org.apache.flink.streaming.runtime.io

Class CheckpointedInputGate

java.lang.Object

org.apache.flink.streaming.runtime.io.CheckpointedInputGate

All Implemented Interfaces:

AvailabilityProvider, PullingAsyncDataInput<BufferOrEvent>

@Internal
public class CheckpointedInputGate
extends Object
implements PullingAsyncDataInput<BufferOrEvent>

The CheckpointedInputGate uses CheckpointBarrierHandler to handle incoming CheckpointBarrier from the InputGate.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.flink.runtime.io.AvailabilityProvider

AvailabilityProvider.AvailabilityHelper

Field Summary

Fields inherited from interface org.apache.flink.runtime.io.AvailabilityProvider

AVAILABLE

Constructor Summary

Constructors

Constructor and Description
CheckpointedInputGate(InputGate inputGate, BufferStorage bufferStorage, CheckpointBarrierHandler barrierHandler)
CheckpointedInputGate(InputGate inputGate, BufferStorage bufferStorage, CheckpointBarrierHandler barrierHandler, int channelIndexOffset) Creates a new checkpoint stream aligner.
CheckpointedInputGate(InputGate inputGate, BufferStorage bufferStorage, String taskName, AbstractInvokable toNotifyOnCheckpoint)

Method Summary

Modifier and Type	Method and Description
void	cleanup() Cleans up all internally held resources.
long	getAlignmentDurationNanos() Gets the time that the latest alignment took, in nanoseconds.
CompletableFuture<?>	getAvailableFuture()
long	getLatestCheckpointId() Gets the ID defining the current pending, or just completed, checkpoint.
int	getNumberOfInputChannels()
boolean	isEmpty() Checks if the barrier handler has buffered any data internally.
boolean	isFinished()
Optional<BufferOrEvent>	pollNext() Poll the next element.
String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.flink.runtime.io.AvailabilityProvider

isApproximatelyAvailable, isAvailable

Constructor Detail

CheckpointedInputGate

public CheckpointedInputGate(InputGate inputGate,
                             BufferStorage bufferStorage,
                             String taskName,
                             @Nullable
                             AbstractInvokable toNotifyOnCheckpoint)

CheckpointedInputGate

public CheckpointedInputGate(InputGate inputGate,
                             BufferStorage bufferStorage,
                             CheckpointBarrierHandler barrierHandler)

CheckpointedInputGate

public CheckpointedInputGate(InputGate inputGate,
                             BufferStorage bufferStorage,
                             CheckpointBarrierHandler barrierHandler,
                             int channelIndexOffset)

Creates a new checkpoint stream aligner.

The aligner will allow only alignments that buffer up to the given number of bytes. When that number is exceeded, it will stop the alignment and notify the task that the checkpoint has been cancelled.

Parameters:

inputGate - The input gate to draw the buffers and events from.

bufferStorage - The storage to hold the buffers and events for blocked channels.

barrierHandler - Handler that controls which channels are blocked.

channelIndexOffset - Optional offset added to channelIndex returned from the inputGate before passing it to the barrierHandler.

Method Detail

getAvailableFuture

public CompletableFuture<?> getAvailableFuture()

Specified by:

getAvailableFuture in interface AvailabilityProvider

Returns:

a future that is completed if the respective provider is available.

pollNext

public Optional<BufferOrEvent> pollNext()
                                 throws Exception

Description copied from interface: PullingAsyncDataInput

Poll the next element. This method should be non blocking.

Specified by:

pollNext in interface PullingAsyncDataInput<BufferOrEvent>

Returns:

Optional.empty() will be returned if there is no data to return or if PullingAsyncDataInput.isFinished() returns true. Otherwise Optional.of(element).

Throws:

Exception

isEmpty

public boolean isEmpty()

Checks if the barrier handler has buffered any data internally.

Returns:

True, if no data is buffered internally, false otherwise.

isFinished

public boolean isFinished()

Specified by:

isFinished in interface PullingAsyncDataInput<BufferOrEvent>

Returns:

true if is finished and for example end of input was reached, false otherwise.

cleanup

public void cleanup()
             throws IOException

Cleans up all internally held resources.

Throws:

IOException - Thrown if the cleanup of I/O resources failed.

getLatestCheckpointId

public long getLatestCheckpointId()

Gets the ID defining the current pending, or just completed, checkpoint.

Returns:

The ID of the pending of completed checkpoint.

getAlignmentDurationNanos

public long getAlignmentDurationNanos()

Gets the time that the latest alignment took, in nanoseconds. If there is currently an alignment in progress, it will return the time spent in the current alignment so far.

Returns:

The duration in nanoseconds

getNumberOfInputChannels

public int getNumberOfInputChannels()

Returns:

number of underlying input channels.

toString

public String toString()

Overrides:

toString in class Object