c-crdtlib/crdtlib.crdt/LWWMap

LWWMap

class LWWMap : DeltaCRDT

A delta-based CRDT map implementing last writer wins (LWW) policy.

Each entry behaves like a LWWRegister: only the last written value is retained.

When merging, for each key, only the value associated with the greatest timestamp is retained. A deletion is represented as a null value and handled the same way.

Its JSON serialization respects the following schema:

{
  "type": "LWWMap",
  "metadata": {
      "entries": {
          // $key is a string
          (( "$key": Timestamp.toJson(), )*( "$key": Timestamp.toJson() ))?
      }
  }
  // $key is a string and $value can be Boolean, double, integer or string
  ( , "$key": "$value" )*
}

Constructors

LWWMap

common

fun LWWMap()

Default constructor.

LWWMap

common

fun LWWMap(env: Environment)

Types

Companion

common

object Companion

Functions

deleteBoolean

common

fun deleteBoolean(key: String): LWWMap

Removes the specified key / Boolean value pair from this map.

deleteDouble

common

fun deleteDouble(key: String): LWWMap

Removes the specified key / Double value pair from this map.

deleteInt

common

fun deleteInt(key: String): LWWMap

Removes the specified key / Int value pair from this map.

deleteString

common

fun deleteString(key: String): LWWMap

Removes the specified key / String value pair from this map.

equals

common

open operator fun equals(other: Any?): Boolean

generateDelta

common

open override fun generateDelta(vv: VersionVector): LWWMap

Return a delta from a given version vector vv to current state.

getBoolean

common

fun getBoolean(key: String): Boolean?

Get the Boolean value corresponding to a given key, or null if the key is not present in the map.

getDouble

common

fun getDouble(key: String): Double?

Get the Double value corresponding to a given key, or null if the key is not present in the map.

getInt

common

fun getInt(key: String): Int?

Get the Int value corresponding to a given key, or null if the key is not present in the map.

getString

common

fun getString(key: String): String?

Get the String value corresponding to a given key, or null if the key is not present in the map.

hashCode

common

open fun hashCode(): Int

iteratorBoolean

common

fun iteratorBoolean(): Iterator<Pair<String, Boolean>>

Gets an iterator over the Boolean values in the map.

iteratorDouble

common

fun iteratorDouble(): Iterator<Pair<String, Double>>

Gets an iterator over the Double values in the map.

iteratorInt

common

fun iteratorInt(): Iterator<Pair<String, Int>>

Gets an iterator over the Int values in the map.

iteratorString

common

fun iteratorString(): Iterator<Pair<String, String>>

Gets an iterator over the String values in the map.

merge

common

open override fun merge(delta: DeltaCRDT)

Merge a given delta into this DeltaCRDTThe merge is unidirectional: only the local replica is modified.

put

common

fun put(key: String, value: Boolean?): LWWMap

Puts a key / Boolean value pair into the map.

fun put(key: String, value: Double?): LWWMap

Puts a key / Double value pair into the map.

fun put(key: String, value: Int?): LWWMap

Puts a key / Int value pair into the map.

fun put(key: String, value: String?): LWWMap

Puts a key / String value pair into the map.

toJson

common

open override fun toJson(): String

Serialize this DeltaCRDT to a JSON string.

toString

common

open fun toString(): String