Class SearcherManager

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

Use Acquire() to obtain the current searcher, and Release(G) to release it, like this:

IndexSearcher s = manager.Acquire();
try 
{
    // Do searching, doc retrieval, etc. with s
} 
finally 
{
    manager.Release(s);
    // Do not use s after this!
    s = null;
}

In addition you should periodically call MaybeRefresh(). While it's possible to call this just before running each query, this is discouraged since it penalizes the unlucky queries that do the reopen. It's better to use a separate background thread, that periodically calls MaybeRefresh(). Finally, be sure to call Dispose() once you are done.

Note

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

Inheritance

object

ReferenceManager<IndexSearcher>

SearcherManager

Implements

IDisposable

Inherited Members

ReferenceManager<IndexSearcher>.Acquire()

ReferenceManager<IndexSearcher>.Dispose()

ReferenceManager<IndexSearcher>.MaybeRefresh()

ReferenceManager<IndexSearcher>.MaybeRefreshBlocking()

ReferenceManager<IndexSearcher>.Release(IndexSearcher)

ReferenceManager<IndexSearcher>.AddListener(ReferenceManager.IRefreshListener)

ReferenceManager<IndexSearcher>.RemoveListener(ReferenceManager.IRefreshListener)

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: Lucene.Net.Search

Assembly: Lucene.Net.dll

Syntax

public sealed class SearcherManager : ReferenceManager<IndexSearcher>, IDisposable

Constructors

SearcherManager(IndexWriter, bool, SearcherFactory)

Creates and returns a new SearcherManager from the given IndexWriter.

Declaration

public SearcherManager(IndexWriter writer, bool applyAllDeletes, SearcherFactory searcherFactory)

Parameters

Type	Name	Description
IndexWriter	writer	The IndexWriter to open the IndexReader from.
bool	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 OpenIfChanged(DirectoryReader, IndexWriter, bool).
SearcherFactory	searcherFactory	An optional SearcherFactory. Pass null if you don't require the searcher to be warmed before going live or other custom behavior.

Exceptions

Type	Condition
IOException	if there is a low-level I/O error

See Also

SearcherFactory

SearcherManager(Directory, SearcherFactory)

Creates and returns a new SearcherManager from the given Directory.

Declaration

public SearcherManager(Directory dir, SearcherFactory searcherFactory)

Parameters

Type	Name	Description
Directory	dir	The directory to open the DirectoryReader on.
SearcherFactory	searcherFactory	An optional SearcherFactory. Pass null if you don't require the searcher to be warmed before going live or other custom behavior.

Exceptions

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

See Also

SearcherFactory

Methods

DecRef(IndexSearcher)

Decrement reference counting on the given reference.

Declaration

protected override void DecRef(IndexSearcher reference)

Parameters

Type	Name	Description
IndexSearcher	reference

Overrides

ReferenceManager<IndexSearcher>.DecRef(IndexSearcher)

Exceptions

Type	Condition
IOException	If reference decrement on the given resource failed.

See Also

SearcherFactory

GetRefCount(IndexSearcher)

Returns the current reference count of the given reference.

Declaration

protected override int GetRefCount(IndexSearcher reference)

Parameters

Type	Name	Description
IndexSearcher	reference

Returns

Type	Description
int

Overrides

ReferenceManager<IndexSearcher>.GetRefCount(IndexSearcher)

See Also

SearcherFactory

GetSearcher(SearcherFactory, IndexReader)

Expert: creates a searcher from the provided IndexReader using the provided SearcherFactory. NOTE: this decRefs incoming reader on throwing an exception.

Declaration

public static IndexSearcher GetSearcher(SearcherFactory searcherFactory, IndexReader reader)

Parameters

Type	Name	Description
SearcherFactory	searcherFactory
IndexReader	reader

Returns

Type	Description
IndexSearcher

See Also

SearcherFactory

IsSearcherCurrent()

Returns true if no changes have occured since this searcher ie. reader was opened, otherwise false.

Declaration

public bool IsSearcherCurrent()

Returns

Type	Description
bool

See Also

IsCurrent()

RefreshIfNeeded(IndexSearcher)

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

Declaration

protected override IndexSearcher RefreshIfNeeded(IndexSearcher referenceToRefresh)

Parameters

Type	Name	Description
IndexSearcher	referenceToRefresh

Returns

Type	Description
IndexSearcher

Overrides

ReferenceManager<IndexSearcher>.RefreshIfNeeded(IndexSearcher)

Exceptions

Type	Condition
ObjectDisposedException	If the reference manager has been Dispose()d.
IOException	If the refresh operation failed

See Also

SearcherFactory

TryIncRef(IndexSearcher)

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

Declaration

protected override bool TryIncRef(IndexSearcher reference)

Parameters

Type	Name	Description
IndexSearcher	reference

Returns

Type	Description
bool

Overrides

ReferenceManager<IndexSearcher>.TryIncRef(IndexSearcher)

Exceptions

Type	Condition
ObjectDisposedException	if the reference manager has been Dispose()d.

See Also

SearcherFactory

Implements

IDisposable

Extension Methods

ReferenceManagerExtensions.GetContext<T>(ReferenceManager<T>)

See Also

SearcherFactory