Package org.apache.lucene.index

Class SegmentReader

java.lang.Object

org.apache.lucene.index.IndexReader

org.apache.lucene.index.LeafReader

org.apache.lucene.index.CodecReader

org.apache.lucene.index.SegmentReader

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, Accountable

public final class SegmentReader
extends CodecReader

IndexReader implementation over a single segment.

Instances pointing to the same segment (but with different deletes, etc) may share the same core data.

Nested Class Summary

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

IndexReader.CacheHelper, IndexReader.CacheKey, IndexReader.ClosedListener

Field Summary

Fields

Modifier and Type	Field	Description
(package private) SegmentCoreReaders	core
private IndexReader.CacheHelper	coreCacheHelper	Wrap the cache helper of the core to add ensureOpen() calls that make sure users do not register closed listeners on closed indices.
(package private) DocValuesProducer	docValuesProducer
(package private) FieldInfos	fieldInfos
private Bits	hardLiveDocs
(package private) boolean	isNRT	True if we are holding RAM only liveDocs or DV updates, i.e.
private Bits	liveDocs
private LeafMetaData	metaData
private int	numDocs
private SegmentCommitInfo	originalSi
private IndexReader.CacheHelper	readerCacheHelper
private java.util.Set<IndexReader.ClosedListener>	readerClosedListeners
(package private) SegmentDocValues	segDocValues
private SegmentCommitInfo	si

Fields inherited from interface org.apache.lucene.util.Accountable

NULL_ACCOUNTABLE

Constructor Summary

Constructors

Constructor	Description
SegmentReader(SegmentCommitInfo si, int createdVersionMajor, IOContext context)	Constructs a new SegmentReader with a new core.
SegmentReader(SegmentCommitInfo si, SegmentReader sr, Bits liveDocs, Bits hardLiveDocs, int numDocs, boolean isNRT)	Create new SegmentReader sharing core from a previous SegmentReader and using the provided liveDocs, and recording whether those liveDocs were carried in ram (isNRT=true).

Method Summary

Modifier and Type	Method	Description
private static boolean	assertLiveDocs(boolean isNRT, Bits hardLiveDocs, Bits liveDocs)
void	checkIntegrity()	Checks consistency of this reader.
Directory	directory()	Returns the directory this index resides in.
protected void	doClose()	Implements close.
IndexReader.CacheHelper	getCoreCacheHelper()	Optional method: Return a IndexReader.CacheHelper that can be used to cache based on the content of this leaf regardless of deletions.
DocValuesProducer	getDocValuesReader()	Expert: retrieve underlying DocValuesProducer
FieldInfos	getFieldInfos()	Get the FieldInfos describing all fields in this reader.
StoredFieldsReader	getFieldsReader()	Expert: retrieve thread-private StoredFieldsReader
Bits	getHardLiveDocs()	Returns the live docs that are not hard-deleted.
Bits	getLiveDocs()	Returns the Bits representing live (not deleted) docs.
LeafMetaData	getMetaData()	Return metadata about this leaf.
NormsProducer	getNormsReader()	Expert: retrieve underlying NormsProducer
(package private) SegmentCommitInfo	getOriginalSegmentInfo()	Returns the original SegmentInfo passed to the segment reader on creation time.
PointsReader	getPointsReader()	Expert: retrieve underlying PointsReader
FieldsProducer	getPostingsReader()	Expert: retrieve underlying FieldsProducer
IndexReader.CacheHelper	getReaderCacheHelper()	Optional method: Return a IndexReader.CacheHelper that can be used to cache based on the content of this reader.
SegmentCommitInfo	getSegmentInfo()	Return the SegmentInfoPerCommit of the segment this reader is reading.
java.lang.String	getSegmentName()	Return the name of the segment this reader is reading.
TermVectorsReader	getTermVectorsReader()	Expert: retrieve thread-private TermVectorsReader
private DocValuesProducer	initDocValuesProducer()	init most recent DocValues for the current commit
private FieldInfos	initFieldInfos()	init most recent FieldInfos for the current commit
int	maxDoc()	Returns one greater than the largest possible document number.
(package private) void	notifyReaderClosedListeners()
int	numDocs()	Returns the number of documents in this index.
java.lang.String	toString()

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

document, getBinaryDocValues, getChildResources, getNormValues, getNumericDocValues, getPointValues, getSortedDocValues, getSortedNumericDocValues, getSortedSetDocValues, getTermVectors, ramBytesUsed, terms

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

docFreq, getContext, getDocCount, getSumDocFreq, getSumTotalTermFreq, postings, postings, totalTermFreq

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

close, decRef, document, document, ensureOpen, equals, getRefCount, getTermVector, hasDeletions, hashCode, incRef, leaves, numDeletedDocs, registerParentReader, tryIncRef

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

si

private final SegmentCommitInfo si

originalSi

private final SegmentCommitInfo originalSi

metaData

private final LeafMetaData metaData

liveDocs

private final Bits liveDocs

hardLiveDocs

private final Bits hardLiveDocs

numDocs

private final int numDocs

core

final SegmentCoreReaders core

segDocValues

final SegmentDocValues segDocValues

isNRT

final boolean isNRT

True if we are holding RAM only liveDocs or DV updates, i.e. the SegmentCommitInfo delGen doesn't match our liveDocs.

docValuesProducer

final DocValuesProducer docValuesProducer

fieldInfos

final FieldInfos fieldInfos

readerClosedListeners

private final java.util.Set<IndexReader.ClosedListener> readerClosedListeners

readerCacheHelper

private final IndexReader.CacheHelper readerCacheHelper

coreCacheHelper

private final IndexReader.CacheHelper coreCacheHelper

Wrap the cache helper of the core to add ensureOpen() calls that make sure users do not register closed listeners on closed indices.

Constructor Detail

SegmentReader

SegmentReader(SegmentCommitInfo si,
              int createdVersionMajor,
              IOContext context)
       throws java.io.IOException

Constructs a new SegmentReader with a new core.

Throws:

CorruptIndexException - if the index is corrupt

java.io.IOException - if there is a low-level IO error

SegmentReader

SegmentReader(SegmentCommitInfo si,
              SegmentReader sr,
              Bits liveDocs,
              Bits hardLiveDocs,
              int numDocs,
              boolean isNRT)
       throws java.io.IOException

Create new SegmentReader sharing core from a previous SegmentReader and using the provided liveDocs, and recording whether those liveDocs were carried in ram (isNRT=true).

Throws:

java.io.IOException

Method Detail

assertLiveDocs

private static boolean assertLiveDocs(boolean isNRT,
                                      Bits hardLiveDocs,
                                      Bits liveDocs)

initDocValuesProducer

private DocValuesProducer initDocValuesProducer()
                                         throws java.io.IOException

init most recent DocValues for the current commit

Throws:

java.io.IOException

initFieldInfos

private FieldInfos initFieldInfos()
                           throws java.io.IOException

init most recent FieldInfos for the current commit

Throws:

java.io.IOException

getLiveDocs

public Bits getLiveDocs()

Description copied from class: LeafReader

Returns the Bits representing live (not deleted) docs. A set bit indicates the doc ID has not been deleted. If this method returns null it means there are no deleted documents (all documents are live). The returned instance has been safely published for use by multiple threads without additional synchronization.

Specified by:

getLiveDocs in class LeafReader

doClose

protected void doClose()
                throws java.io.IOException

Description copied from class: IndexReader

Implements close.

Overrides:

doClose in class CodecReader

Throws:

java.io.IOException

getFieldInfos

public FieldInfos getFieldInfos()

Description copied from class: LeafReader

Get the FieldInfos describing all fields in this reader. Note: Implementations should cache the FieldInfos instance returned by this method such that subsequent calls to this method return the same instance.

Specified by:

getFieldInfos in class LeafReader

numDocs

public int numDocs()

Description copied from class: IndexReader

Returns the number of documents in this index.

NOTE: This operation may run in O(maxDoc). Implementations that can't return this number in constant-time should cache it.

Specified by:

numDocs in class IndexReader

maxDoc

public int maxDoc()

Description copied from class: IndexReader

Returns one greater than the largest possible document number. This may be used to, e.g., determine how big to allocate an array which will have an element for every document number in an index.

Specified by:

maxDoc in class IndexReader

getTermVectorsReader

public TermVectorsReader getTermVectorsReader()

Description copied from class: CodecReader

Expert: retrieve thread-private TermVectorsReader

Specified by:

getTermVectorsReader in class CodecReader

getFieldsReader

public StoredFieldsReader getFieldsReader()

Description copied from class: CodecReader

Expert: retrieve thread-private StoredFieldsReader

Specified by:

getFieldsReader in class CodecReader

getPointsReader

public PointsReader getPointsReader()

Description copied from class: CodecReader

Expert: retrieve underlying PointsReader

Specified by:

getPointsReader in class CodecReader

getNormsReader

public NormsProducer getNormsReader()

Description copied from class: CodecReader

Expert: retrieve underlying NormsProducer

Specified by:

getNormsReader in class CodecReader

getDocValuesReader

public DocValuesProducer getDocValuesReader()

Description copied from class: CodecReader

Expert: retrieve underlying DocValuesProducer

Specified by:

getDocValuesReader in class CodecReader

getPostingsReader

public FieldsProducer getPostingsReader()

Description copied from class: CodecReader

Expert: retrieve underlying FieldsProducer

Specified by:

getPostingsReader in class CodecReader

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getSegmentName

public java.lang.String getSegmentName()

Return the name of the segment this reader is reading.

getSegmentInfo

public SegmentCommitInfo getSegmentInfo()

Return the SegmentInfoPerCommit of the segment this reader is reading.

directory

public Directory directory()

Returns the directory this index resides in.

notifyReaderClosedListeners

void notifyReaderClosedListeners()
                          throws java.io.IOException

Overrides:

notifyReaderClosedListeners in class IndexReader

Throws:

java.io.IOException

getReaderCacheHelper

public IndexReader.CacheHelper getReaderCacheHelper()

Description copied from class: IndexReader

Optional method: Return a IndexReader.CacheHelper that can be used to cache based on the content of this reader. Two readers that have different data or different sets of deleted documents will be considered different.

A return value of null indicates that this reader is not suited for caching, which is typically the case for short-lived wrappers that alter the content of the wrapped reader.

Specified by:

getReaderCacheHelper in class IndexReader

getCoreCacheHelper

public IndexReader.CacheHelper getCoreCacheHelper()

Description copied from class: LeafReader

Optional method: Return a IndexReader.CacheHelper that can be used to cache based on the content of this leaf regardless of deletions. Two readers that have the same data but different sets of deleted documents or doc values updates may be considered equal. Consider using IndexReader.getReaderCacheHelper() if you need deletions or dv updates to be taken into account.

A return value of null indicates that this reader is not suited for caching, which is typically the case for short-lived wrappers that alter the content of the wrapped leaf reader.

Specified by:

getCoreCacheHelper in class LeafReader

getMetaData

public LeafMetaData getMetaData()

Description copied from class: LeafReader

Return metadata about this leaf.

Specified by:

getMetaData in class LeafReader

getOriginalSegmentInfo

SegmentCommitInfo getOriginalSegmentInfo()

Returns the original SegmentInfo passed to the segment reader on creation time. getSegmentInfo() returns a clone of this instance.

getHardLiveDocs

public Bits getHardLiveDocs()

Returns the live docs that are not hard-deleted. This is an expert API to be used with soft-deletes to filter out document that hard deleted for instance due to aborted documents or to distinguish soft and hard deleted documents ie. a rolled back tombstone.

checkIntegrity

public void checkIntegrity()
                    throws java.io.IOException

Description copied from class: LeafReader

Checks consistency of this reader.

Note that this may be costly in terms of I/O, e.g. may involve computing a checksum value against large data files.

Overrides:

checkIntegrity in class CodecReader

Throws:

java.io.IOException