/*
* Copyright 2003-2007 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package groovy.lang;
import groovy.lang.MetaClassRegistry.MetaClassCreationHandle;
import org.codehaus.groovy.runtime.metaclass.ConcurrentReaderHashMap;
import java.util.*;
/**
* <p>A handle for the MetaClassRegistry that changes all classes loaded into the Grails VM
* to use ExpandoMetaClass instances
*
* <p>The handle should be registered with the Groovy runtime <strong>before</before> Groovy loads, for example
* in your main method.
*
* <code>GroovySystem.metaClassRegistry.metaClassCreationHandle = new ExpandoMetaClassCreationHandle()</code>
*
* @see groovy.lang.MetaClassRegistry
* @see groovy.lang.MetaClassRegistry.MetaClassCreationHandle
* @see org.codehaus.groovy.runtime.metaclass.MetaClassRegistryImpl#setMetaClassCreationHandle(groovy.lang.MetaClassRegistry.MetaClassCreationHandle)
*
* @author Graeme Rocher
* @since 1.1
*/
public class ExpandoMetaClassCreationHandle extends MetaClassCreationHandle {
public static final ExpandoMetaClassCreationHandle instance = new ExpandoMetaClassCreationHandle();
private final Map modifiedExpandos = new ConcurrentReaderHashMap();
/* (non-Javadoc)
* @see groovy.lang.MetaClassRegistry.MetaClassCreationHandle#create(java.lang.Class, groovy.lang.MetaClassRegistry)
*/
protected MetaClass createNormalMetaClass(Class theClass, MetaClassRegistry registry) {
if(theClass != ExpandoMetaClass.class) {
ExpandoMetaClass emc = new ExpandoMetaClass(theClass, false ,true);
Set modifiedSuperExpandos = retrieveModifiedSuperExpandos(emc);
emc.refreshInheritedMethods(modifiedSuperExpandos);
return emc;
}
else {
return super.create(theClass, registry);
}
}
/*
* Looks for modified super class ExpandoMetaClass instances for the given child ExpandoMetaClass
*/
private Set retrieveModifiedSuperExpandos(ExpandoMetaClass child) {
Set modifiedSupers = new HashSet();
List superClasses = child.getSuperClasses();
for (Iterator i = superClasses.iterator(); i.hasNext();) {
Class c = (Class) i.next();
Class[] interfaces = c.getInterfaces();
populateSupersFromInterfaces(modifiedSupers, interfaces);
if(modifiedExpandos.containsKey(c)) {
modifiedSupers.add(modifiedExpandos.get(c));
}
}
Class[] interfaces = child.getJavaClass().getInterfaces();
populateSupersFromInterfaces(modifiedSupers, interfaces);
return modifiedSupers;
}
/*
* Searches through a given array of interfaces for modified ExpandoMetaClass instances for each interface
*/
private void populateSupersFromInterfaces(Set modifiedSupers, Class[] interfaces) {
for (int i = 0; i < interfaces.length; i++) {
Class anInterface = interfaces[i];
final Class[] superInterfaces = anInterface.getInterfaces();
if(modifiedExpandos.containsKey(anInterface)) {
modifiedSupers.add(modifiedExpandos.get(anInterface));
}
if(superInterfaces.length > 0)
populateSupersFromInterfaces(modifiedSupers, superInterfaces);
}
}
/**
* Registers a modified ExpandoMetaClass with the creation handle
*
* @param emc The EMC
*/
public void registerModifiedMetaClass(ExpandoMetaClass emc) {
modifiedExpandos.put(emc.getJavaClass(), emc);
}
public boolean hasModifiedMetaClass(ExpandoMetaClass emc) {
return modifiedExpandos.containsKey(emc.getJavaClass());
}
/**
* <p>Enables the ExpandoMetaClassCreationHandle with the registry
*
* <code>ExpandoMetaClassCreationHandle.enable();</code>
*
*/
public static void enable() {
final MetaClassRegistry metaClassRegistry = GroovySystem.getMetaClassRegistry();
if (metaClassRegistry.getMetaClassCreationHandler() != instance) {
instance.modifiedExpandos.clear();
metaClassRegistry.setMetaClassCreationHandle(instance);
}
}
public static void disable() {
final MetaClassRegistry metaClassRegistry = GroovySystem.getMetaClassRegistry();
if (metaClassRegistry.getMetaClassCreationHandler() == instance) {
instance.modifiedExpandos.clear();
metaClassRegistry.setMetaClassCreationHandle(new MetaClassCreationHandle());
}
}
}