Package org.apache.druid.query.operator.window.value

Class WindowValueProcessorBase

java.lang.Object

org.apache.druid.query.operator.window.value.WindowValueProcessorBase

All Implemented Interfaces:

Processor

Direct Known Subclasses:

WindowFirstProcessor, WindowLastProcessor, WindowOffsetProcessor

public abstract class WindowValueProcessorBase
extends Object
implements Processor

Constructor Summary

Constructors

Constructor	Description
WindowValueProcessorBase(String inputColumn, String outputColumn)

Method Summary

Modifier and Type	Method	Description
String	getInputColumn()
String	getOutputColumn()
protected String	internalToString()
protected boolean	intervalValidation(WindowValueProcessorBase other)
RowsAndColumns	processInternal(RowsAndColumns input, Function<Column,Column> fn)	This implements the common logic between the various value processors.
String	toString()
boolean	validateEquivalent(Processor otherProcessor)	Validates the equivalence of the Processors.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.druid.query.operator.window.Processor

process

Constructor Detail

WindowValueProcessorBase

public WindowValueProcessorBase(String inputColumn,
                                String outputColumn)

Method Detail

getInputColumn

public String getInputColumn()

getOutputColumn

public String getOutputColumn()

processInternal

public RowsAndColumns processInternal(RowsAndColumns input,
                                      Function<Column,Column> fn)

This implements the common logic between the various value processors. It looks like it could be static, but if it is static then the lambda becomes polymorphic. We keep it as a member method of the base class so taht the JVM can inline it and specialize the lambda

Parameters:

input - incoming RowsAndColumns, as in Processor.process

fn - function that converts the input column into the output column

Returns:

RowsAndColumns, as in Processor.process

validateEquivalent

public boolean validateEquivalent(Processor otherProcessor)

Description copied from interface: Processor

Validates the equivalence of the Processors. This is similar to @{code .equals} but is its own method so that it can ignore certain fields that would be important for a true equality check. Namely, two Processors defined the same way but with different output names can be considered equivalent even though they are not equal.

This primarily exists to simplify tests, where this equivalence can be used to validate that the Processors created by the SQL planner are actually equivalent to what we expect without needing to be overly dependent on how the planner names the output columns

Specified by:

validateEquivalent in interface Processor

Parameters:

otherProcessor - the processor to test equivalence of

Returns:

boolean identifying if these processors should be considered equivalent to each other.

intervalValidation

protected boolean intervalValidation(WindowValueProcessorBase other)

toString

public String toString()

Overrides:

toString in class Object

internalToString

protected String internalToString()