Package org.apache.lucene.codecs.blocktree

Class SegmentTermsEnum

java.lang.Object

org.apache.lucene.index.TermsEnum

org.apache.lucene.index.BaseTermsEnum

org.apache.lucene.codecs.blocktree.SegmentTermsEnum

All Implemented Interfaces:

BytesRefIterator

final class SegmentTermsEnum
extends BaseTermsEnum

Iterates through terms in this field.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.index.TermsEnum

TermsEnum.SeekStatus

Field Summary

Fields

Modifier and Type	Field	Description
private FST.Arc<BytesRef>[]	arcs
(package private) SegmentTermsEnumFrame	currentFrame
private boolean	eof
(package private) final FieldReader	fr
private final FST.BytesReader	fstReader
(package private) IndexInput	in
private final ByteArrayDataInput	scratchReader
private SegmentTermsEnumFrame[]	stack
private final SegmentTermsEnumFrame	staticFrame
private int	targetBeforeCurrentLength
(package private) final BytesRefBuilder	term
(package private) boolean	termExists
private int	validIndexPrefix

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

EMPTY

Constructor Summary

Constructors

Constructor	Description
SegmentTermsEnum(FieldReader fr)

Method Summary

Modifier and Type	Method	Description
private boolean	clearEOF()
Stats	computeBlockStats()	Runs next() through the entire terms dict, computing aggregate statistics.
int	docFreq()	Returns the number of documents containing the current term.
private FST.Arc<BytesRef>	getArc(int ord)
private SegmentTermsEnumFrame	getFrame(int ord)
ImpactsEnum	impacts(int flags)	Return a ImpactsEnum.
(package private) void	initIndexInput()
BytesRef	next()	Increments the iteration to the next BytesRef in the iterator.
long	ord()	Returns ordinal position for current term.
PostingsEnum	postings(PostingsEnum reuse, int flags)	Get PostingsEnum for the current term, with control over whether freqs, positions, offsets or payloads are required.
private void	printSeekState(PrintStream out)
(package private) SegmentTermsEnumFrame	pushFrame(FST.Arc<BytesRef> arc, long fp, int length)
(package private) SegmentTermsEnumFrame	pushFrame(FST.Arc<BytesRef> arc, BytesRef frameData, int length)
TermsEnum.SeekStatus	seekCeil(BytesRef target)	Seeks to the specified term, if it exists, or to the next (ceiling) term.
void	seekExact(long ord)	Seeks to the specified term by ordinal (position) as previously returned by TermsEnum.ord().
boolean	seekExact(BytesRef target)	Attempts to seek to the exact term, returning true if the term is found.
void	seekExact(BytesRef target, TermState otherState)	Expert: Seeks a specific position by TermState previously obtained from TermsEnum.termState().
private boolean	setEOF()
BytesRef	term()	Returns current term.
TermState	termState()	Expert: Returns the TermsEnums internal state to position the TermsEnum without re-seeking the term dictionary.
long	totalTermFreq()	Returns the total number of occurrences of this term across all documents (the sum of the freq() for each doc that has this term).

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

attributes

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

postings

Methods inherited from class java.lang.Object

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

Field Details

in

IndexInput in

stack

private SegmentTermsEnumFrame[] stack

staticFrame

private final SegmentTermsEnumFrame staticFrame

currentFrame

SegmentTermsEnumFrame currentFrame

termExists

boolean termExists

fr

final FieldReader fr

targetBeforeCurrentLength

private int targetBeforeCurrentLength

scratchReader

private final ByteArrayDataInput scratchReader

validIndexPrefix

private int validIndexPrefix

eof

private boolean eof

term

final BytesRefBuilder term

fstReader

private final FST.BytesReader fstReader

arcs

private FST.Arc<BytesRef>[] arcs

Constructor Details

SegmentTermsEnum

public SegmentTermsEnum(FieldReader fr)
                 throws IOException

Throws:

IOException

Method Details

initIndexInput

void initIndexInput()

computeBlockStats

public Stats computeBlockStats()
                        throws IOException

Runs next() through the entire terms dict, computing aggregate statistics.

Throws:

IOException

getFrame

private SegmentTermsEnumFrame getFrame(int ord)
                                throws IOException

Throws:

IOException

getArc

private FST.Arc<BytesRef> getArc(int ord)

pushFrame

SegmentTermsEnumFrame pushFrame(FST.Arc<BytesRef> arc,
 BytesRef frameData,
 int length)
                         throws IOException

Throws:

IOException

pushFrame

SegmentTermsEnumFrame pushFrame(FST.Arc<BytesRef> arc,
 long fp,
 int length)
                         throws IOException

Throws:

IOException

clearEOF

private boolean clearEOF()

setEOF

private boolean setEOF()

seekExact

public boolean seekExact(BytesRef target)
                  throws IOException

Description copied from class: TermsEnum

Attempts to seek to the exact term, returning true if the term is found. If this returns false, the enum is unpositioned. For some codecs, seekExact may be substantially faster than TermsEnum.seekCeil(org.apache.lucene.util.BytesRef).

Overrides:

seekExact in class BaseTermsEnum

Returns:

true if the term is found; return false if the enum is unpositioned.

Throws:

IOException

seekCeil

public TermsEnum.SeekStatus seekCeil(BytesRef target)
                              throws IOException

Description copied from class: TermsEnum

Seeks to the specified term, if it exists, or to the next (ceiling) term. Returns SeekStatus to indicate whether exact term was found, a different term was found, or EOF was hit. The target term may be before or after the current term. If this returns SeekStatus.END, the enum is unpositioned.

Specified by:

seekCeil in class TermsEnum

Throws:

IOException

printSeekState

private void printSeekState(PrintStream out)
                     throws IOException

Throws:

IOException

next

public BytesRef next()
              throws IOException

Description copied from interface: BytesRefIterator

Increments the iteration to the next BytesRef in the iterator. Returns the resulting BytesRef or null if the end of the iterator is reached. The returned BytesRef may be re-used across calls to next. After this method returns null, do not call it again: the results are undefined.

Returns:

the next BytesRef in the iterator or null if the end of the iterator is reached.

Throws:

IOException - If there is a low-level I/O error.

term

public BytesRef term()

Description copied from class: TermsEnum

Returns current term. Do not call this when the enum is unpositioned.

Specified by:

term in class TermsEnum

docFreq

public int docFreq()
            throws IOException

Description copied from class: TermsEnum

Returns the number of documents containing the current term. Do not call this when the enum is unpositioned. TermsEnum.SeekStatus.END.

Specified by:

docFreq in class TermsEnum

Throws:

IOException

totalTermFreq

public long totalTermFreq()
                   throws IOException

Description copied from class: TermsEnum

Returns the total number of occurrences of this term across all documents (the sum of the freq() for each doc that has this term). Note that, like other term measures, this measure does not take deleted documents into account.

Specified by:

totalTermFreq in class TermsEnum

Throws:

IOException

postings

public PostingsEnum postings(PostingsEnum reuse,
 int flags)
                      throws IOException

Description copied from class: TermsEnum

Get PostingsEnum for the current term, with control over whether freqs, positions, offsets or payloads are required. Do not call this when the enum is unpositioned. This method will not return null.

NOTE: the returned iterator may return deleted documents, so deleted documents have to be checked on top of the PostingsEnum.

Specified by:

postings in class TermsEnum

Parameters:

reuse - pass a prior PostingsEnum for possible reuse

flags - specifies which optional per-document values you require; see PostingsEnum.FREQS

Throws:

IOException

impacts

public ImpactsEnum impacts(int flags)
                    throws IOException

Description copied from class: TermsEnum

Return a ImpactsEnum.

Specified by:

impacts in class TermsEnum

Throws:

IOException

See Also:

• TermsEnum.postings(PostingsEnum, int)

seekExact

public void seekExact(BytesRef target,
 TermState otherState)

Description copied from class: TermsEnum

Expert: Seeks a specific position by TermState previously obtained from TermsEnum.termState(). Callers should maintain the TermState to use this method. Low-level implementations may position the TermsEnum without re-seeking the term dictionary.

Seeking by TermState should only be used iff the state was obtained from the same TermsEnum instance.

NOTE: Using this method with an incompatible TermState might leave this TermsEnum in undefined state. On a segment level TermState instances are compatible only iff the source and the target TermsEnum operate on the same field. If operating on segment level, TermState instances must not be used across segments.

NOTE: A seek by TermState might not restore the AttributeSource's state. AttributeSource states must be maintained separately if this method is used.

Overrides:

seekExact in class BaseTermsEnum

Parameters:

target - the term the TermState corresponds to

otherState - the TermState

termState

public TermState termState()
                    throws IOException

Description copied from class: TermsEnum

Expert: Returns the TermsEnums internal state to position the TermsEnum without re-seeking the term dictionary.

NOTE: A seek by TermState might not capture the AttributeSource's state. Callers must maintain the AttributeSource states separately

Overrides:

termState in class BaseTermsEnum

Throws:

IOException

See Also:

• TermState
• TermsEnum.seekExact(BytesRef, TermState)

seekExact

public void seekExact(long ord)

Description copied from class: TermsEnum

Seeks to the specified term by ordinal (position) as previously returned by TermsEnum.ord(). The target ord may be before or after the current ord, and must be within bounds.

Specified by:

seekExact in class TermsEnum

ord

public long ord()

Description copied from class: TermsEnum

Returns ordinal position for current term. This is an optional method (the codec may throw UnsupportedOperationException). Do not call this when the enum is unpositioned.

Specified by:

ord in class TermsEnum