Package org.apache.lucene.search
Class FieldComparator.TermValComparator
java.lang.Object
org.apache.lucene.search.FieldComparator<BytesRef>
org.apache.lucene.search.FieldComparator.TermValComparator
- All Implemented Interfaces:
LeafFieldComparator
- Enclosing class:
- FieldComparator<T>
public static class FieldComparator.TermValComparator
extends FieldComparator<BytesRef>
implements LeafFieldComparator
Sorts by field's natural Term sort order. All comparisons are done using BytesRef.compareTo,
which is slow for medium to large result sets but possibly very fast for very small results
sets.
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Nested Class Summary
Nested classes/interfaces inherited from class org.apache.lucene.search.FieldComparator
FieldComparator.RelevanceComparator, FieldComparator.TermOrdValComparator, FieldComparator.TermValComparator
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Constructor Summary
ConstructorDescriptionTermValComparator
(int numHits, String field, boolean sortMissingLast) Sole constructor. -
Method Summary
Modifier and TypeMethodDescriptionint
compare
(int slot1, int slot2) Compare hit at slot1 with hit at slot2.int
compareBottom
(int doc) Compare the bottom of the queue with this doc.int
compareTop
(int doc) Compare the top value with this doc.int
compareValues
(BytesRef val1, BytesRef val2) Returns a negative integer if first is less than second, 0 if they are equal and a positive integer otherwise.void
copy
(int slot, int doc) This method is called when a new hit is competitive.protected BinaryDocValues
getBinaryDocValues
(LeafReaderContext context, String field) Retrieves the BinaryDocValues for the field in this segmentgetLeafComparator
(LeafReaderContext context) Get a per-segmentLeafFieldComparator
to collect the givenLeafReaderContext
.void
setBottom
(int bottom) Set the bottom slot, ie the "weakest" (sorted last) entry in the queue.void
Sets the Scorer to use in case a document's score is needed.void
setTopValue
(BytesRef value) Record the top value, for future calls toLeafFieldComparator.compareTop(int)
.value
(int slot) Return the actual value in the slot.Methods inherited from class org.apache.lucene.search.FieldComparator
disableSkipping, setSingleSort
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface org.apache.lucene.search.LeafFieldComparator
competitiveIterator, setHitsThresholdReached
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Constructor Details
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TermValComparator
Sole constructor.
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Method Details
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compare
public int compare(int slot1, int slot2) Description copied from class:FieldComparator
Compare hit at slot1 with hit at slot2.- Specified by:
compare
in classFieldComparator<BytesRef>
- Parameters:
slot1
- first slot to compareslot2
- second slot to compare- Returns:
- any
N < 0
if slot2's value is sorted after slot1, anyN > 0
if the slot2's value is sorted before slot1 and0
if they are equal
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compareBottom
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. - Throws:
IOException
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copy
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:
IOException
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getBinaryDocValues
protected BinaryDocValues getBinaryDocValues(LeafReaderContext context, String field) throws IOException Retrieves the BinaryDocValues for the field in this segment- Throws:
IOException
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getLeafComparator
Description copied from class:FieldComparator
Get a per-segmentLeafFieldComparator
to collect the givenLeafReaderContext
. All docIDs supplied to thisLeafFieldComparator
are relative to the current reader (you must add docBase if you need to map it to a top-level docID).- Specified by:
getLeafComparator
in classFieldComparator<BytesRef>
- Parameters:
context
- current reader context- Returns:
- the comparator to use for this segment
- Throws:
IOException
- if there is a low-level IO error
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setBottom
public void setBottom(int bottom) 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:
bottom
- the currently weakest (sorted last) slot in the queue
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setTopValue
Description copied from class:FieldComparator
Record the top value, for future calls toLeafFieldComparator.compareTop(int)
. This is only called for searches that use searchAfter (deep paging), and is called before any calls toFieldComparator.getLeafComparator(LeafReaderContext)
.- Specified by:
setTopValue
in classFieldComparator<BytesRef>
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value
Description copied from class:FieldComparator
Return the actual value in the slot.- Specified by:
value
in classFieldComparator<BytesRef>
- Parameters:
slot
- the value- Returns:
- value in this slot
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compareValues
Description copied from class:FieldComparator
Returns a negative integer if first is less than second, 0 if they are equal and a positive integer otherwise. Default impl to assume the type implements Comparable and invoke .compareTo; be sure to override this method if your FieldComparator's type isn't a Comparable or if your values may sometimes be null- Overrides:
compareValues
in classFieldComparator<BytesRef>
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compareTop
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. - Throws:
IOException
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setScorer
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.
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