org.apache.lucene.index

Class TermStates

java.lang.Object

org.apache.lucene.index.TermStates

public final class TermStates
extends java.lang.Object

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

Field Summary

Fields

Modifier and Type	Field and Description
private int	docFreq
private static TermState	EMPTY_TERMSTATE
private TermState[]	states
private Term	term
private java.lang.Object	topReaderContextIdentity
private long	totalTermFreq

Constructor Summary

Constructors

Modifier	Constructor and Description
	TermStates(IndexReaderContext context) Creates an empty TermStates from a IndexReaderContext
	TermStates(IndexReaderContext context, TermState state, int ord, int docFreq, long totalTermFreq) Creates a TermStates with an initial TermState, IndexReader pair.
private	TermStates(Term term, IndexReaderContext context)

Method Summary

Modifier and Type	Method and Description
void	accumulateStatistics(int docFreq, long totalTermFreq) Expert: Accumulate term statistics.
static TermStates	build(IndexReaderContext context, Term term, boolean needsStats) Creates a TermStates from a top-level IndexReaderContext and the given Term.
void	clear() Clears the TermStates 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(LeafReaderContext ctx) Returns the TermState for a leaf reader context or null if no TermState for the context was registered.
private static TermsEnum	loadTermsEnum(LeafReaderContext ctx, Term term)
void	register(TermState state, int ord) Expert: Registers and associates a TermState with an leaf ordinal.
void	register(TermState state, int ord, int docFreq, long totalTermFreq) Registers and associates a TermState with an leaf ordinal.
java.lang.String	toString()
long	totalTermFreq() Returns the accumulated term frequency of all TermState instances passed to register(TermState, int, int, long).
boolean	wasBuiltFor(IndexReaderContext context) Expert: Return whether this TermStates was built for the given IndexReaderContext.

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY_TERMSTATE

private static final TermState EMPTY_TERMSTATE

topReaderContextIdentity

private final java.lang.Object topReaderContextIdentity

states

private final TermState[] states

term

private final Term term

docFreq

private int docFreq

totalTermFreq

private long totalTermFreq

Constructor Detail

TermStates

private TermStates(Term term,
                   IndexReaderContext context)

TermStates

public TermStates(IndexReaderContext context)

Creates an empty TermStates from a IndexReaderContext

TermStates

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

Creates a TermStates with an initial TermState, IndexReader pair.

Method Detail

wasBuiltFor

public boolean wasBuiltFor(IndexReaderContext context)

Expert: Return whether this TermStates was built for the given IndexReaderContext. This is typically used for assertions.

build

public static TermStates build(IndexReaderContext context,
                               Term term,
                               boolean needsStats)
                        throws java.io.IOException

Creates a TermStates 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 TermStates using the leaf reader's ordinal.

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

Parameters:

needsStats - if true then all leaf contexts will be visited up-front to collect term statistics. Otherwise, the TermState objects will be built only when requested

Throws:

java.io.IOException

loadTermsEnum

private static TermsEnum loadTermsEnum(LeafReaderContext ctx,
                                       Term term)
                                throws java.io.IOException

Throws:

java.io.IOException

clear

public void clear()

Clears the TermStates 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.

register

public void register(TermState state,
                     int ord)

Expert: Registers and associates a TermState with an leaf ordinal. The leaf ordinal should be derived from a IndexReaderContext's leaf ord. On the contrary to register(TermState, int, int, long) this method does NOT update term statistics.

accumulateStatistics

public void accumulateStatistics(int docFreq,
                                 long totalTermFreq)

Expert: Accumulate term statistics.

get

public TermState get(LeafReaderContext ctx)
              throws java.io.IOException

Returns the TermState for a leaf reader context or null if no TermState for the context was registered.

Parameters:

ctx - the LeafReaderContext to get the TermState for.

Returns:

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

Throws:

java.io.IOException

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).

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object