Package org.apache.lucene.index
Class MultiPostingsEnum
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- org.apache.lucene.search.DocIdSetIterator
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- org.apache.lucene.index.PostingsEnum
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- org.apache.lucene.index.MultiPostingsEnum
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public final class MultiPostingsEnum extends PostingsEnum
ExposesPostingsEnum, merged fromPostingsEnumAPI of sub-segments.- WARNING: This API is experimental and might change in incompatible ways in the next release.
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Nested Class Summary
Nested Classes Modifier and Type Class Description static classMultiPostingsEnum.EnumWithSliceHolds aPostingsEnumalong with the correspondingReaderSlice.
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Field Summary
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Fields inherited from class org.apache.lucene.index.PostingsEnum
ALL, FREQS, NONE, OFFSETS, PAYLOADS, POSITIONS
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Fields inherited from class org.apache.lucene.search.DocIdSetIterator
NO_MORE_DOCS
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Constructor Summary
Constructors Constructor Description MultiPostingsEnum(MultiTermsEnum parent, int subReaderCount)Sole constructor.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description intadvance(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.booleancanReuse(MultiTermsEnum parent)Returnstrueif this instance can be reused by the providedMultiTermsEnum.longcost()Returns the estimated cost of thisDocIdSetIterator.intdocID()Returns the following:-1ifDocIdSetIterator.nextDoc()orDocIdSetIterator.advance(int)were not called yet.intendOffset()Returns end offset for the current position, or -1 if offsets were not indexed.intfreq()Returns term frequency in the current document, or 1 if the field was indexed withIndexOptions.DOCS.intgetNumSubs()How many sub-readers we are merging.BytesRefgetPayload()Returns the payload at this position, or null if no payload was indexed.MultiPostingsEnum.EnumWithSlice[]getSubs()Returns sub-readers we are merging.intnextDoc()Advances to the next document in the set and returns the doc it is currently on, orDocIdSetIterator.NO_MORE_DOCSif 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.intnextPosition()Returns the next position, or -1 if positions were not indexed.MultiPostingsEnumreset(MultiPostingsEnum.EnumWithSlice[] subs, int numSubs)Re-use and reset this instance on the provided slices.intstartOffset()Returns start offset for the current position, or -1 if offsets were not indexed.StringtoString()-
Methods inherited from class org.apache.lucene.index.PostingsEnum
featureRequested
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Methods inherited from class org.apache.lucene.search.DocIdSetIterator
all, empty, range, slowAdvance
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Constructor Detail
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MultiPostingsEnum
public MultiPostingsEnum(MultiTermsEnum parent, int subReaderCount)
Sole constructor.- Parameters:
parent- TheMultiTermsEnumthat created us.subReaderCount- How many sub-readers are being merged.
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Method Detail
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canReuse
public boolean canReuse(MultiTermsEnum parent)
Returnstrueif this instance can be reused by the providedMultiTermsEnum.
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reset
public MultiPostingsEnum reset(MultiPostingsEnum.EnumWithSlice[] subs, int numSubs)
Re-use and reset this instance on the provided slices.
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getNumSubs
public int getNumSubs()
How many sub-readers we are merging.- See Also:
getSubs()
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getSubs
public MultiPostingsEnum.EnumWithSlice[] getSubs()
Returns sub-readers we are merging.
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freq
public int freq() throws IOExceptionDescription copied from class:PostingsEnumReturns term frequency in the current document, or 1 if the field was indexed withIndexOptions.DOCS. Do not call this beforeDocIdSetIterator.nextDoc()is first called, nor afterDocIdSetIterator.nextDoc()returnsDocIdSetIterator.NO_MORE_DOCS.NOTE: if the
PostingsEnumwas obtain withPostingsEnum.NONE, the result of this method is undefined.- Specified by:
freqin classPostingsEnum- Throws:
IOException
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docID
public int docID()
Description copied from class:DocIdSetIteratorReturns the following:-1ifDocIdSetIterator.nextDoc()orDocIdSetIterator.advance(int)were not called yet.DocIdSetIterator.NO_MORE_DOCSif the iterator has exhausted.- Otherwise it should return the doc ID it is currently on.
- Specified by:
docIDin classDocIdSetIterator
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advance
public int advance(int target) throws IOExceptionDescription copied from class:DocIdSetIteratorAdvances 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 returnsDocIdSetIterator.NO_MORE_DOCSif 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 > currentit 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_DOCSfor 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:
advancein classDocIdSetIterator- Throws:
IOException
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nextDoc
public int nextDoc() throws IOExceptionDescription copied from class:DocIdSetIteratorAdvances to the next document in the set and returns the doc it is currently on, orDocIdSetIterator.NO_MORE_DOCSif 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:
nextDocin classDocIdSetIterator- Throws:
IOException
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nextPosition
public int nextPosition() throws IOExceptionDescription copied from class:PostingsEnumReturns the next position, or -1 if positions were not indexed. Calling this more thanPostingsEnum.freq()times is undefined.- Specified by:
nextPositionin classPostingsEnum- Throws:
IOException
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startOffset
public int startOffset() throws IOExceptionDescription copied from class:PostingsEnumReturns start offset for the current position, or -1 if offsets were not indexed.- Specified by:
startOffsetin classPostingsEnum- Throws:
IOException
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endOffset
public int endOffset() throws IOExceptionDescription copied from class:PostingsEnumReturns end offset for the current position, or -1 if offsets were not indexed.- Specified by:
endOffsetin classPostingsEnum- Throws:
IOException
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getPayload
public BytesRef getPayload() throws IOException
Description copied from class:PostingsEnumReturns the payload at this position, or null if no payload was indexed. You should not modify anything (neither members of the returned BytesRef nor bytes in the byte[]).- Specified by:
getPayloadin classPostingsEnum- Throws:
IOException
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cost
public long cost()
Description copied from class:DocIdSetIteratorReturns the estimated cost of thisDocIdSetIterator.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:
costin classDocIdSetIterator
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