org.apache.mahout.cf.taste.impl.model

Class MemoryIDMigrator

java.lang.Object

org.apache.mahout.cf.taste.impl.model.AbstractIDMigrator

org.apache.mahout.cf.taste.impl.model.MemoryIDMigrator

All Implemented Interfaces:

Refreshable, IDMigrator, UpdatableIDMigrator

public final class MemoryIDMigrator
extends AbstractIDMigrator
implements UpdatableIDMigrator

Implementation which stores the reverse long-to-String mapping in memory.

Constructor Summary

Constructors

Constructor and Description
MemoryIDMigrator()

Method Summary

Modifier and Type	Method and Description
void	initialize(Iterable<String> stringIDs) Make the mapping aware of the given string IDs.
void	storeMapping(long longID, String stringID) Stores the reverse long-to-String mapping in some kind of backing store.
String	toStringID(long longID)

Methods inherited from class org.apache.mahout.cf.taste.impl.model.AbstractIDMigrator

hash, refresh, toLongID

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.mahout.cf.taste.model.IDMigrator

toLongID

Methods inherited from interface org.apache.mahout.cf.taste.common.Refreshable

refresh

Constructor Detail

MemoryIDMigrator

public MemoryIDMigrator()

Method Detail

storeMapping

public void storeMapping(long longID,
                         String stringID)

Description copied from interface: UpdatableIDMigrator

Stores the reverse long-to-String mapping in some kind of backing store. Note that this must be called directly (or indirectly through UpdatableIDMigrator.initialize(Iterable)) for every String that might be encountered in the application, or else the mapping will not be known.

Specified by:

storeMapping in interface UpdatableIDMigrator

Parameters:

longID - long ID

stringID - string ID that maps to/from that long ID

toStringID

public String toStringID(long longID)

Specified by:

toStringID in interface IDMigrator

Returns:

the string ID most recently associated with the given long ID, or null if doesn't exist

initialize

public void initialize(Iterable<String> stringIDs)

Description copied from interface: UpdatableIDMigrator

Make the mapping aware of the given string IDs. This must be called initially before the implementation is used, or else it will not be aware of reverse long-to-String mappings.

Specified by:

initialize in interface UpdatableIDMigrator