StateManager¶

StateManager is an abstraction of state managers that act as middlemen between state stores and FlatMapGroupsWithStateExec physical operator used in Arbitrary Stateful Streaming Aggregation.

Contract¶

getAllState¶

getAllState(
  store: StateStore): Iterator[StateData]

Retrieves all state data (for all keys) from the given StateStore

Used when:

• InputProcessor is requested to processTimedOutState

getState¶

getState(
  store: StateStore,
  keyRow: UnsafeRow): StateData

Gets the state data for the given key from the given StateStore

Used when:

• InputProcessor is requested to processNewData and processNewDataWithInitialState

putState¶

putState(
  store: StateStore,
  keyRow: UnsafeRow,
  state: Any,
  timeoutTimestamp: Long): Unit

Persists (puts) the given state (value) for the given key in the given StateStore

Used when:

• InputProcessor is requested to callFunctionAndUpdateState (right after all rows have been processed)

removeState¶

removeState(
  store: StateStore,
  keyRow: UnsafeRow): Unit

Removes the state for the given key from the given StateStore

Used when:

• InputProcessor is requested to callFunctionAndUpdateState (right after all rows have been processed)

stateSchema¶

stateSchema: StructType

Used when:

• FlatMapGroupsWithStateExec is requested to execute
• StateManagerImplBase is requested for the stateDeserializerFunc

Implementations¶

• StateManagerImplBase