/*
* JBoss, Home of Professional Open Source
* Copyright 2006, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This 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 2.1 of
* the License, or (at your option) any later version.
*
* This software 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 software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.metadata.plugins.loader.thread;
import java.lang.annotation.Annotation;
import java.security.AccessController;
import org.jboss.metadata.plugins.loader.AbstractMutableMetaDataLoader;
import org.jboss.metadata.plugins.loader.memory.MemoryMetaDataLoader;
import org.jboss.metadata.spi.retrieval.AnnotationItem;
import org.jboss.metadata.spi.retrieval.AnnotationsItem;
import org.jboss.metadata.spi.retrieval.Item;
import org.jboss.metadata.spi.retrieval.MetaDataItem;
import org.jboss.metadata.spi.retrieval.MetaDatasItem;
import org.jboss.metadata.spi.retrieval.ValidTime;
import org.jboss.metadata.spi.retrieval.basic.BasicAnnotationsItem;
import org.jboss.metadata.spi.retrieval.basic.BasicMetaDatasItem;
import org.jboss.metadata.spi.scope.CommonLevels;
import org.jboss.metadata.spi.scope.Scope;
import org.jboss.metadata.spi.scope.ScopeKey;
/**
* ThreadLocalMetaDataLoader.
*
* @author <a href="adrian@jboss.com">Adrian Brock</a>
* @version $Revision: 69888 $
*/
public class ThreadLocalMetaDataLoader extends AbstractMutableMetaDataLoader
{
/** The singleton instance */
public static final ThreadLocalMetaDataLoader INSTANCE = new ThreadLocalMetaDataLoader();
private static final GetThreadName GET_THREAD_NAME = new GetThreadName();
/** The thread local */
private ThreadLocal<MemoryMetaDataLoader> threadLocal = new ThreadLocal<MemoryMetaDataLoader>();
/** No annotations */
private final BasicAnnotationsItem NO_ANNOTATIONS = new BasicAnnotationsItem(this, BasicAnnotationsItem.NO_ANNOTATION_ITEMS);
/** No meta data */
private final BasicMetaDatasItem NO_META_DATA = new BasicMetaDatasItem(this, BasicMetaDatasItem.NO_META_DATA_ITEMS);
/**
* Get the thread scope key
*
* @return the scope key
*/
private static final ScopeKey getThreadScopeKey()
{
String name = AccessController.doPrivileged(GET_THREAD_NAME);
Scope scope = new Scope(CommonLevels.THREAD, name);
return new ScopeKey(scope);
}
/**
* Singleton
*/
private ThreadLocalMetaDataLoader()
{
super(true);
}
/**
* Clear all the values for the current thread
*/
public void clear()
{
threadLocal.set(null);
}
public ScopeKey getScope()
{
MemoryMetaDataLoader delegate = threadLocal.get();
if (delegate == null)
return getThreadScopeKey();
else
return delegate.getScope();
}
// The only items we produce are the no annotations and no metadata
// these should not be cached
public <T> boolean isCachable(Item<T> item)
{
return false;
}
public ValidTime getValidTime()
{
MemoryMetaDataLoader delegate = threadLocal.get();
if (delegate == null)
return super.getValidTime();
return delegate.getValidTime();
}
public void invalidate()
{
MemoryMetaDataLoader delegate = threadLocal.get();
if (delegate == null)
super.invalidate();
else
delegate.invalidate();
}
public AnnotationsItem retrieveAnnotations()
{
MemoryMetaDataLoader delegate = threadLocal.get();
if (delegate == null)
return NO_ANNOTATIONS;
return delegate.retrieveAnnotations();
}
public <T extends Annotation> AnnotationItem<T> retrieveAnnotation(Class<T> annotationType)
{
MemoryMetaDataLoader delegate = threadLocal.get();
if (delegate == null)
return null;
return delegate.retrieveAnnotation(annotationType);
}
public <T extends Annotation> T addAnnotation(T annotation)
{
MemoryMetaDataLoader delegate = threadLocal.get();
if (delegate == null)
{
delegate = new MemoryMetaDataLoader(getThreadScopeKey(), false, true);
threadLocal.set(delegate);
}
return delegate.addAnnotation(annotation);
}
public <T extends Annotation> T removeAnnotation(Class<T> annotationType)
{
MemoryMetaDataLoader delegate = threadLocal.get();
if (delegate == null)
return null;
return delegate.removeAnnotation(annotationType);
}
public MetaDatasItem retrieveMetaData()
{
MemoryMetaDataLoader delegate = threadLocal.get();
if (delegate == null)
return NO_META_DATA;
return delegate.retrieveMetaData();
}
public <T> MetaDataItem<T> retrieveMetaData(Class<T> type)
{
MemoryMetaDataLoader delegate = threadLocal.get();
if (delegate == null)
return null;
return delegate.retrieveMetaData(type);
}
public MetaDataItem<?> retrieveMetaData(String name)
{
MemoryMetaDataLoader delegate = threadLocal.get();
if (delegate == null)
return null;
return delegate.retrieveMetaData(name);
}
public <T> T addMetaData(T metaData, Class<T> type)
{
MemoryMetaDataLoader delegate = threadLocal.get();
if (delegate == null)
{
delegate = new MemoryMetaDataLoader(getThreadScopeKey(), false, true);
threadLocal.set(delegate);
}
return delegate.addMetaData(metaData, type);
}
public <T> T removeMetaData(Class<T> type)
{
MemoryMetaDataLoader delegate = threadLocal.get();
if (delegate == null)
return null;
return delegate.removeMetaData(type);
}
public <T> T addMetaData(String name, T metaData, Class<T> type)
{
MemoryMetaDataLoader delegate = threadLocal.get();
if (delegate == null)
{
delegate = new MemoryMetaDataLoader(getThreadScopeKey(), false, true);
threadLocal.set(delegate);
}
return delegate.addMetaData(name, metaData, type);
}
public <T> T removeMetaData(String name, Class<T> type)
{
MemoryMetaDataLoader delegate = threadLocal.get();
if (delegate == null)
return null;
return delegate.removeMetaData(name, type);
}
public boolean isEmpty()
{
MemoryMetaDataLoader delegate = threadLocal.get();
return delegate == null || delegate.isEmpty();
}
}