uk.ac.starlink.util

Interface SplitCollector<S extends Splittable<S>,A>

Type Parameters:

A - accumulator type

S - splittable content type

All Known Implementing Classes:

BinListCollector, RangeCollector, RowCollector

public interface SplitCollector<S extends Splittable<S>,A>

Defines an object that can collect values from a Splittable into an accumulator. The order of the split items is not considered significant, so splittables may be presented to accumulator instances in any order.

Since:

12 Sep 2019

Author:

Mark Taylor

Method Summary

Modifier and Type	Method and Description
void	accumulate(S splittable, A accumulator) Consumes the content of a splittable, collecting results into the supplied accumulator.
A	combine(A acc1, A acc2) Combines the content of two accumulators.
A	createAccumulator() Returns a new accumulator into which results can be collected.

Method Detail

createAccumulator

A createAccumulator()

Returns a new accumulator into which results can be collected. Accumulator instances may only be used from one thread at any one time.

Returns:

new accumulator

accumulate

void accumulate(S splittable,
                A accumulator)

Consumes the content of a splittable, collecting results into the supplied accumulator. This method may not be called concurrently on the same splittable.

Parameters:

splittable - splittable object

accumulator - accumulator

combine

A combine(A acc1,
          A acc2)

Combines the content of two accumulators. The returned value may or may not be the same object as one of the input values. The input values should not be used following this call. The sequence of the input values is not significant.

Parameters:

acc1 - one input accumulator

acc2 - other input accumulator

Returns:

accumulator containing the combined result of the inputs