Class DocComparator.DocLeafComparator
- java.lang.Object
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- org.apache.lucene.search.comparators.DocComparator.DocLeafComparator
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- All Implemented Interfaces:
LeafFieldComparator
- Enclosing class:
- DocComparator
private class DocComparator.DocLeafComparator extends java.lang.Object implements LeafFieldComparator
DocLeafComparator with skipping functionality. When sort by _doc asc, after collecting top N matches and enough hits, the comparator can skip all the following documents. When sort by _doc asc and "top" document is set after which search should start, the comparator provides an iterator that can quickly skip to the desired "top" document.
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Field Summary
Fields Modifier and Type Field Description private DocIdSetIterator
competitiveIterator
private int
docBase
private int
maxDoc
private int
minDoc
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Constructor Summary
Constructors Constructor Description DocLeafComparator(LeafReaderContext context)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description int
compareBottom(int doc)
Compare the bottom of the queue with this doc.int
compareTop(int doc)
Compare the top value with this doc.DocIdSetIterator
competitiveIterator()
Returns a competitive iteratorvoid
copy(int slot, int doc)
This method is called when a new hit is competitive.void
setBottom(int slot)
Set the bottom slot, ie the "weakest" (sorted last) entry in the queue.void
setHitsThresholdReached()
Informs this leaf comparator that hits threshold is reached.void
setScorer(Scorable scorer)
Sets the Scorer to use in case a document's score is needed.private void
updateIterator()
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Field Detail
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docBase
private final int docBase
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minDoc
private final int minDoc
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maxDoc
private final int maxDoc
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competitiveIterator
private DocIdSetIterator competitiveIterator
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Constructor Detail
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DocLeafComparator
public DocLeafComparator(LeafReaderContext context)
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Method Detail
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setBottom
public void setBottom(int slot)
Description copied from interface:LeafFieldComparator
Set the bottom slot, ie the "weakest" (sorted last) entry in the queue. WhenLeafFieldComparator.compareBottom(int)
is called, you should compare against this slot. This will always be called beforeLeafFieldComparator.compareBottom(int)
.- Specified by:
setBottom
in interfaceLeafFieldComparator
- Parameters:
slot
- the currently weakest (sorted last) slot in the queue
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compareBottom
public int compareBottom(int doc)
Description copied from interface:LeafFieldComparator
Compare the bottom of the queue with this doc. This will only invoked after setBottom has been called. This should return the same result asFieldComparator.compare(int,int)
} as if bottom were slot1 and the new document were slot 2.For a search that hits many results, this method will be the hotspot (invoked by far the most frequently).
- Specified by:
compareBottom
in interfaceLeafFieldComparator
- Parameters:
doc
- that was hit- Returns:
- any
N < 0
if the doc's value is sorted after the bottom entry (not competitive), anyN > 0
if the doc's value is sorted before the bottom entry and0
if they are equal.
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compareTop
public int compareTop(int doc)
Description copied from interface:LeafFieldComparator
Compare the top value with this doc. This will only invoked after setTopValue has been called. This should return the same result asFieldComparator.compare(int,int)
} as if topValue were slot1 and the new document were slot 2. This is only called for searches that use searchAfter (deep paging).- Specified by:
compareTop
in interfaceLeafFieldComparator
- Parameters:
doc
- that was hit- Returns:
- any
N < 0
if the doc's value is sorted after the top entry (not competitive), anyN > 0
if the doc's value is sorted before the top entry and0
if they are equal.
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copy
public void copy(int slot, int doc) throws java.io.IOException
Description copied from interface:LeafFieldComparator
This method is called when a new hit is competitive. You should copy any state associated with this document that will be required for future comparisons, into the specified slot.- Specified by:
copy
in interfaceLeafFieldComparator
- Parameters:
slot
- which slot to copy the hit todoc
- docID relative to current reader- Throws:
java.io.IOException
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setScorer
public void setScorer(Scorable scorer) throws java.io.IOException
Description copied from interface:LeafFieldComparator
Sets the Scorer to use in case a document's score is needed.- Specified by:
setScorer
in interfaceLeafFieldComparator
- Parameters:
scorer
- Scorer instance that you should use to obtain the current hit's score, if necessary.- Throws:
java.io.IOException
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competitiveIterator
public DocIdSetIterator competitiveIterator()
Description copied from interface:LeafFieldComparator
Returns a competitive iterator- Specified by:
competitiveIterator
in interfaceLeafFieldComparator
- Returns:
- an iterator over competitive docs that are stronger than already collected docs
or
null
if such an iterator is not available for the current comparator or segment.
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setHitsThresholdReached
public void setHitsThresholdReached()
Description copied from interface:LeafFieldComparator
Informs this leaf comparator that hits threshold is reached. This method is called from a collector when hits threshold is reached.- Specified by:
setHitsThresholdReached
in interfaceLeafFieldComparator
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updateIterator
private void updateIterator()
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