/*
* Copyright 2003-2010 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 org.codehaus.groovy.runtime.metaclass;
import groovy.lang.*;
import org.codehaus.groovy.reflection.*;
import org.codehaus.groovy.runtime.*;
import org.codehaus.groovy.vmplugin.VMPluginFactory;
import org.codehaus.groovy.util.FastArray;
import org.codehaus.groovy.util.ManagedLinkedList;
import org.codehaus.groovy.util.ReferenceBundle;
import java.lang.reflect.Constructor;
import java.lang.reflect.Modifier;
import java.util.*;
/**
* A registry of MetaClass instances which caches introspection &
* reflection information and allows methods to be dynamically added to
* existing classes at runtime
*
* @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
* @author John Wilson
* @author <a href="mailto:blackdrag@gmx.org">Jochen Theodorou</a>
* @author Graeme Rocher
* @author Alex Tkachman
*
* @version $Revision$
*/
public class MetaClassRegistryImpl implements MetaClassRegistry{
private boolean useAccessible;
private FastArray instanceMethods = new FastArray();
private FastArray staticMethods = new FastArray();
private LinkedList changeListenerList = new LinkedList();
private ManagedLinkedList metaClassInfo = new ManagedLinkedList<MetaClass>(ReferenceBundle.getWeakBundle());
public static final int LOAD_DEFAULT = 0;
public static final int DONT_LOAD_DEFAULT = 1;
private static MetaClassRegistry instanceInclude;
private static MetaClassRegistry instanceExclude;
public MetaClassRegistryImpl() {
this(LOAD_DEFAULT, true);
}
public MetaClassRegistryImpl(int loadDefault) {
this(loadDefault, true);
}
/**
* @param useAccessible defines whether or not the {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)}
* method will be called to enable access to all methods when using reflection
*/
public MetaClassRegistryImpl(boolean useAccessible) {
this(LOAD_DEFAULT, useAccessible);
}
public MetaClassRegistryImpl(final int loadDefault, final boolean useAccessible) {
this.useAccessible = useAccessible;
if (loadDefault == LOAD_DEFAULT) {
Map<CachedClass, List<MetaMethod>> map = new HashMap<CachedClass, List<MetaMethod>>();
// let's register the default methods
registerMethods(null, true, true, map);
final Class[] additionals = DefaultGroovyMethods.additionals;
for (int i = 0; i != additionals.length; ++i) {
createMetaMethodFromClass(map, additionals[i]);
}
Class[] pluginDGMs = VMPluginFactory.getPlugin().getPluginDefaultGroovyMethods();
for (Class plugin : pluginDGMs) {
registerMethods(plugin, false, true, map);
}
registerMethods(DefaultGroovyStaticMethods.class, false, false, map);
Class[] staticPluginDGMs = VMPluginFactory.getPlugin().getPluginStaticGroovyMethods();
for (Class plugin : staticPluginDGMs) {
registerMethods(plugin, false, false, map);
}
for (Map.Entry<CachedClass, List<MetaMethod>> e : map.entrySet()) {
CachedClass cls = e.getKey();
cls.setNewMopMethods(e.getValue());
}
}
installMetaClassCreationHandle();
final MetaClass emcMetaClass = metaClassCreationHandle.create(ExpandoMetaClass.class, this);
emcMetaClass.initialize();
ClassInfo.getClassInfo(ExpandoMetaClass.class).setStrongMetaClass(emcMetaClass);
addMetaClassRegistryChangeEventListener(new MetaClassRegistryChangeEventListener(){
public void updateConstantMetaClass(MetaClassRegistryChangeEvent cmcu) {
synchronized (metaClassInfo) {
metaClassInfo.add(cmcu.getNewMetaClass());
if (cmcu.getClassToUpdate()==Integer.class) {
if (cmcu.getNewMetaClass()==null) {
// means removal
DefaultMetaClassInfo.setOrigInt(true);
} else {
DefaultMetaClassInfo.setOrigInt(false);
}
}
}
}
});
}
/**
* Looks for a class called 'groovy.runtime.metaclass.CustomMetaClassCreationHandle' and if it exists uses it as the MetaClassCreationHandle
* otherwise uses the default
*
* @see groovy.lang.MetaClassRegistry.MetaClassCreationHandle
*/
private void installMetaClassCreationHandle() {
try {
final Class customMetaClassHandle = Class.forName("groovy.runtime.metaclass.CustomMetaClassCreationHandle");
final Constructor customMetaClassHandleConstructor = customMetaClassHandle.getConstructor(new Class[]{});
this.metaClassCreationHandle = (MetaClassCreationHandle)customMetaClassHandleConstructor.newInstance();
} catch (final ClassNotFoundException e) {
this.metaClassCreationHandle = new MetaClassCreationHandle();
} catch (final Exception e) {
throw new GroovyRuntimeException("Could not instantiate custom Metaclass creation handle: "+ e, e);
}
}
private void registerMethods(final Class theClass, final boolean useMethodWrapper, final boolean useInstanceMethods, Map<CachedClass, List<MetaMethod>> map) {
if (useMethodWrapper) {
// Here we instantiate objects representing MetaMethods for DGM methods.
// Calls for such meta methods done without reflection, so more effectively.
try {
List<GeneratedMetaMethod.DgmMethodRecord> records = GeneratedMetaMethod.DgmMethodRecord.loadDgmInfo();
for (GeneratedMetaMethod.DgmMethodRecord record : records) {
Class[] newParams = new Class[record.parameters.length - 1];
System.arraycopy(record.parameters, 1, newParams, 0, record.parameters.length-1);
MetaMethod method = new GeneratedMetaMethod.Proxy(
record.className,
record.methodName,
ReflectionCache.getCachedClass(record.parameters[0]),
record.returnType,
newParams
);
final CachedClass declClass = method.getDeclaringClass();
List<MetaMethod> arr = map.get(declClass);
if (arr == null) {
arr = new ArrayList<MetaMethod>(4);
map.put(declClass, arr);
}
arr.add(method);
instanceMethods.add(method);
}
} catch (Throwable e) {
e.printStackTrace();
// we print the error, but we don't stop with an exception here
// since it is more comfortable this way for development
}
} else {
CachedMethod[] methods = ReflectionCache.getCachedClass(theClass).getMethods();
for (CachedMethod method : methods) {
final int mod = method.getModifiers();
if (Modifier.isStatic(mod) && Modifier.isPublic(mod) && method.getCachedMethod().getAnnotation(Deprecated.class) == null) {
CachedClass[] paramTypes = method.getParameterTypes();
if (paramTypes.length > 0) {
List<MetaMethod> arr = map.get(paramTypes[0]);
if (arr == null) {
arr = new ArrayList<MetaMethod>(4);
map.put(paramTypes[0], arr);
}
if (useInstanceMethods) {
final NewInstanceMetaMethod metaMethod = new NewInstanceMetaMethod(method);
arr.add(metaMethod);
instanceMethods.add(metaMethod);
} else {
final NewStaticMetaMethod metaMethod = new NewStaticMetaMethod(method);
arr.add(metaMethod);
staticMethods.add(metaMethod);
}
}
}
}
}
}
private void createMetaMethodFromClass(Map<CachedClass, List<MetaMethod>> map, Class aClass) {
try {
MetaMethod method = (MetaMethod) aClass.newInstance();
final CachedClass declClass = method.getDeclaringClass();
List<MetaMethod> arr = map.get(declClass);
if (arr == null) {
arr = new ArrayList<MetaMethod>(4);
map.put(declClass, arr);
}
arr.add(method);
instanceMethods.add(method);
} catch (InstantiationException e) { /* ignore */
} catch (IllegalAccessException e) { /* ignore */
}
}
public final MetaClass getMetaClass(Class theClass) {
return ClassInfo.getClassInfo(theClass).getMetaClass();
}
public MetaClass getMetaClass(Object obj) {
return ClassInfo.getClassInfo(obj.getClass()).getMetaClass(obj);
}
/**
* if oldMc is null, newMc will replace whatever meta class was used before.
* if oldMc is not null, then newMc will be used only if he stored mc is
* the same as oldMc
*/
private void setMetaClass(Class theClass, MetaClass oldMc, MetaClass newMc) {
final ClassInfo info = ClassInfo.getClassInfo(theClass);
MetaClass mc = null;
info.lock();
try {
mc = info.getStrongMetaClass();
info.setStrongMetaClass(newMc);
} finally {
info.unlock();
}
if ((oldMc == null && mc != newMc) || (oldMc != null && mc != newMc && mc != oldMc)) {
fireConstantMetaClassUpdate(theClass, newMc);
}
}
public void removeMetaClass(Class theClass) {
setMetaClass(theClass, null, null);
}
/**
* Registers a new MetaClass in the registry to customize the type
*
* @param theClass
* @param theMetaClass
*/
public void setMetaClass(Class theClass, MetaClass theMetaClass) {
setMetaClass(theClass,null,theMetaClass);
}
public void setMetaClass(Object obj, MetaClass theMetaClass) {
Class theClass = obj.getClass ();
final ClassInfo info = ClassInfo.getClassInfo(theClass);
info.lock();
try {
info.setPerInstanceMetaClass(obj, theMetaClass);
}
finally {
info.unlock();
}
fireConstantMetaClassUpdate(theClass, theMetaClass);
}
public boolean useAccessible() {
return useAccessible;
}
// the following is experimental code, not intended for stable use yet
private volatile MetaClassCreationHandle metaClassCreationHandle = new MetaClassCreationHandle();
/**
* Gets a handle internally used to create MetaClass implementations
* WARNING: experimental code, likely to change soon
* @return the handle
*/
public MetaClassCreationHandle getMetaClassCreationHandler() {
return metaClassCreationHandle;
}
/**
* Sets a handle internally used to create MetaClass implementations.
* When replacing the handle with a custom version, you should
* reuse the old handle to keep custom logic and to use the
* default logic as fall back.
* WARNING: experimental code, likely to change soon
* @param handle the handle
*/
public void setMetaClassCreationHandle(MetaClassCreationHandle handle) {
if(handle == null) throw new IllegalArgumentException("Cannot set MetaClassCreationHandle to null value!");
ClassInfo.clearModifiedExpandos();
handle.setDisableCustomMetaClassLookup(metaClassCreationHandle.isDisableCustomMetaClassLookup());
metaClassCreationHandle = handle;
}
/**
* Adds a listener for constant meta classes.
* @param listener the listener
*/
public void addMetaClassRegistryChangeEventListener(MetaClassRegistryChangeEventListener listener) {
synchronized (changeListenerList) {
changeListenerList.add(listener);
}
}
/**
* Removes a constant meta class listener.
* @param listener the listener
*/
public void removeMetaClassRegistryChangeEventListener(MetaClassRegistryChangeEventListener listener) {
synchronized (changeListenerList) {
Object first = changeListenerList.getFirst();
changeListenerList.remove(listener);
// we want to keep the first entry!
if (changeListenerList.size() == 0) changeListenerList.addFirst(first);
}
}
/**
* Causes the execution of all registered listeners. This method is used mostly
* internal to kick of the listener notification. It can also be used by subclasses
* to achieve the same.
*
* @param c the class
* @param newMc the new MetaClass
*/
protected void fireConstantMetaClassUpdate(Class c, MetaClass newMc) {
MetaClassRegistryChangeEventListener[] listener = getMetaClassRegistryChangeEventListeners();
MetaClassRegistryChangeEvent cmcu = new MetaClassRegistryChangeEvent(this, c, newMc);
for (int i = 0; i<listener.length; i++) {
listener[i].updateConstantMetaClass(cmcu);
}
}
/**
* Gets an array of of all registered ConstantMetaClassListener instances.
*/
public MetaClassRegistryChangeEventListener[] getMetaClassRegistryChangeEventListeners() {
synchronized (changeListenerList) {
return (MetaClassRegistryChangeEventListener[]) changeListenerList.toArray(
new MetaClassRegistryChangeEventListener[changeListenerList.size()]);
}
}
/**
* Singleton of MetaClassRegistry.
*
* @param includeExtension
* @return the registry
*/
public static MetaClassRegistry getInstance(int includeExtension) {
if (includeExtension != DONT_LOAD_DEFAULT) {
if (instanceInclude == null) {
instanceInclude = new MetaClassRegistryImpl();
}
return instanceInclude;
} else {
if (instanceExclude == null) {
instanceExclude = new MetaClassRegistryImpl(DONT_LOAD_DEFAULT);
}
return instanceExclude;
}
}
public FastArray getInstanceMethods() {
return instanceMethods;
}
public FastArray getStaticMethods() {
return staticMethods;
}
/**
* Returns an iterator to iterate over all constant meta classes.
* This iterator can be seen as making a snapshot of the current state
* of the registry. The snapshot will include all meta classes that has
* been used unless they are already collected. Collected meta classes
* will be skipped automatically, so you can expect that each element
* of the iteration is not null. Calling this method is thread safe, the
* usage of the iterator is not.
*
* @return the iterator.
*/
public Iterator iterator() {
final MetaClass[] refs;
synchronized (metaClassInfo) {
refs = (MetaClass[]) metaClassInfo.toArray(new MetaClass[0]);
}
return new Iterator() {
// index in the ref array
private int index = 0;
// the current meta class
private MetaClass currentMeta;
// used to ensure that hasNext has been called
private boolean hasNextCalled = false;
// the cached hasNext call value
private boolean hasNext = false;
public boolean hasNext() {
if (hasNextCalled) return hasNext;
hasNextCalled = true;
if(index < refs.length) {
hasNext = true;
currentMeta = refs[index];
index++;
} else {
hasNext = false;
}
return hasNext;
}
private void ensureNext() {
// we ensure that hasNext has been called before
// next is called
hasNext();
hasNextCalled = false;
}
public Object next() {
ensureNext();
return currentMeta;
}
public void remove() {
ensureNext();
setMetaClass(currentMeta.getTheClass(), currentMeta, null);
currentMeta = null;
}
};
}
}