1 /*******************************************************************************
\r
2 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
\r
3 * in Industry THTH ry.
\r
4 * All rights reserved. This program and the accompanying materials
\r
5 * are made available under the terms of the Eclipse Public License v1.0
\r
6 * which accompanies this distribution, and is available at
\r
7 * http://www.eclipse.org/legal/epl-v10.html
\r
10 * VTT Technical Research Centre of Finland - initial API and implementation
\r
11 *******************************************************************************/
\r
12 package org.simantics.db.common.procedure.single.wrapper;
\r
14 import java.util.concurrent.atomic.AtomicBoolean;
\r
16 import org.simantics.db.AsyncReadGraph;
\r
17 import org.simantics.db.common.procedure.adapter.AsyncMultiProcedureAdapter;
\r
18 import org.simantics.db.exception.ManyObjectsForFunctionalRelationException;
\r
19 import org.simantics.db.procedure.AsyncProcedure;
\r
21 final public class SingleFunctionalOrNullProcedure<Result> extends AsyncMultiProcedureAdapter<Result> {
\r
23 final String location;
\r
24 final AsyncProcedure<Result> procedure;
\r
25 final AtomicBoolean found = new AtomicBoolean(false);
\r
26 final AtomicBoolean guard = new AtomicBoolean(false);
\r
27 final AtomicBoolean exception = new AtomicBoolean(false);
\r
29 public SingleFunctionalOrNullProcedure(String location, AsyncProcedure<Result> procedure) {
\r
31 this.location = location;
\r
32 this.procedure = procedure;
\r
37 public void execute(AsyncReadGraph graph, Result result) {
\r
39 assert(!guard.get());
\r
41 if(found.compareAndSet(false, true)) {
\r
42 procedure.execute(graph, result);
\r
44 if(exception.compareAndSet(false, true)) {
\r
45 procedure.exception(graph, new ManyObjectsForFunctionalRelationException(location + " -> " + procedure));
\r
52 public void finished(AsyncReadGraph graph) {
\r
54 assert(!guard.get());
\r
58 if(found.compareAndSet(false, true)) {
\r
59 procedure.execute(graph, null);
\r
65 public void exception(AsyncReadGraph graph, Throwable t) {
\r
67 procedure.exception(graph, t);
\r
72 public String toString() {
\r
73 return "SingleFunctionalOrNullProcedure -> " + procedure;
\r