Package com.github.basking2.sdsai.itrex.iterators

Class ParallelMappingIterator<T,R>

java.lang.Object

com.github.basking2.sdsai.itrex.iterators.ParallelMappingIterator<T,R>

All Implemented Interfaces:

Iterator<R>

public class ParallelMappingIterator<T,R>
extends Object
implements Iterator<R>

A ParallelMappingIterator will map elements in threads, using an executor service.

Constructor Summary

Constructors

Constructor	Description
ParallelMappingIterator(boolean ordered, Iterator<T> inputs, Executor executor, int breadth, MappingIterator.Mapper<T,R> mappingFunction)	Constructor with a default error handler.
ParallelMappingIterator(boolean ordered, Iterator<T> inputs, Executor executor, int breadth, MappingIterator.Mapper<T,R> mappingFunction, Consumer<Throwable> reportError)	Constructor.

Method Summary

Modifier and Type	Method	Description
boolean	hasNext()
R	next()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

Constructor Details

ParallelMappingIterator

public ParallelMappingIterator(boolean ordered,
 Iterator<T> inputs,
 Executor executor,
 int breadth,
 MappingIterator.Mapper<T,R> mappingFunction)

Constructor with a default error handler.

Parameters:

ordered - If true, results from this iterator will be emitted in the same order they are read. If true, this will cause head-of-line blocking if a slow element is encountered, but often this is acceptable.

inputs - The inputs to map.

executor - The executor service to dispatch work into.

breadth - How many concurrent tasks should be started.

mappingFunction - A function to map from type T to R.

ParallelMappingIterator

public ParallelMappingIterator(boolean ordered,
 Iterator<T> inputs,
 Executor executor,
 int breadth,
 MappingIterator.Mapper<T,R> mappingFunction,
 Consumer<Throwable> reportError)

Constructor.

Parameters:

ordered - If true, results from this iterator will be emitted in the same order they are read. If true, this will cause head-of-line blocking if a slow element is encountered, but often this is acceptable.

inputs - The inputs to map.

executor - The executor service to dispatch work into.

breadth - How many concurrent tasks should be started.

mappingFunction - A function to map from type T to R.

reportError - If the mapping function throws an exception, how is it handled?

Method Details

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<T>

next

public R next()

Specified by:

next in interface Iterator<T>