org.apache.lucene.index

Class MergingDirectoryReaderWrapper

java.lang.Object

org.apache.lucene.index.IndexReader

org.apache.lucene.index.CompositeReader

org.apache.lucene.index.BaseCompositeReader<LeafReader>

org.apache.lucene.index.DirectoryReader

org.apache.lucene.index.FilterDirectoryReader

org.apache.lucene.index.MergingDirectoryReaderWrapper

All Implemented Interfaces:

Closeable, AutoCloseable

public final class MergingDirectoryReaderWrapper
extends FilterDirectoryReader

DirectoryReader wrapper that uses the merge instances of the wrapped CodecReaders. NOTE: This class will fail to work if the leaves of the wrapped directory are not codec readers.

Nested Class Summary

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

FilterDirectoryReader.SubReaderWrapper

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

IndexReader.CacheHelper, IndexReader.CacheKey, IndexReader.ClosedListener

Field Summary

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

in

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

directory

Constructor Summary

Constructors

Constructor and Description
MergingDirectoryReaderWrapper(DirectoryReader in) Wrap the given directory.

Method Summary

Modifier and Type	Method and Description
protected DirectoryReader	doWrapDirectoryReader(DirectoryReader in) Called by the doOpenIfChanged() methods to return a new wrapped DirectoryReader.
IndexReader.CacheHelper	getReaderCacheHelper() Optional method: Return a IndexReader.CacheHelper that can be used to cache based on the content of this reader.

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

doClose, doOpenIfChanged, doOpenIfChanged, doOpenIfChanged, getDelegate, getIndexCommit, getVersion, isCurrent, unwrap

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

directory, indexExists, listCommits, open, open, open, open, open, open, openIfChanged, openIfChanged, openIfChanged, openIfChanged

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

docFreq, document, getDocCount, getSequentialSubReaders, getSumDocFreq, getSumTotalTermFreq, getTermVectors, maxDoc, numDocs, readerBase, readerIndex, totalTermFreq

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

getContext, toString

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

Constructor Detail

MergingDirectoryReaderWrapper

public MergingDirectoryReaderWrapper(DirectoryReader in)
                              throws IOException

Wrap the given directory.

Throws:

IOException

Method Detail

doWrapDirectoryReader

protected DirectoryReader doWrapDirectoryReader(DirectoryReader in)
                                         throws IOException

Description copied from class: FilterDirectoryReader

Called by the doOpenIfChanged() methods to return a new wrapped DirectoryReader. Implementations should just return an instantiation of themselves, wrapping the passed in DirectoryReader.

Specified by:

doWrapDirectoryReader in class FilterDirectoryReader

Parameters:

in - the DirectoryReader to wrap

Returns:

the wrapped DirectoryReader

Throws:

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