Package org.apache.lucene.index

Class NoDeletionPolicy

  • All Implemented Interfaces:
    java.lang.Cloneable
    public final class NoDeletionPolicy
extends IndexDeletionPolicy
    An IndexDeletionPolicy which keeps all index commits around, never deleting them. This class is a singleton and can be accessed by referencing INSTANCE.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      IndexDeletionPolicy clone()  
      void onCommit​(java.util.List<? extends IndexCommit> commits)
      This is called each time the writer completed a commit.
      void onInit​(java.util.List<? extends IndexCommit> commits)
      This is called once when a writer is first instantiated to give the policy a chance to remove old commit points.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • INSTANCE

        public static final IndexDeletionPolicy INSTANCE
        The single instance of this class.

    • Method Detail

      • onCommit

        public void onCommit​(java.util.List<? extends IndexCommit> commits)
        Description copied from class: IndexDeletionPolicy

        This is called each time the writer completed a commit. This gives the policy a chance to remove old commit points with each commit.

        The policy may now choose to delete old commit points by calling method delete() of IndexCommit.

        This method is only called when IndexWriter.commit() or IndexWriter.close() is called, or possibly not at all if the IndexWriter.rollback() is called.

        Note: the last CommitPoint is the most recent one, i.e. the "front index state". Be careful not to delete it, unless you know for sure what you are doing, and unless you can afford to lose the index content while doing that.

        Specified by:
        onCommit in class IndexDeletionPolicy
        Parameters:
        commits - List of IndexCommit, sorted by age (the 0th one is the oldest commit).

      • onInit

        public void onInit​(java.util.List<? extends IndexCommit> commits)
        Description copied from class: IndexDeletionPolicy

        This is called once when a writer is first instantiated to give the policy a chance to remove old commit points.

        The writer locates all index commits present in the index directory and calls this method. The policy may choose to delete some of the commit points, doing so by calling method delete() of IndexCommit.

        Note: the last CommitPoint is the most recent one, i.e. the "front index state". Be careful not to delete it, unless you know for sure what you are doing, and unless you can afford to lose the index content while doing that.

        Specified by:
        onInit in class IndexDeletionPolicy
        Parameters:
        commits - List of current point-in-time commits, sorted by age (the 0th one is the oldest commit). Note that for a new index this method is invoked with an empty list.