CaRMtl/org/mozilla/javascript/SpecialRef.java

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/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (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.mozilla.org/MPL/
*
* 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.
*
* The Original Code is Rhino code, released
* May 6, 1999.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1997-1999
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Igor Bukanov, igor@fastmail.fm
*
* Alternatively, the contents of this file may be used under the terms of
* the GNU General Public License Version 2 or later (the "GPL"), in which
* case the provisions of the GPL are applicable instead of those above. If
* you wish to allow use of your version of this file only under the terms of
* the GPL and not to allow others to use your version of this file under the
* MPL, indicate your decision by deleting the provisions above and replacing
* them with the notice and other provisions required by the GPL. If you do
* not delete the provisions above, a recipient may use your version of this
* file under either the MPL or the GPL.
*
* ***** END LICENSE BLOCK ***** */
package org.mozilla.javascript;
class SpecialRef extends Ref
{
static final long serialVersionUID = -7521596632456797847L;
private static final int SPECIAL_NONE = 0;
private static final int SPECIAL_PROTO = 1;
private static final int SPECIAL_PARENT = 2;
private Scriptable target;
private int type;
private String name;
private SpecialRef(Scriptable target, int type, String name)
{
this.target = target;
this.type = type;
this.name = name;
}
static Ref createSpecial(Context cx, Object object, String name)
{
Scriptable target = ScriptRuntime.toObjectOrNull(cx, object);
if (target == null) {
throw ScriptRuntime.undefReadError(object, name);
}
int type;
if (name.equals("__proto__")) {
type = SPECIAL_PROTO;
} else if (name.equals("__parent__")) {
type = SPECIAL_PARENT;
} else {
throw new IllegalArgumentException(name);
}
if (!cx.hasFeature(Context.FEATURE_PARENT_PROTO_PROPERTIES)) {
// Clear special after checking for valid name!
type = SPECIAL_NONE;
}
return new SpecialRef(target, type, name);
}
@Override
public Object get(Context cx)
{
switch (type) {
case SPECIAL_NONE:
return ScriptRuntime.getObjectProp(target, name, cx);
case SPECIAL_PROTO:
return target.getPrototype();
case SPECIAL_PARENT:
return target.getParentScope();
default:
throw Kit.codeBug();
}
}
@Override
public Object set(Context cx, Object value)
{
switch (type) {
case SPECIAL_NONE:
return ScriptRuntime.setObjectProp(target, name, value, cx);
case SPECIAL_PROTO:
case SPECIAL_PARENT:
{
Scriptable obj = ScriptRuntime.toObjectOrNull(cx, value);
if (obj != null) {
// Check that obj does not contain on its prototype/scope
// chain to prevent cycles
Scriptable search = obj;
do {
if (search == target) {
throw Context.reportRuntimeError1(
"msg.cyclic.value", name);
}
if (type == SPECIAL_PROTO) {
search = search.getPrototype();
} else {
search = search.getParentScope();
}
} while (search != null);
}
if (type == SPECIAL_PROTO) {
target.setPrototype(obj);
} else {
target.setParentScope(obj);
}
return obj;
}
default:
throw Kit.codeBug();
}
}
@Override
public boolean has(Context cx)
{
if (type == SPECIAL_NONE) {
return ScriptRuntime.hasObjectElem(target, name, cx);
}
return true;
}
@Override
public boolean delete(Context cx)
{
if (type == SPECIAL_NONE) {
return ScriptRuntime.deleteObjectElem(target, name, cx);
}
return false;
}
}