org.apache.mahout.cf.taste.impl.neighborhood

Class CachingUserNeighborhood

java.lang.Object

org.apache.mahout.cf.taste.impl.neighborhood.CachingUserNeighborhood

All Implemented Interfaces:

Refreshable, UserNeighborhood

public final class CachingUserNeighborhood
extends Object
implements UserNeighborhood

A caching wrapper around an underlying UserNeighborhood implementation.

Constructor Summary

Constructors

Constructor and Description
CachingUserNeighborhood(UserNeighborhood neighborhood, DataModel dataModel)

Method Summary

Modifier and Type	Method and Description
long[]	getUserNeighborhood(long userID)
void	refresh(Collection<Refreshable> alreadyRefreshed) Triggers "refresh" -- whatever that means -- of the implementation.

Methods inherited from class java.lang.Object

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

Constructor Detail

CachingUserNeighborhood

public CachingUserNeighborhood(UserNeighborhood neighborhood,
                               DataModel dataModel)
                        throws TasteException

Throws:

TasteException

Method Detail

getUserNeighborhood

public long[] getUserNeighborhood(long userID)
                           throws TasteException

Specified by:

getUserNeighborhood in interface UserNeighborhood

Parameters:

userID - ID of user for which a neighborhood will be computed

Returns:

IDs of users in the neighborhood

Throws:

TasteException - if an error occurs while accessing data

refresh

public void refresh(Collection<Refreshable> alreadyRefreshed)

Description copied from interface: Refreshable

Triggers "refresh" -- whatever that means -- of the implementation. The general contract is that any Refreshable should always leave itself in a consistent, operational state, and that the refresh atomically updates internal state from old to new.

Specified by:

refresh in interface Refreshable

Parameters:

alreadyRefreshed - Refreshables that are known to have already been refreshed as a result of an initial call to a {#refresh(Collection)} method on some object. This ensure that objects in a refresh dependency graph aren't refreshed twice needlessly.