CRDTORMapHandler<K, V> class

CRDT OR-Map

Description

A CRDTORMap is a map data structure that uses the Observed-Removed Map (OR-Map) algorithm to resolve conflicts.

Algorithm

Adding or updating a key-value pair produces a unique tag for the pair. Removing a key consists in tomb-stoning all tags for that key. A key is considered present iff it has at least one tag not tomb-stoned.

More detail about OR-Set (the foundation) can be found in this paper

Example

final doc = CRDTDocument();
final map = CRDTORMapHandler<String, int>(doc, 'map');
map.put('a', 1);
map.put('b', 2);
map.put('a', 10); // Update value for key 'a'
map.remove('b');
print(map.value); // Prints {'a': 10}

Inheritance

Object
Handler<ORMapState<K, V>>
CRDTORMapHandler

Constructors

CRDTORMapHandler(BaseCRDTDocument doc, String _id, {ValueCodec<K>? keyCodec, ValueCodec<V>? valueCodec}): Creates a new CRDT OR-MapHandler with the given document and ID

Properties

cachedState → ORMapState<K, V>?: Returns the cached state
no setterinherited
deleteType → OperationType: Cached delete type instances for this handler, used in operations.
latefinalinherited
doc → BaseCRDTDocument: The document that owns this handler
finalinherited
entries → Iterable<MapEntry<K, V>>: Returns the current entries in the map.
no setter
hashCode → int: The hash code for this object.
no setterinherited
id → String: The unique identifier for this consumer
no setteroverride
insertType → OperationType: Cached insert type instances for this handler, used in operations.
latefinalinherited
keys → Iterable<K>: Returns the current keys in the map.
no setter
operationFactory → OperationFactory: The factory function that creates an operation from a payload
latefinal
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
updateType → OperationType: Cached update type instances for this handler, used in operations.
latefinalinherited
useIncrementalCacheUpdate ↔ bool: Whether to use incremental cache update
getter/setter pairinherited
value → Map<K, V>: Returns the current map value computed from changes and snapshot.
no setter
values → Iterable<V>: Returns the current values in the map.
no setter

Methods

compound(Operation accumulator, Operation current) → Operation?: During transaction consecutive operations can be compounded.
inherited
containsKey(K key) → bool: Returns whether the map contains key.
getSnapshotState() → Uint8List: Returns the current state for snapshotting as a binary blob.
override
incrementCachedState({required Operation operation, required ORMapState<K, V> state}) → ORMapState<K, V>?: When the document receives an operation and a change is applied anyone using CacheableStateProvider is allowed to increment the cached state.
override
invalidateCache() → void: Invalidates the cached state
inherited
lastSnapshot() → Uint8List?: Returns the last snapshot bytes for this consumer (the value previously produced by getSnapshotState) or null if no snapshot is available.
inherited
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
operations() → List<Operation>: Returns the Operations required by this consumer to compute its state.
inherited
put(K key, V value) → void: Puts value for key in the map, producing a unique tag.
remove(K key) → void: Removes key from the map by tomb-stoning all observed tags for that key.
snapshotVersionVector() → VersionVector?: Returns the version vector of the last snapshot for this consumer.
inherited
toString() → String: A string representation of this object.
inherited
updateCachedState(ORMapState<K, V> newState) → void: Updates the cached state
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited
operator [](K key) → V?: Returns the value for key, or null if not present.