org.apache.beam.runners.direct

Class CopyOnAccessInMemoryStateInternals<K>

java.lang.Object

org.apache.beam.runners.direct.CopyOnAccessInMemoryStateInternals<K>

All Implemented Interfaces:

StateInternals<K>

public class CopyOnAccessInMemoryStateInternals<K>
extends Object
implements StateInternals<K>

StateInternals built on top of an underlying StateTable that contains instances of InMemoryStateInternals.InMemoryState. Whenever state that exists in the underlying StateTable is accessed, an independent copy will be created within this table.

Method Summary

Modifier and Type	Method and Description
CopyOnAccessInMemoryStateInternals<K>	commit() Ensures this CopyOnAccessInMemoryStateInternals is complete.
org.joda.time.Instant	getEarliestWatermarkHold() Gets the earliest Watermark Hold present in this table.
K	getKey()
boolean	isEmpty()
<T extends State> T	state(StateNamespace namespace, StateTag<? super K,T> address)
<T extends State> T	state(StateNamespace namespace, StateTag<? super K,T> address, StateContext<?> c)
static <K> CopyOnAccessInMemoryStateInternals<K>	withUnderlying(K key, CopyOnAccessInMemoryStateInternals<K> underlying) Creates a new CopyOnAccessInMemoryStateInternals with the underlying (possibly null) StateInternals.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

withUnderlying

public static <K> CopyOnAccessInMemoryStateInternals<K> withUnderlying(K key,
                                                                       @Nullable
                                                                       CopyOnAccessInMemoryStateInternals<K> underlying)

Creates a new CopyOnAccessInMemoryStateInternals with the underlying (possibly null) StateInternals.

commit

public CopyOnAccessInMemoryStateInternals<K> commit()

Ensures this CopyOnAccessInMemoryStateInternals is complete. Other copies of state for the same Step and Key may be discarded after invoking this method.

For each StateNamespace, for each address in that namespace that has not been bound in this CopyOnAccessInMemoryStateInternals, put a reference to that state within this StateInternals.

Additionally, stores the WatermarkHoldState with the earliest time bound in the state table after the commit is completed, enabling calls to getEarliestWatermarkHold().

Returns:

this table

getEarliestWatermarkHold

public org.joda.time.Instant getEarliestWatermarkHold()

Gets the earliest Watermark Hold present in this table.

Must be called after this state has been committed. Will throw an IllegalStateException if the state has not been committed.

state

public <T extends State> T state(StateNamespace namespace,
                                 StateTag<? super K,T> address)

Specified by:

state in interface StateInternals<K>

state

public <T extends State> T state(StateNamespace namespace,
                                 StateTag<? super K,T> address,
                                 StateContext<?> c)

Specified by:

state in interface StateInternals<K>

getKey

public K getKey()

Specified by:

getKey in interface StateInternals<K>

isEmpty

public boolean isEmpty()