FullRegisterWriteTracker.java

/*
  FullRegisterWriteTracker.java

  (c) 2012-2013 Edward Swartz

  All rights reserved. This program and the accompanying materials
  are made available under the terms of the Eclipse Public License v1.0
  which accompanies this distribution, and is available at
  http://www.eclipse.org/legal/epl-v10.html
 */
package v9t9.common.machine;

import java.util.ArrayList;
import java.util.BitSet;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;


/**
 * Track a series of changes to a set of registers.
 * @author ejs
 *
 */
public class FullRegisterWriteTracker extends BaseRegisterWriteTracker {

	private List<Long> changes = new ArrayList<Long>(1024); 
	
	public FullRegisterWriteTracker(IRegisterAccess access, int baseReg, BitSet regbits) {
		super(access, baseReg, regbits);
	}
	
	public FullRegisterWriteTracker(IRegisterAccess access) {
		super(access);
	}


	/* (non-Javadoc)
	 * @see v9t9.common.machine.BaseRegisterWriteTracker#clearChanges()
	 */
	@Override
	public void clearChanges() {
		synchronized (changes) {
			changes.clear();
		}
	}
	
	/* (non-Javadoc)
	 * @see v9t9.common.machine.BaseRegisterWriteTracker#record(int, int)
	 */
	@Override
	protected void record(int reg, int value) {
		synchronized (changes) {
			long ent = ((long) reg) << 32;
			ent |= (value & 0xffffffffL);
			changes.add(ent);
		}
	}

	/**
	 * Get the changes, as they occurred, in order.  Caller may modify
	 * but cannot own the list.
	 * @return the changes, as <integer32: reg> | <integer32: value>
	 */
	public List<Long> getChanges() {
		return changes;
	}
	
	/**
	 * Get the changes, sorted by register key.  Only the last
	 * change to each register is mentioned.
	 *  Caller may modify.
	 * @return the changes
	 */
	public Map<Integer, Integer> getChangeMap() {
		synchronized (changes) {
			Map<Integer, Integer> map = new TreeMap<Integer, Integer>();
			for (Long ent : changes) {
				map.put((int) (ent >> 32), (int)(ent & 0xffffffff));
			}
			return map;
		}
	}
}