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

java.lang.Object
  extended by org.apache.mahout.cf.taste.impl.model.AbstractIDMigrator
      extended by 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
MemoryIDMigrator()
           
 
Method Summary
 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


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