org.apache.lucene.index

Class ExitableDirectoryReader

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.ExitableDirectoryReader

All Implemented Interfaces:

Closeable, AutoCloseable

public class ExitableDirectoryReader
extends FilterDirectoryReader

The ExitableDirectoryReader wraps a real index DirectoryReader and allows for a QueryTimeout implementation object to be checked periodically to see if the thread should exit or not. If QueryTimeout.shouldExit() returns true, an ExitableDirectoryReader.ExitingReaderException is thrown.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ExitableDirectoryReader.ExitableFilterAtomicReader Wrapper class for another FilterAtomicReader.
static class	ExitableDirectoryReader.ExitableSubReaderWrapper Wrapper class for a SubReaderWrapper that is used by the ExitableDirectoryReader.
static class	ExitableDirectoryReader.ExitableTerms Wrapper class for another Terms implementation that is used by ExitableFields.
static class	ExitableDirectoryReader.ExitableTermsEnum Wrapper class for TermsEnum that is used by ExitableTerms for implementing an exitable enumeration of terms.
static class	ExitableDirectoryReader.ExitingReaderException Exception that is thrown to prematurely terminate a term enumeration.

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
ExitableDirectoryReader(DirectoryReader in, QueryTimeout queryTimeout) Constructor

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.
String	toString()
static DirectoryReader	wrap(DirectoryReader in, QueryTimeout queryTimeout) Wraps a provided DirectoryReader.

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, 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

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

ExitableDirectoryReader

public ExitableDirectoryReader(DirectoryReader in,
                               QueryTimeout queryTimeout)
                        throws IOException

Constructor

Parameters:

in - DirectoryReader that this ExitableDirectoryReader wraps around to make it Exitable.

queryTimeout - The object to periodically check if the query should time out.

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

wrap

public static DirectoryReader wrap(DirectoryReader in,
                                   QueryTimeout queryTimeout)
                            throws IOException

Wraps a provided DirectoryReader. Note that for convenience, the returned reader can be used normally (e.g. passed to DirectoryReader.openIfChanged(DirectoryReader)) and so on.

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

toString

public String toString()

Overrides:

toString in class CompositeReader