io.crate.operation.projectors

Class SortingTopNProjector

java.lang.Object

io.crate.operation.projectors.SortingTopNProjector

All Implemented Interfaces:

Projector, java.util.function.Function<BatchIterator,BatchIterator>, java.util.function.UnaryOperator<BatchIterator>

public class SortingTopNProjector
extends java.lang.Object
implements Projector

Constructor Summary

Constructors

Constructor and Description
SortingTopNProjector(java.util.Collection<? extends Input<?>> inputs, java.lang.Iterable<? extends CollectExpression<Row,?>> collectExpressions, int numOutputs, java.util.Comparator<java.lang.Object[]> ordering, int limit, int offset)

Method Summary

Modifier and Type	Method and Description
BatchIterator	apply(BatchIterator batchIterator)
boolean	providesIndependentScroll() Indicates that the projector supports scrolling independent of the source iterator.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.function.UnaryOperator

identity

Methods inherited from interface java.util.function.Function

andThen, compose

Constructor Detail

SortingTopNProjector

public SortingTopNProjector(java.util.Collection<? extends Input<?>> inputs,
                            java.lang.Iterable<? extends CollectExpression<Row,?>> collectExpressions,
                            int numOutputs,
                            java.util.Comparator<java.lang.Object[]> ordering,
                            int limit,
                            int offset)

Parameters:

inputs - contains output Inputs and orderBy Inputs

collectExpressions - gathered from outputs and orderBy inputs

numOutputs - inputs contains this much output Inputs starting form index 0

ordering - ordering that is used to compare the rows

limit - the number of rows to gather, pass to upStream

offset - the initial offset, this number of rows are skipped

Method Detail

apply

public BatchIterator apply(BatchIterator batchIterator)

Specified by:

apply in interface java.util.function.Function<BatchIterator,BatchIterator>

providesIndependentScroll

public boolean providesIndependentScroll()

Description copied from interface: Projector

Indicates that the projector supports scrolling independent of the source iterator.

If the projector does not support independent scrolling, the source iterator must provide the scrolling capability on its own

Specified by:

providesIndependentScroll in interface Projector