/* -*- tab-width: 4 -*-
*
* Electric(tm) VLSI Design System
*
* File: StratRandomMatch.java
*
* Copyright (c) 2003, Oracle and/or its affiliates. All rights reserved.
*
* Electric(tm) is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* Electric(tm) is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Electric(tm); see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, Mass 02111-1307, USA.
*/
package com.sun.electric.tool.ncc.strategy;
import java.util.Iterator;
import com.sun.electric.tool.ncc.NccGlobals;
import com.sun.electric.tool.ncc.lists.LeafList;
import com.sun.electric.tool.ncc.netlist.NetObject;
import com.sun.electric.tool.ncc.trees.Circuit;
import com.sun.electric.tool.ncc.trees.EquivRecord;
/** StratRandomMatch finds balanced EquivRecords and arbitrarily matches the
* NetObjects that are first in each Circuit. */
public class StratRandomMatch extends Strategy {
private static final Integer CODE_FIRST = new Integer(1);
private static final Integer CODE_REST = new Integer(2);
private StratRandomMatch(NccGlobals globals){super(globals);}
private EquivRecord findSmallestBalanced(Iterator<EquivRecord> frontier) {
//LeafList frontier = StratFrontier.doYourJob(root, globals);
int minSz = Integer.MAX_VALUE;
EquivRecord minRec = null;
while (frontier.hasNext()) {
EquivRecord r = (EquivRecord) frontier.next();
if (!r.isBalanced()) continue;
int sz = r.maxSize();
if (sz<minSz) {
minSz = sz;
minRec = r;
}
}
return minRec;
}
private EquivRecord findSmallestActive() {
EquivRecord w =
findSmallestBalanced(globals.getWireLeafEquivRecs().getNotMatched());
EquivRecord p =
findSmallestBalanced(globals.getPartLeafEquivRecs().getNotMatched());
if (p==null) return w;
if (w==null) return p;
return p.maxSize()<w.maxSize() ? p : w;
}
private LeafList doYourJob() {
EquivRecord smallest = findSmallestActive();
if (smallest==null) return new LeafList();
return doFor(smallest);
}
public Integer doFor(NetObject n){
Circuit ckt = n.getParent();
Iterator<NetObject> ni = ckt.getNetObjs();
Object first = ni.next();
return n==first ? CODE_FIRST : CODE_REST;
}
//----------------------------- intended interface ------------------------
/** Find the smallest active equivalence class. Partition it by matching
* the first NetObject in each Circuit.
* @return the offspring resulting from the partition */
public static LeafList doYourJob(NccGlobals globals){
StratRandomMatch rm = new StratRandomMatch(globals);
return rm.doYourJob();
}
}