node -> count pair for that increment is stored against the element as its "birth dot". Every time the element is re-added to the set, its "birth dot" is updated to that of the node -> count version vector entry resulting from the add. When an element is removed, we simply drop it, no tombstones.

When an element exists in replica A and not replica B, is it because A added it and B has not yet seen that, or that B removed it and A has not yet seen that? In this implementation we compare the dot of the present element to the version vector in the Set it is absent from. If the element dot is not "seen" by the Set version vector, that means the other set has yet to see this add, and the item is in the merged Set. If the Set version vector dominates the dot, that means the other Set has removed this element already, and the item is not in the merged Set.

This class is immutable, i.e. "modifying" methods return a new instance.

Specified by:

underlying in class ORSet.AtomicDeltaOp<A>

Returns:

(undocumented)

merge

public ORSet.DeltaOp merge(ORSet.DeltaOp that)

copy

public <A> ORSet.FullStateDeltaOp<A> copy(ORSet<A> underlying)

copy$default$1

public <A> ORSet<A> copy$default$1()

productPrefix

public java.lang.String productPrefix()

Specified by:

productPrefix in interface scala.Product

productArity

public int productArity()

Specified by:

productArity in interface scala.Product

productElement

public java.lang.Object productElement(int x$1)

Specified by:

productElement in interface scala.Product

productIterator

public scala.collection.Iterator<java.lang.Object> productIterator()

Specified by:

productIterator in interface scala.Product

canEqual

public boolean canEqual(java.lang.Object x$1)

Specified by:

canEqual in interface scala.Equals

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

equals

public boolean equals(java.lang.Object x$1)

Specified by:

equals in interface scala.Equals

Overrides:

equals in class java.lang.Object