org.apache.lucene.index
Class NoDeletionPolicy

java.lang.Object
  org.apache.lucene.index.NoDeletionPolicy

All Implemented Interfaces:

IndexDeletionPolicy

public final class NoDeletionPolicy
extends Object
implements IndexDeletionPolicy

An IndexDeletionPolicy which keeps all index commits around, never deleting them. This class is a singleton and can be accessed by referencing INSTANCE.

Field Summary

static IndexDeletionPolicy

INSTANCE The single instance of this class.

Method Summary

void	onCommit(List<? extends IndexCommit> commits) This is called each time the writer completed a commit.
void	onInit(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

clone, equals, finalize, 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(List<? extends IndexCommit> commits)
              throws IOException

Description copied from interface: 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 interface IndexDeletionPolicy

Parameters:

commits - List of IndexCommit, sorted by age (the 0th one is the oldest commit).

Throws:

IOException

onInit

public void onInit(List<? extends IndexCommit> commits)
            throws IOException

Description copied from interface: 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 interface IndexDeletionPolicy

Parameters:

commits - List of current point-in-time commits, sorted by age (the 0th one is the oldest commit).

Throws:

IOException