final class GCounter extends DeltaReplicatedData with ReplicatedDelta with ReplicatedDataSerialization with RemovedNodePruning with FastMerge

Implements a 'Growing Counter' CRDT, also called a 'G-Counter'.

It is described in the paper A comprehensive study of Convergent and Commutative Replicated Data Types.

A G-Counter is a increment-only counter (inspired by vector clocks) in which only increment and merge are possible. Incrementing the counter adds 1 to the count for the current node. Divergent histories are resolved by taking the maximum count for each node (like a vector clock merge). The value of the counter is the sum of all node counts.

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

Annotations
@SerialVersionUID()
Source
GCounter.scala
Type Hierarchy
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Inherited
  1. GCounter
  2. FastMerge
  3. RemovedNodePruning
  4. ReplicatedDataSerialization
  5. Serializable
  6. ReplicatedDelta
  7. DeltaReplicatedData
  8. ReplicatedData
  9. AnyRef
  10. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
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Visibility
  1. Public
  2. Protected

Type Members

  1. type D = GCounter

    The type of the delta.

    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.

    Definition Classes
    GCounterDeltaReplicatedData
  2. type T = GCounter

    The type of the concrete implementation, e.g.

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

    Definition Classes
    GCounterReplicatedData

Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##: Int
    Definition Classes
    AnyRef → Any
  3. def +(other: String): String
    Implicit
    This member is added by an implicit conversion from GCounter toany2stringadd[GCounter] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  4. def ->[B](y: B): (GCounter, B)
    Implicit
    This member is added by an implicit conversion from GCounter toArrowAssoc[GCounter] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @inline()
  5. def :+(n: Long)(implicit node: SelfUniqueAddress): GCounter

    Increment the counter with the delta n specified.

    Increment the counter with the delta n specified. The delta must be zero or positive.

  6. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  7. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  8. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.CloneNotSupportedException]) @HotSpotIntrinsicCandidate() @native()
  9. val delta: Option[GCounter]

    The accumulated delta of mutator operations since previous #resetDelta.

    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.

    Definition Classes
    GCounterDeltaReplicatedData
  10. def ensuring(cond: (GCounter) => Boolean, msg: => Any): GCounter
    Implicit
    This member is added by an implicit conversion from GCounter toEnsuring[GCounter] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  11. def ensuring(cond: (GCounter) => Boolean): GCounter
    Implicit
    This member is added by an implicit conversion from GCounter toEnsuring[GCounter] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  12. def ensuring(cond: Boolean, msg: => Any): GCounter
    Implicit
    This member is added by an implicit conversion from GCounter toEnsuring[GCounter] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  13. def ensuring(cond: Boolean): GCounter
    Implicit
    This member is added by an implicit conversion from GCounter toEnsuring[GCounter] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  14. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  15. def equals(o: Any): Boolean
    Definition Classes
    GCounter → AnyRef → Any
  16. final def getClass(): Class[_ <: AnyRef]
    Definition Classes
    AnyRef → Any
    Annotations
    @HotSpotIntrinsicCandidate() @native()
  17. def getValue: BigInteger

    Java API: Current total value of the counter.

  18. def hashCode(): Int
    Definition Classes
    GCounter → AnyRef → Any
  19. def increment(node: SelfUniqueAddress, n: Long): GCounter

    Increment the counter with the delta n specified.

    Increment the counter with the delta n specified. The delta n must be zero or positive.

  20. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  21. def merge(that: GCounter): GCounter

    Monotonic merge function.

    Monotonic merge function.

    Definition Classes
    GCounterReplicatedData
  22. def mergeDelta(thatDelta: GCounter): GCounter

    When delta is merged into the full state this method is used.

    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.

    Definition Classes
    GCounterDeltaReplicatedData
  23. def modifiedByNodes: Set[UniqueAddress]

    The nodes that have changed the state for this data and would need pruning when such node is no longer part of the cluster.

    The nodes that have changed the state for this data and would need pruning when such node is no longer part of the cluster.

    Definition Classes
    GCounterRemovedNodePruning
  24. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  25. def needPruningFrom(removedNode: UniqueAddress): Boolean

    Does it have any state changes from a specific node, which has been removed from the cluster.

    Does it have any state changes from a specific node, which has been removed from the cluster.

    Definition Classes
    GCounterRemovedNodePruning
  26. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @HotSpotIntrinsicCandidate() @native()
  27. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @HotSpotIntrinsicCandidate() @native()
  28. def prune(removedNode: UniqueAddress, collapseInto: UniqueAddress): GCounter

    When the removed node has been removed from the cluster the state changes from that node will be pruned by collapsing the data entries to another node.

    When the removed node has been removed from the cluster the state changes from that node will be pruned by collapsing the data entries to another node.

    Definition Classes
    GCounterRemovedNodePruning
  29. def pruningCleanup(removedNode: UniqueAddress): GCounter

    Remove data entries from a node that has been removed from the cluster and already been pruned.

    Remove data entries from a node that has been removed from the cluster and already been pruned.

    Definition Classes
    GCounterRemovedNodePruning
  30. def resetDelta: GCounter

    Reset collection of deltas from mutator operations.

    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.

    Definition Classes
    GCounterDeltaReplicatedData
  31. final def synchronized[T0](arg0: => T0): T0
    Definition Classes
    AnyRef
  32. def toString(): String
    Definition Classes
    GCounter → AnyRef → Any
  33. def value: BigInt

    Scala API: Current total value of the counter.

  34. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  35. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException]) @native()
  36. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  37. def zero: GCounter

    The empty full state.

    The empty full state. This is used when a delta is received and no existing full state exists on the receiving side. Then the delta is merged into the zero to create the initial full state.

    Definition Classes
    GCounterReplicatedDelta

Deprecated Value Members

  1. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.Throwable]) @Deprecated
    Deprecated

    (Since version 9)

  2. def formatted(fmtstr: String): String
    Implicit
    This member is added by an implicit conversion from GCounter toStringFormat[GCounter] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @deprecated @inline()
    Deprecated

    (Since version 2.12.16) Use formatString.format(value) instead of value.formatted(formatString), or use the f"" string interpolator. In Java 15 and later, formatted resolves to the new method in String which has reversed parameters.

  3. def [B](y: B): (GCounter, B)
    Implicit
    This member is added by an implicit conversion from GCounter toArrowAssoc[GCounter] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @deprecated
    Deprecated

    (Since version 2.13.0) Use -> instead. If you still wish to display it as one character, consider using a font with programming ligatures such as Fira Code.

Inherited from FastMerge

Inherited from RemovedNodePruning

Inherited from Serializable

Inherited from ReplicatedDelta

Inherited from DeltaReplicatedData

Inherited from ReplicatedData

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd fromGCounter to any2stringadd[GCounter]

Inherited by implicit conversion StringFormat fromGCounter to StringFormat[GCounter]

Inherited by implicit conversion Ensuring fromGCounter to Ensuring[GCounter]

Inherited by implicit conversion ArrowAssoc fromGCounter to ArrowAssoc[GCounter]

Ungrouped