org.apache.flink.streaming.api.operators

Class AbstractUdfStreamOperator<OUT,F extends org.apache.flink.api.common.functions.Function>

java.lang.Object

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

org.apache.flink.streaming.api.operators.AbstractUdfStreamOperator<OUT,F>

Type Parameters:

OUT - The output type of the operator

F - The type of the user function

All Implemented Interfaces:

Serializable, org.apache.flink.api.common.state.CheckpointListener, KeyContext, KeyContextHandler, org.apache.flink.streaming.api.operators.OutputTypeConfigurable<OUT>, SetupableStreamOperator<OUT>, StreamOperator<OUT>, StreamOperatorStateHandler.CheckpointedStreamOperator, UserFunctionProvider<F>

Direct Known Subclasses:

AsyncWaitOperator, BatchGroupedReduceOperator, CoBroadcastWithKeyedOperator, CoBroadcastWithNonKeyedOperator, CoProcessOperator, CoStreamFlatMap, CoStreamMap, IntervalJoinOperator, KeyedCoProcessOperator, KeyedProcessOperator, LegacyKeyedCoProcessOperator, LegacyKeyedProcessOperator, ProcessOperator, StreamFilter, StreamFlatMap, StreamGroupedReduceOperator, StreamMap, StreamSink, StreamSource, WindowOperator

@PublicEvolving
public abstract class AbstractUdfStreamOperator<OUT,F extends org.apache.flink.api.common.functions.Function>
extends AbstractStreamOperator<OUT>
implements org.apache.flink.streaming.api.operators.OutputTypeConfigurable<OUT>, UserFunctionProvider<F>

This is used as the base class for operators that have a user-defined function. This class handles the opening and closing of the user-defined functions, as part of the operator life cycle.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected F	userFunction The user function.

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

chainingStrategy, config, lastRecordAttributes1, lastRecordAttributes2, latencyStats, LOG, metrics, output, processingTimeService

Constructor Summary

Constructors

Constructor and Description
AbstractUdfStreamOperator(F userFunction)

Method Summary

Modifier and Type	Method and 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.
F	getUserFunction() Gets the user function executed in this operator.
org.apache.flink.configuration.Configuration	getUserFunctionParameters() Since the streaming API does not implement any parametrization of functions via a configuration, the config returned here is actually empty.
void	initializeState(org.apache.flink.runtime.state.StateInitializationContext context) Stream operators with state which can be restored need to override this hook method.
void	notifyCheckpointAborted(long checkpointId)
void	notifyCheckpointComplete(long checkpointId)
void	open() This method is called immediately before any elements are processed, it should contain the operator's initialization logic, e.g.
void	setOutputType(org.apache.flink.api.common.typeinfo.TypeInformation<OUT> outTypeInfo, org.apache.flink.api.common.ExecutionConfig executionConfig)
void	setup(StreamTask<?,?> containingTask, StreamConfig config, Output<StreamRecord<OUT>> output) Initializes the operator.
void	snapshotState(org.apache.flink.runtime.state.StateSnapshotContext context) Stream operators with state, which want to participate in a snapshot need to override this hook method.

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

getChainingStrategy, getContainingTask, getCurrentKey, getExecutionConfig, getInternalTimerService, getKeyedStateBackend, getKeyedStateStore, getMetricGroup, getOperatorConfig, getOperatorID, getOperatorName, getOperatorStateBackend, getOrCreateKeyedState, getPartitionedState, getPartitionedState, getProcessingTimeService, getRuntimeContext, getTimeServiceManager, getUserCodeClassloader, hasKeyContext1, hasKeyContext2, initializeState, isUsingCustomRawKeyedState, prepareSnapshotPreBarrier, processLatencyMarker, processLatencyMarker1, processLatencyMarker2, processRecordAttributes, processRecordAttributes1, processRecordAttributes2, processWatermark, processWatermark1, processWatermark2, processWatermarkStatus, processWatermarkStatus1, processWatermarkStatus2, reportOrForwardLatencyMarker, setChainingStrategy, setCurrentKey, setKeyContextElement1, setKeyContextElement2, setProcessingTimeService, snapshotState

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.streaming.api.operators.KeyContextHandler

hasKeyContext

Field Detail

userFunction

protected final F extends org.apache.flink.api.common.functions.Function userFunction

The user function.

Constructor Detail

AbstractUdfStreamOperator

public AbstractUdfStreamOperator(F userFunction)

Method Detail

getUserFunction

public F getUserFunction()

Gets the user function executed in this operator.

Specified by:

getUserFunction in interface UserFunctionProvider<F extends org.apache.flink.api.common.functions.Function>

Returns:

The user function of this operator.

setup

public void setup(StreamTask<?,?> containingTask,
                  StreamConfig config,
                  Output<StreamRecord<OUT>> output)

Description copied from interface: SetupableStreamOperator

Initializes the operator. Sets access to the context and the output.

Specified by:

setup in interface SetupableStreamOperator<OUT>

Overrides:

setup in class AbstractStreamOperator<OUT>

snapshotState

public void snapshotState(org.apache.flink.runtime.state.StateSnapshotContext context)
                   throws Exception

Description copied from class: AbstractStreamOperator

Stream operators with state, which want to participate in a snapshot need to override this hook method.

Specified by:

snapshotState in interface StreamOperatorStateHandler.CheckpointedStreamOperator

Overrides:

snapshotState in class AbstractStreamOperator<OUT>

Parameters:

context - context that provides information and means required for taking a snapshot

Throws:

Exception

initializeState

public void initializeState(org.apache.flink.runtime.state.StateInitializationContext context)
                     throws Exception

Description copied from class: AbstractStreamOperator

Stream operators with state which can be restored need to override this hook method.

Specified by:

initializeState in interface StreamOperatorStateHandler.CheckpointedStreamOperator

Overrides:

initializeState in class AbstractStreamOperator<OUT>

Parameters:

context - context that allows to register different states.

Throws:

Exception

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<OUT>

Overrides:

open in class AbstractStreamOperator<OUT>

Throws:

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

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<OUT>

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<OUT>

Overrides:

close in class AbstractStreamOperator<OUT>

Throws:

Exception

notifyCheckpointComplete

public void notifyCheckpointComplete(long checkpointId)
                              throws Exception

Specified by:

notifyCheckpointComplete in interface org.apache.flink.api.common.state.CheckpointListener

Overrides:

notifyCheckpointComplete in class AbstractStreamOperator<OUT>

Throws:

Exception

notifyCheckpointAborted

public void notifyCheckpointAborted(long checkpointId)
                             throws Exception

Specified by:

notifyCheckpointAborted in interface org.apache.flink.api.common.state.CheckpointListener

Overrides:

notifyCheckpointAborted in class AbstractStreamOperator<OUT>

Throws:

Exception

setOutputType

public void setOutputType(org.apache.flink.api.common.typeinfo.TypeInformation<OUT> outTypeInfo,
                          org.apache.flink.api.common.ExecutionConfig executionConfig)

Specified by:

setOutputType in interface org.apache.flink.streaming.api.operators.OutputTypeConfigurable<OUT>

getUserFunctionParameters

public org.apache.flink.configuration.Configuration getUserFunctionParameters()

Since the streaming API does not implement any parametrization of functions via a configuration, the config returned here is actually empty.

Returns:

The user function parameters (currently empty)