DeltaReplicatedData

org.apache.pekko.cluster.ddata.DeltaReplicatedData

ReplicatedData with additional support for delta-CRDT replication. delta-CRDT is a way to reduce the need for sending the full state for updates. For example adding element 'c' and 'd' to set {'a', 'b'} would result in sending the delta {'c', 'd'} and merge that with the state on the receiving side, resulting in set {'a', 'b', 'c', 'd'}.

Learn more about this in the paper Delta State Replicated Data Types.

Attributes

Source
ReplicatedData.scala
Graph
Supertypes
class Object
trait Matchable
class Any
Known subtypes
class GCounter
class GSet[A]
class LWWMap[A, B]
class ORMap[A, B]
class ORMultiMap[A, B]
class ORSet[A]
class PNCounter
class PNCounterMap[A]
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Members list

Type members

Types

type D <: ReplicatedDelta

The type of the delta. To be specified by subclass. It may be the same type as T or a different type if needed. For example GSet uses the same type and ORSet uses different types.

The type of the delta. To be specified by subclass. It may be the same type as T or a different type if needed. For example GSet uses the same type and ORSet uses different types.

Attributes

Source
ReplicatedData.scala

Inherited types

type T <: ReplicatedData

The type of the concrete implementation, e.g. GSet[A]. To be specified by subclass.

The type of the concrete implementation, e.g. GSet[A]. To be specified by subclass.

Attributes

Inherited from:
ReplicatedData
Source
ReplicatedData.scala

Value members

Abstract methods

def delta: Option[D]

The accumulated delta of mutator operations since previous resetDelta. When the Replicator invokes the modify function of the Update message and the user code is invoking one or more mutator operations the data is collecting the delta of the operations and makes it available for the Replicator with the delta accessor. The modify function shall still return the full state in the same way as ReplicatedData without support for deltas.

The accumulated delta of mutator operations since previous resetDelta. When the Replicator invokes the modify function of the Update message and the user code is invoking one or more mutator operations the data is collecting the delta of the operations and makes it available for the Replicator with the delta accessor. The modify function shall still return the full state in the same way as ReplicatedData without support for deltas.

Attributes

Source
ReplicatedData.scala
def mergeDelta(thatDelta: D): T

When delta is merged into the full state this method is used. When the type D of the delta is of the same type as the full state T this method can be implemented by delegating to merge.

When delta is merged into the full state this method is used. When the type D of the delta is of the same type as the full state T this method can be implemented by delegating to merge.

Attributes

Source
ReplicatedData.scala
def resetDelta: T

Reset collection of deltas from mutator operations. When the Replicator invokes the modify function of the Update message the delta is always "reset" and when the user code is invoking one or more mutator operations the data is collecting the delta of the operations and makes it available for the Replicator with the delta accessor. When the Replicator has grabbed the delta it will invoke this method to get a clean data instance without the delta.

Reset collection of deltas from mutator operations. When the Replicator invokes the modify function of the Update message the delta is always "reset" and when the user code is invoking one or more mutator operations the data is collecting the delta of the operations and makes it available for the Replicator with the delta accessor. When the Replicator has grabbed the delta it will invoke this method to get a clean data instance without the delta.

Attributes

Source
ReplicatedData.scala

Inherited methods

def merge(that: T): T

Monotonic merge function.

Monotonic merge function.

Attributes

Inherited from:
ReplicatedData
Source
ReplicatedData.scala