K
- type of keyN
- type of namespaceS
- type of state@Internal public class CopyOnWriteStateTableSnapshot<K,N,S> extends Object
CopyOnWriteStateTable
and has a role in operator state checkpointing. Besides
holding the CopyOnWriteStateTable
s internal entries at the time of the snapshot, this class is also responsible for
preparing and writing the state in the process of checkpointing.
IMPORTANT: Please notice that snapshot integrity of entries in this class rely on proper copy-on-write semantics
through the CopyOnWriteStateTable
that created the snapshot object, but all objects in this snapshot must be considered
as READ-ONLY!. The reason is that the objects held by this class may or may not be deep copies of original objects
that may still used in the CopyOnWriteStateTable
. This depends for each entry on whether or not it was subject to
copy-on-write operations by the CopyOnWriteStateTable
. Phrased differently: the CopyOnWriteStateTable
provides
copy-on-write isolation for this snapshot, but this snapshot does not isolate modifications from the
CopyOnWriteStateTable
!
Modifier and Type | Method and Description |
---|---|
void |
release()
Optional hook to release resources for this snapshot at the end of its lifecycle.
|
void |
writeMappingsInKeyGroup(DataOutputView dov,
int keyGroupId) |
public void release()
public void writeMappingsInKeyGroup(DataOutputView dov, int keyGroupId) throws IOException
IOException
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