org.apache.beam.runners.spark.io

Class EmptyCheckpointMark

java.lang.Object

org.apache.beam.runners.spark.io.EmptyCheckpointMark

All Implemented Interfaces:

java.io.Serializable, UnboundedSource.CheckpointMark

public class EmptyCheckpointMark
extends java.lang.Object
implements UnboundedSource.CheckpointMark, java.io.Serializable

Passing null values to Spark's Java API may cause problems because of Guava preconditions. See: JavaUtils.optionToOptional(scala.Option<T>)

See Also:

Serialized Form

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object obj)
void	finalizeCheckpoint() Called by the system to signal that this checkpoint mark has been committed along with all the records which have been read from the UnboundedSource.UnboundedReader since the previous checkpoint was taken.
static EmptyCheckpointMark	get()
int	hashCode()

Methods inherited from class java.lang.Object

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

Method Detail

get

public static EmptyCheckpointMark get()

finalizeCheckpoint

public void finalizeCheckpoint()
                        throws java.io.IOException

Description copied from interface: UnboundedSource.CheckpointMark

Called by the system to signal that this checkpoint mark has been committed along with all the records which have been read from the UnboundedSource.UnboundedReader since the previous checkpoint was taken.

For example, this method could send acknowledgements to an external data source such as Pubsub.

Note that:

• This finalize method may be called from any thread, concurrently with calls to the UnboundedSource.UnboundedReader it was created from.
• Checkpoints will not necessarily be finalized as soon as they are created. A checkpoint may be taken while a previous checkpoint from the same UnboundedSource.UnboundedReader has not yet be finalized.
• In the absence of failures, all checkpoints will be finalized and they will be finalized in the same order they were taken from the UnboundedSource.UnboundedReader.
• It is possible for a checkpoint to be taken but this method never called. This method will never be called if the checkpoint could not be committed, and other failures may cause this method to never be called.
• It is not safe to assume the UnboundedSource.UnboundedReader from which this checkpoint was created still exists at the time this method is called.

Specified by:

finalizeCheckpoint in interface UnboundedSource.CheckpointMark

Throws:

java.io.IOException

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object