Class/Object

akka.cluster.ddata

LWWMap

Related Docs: object LWWMap | package ddata

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final class LWWMap[A, B] extends DeltaReplicatedData with ReplicatedDataSerialization with RemovedNodePruning

Specialized ORMap with LWWRegister values.

LWWRegister relies on synchronized clocks and should only be used when the choice of value is not important for concurrent updates occurring within the clock skew.

Instead of using timestamps based on System.currentTimeMillis() time it is possible to use a timestamp value based on something else, for example an increasing version number from a database record that is used for optimistic concurrency control.

The defaultClock is using max value of System.currentTimeMillis() and currentTimestamp + 1. This means that the timestamp is increased for changes on the same node that occurs within the same millisecond. It also means that it is safe to use the LWWMap without synchronized clocks when there is only one active writer, e.g. a Cluster Singleton. Such a single writer should then first read current value with ReadMajority (or more) before changing and writing the value with WriteMajority (or more).

For first-write-wins semantics you can use the LWWRegister#reverseClock instead of the LWWRegister#defaultClock

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

Annotations
@SerialVersionUID()
Source
LWWMap.scala
Linear Supertypes
RemovedNodePruning, ReplicatedDataSerialization, Serializable, Serializable, DeltaReplicatedData, ReplicatedData, AnyRef, Any
Type Hierarchy
Ordering
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  2. By Inheritance
Inherited
  1. LWWMap
  2. RemovedNodePruning
  3. ReplicatedDataSerialization
  4. Serializable
  5. Serializable
  6. DeltaReplicatedData
  7. ReplicatedData
  8. AnyRef
  9. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
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Visibility
  1. Public
  2. All

Type Members

  1. type D = DeltaOp

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    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
    LWWMap → DeltaReplicatedData

  2. type T = LWWMap[A, B]

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    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
    LWWMap → ReplicatedData

Value Members

  1. final def !=(arg0: Any): Boolean

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    Definition Classes
    AnyRef → Any

  2. final def ##(): Int

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    Definition Classes
    AnyRef → Any

  3. def +(entry: (A, B))(implicit node: Cluster): LWWMap[A, B]

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    Adds an entry to the map

  4. def -(key: A)(implicit node: Cluster): LWWMap[A, B]

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    Removes an entry from the map.

    Removes an entry from the map. Note that if there is a conflicting update on another node the entry will not be removed after merge.

  5. def ->[B](y: B): (LWWMap[A, B], B)

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    Implicit information
    This member is added by an implicit conversion from LWWMap[A, B] to ArrowAssoc[LWWMap[A, B]] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @inline()

  6. final def ==(arg0: Any): Boolean

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    Definition Classes
    AnyRef → Any

  7. final def asInstanceOf[T0]: T0

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    Definition Classes
    Any

  8. def clone(): AnyRef

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    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

  9. def contains(key: A): Boolean

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  10. def delta: Option[D]

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    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
    LWWMap → DeltaReplicatedData

  11. def ensuring(cond: (LWWMap[A, B]) ⇒ Boolean, msg: ⇒ Any): LWWMap[A, B]

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    Implicit information
    This member is added by an implicit conversion from LWWMap[A, B] to Ensuring[LWWMap[A, B]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring

  12. def ensuring(cond: (LWWMap[A, B]) ⇒ Boolean): LWWMap[A, B]

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    Implicit information
    This member is added by an implicit conversion from LWWMap[A, B] to Ensuring[LWWMap[A, B]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring

  13. def ensuring(cond: Boolean, msg: ⇒ Any): LWWMap[A, B]

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    Implicit information
    This member is added by an implicit conversion from LWWMap[A, B] to Ensuring[LWWMap[A, B]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring

  14. def ensuring(cond: Boolean): LWWMap[A, B]

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    Implicit information
    This member is added by an implicit conversion from LWWMap[A, B] to Ensuring[LWWMap[A, B]] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring

  15. def entries: Map[A, B]

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    Scala API: All entries of the map.

  16. final def eq(arg0: AnyRef): Boolean

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    Definition Classes
    AnyRef

  17. def equals(o: Any): Boolean

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    Definition Classes
    LWWMap → AnyRef → Any

  18. def finalize(): Unit

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    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )

  19. def formatted(fmtstr: String): String

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    Implicit information
    This member is added by an implicit conversion from LWWMap[A, B] to StringFormat[LWWMap[A, B]] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @inline()

  20. def get(key: A): Option[B]

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  21. final def getClass(): Class[_]

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    Definition Classes
    AnyRef → Any

  22. def getEntries(): Map[A, B]

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    Java API: All entries of the map.

  23. def hashCode(): Int

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    Definition Classes
    LWWMap → AnyRef → Any

  24. def isEmpty: Boolean

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  25. final def isInstanceOf[T0]: Boolean

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    Definition Classes
    Any

  26. def merge(that: LWWMap[A, B]): LWWMap[A, B]

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    Monotonic merge function.

    Monotonic merge function.

    Definition Classes
    LWWMap → ReplicatedData

  27. def mergeDelta(thatDelta: D): LWWMap[A, B]

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    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
    LWWMap → DeltaReplicatedData

  28. def modifiedByNodes: Set[UniqueAddress]

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    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
    LWWMap → RemovedNodePruning

  29. final def ne(arg0: AnyRef): Boolean

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    Definition Classes
    AnyRef

  30. def needPruningFrom(removedNode: UniqueAddress): Boolean

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    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
    LWWMap → RemovedNodePruning

  31. final def notify(): Unit

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    Definition Classes
    AnyRef

  32. final def notifyAll(): Unit

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    Definition Classes
    AnyRef

  33. def prune(removedNode: UniqueAddress, collapseInto: UniqueAddress): LWWMap[A, B]

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    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
    LWWMap → RemovedNodePruning

  34. def pruningCleanup(removedNode: UniqueAddress): LWWMap[A, B]

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    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
    LWWMap → RemovedNodePruning

  35. def put(key: A, value: B)(implicit node: Cluster, clock: Clock[B] = defaultClock[B]): LWWMap[A, B]

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    Adds an entry to the map.

    Adds an entry to the map.

    You can provide your clock implementation instead of using timestamps based on System.currentTimeMillis() time. The timestamp can for example be an increasing version number from a database record that is used for optimistic concurrency control.

  36. def put(node: Cluster, key: A, value: B, clock: Clock[B]): LWWMap[A, B]

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    Adds an entry to the map.

    Adds an entry to the map.

    You can provide your clock implementation instead of using timestamps based on System.currentTimeMillis() time. The timestamp can for example be an increasing version number from a database record that is used for optimistic concurrency control.

  37. def put(node: Cluster, key: A, value: B): LWWMap[A, B]

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    Adds an entry to the map

  38. def remove(node: Cluster, key: A): LWWMap[A, B]

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    Removes an entry from the map.

    Removes an entry from the map. Note that if there is a conflicting update on another node the entry will not be removed after merge.

  39. def resetDelta: LWWMap[A, B]

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    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
    LWWMap → DeltaReplicatedData

  40. def size: Int

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  41. final def synchronized[T0](arg0: ⇒ T0): T0

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    Definition Classes
    AnyRef

  42. def toString(): String

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    Definition Classes
    LWWMap → AnyRef → Any

  43. final def wait(): Unit

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    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

  44. final def wait(arg0: Long, arg1: Int): Unit

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    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

  45. final def wait(arg0: Long): Unit

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    Definition Classes
    AnyRef
    Annotations
    @throws( ... )

  46. def →[B](y: B): (LWWMap[A, B], B)

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    Implicit information
    This member is added by an implicit conversion from LWWMap[A, B] to ArrowAssoc[LWWMap[A, B]] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc

Shadowed Implicit Value Members

  1. def +(other: String): String

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    Implicit information
    This member is added by an implicit conversion from LWWMap[A, B] to any2stringadd[LWWMap[A, B]] performed by method any2stringadd in scala.Predef.
    Shadowing
    This implicitly inherited member is shadowed by one or more members in this class.
    To access this member you can use a type ascription:
    (lWWMap: any2stringadd[LWWMap[A, B]]).+(other)
    Definition Classes
    any2stringadd

Inherited from RemovedNodePruning

Inherited from ReplicatedDataSerialization

Inherited from Serializable

Inherited from Serializable

Inherited from DeltaReplicatedData

Inherited from ReplicatedData

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd from LWWMap[A, B] to any2stringadd[LWWMap[A, B]]

Inherited by implicit conversion StringFormat from LWWMap[A, B] to StringFormat[LWWMap[A, B]]

Inherited by implicit conversion Ensuring from LWWMap[A, B] to Ensuring[LWWMap[A, B]]

Inherited by implicit conversion ArrowAssoc from LWWMap[A, B] to ArrowAssoc[LWWMap[A, B]]

Ungrouped