org.apache.lucene.index
Class TermContext

java.lang.Object
  org.apache.lucene.index.TermContext

public final class TermContext
extends Object

Maintains a IndexReader TermState view over IndexReader instances containing a single term. The TermContext doesn't track if the given TermState objects are valid, neither if the TermState instances refer to the same terms in the associated readers.

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

Field Summary

IndexReaderContext

topReaderContext Holds the IndexReaderContext of the top-level IndexReader, used internally only for asserting.

Constructor Summary

TermContext(IndexReaderContext context)
Creates an empty TermContext from a IndexReaderContext

TermContext(IndexReaderContext context, TermState state, int ord, int docFreq, long totalTermFreq)
Creates a TermContext with an initial TermState, IndexReader pair.

Method Summary

static TermContext	build(IndexReaderContext context, Term term, boolean cache) Creates a TermContext from a top-level IndexReaderContext and the given Term.
void	clear() Clears the TermContext internal state and removes all registered TermStates
int	docFreq() Returns the accumulated document frequency of all TermState instances passed to register(TermState, int, int, long).
TermState	get(int ord) Returns the TermState for an leaf ordinal or null if no TermState for the ordinal was registered.
void	register(TermState state, int ord, int docFreq, long totalTermFreq) Registers and associates a TermState with an leaf ordinal.
void	setDocFreq(int docFreq) expert: only available for queries that want to lie about docfreq
long	totalTermFreq() Returns the accumulated term frequency of all TermState instances passed to register(TermState, int, int, long).

Methods inherited from class java.lang.Object

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

Field Detail

topReaderContext

public final IndexReaderContext topReaderContext

Holds the IndexReaderContext of the top-level IndexReader, used internally only for asserting.

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

Constructor Detail

TermContext

public TermContext(IndexReaderContext context)

Creates an empty TermContext from a IndexReaderContext

TermContext

public TermContext(IndexReaderContext context,
                   TermState state,
                   int ord,
                   int docFreq,
                   long totalTermFreq)

Creates a TermContext with an initial TermState, IndexReader pair.

Method Detail

build

public static TermContext build(IndexReaderContext context,
                                Term term,
                                boolean cache)
                         throws IOException

Creates a TermContext from a top-level IndexReaderContext and the given Term. This method will lookup the given term in all context's leaf readers and register each of the readers containing the term in the returned TermContext using the leaf reader's ordinal.

Note: the given context must be a top-level context.

Throws:

IOException

clear

public void clear()

Clears the TermContext internal state and removes all registered TermStates

register

public void register(TermState state,
                     int ord,
                     int docFreq,
                     long totalTermFreq)

Registers and associates a TermState with an leaf ordinal. The leaf ordinal should be derived from a IndexReaderContext's leaf ord.

get

public TermState get(int ord)

Returns the TermState for an leaf ordinal or null if no TermState for the ordinal was registered.

Parameters:

ord - the readers leaf ordinal to get the TermState for.

Returns:

the TermState for the given readers ord or null if no TermState for the reader was registered

docFreq

public int docFreq()

Returns the accumulated document frequency of all TermState instances passed to register(TermState, int, int, long).

Returns:

the accumulated document frequency of all TermState instances passed to register(TermState, int, int, long).

totalTermFreq

public long totalTermFreq()

Returns the accumulated term frequency of all TermState instances passed to register(TermState, int, int, long).

Returns:

the accumulated term frequency of all TermState instances passed to register(TermState, int, int, long).

setDocFreq

public void setDocFreq(int docFreq)

expert: only available for queries that want to lie about docfreq

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