org.apache.flink.api.connector.source.lib

Class NumberSequenceSource

java.lang.Object

org.apache.flink.api.connector.source.lib.NumberSequenceSource

All Implemented Interfaces:

Serializable, Source<Long,NumberSequenceSource.NumberSequenceSplit,Collection<NumberSequenceSource.NumberSequenceSplit>>, ResultTypeQueryable<Long>

@Public
public class NumberSequenceSource
extends Object
implements Source<Long,NumberSequenceSource.NumberSequenceSplit,Collection<NumberSequenceSource.NumberSequenceSplit>>, ResultTypeQueryable<Long>

A data source that produces a sequence of numbers (longs). This source is useful for testing and for cases that just need a stream of N events of any kind.

The source splits the sequence into as many parallel sub-sequences as there are parallel source readers. Each sub-sequence will be produced in order. Consequently, if the parallelism is limited to one, this will produce one sequence in order.

This source is always bounded. For very long sequences (for example over the entire domain of long integer values), user may want to consider executing the application in a streaming manner, because, despite the fact that the produced stream is bounded, the end bound is pretty far away.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	NumberSequenceSource.NumberSequenceSplit A split of the source, representing a number sub-sequence.

Constructor Summary

Constructors

Constructor and Description
NumberSequenceSource(long from, long to) Creates a new NumberSequenceSource that produces parallel sequences covering the range from to to (both boundaries are inclusive).

Method Summary

Modifier and Type	Method and Description
SplitEnumerator<NumberSequenceSource.NumberSequenceSplit,Collection<NumberSequenceSource.NumberSequenceSplit>>	createEnumerator(SplitEnumeratorContext<NumberSequenceSource.NumberSequenceSplit> enumContext) Creates a new SplitEnumerator for this source, starting a new input.
SourceReader<Long,NumberSequenceSource.NumberSequenceSplit>	createReader(SourceReaderContext readerContext) Creates a new reader to read data from the splits it gets assigned.
Boundedness	getBoundedness() Get the boundedness of this source.
SimpleVersionedSerializer<Collection<NumberSequenceSource.NumberSequenceSplit>>	getEnumeratorCheckpointSerializer() Creates the serializer for the SplitEnumerator checkpoint.
long	getFrom()
TypeInformation<Long>	getProducedType() Gets the data type (as a TypeInformation) produced by this function or input format.
SimpleVersionedSerializer<NumberSequenceSource.NumberSequenceSplit>	getSplitSerializer() Creates a serializer for the source splits.
long	getTo()
SplitEnumerator<NumberSequenceSource.NumberSequenceSplit,Collection<NumberSequenceSource.NumberSequenceSplit>>	restoreEnumerator(SplitEnumeratorContext<NumberSequenceSource.NumberSequenceSplit> enumContext, Collection<NumberSequenceSource.NumberSequenceSplit> checkpoint) Restores an enumerator from a checkpoint.
protected List<NumberSequenceSource.NumberSequenceSplit>	splitNumberRange(long from, long to, int numSplits)

Methods inherited from class java.lang.Object

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

Constructor Detail

NumberSequenceSource

public NumberSequenceSource(long from,
                            long to)

Creates a new NumberSequenceSource that produces parallel sequences covering the range from to to (both boundaries are inclusive).

Method Detail

getFrom

public long getFrom()

getTo

public long getTo()

getProducedType

public TypeInformation<Long> getProducedType()

Description copied from interface: ResultTypeQueryable

Gets the data type (as a TypeInformation) produced by this function or input format.

Specified by:

getProducedType in interface ResultTypeQueryable<Long>

Returns:

The data type produced by this function or input format.

getBoundedness

public Boundedness getBoundedness()

Description copied from interface: Source

Get the boundedness of this source.

Specified by:

getBoundedness in interface Source<Long,NumberSequenceSource.NumberSequenceSplit,Collection<NumberSequenceSource.NumberSequenceSplit>>

Returns:

the boundedness of this source.

createReader

public SourceReader<Long,NumberSequenceSource.NumberSequenceSplit> createReader(SourceReaderContext readerContext)

Description copied from interface: Source

Creates a new reader to read data from the splits it gets assigned. The reader starts fresh and does not have any state to resume.

Specified by:

createReader in interface Source<Long,NumberSequenceSource.NumberSequenceSplit,Collection<NumberSequenceSource.NumberSequenceSplit>>

Parameters:

readerContext - The context for the source reader.

Returns:

A new SourceReader.

createEnumerator

public SplitEnumerator<NumberSequenceSource.NumberSequenceSplit,Collection<NumberSequenceSource.NumberSequenceSplit>> createEnumerator(SplitEnumeratorContext<NumberSequenceSource.NumberSequenceSplit> enumContext)

Description copied from interface: Source

Creates a new SplitEnumerator for this source, starting a new input.

Specified by:

createEnumerator in interface Source<Long,NumberSequenceSource.NumberSequenceSplit,Collection<NumberSequenceSource.NumberSequenceSplit>>

Parameters:

enumContext - The context for the split enumerator.

Returns:

A new SplitEnumerator.

restoreEnumerator

public SplitEnumerator<NumberSequenceSource.NumberSequenceSplit,Collection<NumberSequenceSource.NumberSequenceSplit>> restoreEnumerator(SplitEnumeratorContext<NumberSequenceSource.NumberSequenceSplit> enumContext,
                                                                                                                                        Collection<NumberSequenceSource.NumberSequenceSplit> checkpoint)

Description copied from interface: Source

Restores an enumerator from a checkpoint.

Specified by:

restoreEnumerator in interface Source<Long,NumberSequenceSource.NumberSequenceSplit,Collection<NumberSequenceSource.NumberSequenceSplit>>

Parameters:

enumContext - The context for the restored split enumerator.

checkpoint - The checkpoint to restore the SplitEnumerator from.

Returns:

A SplitEnumerator restored from the given checkpoint.

getSplitSerializer

public SimpleVersionedSerializer<NumberSequenceSource.NumberSequenceSplit> getSplitSerializer()

Description copied from interface: Source

Creates a serializer for the source splits. Splits are serialized when sending them from enumerator to reader, and when checkpointing the reader's current state.

Specified by:

getSplitSerializer in interface Source<Long,NumberSequenceSource.NumberSequenceSplit,Collection<NumberSequenceSource.NumberSequenceSplit>>

Returns:

The serializer for the split type.

getEnumeratorCheckpointSerializer

public SimpleVersionedSerializer<Collection<NumberSequenceSource.NumberSequenceSplit>> getEnumeratorCheckpointSerializer()

Description copied from interface: Source

Creates the serializer for the SplitEnumerator checkpoint. The serializer is used for the result of the SplitEnumerator.snapshotState(long) method.

Specified by:

getEnumeratorCheckpointSerializer in interface Source<Long,NumberSequenceSource.NumberSequenceSplit,Collection<NumberSequenceSource.NumberSequenceSplit>>

Returns:

The serializer for the SplitEnumerator checkpoint.

splitNumberRange

protected List<NumberSequenceSource.NumberSequenceSplit> splitNumberRange(long from,
                                                                          long to,
                                                                          int numSplits)