Module datarush.library

Package com.pervasive.datarush.ports.record

Class HashPartitioningFunction

java.lang.Object

com.pervasive.datarush.ports.record.HashPartitioningFunction

All Implemented Interfaces:

PartitioningFunction

public final class HashPartitioningFunction
extends Object
implements PartitioningFunction

A default hash partitioning function

Nested Class Summary

Nested classes/interfaces inherited from interface com.pervasive.datarush.ports.record.PartitioningFunction

PartitioningFunction.Evaluator

Field Summary

Fields

Modifier and Type	Field	Description
static HashPartitioningFunction	INSTANCE	The single instance of this class

Method Summary

Modifier and Type	Method	Description
PartitioningFunction.Evaluator	getEvaluator(PartitioningFunctionContext ctx)	Create an Evaluator bound to the specified context.
boolean	isEquivalentPartitioning(PartitioningFunction other)	Returns true iff, given a single row of input, this function is guaranteed to produce the same partitioning as the other function.
boolean	isFunctionOfInput()	Returns true iff, given two identical rows of input, this function will return the same value.
PartitioningFunction	remapFieldReferences(Map<String,String> oldToNewMapping)	Creates a new function, equivalent to the given function, but with all field references renamed according to the given mapping.
void	validateForType(RecordTokenType type)	Performs validation of the specified input type

Methods inherited from class java.lang.Object

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

Field Details

INSTANCE

public static HashPartitioningFunction INSTANCE

The single instance of this class

Method Details

getEvaluator

public PartitioningFunction.Evaluator getEvaluator(PartitioningFunctionContext ctx)

Description copied from interface: PartitioningFunction

Create an Evaluator bound to the specified context.

Specified by:

getEvaluator in interface PartitioningFunction

Parameters:

ctx - the partitioning context

Returns:

an Evaluator bound to the specified context.

validateForType

public void validateForType(RecordTokenType type)

Description copied from interface: PartitioningFunction

Performs validation of the specified input type

Specified by:

validateForType in interface PartitioningFunction

Parameters:

type - the input type

isEquivalentPartitioning

public boolean isEquivalentPartitioning(PartitioningFunction other)

Description copied from interface: PartitioningFunction

Returns true iff, given a single row of input, this function is guaranteed to produce the same partitioning as the other function. A return of true thus implies the following:

both functions are deterministic

both function are stateless (not sensitive to previous values read or to input ordering)

In addition, in order to be consistent with PartitioningFunction.isFunctionOfInput(), this function must return false if PartitioningFunction.isFunctionOfInput() returns false.