Package org.apache.lucene.search

Class SearcherManager

java.lang.Object
org.apache.lucene.search.ReferenceManager<IndexSearcher>
org.apache.lucene.search.SearcherManager
All Implemented Interfaces:
Closeable, AutoCloseable
public final class SearcherManager extends ReferenceManager<IndexSearcher>
Utility class to safely share IndexSearcher instances across multiple threads, while periodically reopening. This class ensures each searcher is closed only once all threads have finished using it.

Use ReferenceManager.acquire() to obtain the current searcher, and ReferenceManager.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 ReferenceManager.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 maybeReopen. Finally, be sure to call ReferenceManager.close() once you are done.

See Also:

  • Constructor Details

    • SearcherManager

      public SearcherManager(IndexWriter writer, boolean applyAllDeletes, SearcherFactory searcherFactory) throws IOException
      Creates and returns a new SearcherManager from the given IndexWriter.
      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).
      searcherFactory - An optional SearcherFactory. Pass null if you don't require the searcher to be warmed before going live or other custom behavior.
      Throws:
      IOException - if there is a low-level I/O error

    • SearcherManager

      public SearcherManager(Directory dir, SearcherFactory searcherFactory) throws IOException
      Creates and returns a new SearcherManager from the given Directory.
      Parameters:
      dir - the directory to open the DirectoryReader on.
      searcherFactory - An optional SearcherFactory. Pass null if you don't require the searcher to be warmed before going live or other custom behavior.
      Throws:
      IOException - if there is a low-level I/O error

  • Method Details