it.unimi.di.mg4j.search
Class AbstractIntervalDocumentIterator

java.lang.Object
  it.unimi.di.mg4j.search.AbstractDocumentIterator
      it.unimi.di.mg4j.search.AbstractIntervalDocumentIterator

All Implemented Interfaces:

DocumentIterator

Direct Known Subclasses:

AbstractCompositeDocumentIterator, AlignDocumentIterator, DifferenceDocumentIterator, LowPassDocumentIterator

public abstract class AbstractIntervalDocumentIterator
extends AbstractDocumentIterator

An abstract iterator on documents that provides basic support for handling interval iterators.

Implementing subclasses must override getIntervalIterator(Index, int, boolean, Object) so that it returns the correct interval iterator. Note that because of delays in class initialization, the constructor of this class takes a number of apparently disparate parameters: they are necessary to initialize various kinds of interval iterators. This class provides static methods that help in building the correct value for the parameters of the constructor.

Field Summary

protected Index2IntervalIteratorMap	currentIterators A map from indices to the iterators returned for the current document.
protected ReferenceSet<Index>	indices The set of indices involved in this iterator.
protected Index2IntervalIteratorMap	intervalIterators A map from indices to interval iterators.
protected Index	soleIndex If not null, the sole index involved in this document iterator.
protected IntervalIterator	soleIntervalIterator If not null, the sole interval iterator involved in this document iterator.
protected Reference2ReferenceMap<Index,IntervalIterator>	unmodifiableCurrentIterators An unmodifiable wrapper around currentIterators.

Fields inherited from class it.unimi.di.mg4j.search.AbstractDocumentIterator

curr, weight

Fields inherited from interface it.unimi.di.mg4j.search.DocumentIterator

END_OF_LIST

Constructor Summary

protected

AbstractIntervalDocumentIterator(int n, ReferenceSet<Index> indices, boolean allIndexIterators, Object arg) Creates a new instance.

Method Summary

protected static boolean	allIndexIterators(DocumentIterator... documentIterator) A commodity static methods that checks whether all specified document iterators are actually index iterators.
protected abstract IntervalIterator	getIntervalIterator(Index index, int n, boolean allIndexIterators, Object arg) Creates an interval iterator suitable for this AbstractIntervalDocumentIterator.
ReferenceSet<Index>	indices() Returns the set of indices over which this iterator is built.
protected static ReferenceArraySet<Index>	indices(Index index, DocumentIterator... documentIterator) A commodity static methods that computes the union of the indices of the given document iterators.

Methods inherited from class it.unimi.di.mg4j.search.AbstractDocumentIterator

document, ensureOnADocument, mayHaveNext, weight, weight

Methods inherited from class java.lang.Object

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

Methods inherited from interface it.unimi.di.mg4j.search.DocumentIterator

accept, acceptOnTruePaths, dispose, intervalIterator, intervalIterator, intervalIterators, nextDocument, skipTo

Field Detail

indices

protected final ReferenceSet<Index> indices

The set of indices involved in this iterator.

soleIndex

protected final Index soleIndex

If not null, the sole index involved in this document iterator.

soleIntervalIterator

protected final IntervalIterator soleIntervalIterator

If not null, the sole interval iterator involved in this document iterator.

intervalIterators

protected final Index2IntervalIteratorMap intervalIterators

A map from indices to interval iterators.

currentIterators

protected final Index2IntervalIteratorMap currentIterators

A map from indices to the iterators returned for the current document. The key set may not contain an index because the related iterator has never been requested. Note that implementing subclasses might use this map just to store the result of DocumentIterator.intervalIterators(), leaving the tracking of current iterators to some other mechanism.

unmodifiableCurrentIterators

protected final Reference2ReferenceMap<Index,IntervalIterator> unmodifiableCurrentIterators

An unmodifiable wrapper around currentIterators.

Constructor Detail

AbstractIntervalDocumentIterator

protected AbstractIntervalDocumentIterator(int n,
                                           ReferenceSet<Index> indices,
                                           boolean allIndexIterators,
                                           Object arg)

Creates a new instance.

Parameters:

n - the number of underlying iterators.

indices - the set of indices appearing in the underlying iterators.

allIndexIterators - whether all underlying iterators are index iterators.

arg - an argument that will be passed to getIntervalIterator(Index, int, boolean, Object).

Method Detail

getIntervalIterator

protected abstract IntervalIterator getIntervalIterator(Index index,
                                                        int n,
                                                        boolean allIndexIterators,
                                                        Object arg)

Creates an interval iterator suitable for this AbstractIntervalDocumentIterator.

Parameters:

index - the reference index for the iterator, or null.

n - the number of underlying or component iterators.

allIndexIterators - whether all underlying or component iterators are index iterators.

arg - an optional argument.

Returns:

an interval iterator suitable for this AbstractIntervalDocumentIterator.

indices

public ReferenceSet<Index> indices()

Description copied from interface: DocumentIterator

Returns the set of indices over which this iterator is built.

Returns:

the set of indices over which this iterator is built.

indices

protected static ReferenceArraySet<Index> indices(Index index,
                                                  DocumentIterator... documentIterator)

A commodity static methods that computes the union of the indices of the given document iterators.

Parameters:

index - an index that will be passed to AbstractCompositeDocumentIterator.AbstractCompositeDocumentIterator(Index, Object, DocumentIterator...).

documentIterator - a list of document iterators.

Returns:

a set containing the union of the indices of the given document iterators.

allIndexIterators

protected static boolean allIndexIterators(DocumentIterator... documentIterator)

A commodity static methods that checks whether all specified document iterators are actually index iterators.

Parameters:

documentIterator - a list of document iterators.

Returns:

true if all elements of documentIterator are actually index iterators.