net.openhft.chronicle.wire.domestic.reduction

Interface Reduction<T>

All Superinterfaces:

ExcerptListener

All Known Implementing Classes:

Reductions.Counting, ReductionUtil.CollectorReduction, ReductionUtil.DoubleSupplierReduction, ReductionUtil.LongSupplierReduction

public interface Reduction<T>
extends ExcerptListener

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	Reduction.DoubleReductionBuilder
static interface	Reduction.LongReductionBuilder
static interface	Reduction.ReductionBuilder<E>

Method Summary

Modifier and Type	Method and Description
default long	accept(@NotNull MarshallableIn tailer) Accepts the input of the provided tailer and reduces (folds) the contents of it into this Reduction returning the last seen index or -1 if no index was seen.
static <E> Reduction.ReductionBuilder<E>	of(@NotNull DocumentExtractor<E> extractor) Creates and returns a new ReductionBuilder that will use the provided {@code extractor) to extract elements of type E.
static Reduction.DoubleReductionBuilder	ofDouble(@NotNull ToDoubleDocumentExtractor extractor) Creates and returns a new DoubleReductionBuilder that will use the provided extractor) to extract elements of type {@code double}.
static Reduction.LongReductionBuilder	ofLong(@NotNull ToLongDocumentExtractor extractor) Creates and returns a new LongReductionBuilder that will use the provided extractor) to extract elements of type {@code long}.
void	onExcerpt(@NotNull Wire wire, long index) Consumes an excerpt from the provided wire at the index at the provided index.
T	reduction() Returns a view of the underlying reduction.

Methods inherited from interface net.openhft.chronicle.wire.ExcerptListener

andThen

Method Detail

onExcerpt

void onExcerpt(@NotNull
               @NotNull Wire wire,
               long index)
        throws net.openhft.chronicle.core.io.InvalidMarshallableException

Consumes an excerpt from the provided wire at the index at the provided index.

If this method throws an Exception, it is relayed to the call site. Therefore, care should be taken to minimise the probability of throwing Exceptions.

If this method is referenced as an ExcerptListener then the Reduction must be thread-safe.

Specified by:

onExcerpt in interface ExcerptListener

Parameters:

wire - representing access to the excerpt that was stored (non-null).

index - in the queue where the except was placed (non-negative)

Throws:

net.openhft.chronicle.core.io.InvalidMarshallableException

reduction

@NotNull
T reduction()

Returns a view of the underlying reduction.

Returns:

Reduction view.

accept

default long accept(@NotNull
                    @NotNull MarshallableIn tailer)
             throws net.openhft.chronicle.core.io.InvalidMarshallableException

Accepts the input of the provided tailer and reduces (folds) the contents of it into this Reduction returning the last seen index or -1 if no index was seen.

This method can be used to initialise a Reduction before appending new values.

It is the responsibility of the caller to make sure no simultaneous appenders are using this Reduction during the entire fold operation.

Parameters:

tailer - to reduce (fold) from

Returns:

the last index seen or -1 if no index was seen

Throws:

NullPointerException - if the provided tailer is null

net.openhft.chronicle.core.io.InvalidMarshallableException

of

static <E> Reduction.ReductionBuilder<E> of(@NotNull
                                            @NotNull DocumentExtractor<E> extractor)

Creates and returns a new ReductionBuilder that will use the provided {@code extractor) to extract elements of type E.

Type Parameters:

E - element type

Parameters:

extractor - (non-null)

Returns:

a new ReductionBuilder

See Also:

LongReductionBuilder, DoubleReductionBuilder

ofLong

static Reduction.LongReductionBuilder ofLong(@NotNull
                                             @NotNull ToLongDocumentExtractor extractor)

Creates and returns a new LongReductionBuilder that will use the provided extractor) to extract elements of type {@code long}.

Parameters:

extractor - (non-null)

Returns:

a new LongReductionBuilder

See Also:

#ofLong(ToLongDocumentExtractor)} and {@link #ofDouble(ToDoubleDocumentExtractor)}

ofDouble

static Reduction.DoubleReductionBuilder ofDouble(@NotNull
                                                 @NotNull ToDoubleDocumentExtractor extractor)

Creates and returns a new DoubleReductionBuilder that will use the provided extractor) to extract elements of type {@code double}.

Parameters:

extractor - (non-null)

Returns:

a new DoubleReductionBuilder

See Also:

#of(DocumentExtractor)} and {@link #ofLong(ToLongDocumentExtractor)}