Package org.apache.lucene.index

Class FilterLeafReader

java.lang.Object

org.apache.lucene.index.IndexReader

org.apache.lucene.index.LeafReader

org.apache.lucene.index.FilterLeafReader

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

ExitableDirectoryReader.ExitableFilterAtomicReader

public abstract class FilterLeafReader
extends LeafReader

A FilterLeafReader contains another LeafReader, which it uses as its basic source of data, possibly transforming the data along the way or providing additional functionality. The class FilterLeafReader itself simply implements all abstract methods of IndexReader with versions that pass all requests to the contained index reader. Subclasses of FilterLeafReader may further override some of these methods and may also provide additional methods and fields.

NOTE: If you override getLiveDocs(), you will likely need to override numDocs() as well and vice-versa.

NOTE: If this FilterLeafReader does not change the content the contained reader, you could consider delegating calls to LeafReader.getCoreCacheHelper() and IndexReader.getReaderCacheHelper().

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	FilterLeafReader.FilterFields	Base class for filtering Fields implementations.
static class	FilterLeafReader.FilterPostingsEnum	Base class for filtering PostingsEnum implementations.
static class	FilterLeafReader.FilterTerms	Base class for filtering Terms implementations.
static class	FilterLeafReader.FilterTermsEnum	Base class for filtering TermsEnum implementations.

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
protected LeafReader	in	The underlying LeafReader.

Constructor Summary

Constructors

Constructor	Description
FilterLeafReader(LeafReader in)	Construct a FilterLeafReader based on the specified base reader.

Method Summary

Modifier and Type	Method	Description
void	checkIntegrity()	Checks consistency of this reader.
protected void	doClose()	Implements close.
void	document(int docID, StoredFieldVisitor visitor)	Expert: visits the fields of a stored document, for custom processing/loading of each field.
BinaryDocValues	getBinaryDocValues(String field)	Returns BinaryDocValues for this field, or null if no binary doc values were indexed for this field.
LeafReader	getDelegate()	Returns the wrapped LeafReader.
FieldInfos	getFieldInfos()	Get the FieldInfos describing all fields in this reader.
Bits	getLiveDocs()	Returns the Bits representing live (not deleted) docs.
LeafMetaData	getMetaData()	Return metadata about this leaf.
NumericDocValues	getNormValues(String field)	Returns NumericDocValues representing norms for this field, or null if no NumericDocValues were indexed.
NumericDocValues	getNumericDocValues(String field)	Returns NumericDocValues for this field, or null if no numeric doc values were indexed for this field.
PointValues	getPointValues(String field)	Returns the PointValues used for numeric or spatial searches for the given field, or null if there are no point fields.
SortedDocValues	getSortedDocValues(String field)	Returns SortedDocValues for this field, or null if no SortedDocValues were indexed for this field.
SortedNumericDocValues	getSortedNumericDocValues(String field)	Returns SortedNumericDocValues for this field, or null if no SortedNumericDocValues were indexed for this field.
SortedSetDocValues	getSortedSetDocValues(String field)	Returns SortedSetDocValues for this field, or null if no SortedSetDocValues were indexed for this field.
Fields	getTermVectors(int docID)	Retrieve term vectors for this document, or null if term vectors were not indexed.
int	maxDoc()	Returns one greater than the largest possible document number.
int	numDocs()	Returns the number of documents in this index.
Terms	terms(String field)	Returns the Terms index for this field, or null if it has none.
String	toString()
static LeafReader	unwrap(LeafReader reader)	Get the wrapped instance by reader as long as this reader is an instance of FilterLeafReader.

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

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

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

close, decRef, document, document, ensureOpen, equals, getReaderCacheHelper, 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

in

protected final LeafReader in

The underlying LeafReader.

Constructor Detail

FilterLeafReader

public FilterLeafReader(LeafReader in)

Construct a FilterLeafReader based on the specified base reader.

Note that base reader is closed if this FilterLeafReader is closed.

Parameters:

in - specified base reader.

Method Detail

unwrap

public static LeafReader unwrap(LeafReader reader)

Get the wrapped instance by reader as long as this reader is an instance of FilterLeafReader.

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

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

getPointValues

public PointValues getPointValues(String field)
                           throws IOException

Description copied from class: LeafReader

Returns the PointValues used for numeric or spatial searches for the given field, or null if there are no point fields.

Specified by:

getPointValues in class LeafReader

Throws:

IOException

getTermVectors

public Fields getTermVectors(int docID)
                      throws IOException

Description copied from class: IndexReader

Retrieve term vectors for this document, or null if term vectors were not indexed. The returned Fields instance acts like a single-document inverted index (the docID will be 0).

Specified by:

getTermVectors in class IndexReader

Throws:

IOException

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

document

public void document(int docID,
                     StoredFieldVisitor visitor)
              throws IOException

Description copied from class: IndexReader

Expert: visits the fields of a stored document, for custom processing/loading of each field. If you simply want to load all fields, use IndexReader.document(int). If you want to load a subset, use DocumentStoredFieldVisitor.

Specified by:

document in class IndexReader

Throws:

IOException

doClose

protected void doClose()
                throws IOException

Description copied from class: IndexReader

Implements close.

Specified by:

doClose in class IndexReader

Throws:

IOException

terms

public Terms terms(String field)
            throws IOException

Description copied from class: LeafReader

Returns the Terms index for this field, or null if it has none.

Specified by:

terms in class LeafReader

Throws:

IOException

toString

public String toString()

Overrides:

toString in class Object

getNumericDocValues

public NumericDocValues getNumericDocValues(String field)
                                     throws IOException

Description copied from class: LeafReader

Returns NumericDocValues for this field, or null if no numeric doc values were indexed for this field. The returned instance should only be used by a single thread.

Specified by:

getNumericDocValues in class LeafReader

Throws:

IOException

getBinaryDocValues

public BinaryDocValues getBinaryDocValues(String field)
                                   throws IOException

Description copied from class: LeafReader

Returns BinaryDocValues for this field, or null if no binary doc values were indexed for this field. The returned instance should only be used by a single thread.

Specified by:

getBinaryDocValues in class LeafReader

Throws:

IOException

getSortedDocValues

public SortedDocValues getSortedDocValues(String field)
                                   throws IOException

Description copied from class: LeafReader

Returns SortedDocValues for this field, or null if no SortedDocValues were indexed for this field. The returned instance should only be used by a single thread.

Specified by:

getSortedDocValues in class LeafReader

Throws:

IOException

getSortedNumericDocValues

public SortedNumericDocValues getSortedNumericDocValues(String field)
                                                 throws IOException

Description copied from class: LeafReader

Returns SortedNumericDocValues for this field, or null if no SortedNumericDocValues were indexed for this field. The returned instance should only be used by a single thread.

Specified by:

getSortedNumericDocValues in class LeafReader

Throws:

IOException

getSortedSetDocValues

public SortedSetDocValues getSortedSetDocValues(String field)
                                         throws IOException

Description copied from class: LeafReader

Returns SortedSetDocValues for this field, or null if no SortedSetDocValues were indexed for this field. The returned instance should only be used by a single thread.

Specified by:

getSortedSetDocValues in class LeafReader

Throws:

IOException

getNormValues

public NumericDocValues getNormValues(String field)
                               throws IOException

Description copied from class: LeafReader

Returns NumericDocValues representing norms for this field, or null if no NumericDocValues were indexed. The returned instance should only be used by a single thread.

Specified by:

getNormValues in class LeafReader

Throws:

IOException

getMetaData

public LeafMetaData getMetaData()

Description copied from class: LeafReader

Return metadata about this leaf.

Specified by:

getMetaData in class LeafReader

checkIntegrity

public void checkIntegrity()
                    throws 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.

Specified by:

checkIntegrity in class LeafReader

Throws:

IOException

getDelegate

public LeafReader getDelegate()

Returns the wrapped LeafReader.