org.sindice.siren.search.node

Class NodeScorer

java.lang.Object

org.apache.lucene.search.DocIdSetIterator

org.apache.lucene.search.Scorer

org.sindice.siren.search.node.NodeScorer

Direct Known Subclasses:

NodeConstantScoreQuery.NodeConstantScorer

public abstract class NodeScorer
extends org.apache.lucene.search.Scorer

The abstract Scorer class that defines the interface for iterating over an ordered list of nodes matching a query.

Subclasses should implement docID(), nextDoc() and advance(int) for compatibility with Scorer if needed.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.search.Scorer

org.apache.lucene.search.Scorer.ChildScorer

Field Summary

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

weight

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

NO_MORE_DOCS

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	NodeScorer(org.apache.lucene.search.Weight weight)

Method Summary

Methods

Modifier and Type	Method and Description
int	advance(int target)
abstract int	doc() Returns the following: -1 or #NO_MORE_DOC if nextCandidateDocument() or skipToCandidate(int) were not called yet.
int	docID()
float	freq()
abstract float	freqInNode() Returns the number of occurrences in the current node
abstract boolean	nextCandidateDocument() Advances to the next candidate document in the set, or returns false if there are no more docs in the set.
int	nextDoc()
abstract boolean	nextNode() Move to the next node path in the current document matching the query.
abstract org.apache.lucene.util.IntsRef	node() Returns the following: -1 or #NO_MORE_NOD if nextNode() were not called yet.
float	score() Methods implemented in LuceneProxyNodeScorer
void	score(org.apache.lucene.search.Collector collector)
boolean	score(org.apache.lucene.search.Collector collector, int max, int firstDocID)
abstract float	scoreInNode() Returns the score of the current node of the current document matching the query.
abstract boolean	skipToCandidate(int target) Skip to the first candidate document beyond (see NOTE below) the current whose number is greater than or equal to target.

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

getChildren, getWeight

Methods inherited from class java.lang.Object

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

Constructor Detail

NodeScorer

protected NodeScorer(org.apache.lucene.search.Weight weight)

Method Detail

nextCandidateDocument

public abstract boolean nextCandidateDocument()
                                       throws IOException

Advances to the next candidate document in the set, or returns false if there are no more docs in the set.

A candidate document is a document that represents a potential match for the query. All the sub-scorers agree on its document id. However finding the matching node within this document still needs to be done. If the sub-scorers do not agree on a node by calling nextNode(), the document must be considered as a non-matching document.

This method is useful for optimisation, i.e., lazy loading and comparison of node information. It allows to iterate over documents and find candidate without loading node information. Node information are loaded and compared only when a candidate is found.

Throws:

IOException

nextNode

public abstract boolean nextNode()
                          throws IOException

Move to the next node path in the current document matching the query.

Should not be called until nextCandidateDocument() or skipToCandidate(int) are called for the first time.

Returns:

false if there is no more node for the current entity or if nextCandidateDocument() or skipToCandidate(int) were not called yet.

Throws:

IOException

skipToCandidate

public abstract boolean skipToCandidate(int target)
                                 throws IOException

Skip to the first candidate document beyond (see NOTE below) the current whose number is greater than or equal to target. Returns false if there are no more docs in the set.

NOTE: when target ≤ current implementations must not advance beyond their current doc().

Throws:

IOException

doc

public abstract int doc()

Returns the following:

• -1 or #NO_MORE_DOC if nextCandidateDocument() or skipToCandidate(int) were not called yet.
• #NO_MORE_DOC if the iterator has exhausted.
• Otherwise it should return the doc ID it is currently on.

node

public abstract org.apache.lucene.util.IntsRef node()

Returns the following:

• -1 or #NO_MORE_NOD if nextNode() were not called yet.
• #NO_MORE_NOD if the iterator has exhausted.
• Otherwise it should return the node it is currently on.

freqInNode

public abstract float freqInNode()
                          throws IOException

Returns the number of occurrences in the current node

Throws:

IOException

scoreInNode

public abstract float scoreInNode()
                           throws IOException

Returns the score of the current node of the current document matching the query.

Throws:

IOException

score

public float score()
            throws IOException

Methods implemented in LuceneProxyNodeScorer

Specified by:

score in class org.apache.lucene.search.Scorer

Throws:

IOException

score

public void score(org.apache.lucene.search.Collector collector)
           throws IOException

Overrides:

score in class org.apache.lucene.search.Scorer

Throws:

IOException

score

public boolean score(org.apache.lucene.search.Collector collector,
            int max,
            int firstDocID)
              throws IOException

Overrides:

score in class org.apache.lucene.search.Scorer

Throws:

IOException

freq

public float freq()
           throws IOException

Specified by:

freq in class org.apache.lucene.search.Scorer

Throws:

IOException

docID

public int docID()

Specified by:

docID in class org.apache.lucene.search.DocIdSetIterator

nextDoc

public int nextDoc()
            throws IOException

Specified by:

nextDoc in class org.apache.lucene.search.DocIdSetIterator

Throws:

IOException

advance

public int advance(int target)
            throws IOException

Specified by:

advance in class org.apache.lucene.search.DocIdSetIterator

Throws:

IOException