org.apache.flink.api.java.functions

Class SampleInPartition<T>

java.lang.Object

org.apache.flink.api.common.functions.AbstractRichFunction

org.apache.flink.api.common.functions.RichMapPartitionFunction<T,IntermediateSampleData<T>>

org.apache.flink.api.java.functions.SampleInPartition<T>

Type Parameters:

T - The type of input data

All Implemented Interfaces:

Serializable, Function, MapPartitionFunction<T,IntermediateSampleData<T>>, RichFunction

@Internal
public class SampleInPartition<T>
extends RichMapPartitionFunction<T,IntermediateSampleData<T>>

SampleInPartition wraps the sample logic on the partition side (the first phase of distributed sample algorithm). It executes the partition side sample logic in a mapPartition function.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
SampleInPartition(boolean withReplacement, int numSample, long seed) Create a function instance of SampleInPartition.

Method Summary

Modifier and Type	Method and Description
void	mapPartition(Iterable<T> values, Collector<IntermediateSampleData<T>> out) A user-implemented function that modifies or transforms an incoming object.

Methods inherited from class org.apache.flink.api.common.functions.AbstractRichFunction

close, getIterationRuntimeContext, getRuntimeContext, open, setRuntimeContext

Methods inherited from class java.lang.Object

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

Constructor Detail

SampleInPartition

public SampleInPartition(boolean withReplacement,
                         int numSample,
                         long seed)

Create a function instance of SampleInPartition.

Parameters:

withReplacement - Whether element can be selected more than once.

numSample - Fixed sample size.

seed - Random generator seed.

Method Detail

mapPartition

public void mapPartition(Iterable<T> values,
                         Collector<IntermediateSampleData<T>> out)
                  throws Exception

Description copied from interface: MapPartitionFunction

A user-implemented function that modifies or transforms an incoming object.

Specified by:

mapPartition in interface MapPartitionFunction<T,IntermediateSampleData<T>>

Specified by:

mapPartition in class RichMapPartitionFunction<T,IntermediateSampleData<T>>

Parameters:

values - All records for the mapper

out - The collector to hand results to.

Throws:

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