net.openhft.chronicle.wire.domestic.reduction

Class Reductions

java.lang.Object

net.openhft.chronicle.wire.domestic.reduction.Reductions

public final class Reductions
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Reductions.Counting A Reduction class that counts the number of excerpts that have been processed.

Method Summary

Modifier and Type	Method and Description
static Reduction<LongSupplier>	counting() Creates and returns a new Reduction that will count the number of excerpts.
static Reduction<DoubleSupplier>	reducingDouble(@NotNull ToDoubleDocumentExtractor extractor, double identity, @NotNull DoubleBinaryOperator accumulator) Creates and returns a new Reduction that will extract elements of type double using the provided extractor and will accumulate values using the provided accumulator.
static Reduction<LongSupplier>	reducingLong(@NotNull ToLongDocumentExtractor extractor, long identity, @NotNull LongBinaryOperator accumulator) Creates and returns a new Reduction that will extract elements of type long using the provided extractor and will accumulate values using the provided accumulator.

Methods inherited from class java.lang.Object

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

Method Detail

reducingLong

public static Reduction<LongSupplier> reducingLong(@NotNull
                                                   @NotNull ToLongDocumentExtractor extractor,
                                                   long identity,
                                                   @NotNull
                                                   @NotNull LongBinaryOperator accumulator)

Creates and returns a new Reduction that will extract elements of type long using the provided extractor and will accumulate values using the provided accumulator. The initial state of the reduction will be the provided identity.

The returned Reduction is guaranteed to not create any internal objects.

Parameters:

extractor - to apply on each document (non-null)

identity - initial start value

accumulator - to apply for each element (non-null)

Returns:

a new Reduction reducing long values

Throws:

NullPointerException - if any objects provided are null.

reducingDouble

public static Reduction<DoubleSupplier> reducingDouble(@NotNull
                                                       @NotNull ToDoubleDocumentExtractor extractor,
                                                       double identity,
                                                       @NotNull
                                                       @NotNull DoubleBinaryOperator accumulator)

Creates and returns a new Reduction that will extract elements of type double using the provided extractor and will accumulate values using the provided accumulator. The initial state of the reduction will be the provided identity.

The returned Reduction is guaranteed to not create any internal objects.

Parameters:

extractor - to apply on each document (non-null)

identity - initial start value

accumulator - to apply for each element (non-null)

Returns:

a new Reduction reducing double values

Throws:

NullPointerException - if any objects provided are null.

counting

public static Reduction<LongSupplier> counting()

Creates and returns a new Reduction that will count the number of excerpts.

The returned Reduction is guaranteed to not create any internal objects.

Returns:

a new Reduction counting excerpts