BEGIN LICENSE BLOCK *****
Version: EPL 2.0/GPL 2.0/LGPL 2.1
The contents of this file are subject to the Eclipse Public
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.eclipse.org/legal/epl-v20.html
Software distributed under the License is distributed on an "AS
IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
implied. See the License for the specific language governing
rights and limitations under the License.
Copyright (C) 2002-2004 Jan Arne Petersen
Copyright (C) 2004-2006 Thomas E Enebo
Copyright (C) 2004 Stefan Matthias Aust
Alternatively, the contents of this file may be used under the terms of
either of the GNU General Public License Version 2 or later (the "GPL"),
or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
in which case the provisions of the GPL or the LGPL are applicable instead
of those above. If you wish to allow use of your version of this file only
under the terms of either the GPL or the LGPL, and not to allow others to
use your version of this file under the terms of the EPL, indicate your
decision by deleting the provisions above and replace them with the notice
and other provisions required by the GPL or the LGPL. If you do not delete
the provisions above, a recipient may use your version of this file under
the terms of any one of the EPL, the GPL or the LGPL.
END LICENSE BLOCK /***** BEGIN LICENSE BLOCK *****
* Version: EPL 2.0/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Eclipse Public
* 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.eclipse.org/legal/epl-v20.html
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* Copyright (C) 2002-2004 Jan Arne Petersen <jpetersen@uni-bonn.de>
* Copyright (C) 2004-2006 Thomas E Enebo <enebo@acm.org>
* Copyright (C) 2004 Stefan Matthias Aust <sma@3plus4.de>
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the EPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the EPL, the GPL or the LGPL.
***** END LICENSE BLOCK *****/
package org.jruby;
import org.jruby.runtime.builtin.IRubyObject;
import org.jruby.util.cli.Options;
import org.jruby.util.log.Logger;
import org.jruby.util.log.LoggerFactory;
public final class MetaClass extends RubyClass {
@Deprecated
public MetaClass(Ruby runtime, RubyClass superClass, IRubyObject attached) {
this(runtime, superClass, (RubyBasicObject) attached);
}
rb_class_boot for meta classes (makeMetaClass(RubyClass)
) /**
* rb_class_boot for meta classes ({@link #makeMetaClass(RubyClass)})
*/
MetaClass(Ruby runtime, RubyClass superClass, RubyBasicObject attached) {
super(runtime, superClass, false);
this.attached = attached;
// use same ClassIndex as metaclass, since we're technically still of that type
setClassIndex(superClass.getClassIndex());
superClass.addSubclass(this);
if (LOG_SINGLETONS || LOG_SINGLETONS_VERBOSE) {
logSingleton(runtime, superClass, attached);
}
}
private static void logSingleton(Ruby runtime, RubyClass superClass, RubyBasicObject attached) {
if (runtime.isBooting()) return; // don't log singleton created during boot
String attachedString = attached == null ? "null object" : "object of type " + attached.getMetaClass();
LOG.info("singleton class created for type " + superClass + " attached to " + attachedString);
if (LOG_SINGLETONS_VERBOSE) {
LOG.info(new Exception("singleton creation stack trace"));
}
}
@Override
public final IRubyObject allocate(){
throw runtime.newTypeError("can't create instance of virtual class");
}
@Override
public boolean isSingleton() {
return true;
}
rb_make_metaclass
Params: - superClass –
Returns: singleton-class for this (singleton) class
/**
* rb_make_metaclass
* @param superClass
* @return singleton-class for this (singleton) class
*/
@Override
public RubyClass makeMetaClass(RubyClass superClass) {
MetaClass klass = new MetaClass(runtime, getSuperSingletonMetaClass(), this);
setMetaClass(klass);
// Foo.singleton_class.singleton_class: #<Class:#<Class:Foo>>
// #<Class:#<Class:Foo>>'s singleton_class == #<Class:#<Class:Foo>>
klass.setMetaClass(klass);
return klass;
}
private RubyClass getSuperSingletonMetaClass() {
if (attached instanceof RubyClass) {
RubyClass superClass = ((RubyClass) attached).getSuperClass();
if (superClass != null) superClass = superClass.getRealClass();
// #<Class:BasicObject>'s singleton class == Class.singleton_class
if (superClass == null) return runtime.getClassClass().getSingletonClass();
return superClass.getMetaClass().getSingletonClass();
}
return getSuperClass().getRealClass().getMetaClass(); // NOTE: is this correct?
}
@Override
RubyClass toSingletonClass(RubyBasicObject target) {
return attached == target ? this : super.toSingletonClass(target);
}
public RubyBasicObject getAttached() {
return attached;
}
public void setAttached(RubyBasicObject attached) {
this.attached = attached;
}
private RubyBasicObject attached;
private static final Logger LOG = LoggerFactory.getLogger(MetaClass.class);
private static final boolean LOG_SINGLETONS = Options.LOG_SINGLETONS.load();
private static final boolean LOG_SINGLETONS_VERBOSE = Options.LOG_SINGLETONS_VERBOSE.load();
}