/* Copyright (C) 2006 Univ. of Massachusetts Amherst, Computer Science Dept.
This file is part of "MALLET" (MAchine Learning for LanguagE Toolkit).
http://www.cs.umass.edu/~mccallum/mallet
This software is provided under the terms of the Common Public License,
version 1.0, as published by http://www.opensource.org. For further
information, see the file `LICENSE' included with this distribution. */
package cc.mallet.grmm.types;
import gnu.trove.TIntArrayList;
import gnu.trove.TIntObjectHashMap;
import gnu.trove.THashMap;
import java.io.Serializable;
import java.io.ObjectOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.util.List;
import java.util.ArrayList;
/**
* A global mapping between variables and indices.
* All variables belong to exactly one universe.
* $Id: Universe.java,v 1.1 2007/10/22 21:37:44 mccallum Exp $
*/
public class Universe implements Serializable {
private BidirectionalIntObjectMap variableAlphabet;
public static Universe DEFAULT = new Universe ();
public Universe ()
{
variableAlphabet = new BidirectionalIntObjectMap ();
}
public static void resetUniverse()
{
DEFAULT = new Universe();
allProjectionCaches = new THashMap();
}
public int add (Variable var)
{
return variableAlphabet.lookupIndex (var, true);
}
public Variable get (int idx)
{
return (Variable) variableAlphabet.lookupObject (idx);
}
public int getIndex (Variable var)
{
return variableAlphabet.lookupIndex (var);
}
public int size ()
{
return variableAlphabet.size ();
}
private static final long serialVersionUID = 1;
private static final int CURRENT_SERIAL_VERSION = 1;
private void writeObject (ObjectOutputStream out) throws IOException
{
out.defaultWriteObject ();
out.writeInt (CURRENT_SERIAL_VERSION);
out.writeObject (variableAlphabet.toArray ());
}
private void readObject (ObjectInputStream in) throws IOException, ClassNotFoundException
{
in.defaultReadObject ();
int version = in.readInt ();
Object[] vars = (Object[]) in.readObject ();
variableAlphabet = new BidirectionalIntObjectMap (vars.length);
for (int vi = 0; vi < vars.length; vi++) {
add ((Variable) vars[vi]);
}
}
// maintaining global projection caches
// this can get dangerous if variables are thrown away willy nilly (as in test cases) -cas
static THashMap allProjectionCaches = new THashMap ();
public TIntObjectHashMap lookupProjectionCache (VarSet varSet)
{
List sizes = new ArrayList (varSet.size ());
for (int vi = 0; vi < varSet.size (); vi++) {
sizes.add (varSet.get(vi).getNumOutcomes ());
}
TIntObjectHashMap result = (TIntObjectHashMap) allProjectionCaches.get (sizes);
if (result == null) {
result = new TIntObjectHashMap ();
allProjectionCaches.put (sizes, result);
}
return result;
}
}