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  1. Lucene - Core
  2. LUCENE-635

[PATCH] Decouple locking implementation from Directory implementation


    • Improvement
    • Status: Closed
    • Minor
    • Resolution: Fixed
    • 2.0.0
    • 2.1
    • core/index
    • None


      This is a spinoff of http://issues.apache.org/jira/browse/LUCENE-305.

      I've opened this new issue to capture that it's wider scope than

      This is a patch originally created by Jeff Patterson (see above link)
      and then modified as described here:


      with some small additional changes:

      • For each FSDirectory.getDirectory(), I made a corresponding
        version that also accepts a LockFactory instance. So, you can
        construct an FSDirectory with your own LockFactory.
      • Cascaded defaulting for FSDirectory's LockFactory implementation:
        if you pass in a LockFactory instance, it's used; else if
        setDisableLocks was called, we use NoLockFactory; else, if the
        system property "org.apache.lucene.store.FSDirectoryLockFactoryClass"
        is defined, we use that; finally, we'll use the original locking
        implementation (SimpleFSLockFactory).

      The gist is that all locking code has been moved out of *Directory and
      into subclasses of a new abstract LockFactory class. You can now set
      the LockFactory of a Directory to change how it does locking. For
      example, you can create an FSDirectory but set its locking to
      SingleInstanceLockFactory (if you know all writing/reading will take
      place a single JVM).

      The changes pass all unit tests (on Ubuntu Linux Sun Java 1.5 and
      Windows XP Sun Java 1.4), and I added another TestCase to test the
      LockFactory code.

      Note that LockFactory defaults are not changed: FSDirectory defaults
      to SimpleFSLockFactory and RAMDirectory defaults to

      Next step (separate issue) is to create a LockFactory that uses the OS
      native locks (through java.nio).


        1. patch-Jul26.tar
          90 kB
          Michael McCandless
        2. LUCENE-635-Aug3.patch
          43 kB
          Michael McCandless
        3. LUCENE-635-Aug27.patch
          43 kB
          Michael McCandless

        Issue Links



              yseeley@gmail.com Yonik Seeley
              mikemccand Michael McCandless
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