org.apache.openjpa.slice
Interface DistributionPolicy

All Known Implementing Classes:

DistributionPolicy.Default

public interface DistributionPolicy

Policy to select one of the physical databases referred as slice in which a given persistent instance will be stored. The user application is required to implement this interface. Slice will invoke the single method of this interface to determine the target slice for a newly persistent or a detached instance being merged.

Author:

Pinaki Poddar

Nested Class Summary

static class

DistributionPolicy.Default Implements a default distribution policy to store the given instance to a randomly selected available slice.

Method Summary

String

distribute(Object pc, List<String> slices, Object context) Gets the name of the target slice where the given newly persistent or the detached, to-be-merged instance will be stored.

Method Detail

distribute

String distribute(Object pc,
                  List<String> slices,
                  Object context)

Gets the name of the target slice where the given newly persistent or the detached, to-be-merged instance will be stored.

Parameters:

pc - The newly persistent or to-be-merged object.

slices - list of names of the active slices. The ordering of the list is either explicit openjpa.slice.Names property or implicit i.e. alphabetic order of available identifiers if openjpa.slice.Names is unspecified.

context - the generic persistence context managing the given instance.

Returns:

identifier of the slice. This name must match one of the given slice names.

See Also:

DistributedConfiguration.getActiveSliceNames()