org.apache.lucene.search

Class ConjunctionDISI

java.lang.Object

org.apache.lucene.search.DocIdSetIterator

org.apache.lucene.search.ConjunctionDISI

Direct Known Subclasses:

ConjunctionDISI.TwoPhase

public class ConjunctionDISI
extends DocIdSetIterator

A conjunction of DocIdSetIterators. This iterates over the doc ids that are present in each given DocIdSetIterator.
Public only for use in org.apache.lucene.search.spans.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	ConjunctionDISI.TwoPhase A conjunction DISI built on top of approximations.
private static class	ConjunctionDISI.TwoPhaseConjunctionDISI TwoPhaseIterator view of a ConjunctionDISI.TwoPhase conjunction.

Field Summary

Fields

Modifier and Type	Field and Description
(package private) DocIdSetIterator	lead
(package private) DocIdSetIterator[]	others

Fields inherited from class org.apache.lucene.search.DocIdSetIterator

NO_MORE_DOCS

Constructor Summary

Constructors

Constructor and Description
ConjunctionDISI(java.util.List<? extends DocIdSetIterator> iterators)

Method Summary

Modifier and Type	Method and Description
private static void	addIterator(DocIdSetIterator disi, java.util.List<DocIdSetIterator> allIterators, java.util.List<TwoPhaseIterator> twoPhaseIterators)
private static void	addScorer(Scorer scorer, java.util.List<DocIdSetIterator> allIterators, java.util.List<TwoPhaseIterator> twoPhaseIterators) Adds the scorer, possibly splitting up into two phases or collapsing if it is another conjunction
private static void	addSpans(Spans spans, java.util.List<DocIdSetIterator> allIterators, java.util.List<TwoPhaseIterator> twoPhaseIterators) Adds the Spans.
private static void	addTwoPhaseIterator(TwoPhaseIterator twoPhaseIter, java.util.List<DocIdSetIterator> allIterators, java.util.List<TwoPhaseIterator> twoPhaseIterators)
int	advance(int target) Advances to the first beyond the current whose document number is greater than or equal to target, and returns the document number itself.
(package private) TwoPhaseIterator	asTwoPhaseIterator()
long	cost() Returns the estimated cost of this DocIdSetIterator.
int	docID() Returns the following: -1 if DocIdSetIterator.nextDoc() or DocIdSetIterator.advance(int) were not called yet.
private int	doNext(int doc)
static ConjunctionDISI	intersectIterators(java.util.List<DocIdSetIterator> iterators) Create a conjunction over the provided DocIdSetIterators.
static ConjunctionDISI	intersectScorers(java.util.List<Scorer> scorers) Create a conjunction over the provided Scorers, taking advantage of TwoPhaseIterator.
static ConjunctionDISI	intersectSpans(java.util.List<Spans> spanList) Create a conjunction over the provided Scorers, taking advantage of TwoPhaseIterator.
protected boolean	matches()
int	nextDoc() Advances to the next document in the set and returns the doc it is currently on, or DocIdSetIterator.NO_MORE_DOCS if there are no more docs in the set. NOTE: after the iterator has exhausted you should not call this method, as it may result in unpredicted behavior.

Methods inherited from class org.apache.lucene.search.DocIdSetIterator

all, empty, slowAdvance

Methods inherited from class java.lang.Object

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

Field Detail

lead

final DocIdSetIterator lead

others

final DocIdSetIterator[] others

Constructor Detail

ConjunctionDISI

ConjunctionDISI(java.util.List<? extends DocIdSetIterator> iterators)

Method Detail

intersectScorers

public static ConjunctionDISI intersectScorers(java.util.List<Scorer> scorers)

Create a conjunction over the provided Scorers, taking advantage of TwoPhaseIterator.

intersectIterators

public static ConjunctionDISI intersectIterators(java.util.List<DocIdSetIterator> iterators)

Create a conjunction over the provided DocIdSetIterators.

intersectSpans

public static ConjunctionDISI intersectSpans(java.util.List<Spans> spanList)

Create a conjunction over the provided Scorers, taking advantage of TwoPhaseIterator.

addScorer

private static void addScorer(Scorer scorer,
                              java.util.List<DocIdSetIterator> allIterators,
                              java.util.List<TwoPhaseIterator> twoPhaseIterators)

Adds the scorer, possibly splitting up into two phases or collapsing if it is another conjunction

addSpans

private static void addSpans(Spans spans,
                             java.util.List<DocIdSetIterator> allIterators,
                             java.util.List<TwoPhaseIterator> twoPhaseIterators)

Adds the Spans.

addIterator

private static void addIterator(DocIdSetIterator disi,
                                java.util.List<DocIdSetIterator> allIterators,
                                java.util.List<TwoPhaseIterator> twoPhaseIterators)

addTwoPhaseIterator

private static void addTwoPhaseIterator(TwoPhaseIterator twoPhaseIter,
                                        java.util.List<DocIdSetIterator> allIterators,
                                        java.util.List<TwoPhaseIterator> twoPhaseIterators)

matches

protected boolean matches()
                   throws java.io.IOException

Throws:

java.io.IOException

asTwoPhaseIterator

TwoPhaseIterator asTwoPhaseIterator()

doNext

private int doNext(int doc)
            throws java.io.IOException

Throws:

java.io.IOException

advance

public int advance(int target)
            throws java.io.IOException

Description copied from class: DocIdSetIterator

Advances to the first beyond the current whose document number is greater than or equal to target, and returns the document number itself. Exhausts the iterator and returns DocIdSetIterator.NO_MORE_DOCS if target is greater than the highest document number in the set.

The behavior of this method is undefined when called with target ≤ current, or after the iterator has exhausted. Both cases may result in unpredicted behavior.

When target > current it behaves as if written:

 int advance(int target) {
   int doc;
   while ((doc = nextDoc()) < target) {
   }
   return doc;
 }
 

Some implementations are considerably more efficient than that.

NOTE: this method may be called with DocIdSetIterator.NO_MORE_DOCS for efficiency by some Scorers. If your implementation cannot efficiently determine that it should exhaust, it is recommended that you check for that value in each call to this method.

Specified by:

advance in class DocIdSetIterator

Throws:

java.io.IOException

docID

public int docID()

Description copied from class: DocIdSetIterator

Returns the following:

• -1 if DocIdSetIterator.nextDoc() or DocIdSetIterator.advance(int) were not called yet.
• DocIdSetIterator.NO_MORE_DOCS if the iterator has exhausted.
• Otherwise it should return the doc ID it is currently on.

Specified by:

docID in class DocIdSetIterator

nextDoc

public int nextDoc()
            throws java.io.IOException

Description copied from class: DocIdSetIterator

Advances to the next document in the set and returns the doc it is currently on, or DocIdSetIterator.NO_MORE_DOCS if there are no more docs in the set.
NOTE: after the iterator has exhausted you should not call this method, as it may result in unpredicted behavior.

Specified by:

nextDoc in class DocIdSetIterator

Throws:

java.io.IOException

cost

public long cost()

Description copied from class: DocIdSetIterator

Returns the estimated cost of this DocIdSetIterator.

This is generally an upper bound of the number of documents this iterator might match, but may be a rough heuristic, hardcoded value, or otherwise completely inaccurate.

Specified by:

cost in class DocIdSetIterator