/**
* Copyright (C) 2009 STMicroelectronics
*
* This file is part of "Mind Compiler" is free software: you can redistribute
* it and/or modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program 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 Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Contact: mind@ow2.org
*
* Authors: Matthieu Leclercq
* Contributors:
*/
package org.ow2.mind.adl;
import java.util.HashMap;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Set;
import org.objectweb.fractal.adl.ADLException;
import org.objectweb.fractal.adl.ContextLocal;
import org.objectweb.fractal.adl.Definition;
import org.objectweb.fractal.adl.components.ComponentErrors;
import org.ow2.mind.error.ErrorManager;
import com.google.inject.Inject;
import com.google.inject.Singleton;
/**
* Simple delegating loader that manage a cache of already loaded definitions.
* This component also provides the {@link DefinitionCache} interface that can
* be used to add/get definitions to/from the cache. The cache is different for
* each given <code>context</code> (see {@link ContextLocal}).
*/
@Singleton
public class CacheLoader extends AbstractDelegatingLoader
implements
DefinitionCache {
protected final ContextLocal<Map<String, Definition>> contextualCache = new ContextLocal<Map<String, Definition>>();
protected ThreadLocal<Set<String>> loadingDefinitions = new ThreadLocal<Set<String>>();
@Inject
protected ErrorManager errorManagerItf;
// ---------------------------------------------------------------------------
// Implementation of the Loader interface
// ---------------------------------------------------------------------------
public Definition load(final String name, final Map<Object, Object> context)
throws ADLException {
final Map<String, Definition> cache = getCache(context);
Definition d = cache.get(name);
if (d == null) {
Set<String> loadingDefinitions = this.loadingDefinitions.get();
if (loadingDefinitions == null) {
loadingDefinitions = new LinkedHashSet<String>();
this.loadingDefinitions.set(loadingDefinitions);
}
if (!loadingDefinitions.add(name)) {
errorManagerItf.logFatal(ComponentErrors.DEFINITION_CYCLE,
loadingDefinitions.toString());
}
try {
d = clientLoader.load(name, context);
} finally {
loadingDefinitions.remove(name);
}
cache.put(name, d);
}
return d;
}
// ---------------------------------------------------------------------------
// Implementation of the DefinitionCache interface
// ---------------------------------------------------------------------------
public void addInCache(final Definition d, final Map<Object, Object> context) {
getCache(context).put(d.getName(), d);
}
public Definition getInCache(final String name,
final Map<Object, Object> context) {
return getCache(context).get(name);
}
// ---------------------------------------------------------------------------
// Utility methods
// ---------------------------------------------------------------------------
protected Map<String, Definition> getCache(final Map<Object, Object> context) {
Map<String, Definition> cache = contextualCache.get(context);
if (cache == null) {
cache = new HashMap<String, Definition>();
contextualCache.set(context, cache);
}
return cache;
}
}