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
- Alphabetic
- By Inheritance
- LWWMap
- RemovedNodePruning
- ReplicatedDataSerialization
- Serializable
- DeltaReplicatedData
- ReplicatedData
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- by any2stringadd
- by StringFormat
- by Ensuring
- by ArrowAssoc
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Type Members
- type D = DeltaOp
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 exampleGSet
uses the same type andORSet
uses different types.- Definition Classes
- LWWMap → DeltaReplicatedData
- type T = LWWMap[A, B]
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
- final def !=(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
- final def ##: Int
- Definition Classes
- AnyRef → Any
- def +(other: String): String
- def ->[B](y: B): (LWWMap[A, B], B)
- def :+(entry: (A, B))(implicit node: SelfUniqueAddress): LWWMap[A, B]
Adds an entry to the map
- final def ==(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
- final def asInstanceOf[T0]: T0
- Definition Classes
- Any
- def clone(): AnyRef
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.CloneNotSupportedException]) @HotSpotIntrinsicCandidate() @native()
- def contains(key: A): Boolean
- def delta: Option[D]
The accumulated delta of mutator operations since previous #resetDelta.
The accumulated delta of mutator operations since previous #resetDelta. When the
Replicator
invokes themodify
function of theUpdate
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 theReplicator
with the #delta accessor. Themodify
function shall still return the full state in the same way asReplicatedData
without support for deltas.- Definition Classes
- LWWMap → DeltaReplicatedData
- def ensuring(cond: (LWWMap[A, B]) => Boolean, msg: => Any): LWWMap[A, B]
- def ensuring(cond: (LWWMap[A, B]) => Boolean): LWWMap[A, B]
- def ensuring(cond: Boolean, msg: => Any): LWWMap[A, B]
- def ensuring(cond: Boolean): LWWMap[A, B]
- def entries: Map[A, B]
Scala API: All entries of the map.
- final def eq(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
- def equals(o: Any): Boolean
- Definition Classes
- LWWMap → AnyRef → Any
- def get(key: A): Option[B]
- final def getClass(): Class[_ <: AnyRef]
- Definition Classes
- AnyRef → Any
- Annotations
- @HotSpotIntrinsicCandidate() @native()
- def getEntries(): Map[A, B]
Java API: All entries of the map.
- def hashCode(): Int
- Definition Classes
- LWWMap → AnyRef → Any
- def isEmpty: Boolean
- final def isInstanceOf[T0]: Boolean
- Definition Classes
- Any
- def merge(that: LWWMap[A, B]): LWWMap[A, B]
Monotonic merge function.
Monotonic merge function.
- Definition Classes
- LWWMap → ReplicatedData
- def mergeDelta(thatDelta: D): LWWMap[A, B]
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 stateT
this method can be implemented by delegating tomerge
.- Definition Classes
- LWWMap → DeltaReplicatedData
- 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
- LWWMap → RemovedNodePruning
- final def ne(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
- 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
- LWWMap → RemovedNodePruning
- final def notify(): Unit
- Definition Classes
- AnyRef
- Annotations
- @HotSpotIntrinsicCandidate() @native()
- final def notifyAll(): Unit
- Definition Classes
- AnyRef
- Annotations
- @HotSpotIntrinsicCandidate() @native()
- def prune(removedNode: UniqueAddress, collapseInto: UniqueAddress): LWWMap[A, B]
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
- def pruningCleanup(removedNode: UniqueAddress): LWWMap[A, B]
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
- def put(node: SelfUniqueAddress, key: A, value: B, clock: Clock[B]): LWWMap[A, B]
Adds an entry to the map.
Adds an entry to the map.
You can provide your
clock
implementation instead of using timestamps based onSystem.currentTimeMillis()
time. The timestamp can for example be an increasing version number from a database record that is used for optimistic concurrency control. - def put(node: SelfUniqueAddress, key: A, value: B): LWWMap[A, B]
Adds an entry to the map
- def remove(node: SelfUniqueAddress, key: A): LWWMap[A, B]
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.
- def resetDelta: LWWMap[A, B]
Reset collection of deltas from mutator operations.
Reset collection of deltas from mutator operations. When the
Replicator
invokes themodify
function of theUpdate
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 theReplicator
with the #delta accessor. When theReplicator
has grabbed thedelta
it will invoke this method to get a clean data instance without the delta.- Definition Classes
- LWWMap → DeltaReplicatedData
- def size: Int
- final def synchronized[T0](arg0: => T0): T0
- Definition Classes
- AnyRef
- def toString(): String
- Definition Classes
- LWWMap → AnyRef → Any
- final def wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
- final def wait(arg0: Long): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException]) @native()
- final def wait(): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
Deprecated Value Members
- def finalize(): Unit
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.Throwable]) @Deprecated
- Deprecated
(Since version 9)
- def formatted(fmtstr: String): String
- Implicit
- This member is added by an implicit conversion from LWWMap[A, B] toStringFormat[LWWMap[A, B]] performed by method StringFormat in scala.Predef.
- Definition Classes
- StringFormat
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.12.16) Use
formatString.format(value)
instead ofvalue.formatted(formatString)
, or use thef""
string interpolator. In Java 15 and later,formatted
resolves to the new method in String which has reversed parameters.
- def →[B](y: B): (LWWMap[A, B], B)
- Implicit
- This member is added by an implicit conversion from LWWMap[A, B] toArrowAssoc[LWWMap[A, B]] 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.