org.apache.flink.table.runtime.operators.window

Class WindowOperator<K,W extends Window>

java.lang.Object

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

org.apache.flink.table.runtime.operators.window.WindowOperator<K,W>

Type Parameters:

K - The type of key returned by the KeySelector.

W - The type of Window that the WindowAssigner assigns.

All Implemented Interfaces:

Serializable, CheckpointListener, KeyContext, OneInputStreamOperator<RowData,RowData>, SetupableStreamOperator<RowData>, StreamOperator<RowData>, StreamOperatorStateHandler.CheckpointedStreamOperator, Triggerable<K,W>, Disposable

Direct Known Subclasses:

AggregateWindowOperator, TableAggregateWindowOperator

public abstract class WindowOperator<K,W extends Window>
extends AbstractStreamOperator<RowData>
implements OneInputStreamOperator<RowData,RowData>, Triggerable<K,W>

An operator that implements the logic for windowing based on a WindowAssigner and Trigger.

This is the base class for AggregateWindowOperator and TableAggregateWindowOperator. The big difference between AggregateWindowOperator and TableAggregateWindowOperator is AggregateWindowOperator emits only one result for each aggregate group, while TableAggregateWindowOperator can emit multi results for each aggregate group.

When an element arrives it gets assigned a key using a KeySelector and it gets assigned to zero or more windows using a WindowAssigner. Based on this, the element is put into panes. A pane is the bucket of elements that have the same key and same Window. An element can be in multiple panes if it was assigned to multiple windows by the WindowAssigner.

Each pane gets its own instance of the provided Trigger. This trigger determines when the contents of the pane should be processed to emit results. When a trigger fires, the given NamespaceAggsHandleFunctionBase is invoked to produce the results that are emitted for the pane to which the Trigger belongs.

The parameter types: <IN>: RowData <OUT>: JoinedRowData(KEY, AGG_RESULT) <KEY>: GenericRowData <AGG_RESULT>: GenericRowData <ACC>: GenericRowData

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected TimestampedCollector<RowData>	collector This is used for emitting elements with a given timestamp.
protected InternalValueState<K,W,RowData>	previousState
protected boolean	produceUpdates
protected NamespaceAggsHandleFunctionBase<W>	windowAggregator
protected InternalWindowProcessFunction<K,W>	windowFunction

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

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

Method Summary

Modifier and Type	Method and Description
void	close() This method is called after all records have been added to the operators via the methods OneInputStreamOperator.processElement(StreamRecord), or TwoInputStreamOperator.processElement1(StreamRecord) and TwoInputStreamOperator.processElement2(StreamRecord).
protected abstract void	compileGeneratedCode()
void	dispose() 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.
protected abstract void	emitWindowResult(W window) Emits the window result of the given window.
protected Counter	getNumLateRecordsDropped()
protected Gauge<Long>	getWatermarkLatency()
void	onEventTime(InternalTimer<K,W> timer) Invoked when an event-time timer fires.
void	onProcessingTime(InternalTimer<K,W> timer) Invoked when a processing-time timer fires.
void	open() This method is called immediately before any elements are processed, it should contain the operator's initialization logic, e.g.
void	processElement(StreamRecord<RowData> record) Processes one element that arrived at this operator.

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, initializeState, initializeState, isUsingCustomRawKeyedState, notifyCheckpointAborted, notifyCheckpointComplete, numEventTimeTimers, numProcessingTimeTimers, prepareSnapshotPreBarrier, processLatencyMarker, processLatencyMarker1, processLatencyMarker2, processWatermark, processWatermark1, processWatermark2, reportOrForwardLatencyMarker, setChainingStrategy, setCurrentKey, setKeyContextElement1, setKeyContextElement2, setProcessingTimeService, setup, snapshotState, 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.OneInputStreamOperator

processLatencyMarker, processWatermark

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

getMetricGroup, getOperatorID, initializeState, prepareSnapshotPreBarrier, setKeyContextElement1, setKeyContextElement2, snapshotState

Methods inherited from interface org.apache.flink.runtime.state.CheckpointListener

notifyCheckpointAborted, notifyCheckpointComplete

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

getCurrentKey, setCurrentKey

Field Detail

produceUpdates

protected final boolean produceUpdates

windowAggregator

protected NamespaceAggsHandleFunctionBase<W extends Window> windowAggregator

windowFunction

protected transient InternalWindowProcessFunction<K,W extends Window> windowFunction

collector

protected transient TimestampedCollector<RowData> collector

This is used for emitting elements with a given timestamp.

previousState

protected transient InternalValueState<K,W extends Window,RowData> previousState

Method Detail

compileGeneratedCode

protected abstract void compileGeneratedCode()

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<RowData>

Overrides:

open in class AbstractStreamOperator<RowData>

Throws:

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

close

public void close()
           throws Exception

Description copied from class: AbstractStreamOperator

This method is called after all records have been added to the operators via the methods OneInputStreamOperator.processElement(StreamRecord), or TwoInputStreamOperator.processElement1(StreamRecord) and TwoInputStreamOperator.processElement2(StreamRecord).

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

Specified by:

close in interface StreamOperator<RowData>

Overrides:

close in class AbstractStreamOperator<RowData>

Throws:

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

dispose

public void dispose()
             throws Exception

Description copied from class: AbstractStreamOperator

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.

Specified by:

dispose in interface StreamOperator<RowData>

Specified by:

dispose in interface Disposable

Overrides:

dispose in class AbstractStreamOperator<RowData>

Throws:

Exception - if something goes wrong during disposal.

processElement

public void processElement(StreamRecord<RowData> record)
                    throws Exception

Description copied from interface: OneInputStreamOperator

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

Specified by:

processElement in interface OneInputStreamOperator<RowData,RowData>

Throws:

Exception

onEventTime

public void onEventTime(InternalTimer<K,W> timer)
                 throws Exception

Description copied from interface: Triggerable

Invoked when an event-time timer fires.

Specified by:

onEventTime in interface Triggerable<K,W extends Window>

Throws:

Exception

onProcessingTime

public void onProcessingTime(InternalTimer<K,W> timer)
                      throws Exception

Description copied from interface: Triggerable

Invoked when a processing-time timer fires.

Specified by:

onProcessingTime in interface Triggerable<K,W extends Window>

Throws:

Exception

emitWindowResult

protected abstract void emitWindowResult(W window)
                                  throws Exception

Emits the window result of the given window.

Throws:

Exception

getNumLateRecordsDropped

protected Counter getNumLateRecordsDropped()

getWatermarkLatency

protected Gauge<Long> getWatermarkLatency()