Package org.apache.lucene.index

Class ReaderManager

java.lang.Object

org.apache.lucene.search.ReferenceManager<DirectoryReader>

org.apache.lucene.index.ReaderManager

All Implemented Interfaces:

Closeable, AutoCloseable

public final class ReaderManager
extends ReferenceManager<DirectoryReader>

Utility class to safely share DirectoryReader instances across multiple threads, while periodically reopening. This class ensures each reader is closed only once all threads have finished using it.

See Also:

• SearcherManager

WARNING: This API is experimental and might change in incompatible ways in the next release.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.search.ReferenceManager

ReferenceManager.RefreshListener

Field Summary

Fields inherited from class org.apache.lucene.search.ReferenceManager

current

Constructor Summary

Constructors

Constructor	Description
ReaderManager(DirectoryReader reader)	Creates and returns a new ReaderManager from the given already-opened DirectoryReader, stealing the incoming reference.
ReaderManager(IndexWriter writer)	Creates and returns a new ReaderManager from the given IndexWriter.
ReaderManager(IndexWriter writer, boolean applyAllDeletes, boolean writeAllDeletes)	Expert: creates and returns a new ReaderManager from the given IndexWriter, controlling whether past deletions should be applied.
ReaderManager(Directory dir)	Creates and returns a new ReaderManager from the given Directory.

Method Summary

Modifier and Type	Method	Description
protected void	decRef(DirectoryReader reference)	Decrement reference counting on the given reference.
protected int	getRefCount(DirectoryReader reference)	Returns the current reference count of the given reference.
protected DirectoryReader	refreshIfNeeded(DirectoryReader referenceToRefresh)	Refresh the given reference if needed.
protected boolean	tryIncRef(DirectoryReader reference)	Try to increment reference counting on the given reference.

Methods inherited from class org.apache.lucene.search.ReferenceManager

acquire, addListener, afterClose, afterMaybeRefresh, close, maybeRefresh, maybeRefreshBlocking, release, removeListener

Methods inherited from class java.lang.Object

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

Constructor Details

ReaderManager

public ReaderManager(IndexWriter writer)
              throws IOException

Creates and returns a new ReaderManager from the given IndexWriter.

Parameters:

writer - the IndexWriter to open the IndexReader from.

Throws:

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

ReaderManager

public ReaderManager(IndexWriter writer,
 boolean applyAllDeletes,
 boolean writeAllDeletes)
              throws IOException

Expert: creates and returns a new ReaderManager from the given IndexWriter, controlling whether past deletions should be applied.

Parameters:

writer - the IndexWriter to open the IndexReader from.

applyAllDeletes - If true, all buffered deletes will be applied (made visible) in the IndexSearcher / DirectoryReader. If false, the deletes may or may not be applied, but remain buffered (in IndexWriter) so that they will be applied in the future. Applying deletes can be costly, so if your app can tolerate deleted documents being returned you might gain some performance by passing false . See DirectoryReader.openIfChanged(DirectoryReader, IndexWriter, boolean).

writeAllDeletes - If true, new deletes will be forcefully written to index files.

Throws:

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

ReaderManager

public ReaderManager(Directory dir)
              throws IOException

Creates and returns a new ReaderManager from the given Directory.

Parameters:

dir - the directory to open the DirectoryReader on.

Throws:

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

ReaderManager

public ReaderManager(DirectoryReader reader)
              throws IOException

Creates and returns a new ReaderManager from the given already-opened DirectoryReader, stealing the incoming reference.

Parameters:

reader - the directoryReader to use for future reopens

Throws:

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

Method Details

decRef

protected void decRef(DirectoryReader reference)
               throws IOException

Description copied from class: ReferenceManager

Decrement reference counting on the given reference.

Specified by:

decRef in class ReferenceManager<DirectoryReader>

Throws:

IOException - if reference decrement on the given resource failed.

refreshIfNeeded

protected DirectoryReader refreshIfNeeded(DirectoryReader referenceToRefresh)
                                   throws IOException

Description copied from class: ReferenceManager

Refresh the given reference if needed. Returns null if no refresh was needed, otherwise a new refreshed reference.

Specified by:

refreshIfNeeded in class ReferenceManager<DirectoryReader>

Throws:

IOException - if the refresh operation failed

tryIncRef

protected boolean tryIncRef(DirectoryReader reference)

Description copied from class: ReferenceManager

Try to increment reference counting on the given reference. Return true if the operation was successful.

Specified by:

tryIncRef in class ReferenceManager<DirectoryReader>

getRefCount

protected int getRefCount(DirectoryReader reference)

Description copied from class: ReferenceManager

Returns the current reference count of the given reference.

Specified by:

getRefCount in class ReferenceManager<DirectoryReader>