Package org.apache.lucene.index

Class MultiTerms

java.lang.Object

org.apache.lucene.index.Terms

org.apache.lucene.index.MultiTerms

public final class MultiTerms
extends Terms

Exposes flex API, merged from flex API of sub-segments.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Field Summary

Fields inherited from class org.apache.lucene.index.Terms

EMPTY_ARRAY

Constructor Summary

Constructors

Constructor	Description
MultiTerms(Terms[] subs, ReaderSlice[] subSlices)	Sole constructor.

Method Summary

Modifier and Type	Method	Description
int	getDocCount()	Returns the number of documents that have at least one term for this field.
BytesRef	getMax()	Returns the largest term (in lexicographic order) in the field.
BytesRef	getMin()	Returns the smallest term (in lexicographic order) in the field.
ReaderSlice[]	getSubSlices()	Expert: returns pointers to the sub-readers corresponding to the Terms being merged.
Terms[]	getSubTerms()	Expert: returns the Terms being merged.
long	getSumDocFreq()	Returns the sum of TermsEnum.docFreq() for all terms in this field.
long	getSumTotalTermFreq()	Returns the sum of TermsEnum.totalTermFreq() for all terms in this field.
static PostingsEnum	getTermPostingsEnum(IndexReader r, String field, BytesRef term)	Returns PostingsEnum for the specified field and term.
static PostingsEnum	getTermPostingsEnum(IndexReader r, String field, BytesRef term, int flags)	Returns PostingsEnum for the specified field and term, with control over whether freqs, positions, offsets or payloads are required.
static Terms	getTerms(IndexReader r, String field)	This method may return null if the field does not exist or if it has no terms.
boolean	hasFreqs()	Returns true if documents in this field store per-document term frequency (PostingsEnum.freq()).
boolean	hasOffsets()	Returns true if documents in this field store offsets.
boolean	hasPayloads()	Returns true if documents in this field store payloads.
boolean	hasPositions()	Returns true if documents in this field store positions.
TermsEnum	intersect(CompiledAutomaton compiled, BytesRef startTerm)	Returns a TermsEnum that iterates over all terms and documents that are accepted by the provided CompiledAutomaton.
TermsEnum	iterator()	Returns an iterator that will step through all terms.
long	size()	Returns the number of terms for this field, or -1 if this measure isn't stored by the codec.

Methods inherited from class org.apache.lucene.index.Terms

getStats, getTerms

Methods inherited from class java.lang.Object

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

Constructor Detail

MultiTerms

public MultiTerms(Terms[] subs,
                  ReaderSlice[] subSlices)
           throws IOException

Sole constructor. Use getTerms(IndexReader, String) instead if possible.

Parameters:

subs - The Terms instances of all sub-readers.

subSlices - A parallel array (matching subs) describing the sub-reader slices.

Throws:

IOException

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

Method Detail

getTerms

public static Terms getTerms(IndexReader r,
                             String field)
                      throws IOException

This method may return null if the field does not exist or if it has no terms.

Throws:

IOException

getTermPostingsEnum

public static PostingsEnum getTermPostingsEnum(IndexReader r,
                                               String field,
                                               BytesRef term)
                                        throws IOException

Returns PostingsEnum for the specified field and term. This will return null if the field or term does not exist or positions were not indexed.

Throws:

IOException

See Also:

getTermPostingsEnum(IndexReader, String, BytesRef, int)

getTermPostingsEnum

public static PostingsEnum getTermPostingsEnum(IndexReader r,
                                               String field,
                                               BytesRef term,
                                               int flags)
                                        throws IOException

Returns PostingsEnum for the specified field and term, with control over whether freqs, positions, offsets or payloads are required. Some codecs may be able to optimize their implementation when offsets and/or payloads are not required. This will return null if the field or term does not exist. See TermsEnum.postings(PostingsEnum,int).

Throws:

IOException

getSubTerms

public Terms[] getSubTerms()

Expert: returns the Terms being merged.

getSubSlices

public ReaderSlice[] getSubSlices()

Expert: returns pointers to the sub-readers corresponding to the Terms being merged.

intersect

public TermsEnum intersect(CompiledAutomaton compiled,
                           BytesRef startTerm)
                    throws IOException

Description copied from class: Terms

Returns a TermsEnum that iterates over all terms and documents that are accepted by the provided CompiledAutomaton. If the startTerm is provided then the returned enum will only return terms > startTerm, but you still must call next() first to get to the first term. Note that the provided startTerm must be accepted by the automaton.

This is an expert low-level API and will only work for NORMAL compiled automata. To handle any compiled automata you should instead use CompiledAutomaton.getTermsEnum(org.apache.lucene.index.Terms) instead.

NOTE: the returned TermsEnum cannot seek.

Overrides:

intersect in class Terms

Throws:

IOException

getMin

public BytesRef getMin()
                throws IOException

Description copied from class: Terms

Returns the smallest term (in lexicographic order) in the field. Note that, just like other term measures, this measure does not take deleted documents into account. This returns null when there are no terms.

Overrides:

getMin in class Terms

Throws:

IOException

getMax

public BytesRef getMax()
                throws IOException

Description copied from class: Terms

Returns the largest term (in lexicographic order) in the field. Note that, just like other term measures, this measure does not take deleted documents into account. This returns null when there are no terms.

Overrides:

getMax in class Terms

Throws:

IOException

iterator

public TermsEnum iterator()
                   throws IOException

Description copied from class: Terms

Returns an iterator that will step through all terms. This method will not return null.

Specified by:

iterator in class Terms

Throws:

IOException

size

public long size()

Description copied from class: Terms

Returns the number of terms for this field, or -1 if this measure isn't stored by the codec. Note that, just like other term measures, this measure does not take deleted documents into account.

Specified by:

size in class Terms

getSumTotalTermFreq

public long getSumTotalTermFreq()
                         throws IOException

Description copied from class: Terms

Returns the sum of TermsEnum.totalTermFreq() for all terms in this field. Note that, just like other term measures, this measure does not take deleted documents into account.

Specified by:

getSumTotalTermFreq in class Terms

Throws:

IOException

getSumDocFreq

public long getSumDocFreq()
                   throws IOException

Description copied from class: Terms

Returns the sum of TermsEnum.docFreq() for all terms in this field. Note that, just like other term measures, this measure does not take deleted documents into account.

Specified by:

getSumDocFreq in class Terms

Throws:

IOException

getDocCount

public int getDocCount()
                throws IOException

Description copied from class: Terms

Returns the number of documents that have at least one term for this field. Note that, just like other term measures, this measure does not take deleted documents into account.

Specified by:

getDocCount in class Terms

Throws:

IOException

hasFreqs

public boolean hasFreqs()

Description copied from class: Terms

Returns true if documents in this field store per-document term frequency (PostingsEnum.freq()).

Specified by:

hasFreqs in class Terms

hasOffsets

public boolean hasOffsets()

Description copied from class: Terms

Returns true if documents in this field store offsets.

Specified by:

hasOffsets in class Terms

hasPositions

public boolean hasPositions()

Description copied from class: Terms

Returns true if documents in this field store positions.

Specified by:

hasPositions in class Terms

hasPayloads

public boolean hasPayloads()

Description copied from class: Terms

Returns true if documents in this field store payloads.

Specified by:

hasPayloads in class Terms