Package org.apache.lucene.search
Class FieldComparator.TermValComparator
- java.lang.Object
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- org.apache.lucene.search.FieldComparator<BytesRef>
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- org.apache.lucene.search.FieldComparator.TermValComparator
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- Enclosing class:
- FieldComparator<T>
public static final class FieldComparator.TermValComparator extends FieldComparator<BytesRef>
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
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Nested classes/interfaces inherited from class org.apache.lucene.search.FieldComparator
FieldComparator.ByteComparator, FieldComparator.DocComparator, FieldComparator.DoubleComparator, FieldComparator.FloatComparator, FieldComparator.IntComparator, FieldComparator.LongComparator, FieldComparator.NumericComparator<T extends Number>, FieldComparator.RelevanceComparator, FieldComparator.ShortComparator, FieldComparator.TermOrdValComparator, FieldComparator.TermValComparator
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description int
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 -1 if first is less than second.void
copy(int slot, int doc)
This method is called when a new hit is competitive.void
setBottom(int bottom)
Set the bottom slot, ie the "weakest" (sorted last) entry in the queue.FieldComparator<BytesRef>
setNextReader(AtomicReaderContext context)
Set a newAtomicReaderContext
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setTopValue(BytesRef value)
Record the top value, for future calls toFieldComparator.compareTop(int)
.BytesRef
value(int slot)
Return the actual value in the slot.-
Methods inherited from class org.apache.lucene.search.FieldComparator
setScorer
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Method Detail
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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, any N > 0 if the slot2's value is sorted before slot1 and 0 if they are equal
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compareBottom
public int compareBottom(int doc)
Description copied from class:FieldComparator
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 classFieldComparator<BytesRef>
- Parameters:
doc
- that was hit- Returns:
- any N < 0 if the doc's value is sorted after the bottom entry (not competitive), any N > 0 if the doc's value is sorted before the bottom entry and 0 if they are equal.
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copy
public void copy(int slot, int doc)
Description copied from class:FieldComparator
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 classFieldComparator<BytesRef>
- Parameters:
slot
- which slot to copy the hit todoc
- docID relative to current reader
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setNextReader
public FieldComparator<BytesRef> setNextReader(AtomicReaderContext context) throws IOException
Description copied from class:FieldComparator
Set a newAtomicReaderContext
. All subsequent docIDs are relative to the current reader (you must add docBase if you need to map it to a top-level docID).- Specified by:
setNextReader
in classFieldComparator<BytesRef>
- Parameters:
context
- current reader context- Returns:
- the comparator to use for this segment; most comparators can just return "this" to reuse the same comparator across segments
- Throws:
IOException
- if there is a low-level IO error
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setBottom
public void setBottom(int bottom)
Description copied from class:FieldComparator
Set the bottom slot, ie the "weakest" (sorted last) entry in the queue. WhenFieldComparator.compareBottom(int)
is called, you should compare against this slot. This will always be called beforeFieldComparator.compareBottom(int)
.- Specified by:
setBottom
in classFieldComparator<BytesRef>
- Parameters:
bottom
- the currently weakest (sorted last) slot in the queue
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setTopValue
public void setTopValue(BytesRef value)
Description copied from class:FieldComparator
Record the top value, for future calls toFieldComparator.compareTop(int)
. This is only called for searches that use searchAfter (deep paging), and is called before any calls toFieldComparator.setNextReader(org.apache.lucene.index.AtomicReaderContext)
.- Specified by:
setTopValue
in classFieldComparator<BytesRef>
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value
public BytesRef value(int slot)
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
public int compareValues(BytesRef val1, BytesRef val2)
Description copied from class:FieldComparator
Returns -1 if first is less than second. 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
public int compareTop(int doc)
Description copied from class:FieldComparator
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 classFieldComparator<BytesRef>
- Parameters:
doc
- that was hit- Returns:
- any N < 0 if the doc's value is sorted after the bottom entry (not competitive), any N > 0 if the doc's value is sorted before the bottom entry and 0 if they are equal.
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