org.apache.lucene.search

Class ConjunctionDISI

java.lang.Object

org.apache.lucene.search.DocIdSetIterator

org.apache.lucene.search.ConjunctionDISI

public final class ConjunctionDISI
extends DocIdSetIterator

A conjunction of DocIdSetIterators. Requires that all of its sub-iterators must be on the same document all the time. This iterates over the doc ids that are present in each given DocIdSetIterator.
Public only for use in org.apache.lucene.search.spans.

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

Field Summary

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

NO_MORE_DOCS

Method Summary

Modifier and Type	Method and Description
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.
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.
static DocIdSetIterator	intersectIterators(List<DocIdSetIterator> iterators) Create a conjunction over the provided DocIdSetIterators.
static DocIdSetIterator	intersectScorers(Collection<Scorer> scorers) Create a conjunction over the provided Scorers.
static DocIdSetIterator	intersectSpans(List<Spans> spanList) Create a conjunction over the provided Spans.
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, range, slowAdvance

Methods inherited from class java.lang.Object

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

Method Detail

intersectScorers

public static DocIdSetIterator intersectScorers(Collection<Scorer> scorers)

Create a conjunction over the provided Scorers. Note that the returned DocIdSetIterator might leverage two-phase iteration in which case it is possible to retrieve the TwoPhaseIterator using TwoPhaseIterator.unwrap(org.apache.lucene.search.DocIdSetIterator).

intersectIterators

public static DocIdSetIterator intersectIterators(List<DocIdSetIterator> iterators)

Create a conjunction over the provided DocIdSetIterators. Note that the returned DocIdSetIterator might leverage two-phase iteration in which case it is possible to retrieve the TwoPhaseIterator using TwoPhaseIterator.unwrap(org.apache.lucene.search.DocIdSetIterator).

intersectSpans

public static DocIdSetIterator intersectSpans(List<Spans> spanList)

Create a conjunction over the provided Spans. Note that the returned DocIdSetIterator might leverage two-phase iteration in which case it is possible to retrieve the TwoPhaseIterator using TwoPhaseIterator.unwrap(org.apache.lucene.search.DocIdSetIterator).

advance

public int advance(int target)
            throws 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:

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 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:

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