/**
* Copyright (c) Rich Hickey. All rights reserved.
* The use and distribution terms for this software are covered by the
* Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)
* which can be found in the file epl-v10.html at the root of this distribution.
* By using this software in any fashion, you are agreeing to be bound by
* the terms of this license.
* You must not remove this notice, or any other, from this software.
**/
/* rich Jan 1, 2009 */
package clojure.lang;
import java.util.Map;
public abstract class ARef extends AReference implements IRef{
protected volatile IFn validator = null;
private volatile IPersistentMap watches = PersistentHashMap.EMPTY;
public ARef(){
super();
}
public ARef(IPersistentMap meta){
super(meta);
}
void validate(IFn vf, Object val){
try
{
if(vf != null && !RT.booleanCast(vf.invoke(val)))
throw new IllegalStateException("Invalid reference state");
}
catch(RuntimeException re)
{
throw re;
}
catch(Exception e)
{
throw new IllegalStateException("Invalid reference state", e);
}
}
void validate(Object val){
validate(validator, val);
}
public void setValidator(IFn vf){
try
{
validate(vf, deref());
}
catch(Exception e)
{
throw new RuntimeException(e);
}
validator = vf;
}
public IFn getValidator(){
return validator;
}
public IPersistentMap getWatches(){
return watches;
}
synchronized public IRef addWatch(Object key, IFn callback){
watches = watches.assoc(key, callback);
return this;
}
synchronized public IRef removeWatch(Object key){
try
{
watches = watches.without(key);
}
catch(Exception e)
{
throw new RuntimeException(e);
}
return this;
}
public void notifyWatches(Object oldval, Object newval){
IPersistentMap ws = watches;
if(ws.count() > 0)
{
for(ISeq s = ws.seq(); s != null; s = s.next())
{
Map.Entry e = (Map.Entry) s.first();
IFn fn = (IFn) e.getValue();
try
{
if(fn != null)
fn.invoke(e.getKey(), this, oldval, newval);
}
catch(Exception e1)
{
throw new RuntimeException(e1);
}
}
}
}
}