Package org.apache.flink.table.runtime.operators.bundle

Class AbstractMapBundleOperator<K,V,IN,OUT>

java.lang.Object

org.apache.flink.streaming.api.operators.AbstractStreamOperator<OUT>

org.apache.flink.table.runtime.operators.bundle.AbstractMapBundleOperator<K,V,IN,OUT>

Type Parameters:

K - The type of the key in the bundle map

V - The type of the value in the bundle map

IN - Input type for the operator.

OUT - Output type for the operator.

All Implemented Interfaces:

Serializable, CheckpointListener, Input<IN>, KeyContext, KeyContextHandler, OneInputStreamOperator<IN,OUT>, StreamOperator<OUT>, StreamOperatorStateHandler.CheckpointedStreamOperator, YieldingOperator<OUT>, BundleTriggerCallback

Direct Known Subclasses:

KeyedMapBundleOperator, MapBundleOperator

public abstract class AbstractMapBundleOperator<K,V,IN,OUT>
extends AbstractStreamOperator<OUT>
implements OneInputStreamOperator<IN,OUT>, BundleTriggerCallback

The AbstractMapBundleOperator simply used a java Map to store the input elements in key-value form. The map key is typically the same with the state key, so we can do some optimizations before accessing states, like pre aggregate values for each key. And we will only need to access state every key we have, but not every element we processed.

NOTES: if all elements we processed have different keys, such operator will only increase memory footprint, and will not have any performance improvement.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.flink.streaming.api.operators.AbstractStreamOperator

config, lastRecordAttributes1, lastRecordAttributes2, latencyStats, LOG, metrics, output, processingTimeService, stateHandler, stateKeySelector1, stateKeySelector2, timeServiceManager

Method Summary

Modifier and Type	Method	Description
void	close()	This method is called at the very end of the operator's life, both in the case of a successful completion of the operation, and in the case of a failure and canceling.
void	finish()	This method is called at the end of data processing.
void	finishBundle()	This method is invoked to finish current bundle and start a new one when the trigger was fired.
protected abstract K	getKey(IN input)	Get the key for current processing element, which will be used as the map bundle's key.
void	open()	This method is called immediately before any elements are processed, it should contain the operator's initialization logic, e.g. state initialization.
void	prepareSnapshotPreBarrier(long checkpointId)	This method is called when the operator should do a snapshot, before it emits its own checkpoint barrier.
void	processElement(StreamRecord<IN> element)	Processes one element that arrived on this input of the MultipleInputStreamOperator.
void	processWatermark(Watermark mark)	Processes a Watermark that arrived on the first input of this two-input operator.

Methods inherited from class org.apache.flink.streaming.api.operators.AbstractStreamOperator

getContainingTask, getCurrentKey, getExecutionConfig, getInternalTimerService, getKeyedStateBackend, getKeyedStateStore, getMetricGroup, getOperatorConfig, getOperatorID, getOperatorName, getOperatorStateBackend, getOrCreateKeyedState, getPartitionedState, getPartitionedState, getProcessingTimeService, getRuntimeContext, getStateKeySelector1, getStateKeySelector2, getTimeServiceManager, getUserCodeClassloader, hasKeyContext1, hasKeyContext2, initializeState, initializeState, isUsingCustomRawKeyedState, notifyCheckpointAborted, notifyCheckpointComplete, processLatencyMarker, processLatencyMarker1, processLatencyMarker2, processRecordAttributes, processRecordAttributes1, processRecordAttributes2, processWatermark1, processWatermark2, processWatermarkStatus, processWatermarkStatus1, processWatermarkStatus2, reportOrForwardLatencyMarker, setCurrentKey, setKeyContextElement1, setKeyContextElement2, setMailboxExecutor, setProcessingTimeService, setup, snapshotState, snapshotState, useSplittableTimers

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.flink.api.common.state.CheckpointListener

notifyCheckpointAborted, notifyCheckpointComplete

Methods inherited from interface org.apache.flink.streaming.api.operators.Input

processLatencyMarker, processRecordAttributes, processWatermarkStatus

Methods inherited from interface org.apache.flink.streaming.api.operators.KeyContext

getCurrentKey, setCurrentKey

Methods inherited from interface org.apache.flink.streaming.api.operators.KeyContextHandler

hasKeyContext

Methods inherited from interface org.apache.flink.streaming.api.operators.OneInputStreamOperator

setKeyContextElement

Methods inherited from interface org.apache.flink.streaming.api.operators.StreamOperator

getMetricGroup, getOperatorAttributes, getOperatorID, initializeState, setKeyContextElement1, setKeyContextElement2, snapshotState

Method Detail

open

public void open()
          throws Exception

Description copied from class: AbstractStreamOperator

This method is called immediately before any elements are processed, it should contain the operator's initialization logic, e.g. state initialization.

The default implementation does nothing.

Specified by:

open in interface StreamOperator<K>

Overrides:

open in class AbstractStreamOperator<OUT>

Throws:

Exception - An exception in this method causes the operator to fail.

processElement

public void processElement(StreamRecord<IN> element)
                    throws Exception

Description copied from interface: Input

Processes one element that arrived on this input of the MultipleInputStreamOperator. This method is guaranteed to not be called concurrently with other methods of the operator.

Specified by:

processElement in interface Input<K>

Throws:

Exception

getKey

protected abstract K getKey(IN input)
                     throws Exception

Get the key for current processing element, which will be used as the map bundle's key.

Throws:

Exception

finishBundle

public void finishBundle()
                  throws Exception

Description copied from interface: BundleTriggerCallback

This method is invoked to finish current bundle and start a new one when the trigger was fired.

Specified by:

finishBundle in interface BundleTriggerCallback

Throws:

Exception - This method may throw exceptions. Throwing an exception will cause the operation to fail and may trigger recovery.

processWatermark

public void processWatermark(Watermark mark)
                      throws Exception

Description copied from interface: Input

Processes a Watermark that arrived on the first input of this two-input operator. This method is guaranteed to not be called concurrently with other methods of the operator.

Specified by:

processWatermark in interface Input<K>

Overrides:

processWatermark in class AbstractStreamOperator<OUT>

Throws:

Exception

See Also:

Watermark

prepareSnapshotPreBarrier

public void prepareSnapshotPreBarrier(long checkpointId)
                               throws Exception

Description copied from interface: StreamOperator

This method is called when the operator should do a snapshot, before it emits its own checkpoint barrier.

This method is intended not for any actual state persistence, but only for emitting some data before emitting the checkpoint barrier. Operators that maintain some small transient state that is inefficient to checkpoint (especially when it would need to be checkpointed in a re-scalable way) but can simply be sent downstream before the checkpoint. An example are opportunistic pre-aggregation operators, which have small the pre-aggregation state that is frequently flushed downstream.

Important: This method should not be used for any actual state snapshot logic, because it will inherently be within the synchronous part of the operator's checkpoint. If heavy work is done within this method, it will affect latency and downstream checkpoint alignments.

Specified by:

prepareSnapshotPreBarrier in interface StreamOperator<K>

Overrides:

prepareSnapshotPreBarrier in class AbstractStreamOperator<OUT>

Parameters:

checkpointId - The ID of the checkpoint.

Throws:

Exception - Throwing an exception here causes the operator to fail and go into recovery.

finish

public void finish()
            throws Exception

Description copied from interface: StreamOperator

This method is called at the end of data processing.

The method is expected to flush all remaining buffered data. Exceptions during this flushing of buffered data should be propagated, in order to cause the operation to be recognized as failed, because the last data items are not processed properly.

After this method is called, no more records can be produced for the downstream operators.

WARNING: It is not safe to use this method to commit any transactions or other side effects! You can use this method to flush any buffered data that can later on be committed e.g. in a CheckpointListener.notifyCheckpointComplete(long).

NOTE:This method does not need to close any resources. You should release external resources in the StreamOperator.close() method.

Specified by:

finish in interface StreamOperator<K>

Overrides:

finish in class AbstractStreamOperator<OUT>

Throws:

Exception - An exception in this method causes the operator to fail.

close

public void close()
           throws Exception

Description copied from interface: StreamOperator

This method is called at the very end of the operator's life, both in the case of a successful completion of the operation, and in the case of a failure and canceling.

This method is expected to make a thorough effort to release all resources that the operator has acquired.

NOTE:It can not emit any records! If you need to emit records at the end of processing, do so in the StreamOperator.finish() method.

Specified by:

close in interface StreamOperator<K>

Overrides:

close in class AbstractStreamOperator<OUT>

Throws:

Exception