8014785: Ability to extend global instance by binding properties of another object
Reviewed-by: attila, hannesw, jlaskey, lagergren
--- a/nashorn/src/jdk/nashorn/internal/objects/NativeObject.java Tue Jul 09 13:57:24 2013 +0200
+++ b/nashorn/src/jdk/nashorn/internal/objects/NativeObject.java Tue Jul 09 17:37:46 2013 +0530
@@ -27,18 +27,24 @@
import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;
import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED;
+
+import java.lang.invoke.MethodHandle;
+import java.util.ArrayList;
import jdk.nashorn.api.scripting.ScriptObjectMirror;
import jdk.nashorn.internal.objects.annotations.Attribute;
import jdk.nashorn.internal.objects.annotations.Constructor;
import jdk.nashorn.internal.objects.annotations.Function;
import jdk.nashorn.internal.objects.annotations.ScriptClass;
import jdk.nashorn.internal.objects.annotations.Where;
+import jdk.nashorn.internal.runtime.AccessorProperty;
import jdk.nashorn.internal.runtime.ECMAException;
import jdk.nashorn.internal.runtime.JSType;
+import jdk.nashorn.internal.runtime.Property;
import jdk.nashorn.internal.runtime.PropertyMap;
import jdk.nashorn.internal.runtime.ScriptFunction;
import jdk.nashorn.internal.runtime.ScriptObject;
import jdk.nashorn.internal.runtime.ScriptRuntime;
+import jdk.nashorn.internal.runtime.linker.Bootstrap;
import jdk.nashorn.internal.runtime.linker.InvokeByName;
/**
@@ -471,4 +477,114 @@
return false;
}
+
+ /**
+ * Nashorn extension: Object.bindProperties
+ *
+ * Binds the source object's properties to the target object. Binding
+ * properties allows two-way read/write for the properties of the source object.
+ *
+ * Example:
+ * <pre>
+ * var obj = { x: 34, y: 100 };
+ * var foo = {}
+ *
+ * // bind properties of "obj" to "foo" object
+ * Object.bindProperties(foo, obj);
+ *
+ * // now, we can access/write on 'foo' properties
+ * print(foo.x); // prints obj.x which is 34
+ *
+ * // update obj.x via foo.x
+ * foo.x = "hello";
+ * print(obj.x); // prints "hello" now
+ *
+ * obj.x = 42; // foo.x also becomes 42
+ * print(foo.x); // prints 42
+ * </pre>
+ * <p>
+ * The source object bound can be a ScriptObject or a ScriptOjectMirror.
+ * null or undefined source object results in TypeError being thrown.
+ * </p>
+ * Example:
+ * <pre>
+ * var obj = loadWithNewGlobal({
+ * name: "test",
+ * script: "obj = { x: 33, y: 'hello' }"
+ * });
+ *
+ * // bind 'obj's properties to global scope 'this'
+ * Object.bindProperties(this, obj);
+ * print(x); // prints 33
+ * print(y); // prints "hello"
+ * x = Math.PI; // changes obj.x to Math.PI
+ * print(obj.x); // prints Math.PI
+ * </pre>
+ *
+ * Limitations of property binding:
+ * <ul>
+ * <li> Only enumerable, immediate (not proto inherited) properties of the source object are bound.
+ * <li> If the target object already contains a property called "foo", the source's "foo" is skipped (not bound).
+ * <li> Properties added to the source object after binding to the target are not bound.
+ * <li> Property configuration changes on the source object (or on the target) is not propagated.
+ * <li> Delete of property on the target (or the source) is not propagated -
+ * only the property value is set to 'undefined' if the property happens to be a data property.
+ * </ul>
+ * <p>
+ * It is recommended that the bound properties be treated as non-configurable
+ * properties to avoid surprises.
+ * </p>
+ *
+ * @param self self reference
+ * @param target the target object to which the source object's properties are bound
+ * @param source the source object whose properties are bound to the target
+ * @return the target object after property binding
+ */
+ @Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)
+ public static Object bindProperties(final Object self, final Object target, final Object source) {
+ // target object has to be a ScriptObject
+ Global.checkObject(target);
+ // check null or undefined source object
+ Global.checkObjectCoercible(source);
+
+ final ScriptObject targetObj = (ScriptObject)target;
+
+ if (source instanceof ScriptObject) {
+ final ScriptObject sourceObj = (ScriptObject)source;
+ final Property[] properties = sourceObj.getMap().getProperties();
+
+ // filter non-enumerable properties
+ final ArrayList<Property> propList = new ArrayList<>();
+ for (Property prop : properties) {
+ if (prop.isEnumerable()) {
+ propList.add(prop);
+ }
+ }
+
+ if (! propList.isEmpty()) {
+ targetObj.addBoundProperties(sourceObj, propList.toArray(new Property[propList.size()]));
+ }
+ } else if (source instanceof ScriptObjectMirror) {
+ // get enumerable, immediate properties of mirror
+ final ScriptObjectMirror mirror = (ScriptObjectMirror)source;
+ final String[] keys = mirror.getOwnKeys(false);
+ if (keys.length == 0) {
+ // nothing to bind
+ return target;
+ }
+
+ // make accessor properties using dynamic invoker getters and setters
+ final AccessorProperty[] props = new AccessorProperty[keys.length];
+ for (int idx = 0; idx < keys.length; idx++) {
+ final String name = keys[idx];
+ final MethodHandle getter = Bootstrap.createDynamicInvoker("dyn:getMethod|getProp|getElem:" + name, Object.class, ScriptObjectMirror.class);
+ final MethodHandle setter = Bootstrap.createDynamicInvoker("dyn:setProp|setElem:" + name, Object.class, ScriptObjectMirror.class, Object.class);
+ props[idx] = (AccessorProperty.create(name, 0, getter, setter));
+ }
+
+ targetObj.addBoundProperties(source, props);
+ }
+
+ return target;
+ }
}
--- a/nashorn/src/jdk/nashorn/internal/runtime/AccessorProperty.java Tue Jul 09 13:57:24 2013 +0200
+++ b/nashorn/src/jdk/nashorn/internal/runtime/AccessorProperty.java Tue Jul 09 17:37:46 2013 +0530
@@ -147,9 +147,9 @@
* and are thus rebound with that as receiver
*
* @param property accessor property to rebind
- * @param delegate delegate script object to rebind receiver to
+ * @param delegate delegate object to rebind receiver to
*/
- public AccessorProperty(final AccessorProperty property, final ScriptObject delegate) {
+ public AccessorProperty(final AccessorProperty property, final Object delegate) {
super(property);
this.primitiveGetter = bindTo(property.primitiveGetter, delegate);
--- a/nashorn/src/jdk/nashorn/internal/runtime/Context.java Tue Jul 09 13:57:24 2013 +0200
+++ b/nashorn/src/jdk/nashorn/internal/runtime/Context.java Tue Jul 09 17:37:46 2013 +0530
@@ -199,6 +199,7 @@
private static final ClassLoader myLoader = Context.class.getClassLoader();
private static final StructureLoader sharedLoader;
+ private static final AccessControlContext NO_PERMISSIONS_CONTEXT;
static {
sharedLoader = AccessController.doPrivileged(new PrivilegedAction<StructureLoader>() {
@@ -207,6 +208,7 @@
return new StructureLoader(myLoader, null);
}
});
+ NO_PERMISSIONS_CONTEXT = new AccessControlContext(new ProtectionDomain[] { new ProtectionDomain(null, new Permissions()) });
}
/**
@@ -564,7 +566,7 @@
sm.checkPackageAccess(fullName.substring(0, index));
return null;
}
- }, createNoPermissionsContext());
+ }, NO_PERMISSIONS_CONTEXT);
}
}
@@ -707,10 +709,6 @@
return (context != null) ? context : Context.getContextTrusted();
}
- private static AccessControlContext createNoPermissionsContext() {
- return new AccessControlContext(new ProtectionDomain[] { new ProtectionDomain(null, new Permissions()) });
- }
-
private Object evaluateSource(final Source source, final ScriptObject scope, final ScriptObject thiz) {
ScriptFunction script = null;
--- a/nashorn/src/jdk/nashorn/internal/runtime/PropertyMap.java Tue Jul 09 13:57:24 2013 +0200
+++ b/nashorn/src/jdk/nashorn/internal/runtime/PropertyMap.java Tue Jul 09 17:37:46 2013 +0530
@@ -260,7 +260,7 @@
*
* @return New {@link PropertyMap} with {@link Property} added.
*/
- PropertyMap addPropertyBind(final AccessorProperty property, final ScriptObject bindTo) {
+ PropertyMap addPropertyBind(final AccessorProperty property, final Object bindTo) {
return addProperty(new AccessorProperty(property, bindTo));
}
--- a/nashorn/src/jdk/nashorn/internal/runtime/ScriptObject.java Tue Jul 09 13:57:24 2013 +0200
+++ b/nashorn/src/jdk/nashorn/internal/runtime/ScriptObject.java Tue Jul 09 17:37:46 2013 +0530
@@ -203,9 +203,19 @@
* @param source The source object to copy from.
*/
public void addBoundProperties(final ScriptObject source) {
+ addBoundProperties(source, source.getMap().getProperties());
+ }
+
+ /**
+ * Copy all properties from the array with their receiver bound to the source.
+ *
+ * @param source The source object to copy from.
+ * @param properties The array of properties to copy.
+ */
+ public void addBoundProperties(final ScriptObject source, final Property[] properties) {
PropertyMap newMap = this.getMap();
- for (final Property property : source.getMap().getProperties()) {
+ for (final Property property : properties) {
final String key = property.getKey();
if (newMap.findProperty(key) == null) {
@@ -222,6 +232,26 @@
}
/**
+ * Copy all properties from the array with their receiver bound to the source.
+ *
+ * @param source The source object to copy from.
+ * @param properties The collection of accessor properties to copy.
+ */
+ public void addBoundProperties(final Object source, final AccessorProperty[] properties) {
+ PropertyMap newMap = this.getMap();
+
+ for (final AccessorProperty property : properties) {
+ final String key = property.getKey();
+
+ if (newMap.findProperty(key) == null) {
+ newMap = newMap.addPropertyBind(property, source);
+ }
+ }
+
+ this.setMap(newMap);
+ }
+
+ /**
* Bind the method handle to the specified receiver, while preserving its original type (it will just ignore the
* first argument in lieu of the bound argument).
* @param methodHandle Method handle to bind to.
--- a/nashorn/src/jdk/nashorn/internal/runtime/linker/InvokeByName.java Tue Jul 09 13:57:24 2013 +0200
+++ b/nashorn/src/jdk/nashorn/internal/runtime/linker/InvokeByName.java Tue Jul 09 17:37:46 2013 +0530
@@ -83,7 +83,7 @@
*/
public InvokeByName(final String name, final Class<?> targetClass, final Class<?> rtype, final Class<?>... ptypes) {
this.name = name;
- getter = Bootstrap.createDynamicInvoker("dyn:getMethod|getProp|getItem:" + name, Object.class, targetClass);
+ getter = Bootstrap.createDynamicInvoker("dyn:getMethod|getProp|getElem:" + name, Object.class, targetClass);
final Class<?>[] finalPtypes;
final int plength = ptypes.length;
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/test/script/basic/JDK-8014785.js Tue Jul 09 17:37:46 2013 +0530
@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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 General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * JDK-8014785: Ability to extend global instance by binding properties of another object
+ *
+ * @test
+ * @run
+ */
+
+var obj = { x: 34, y: 100 };
+var foo = {}
+
+// bind properties of "obj" to "foo" obj
+Object.bindProperties(foo, obj);
+
+// now we can access/write on foo properties
+print("foo.x = " + foo.x); // prints obj.x which is 34
+
+// update obj.x via foo.x
+foo.x = "hello";
+print("obj.x = " + obj.x); // prints "hello" now
+
+obj.x = 42; // foo.x also becomes 42
+print("obj.x = " + obj.x); // prints 42
+print("foo.x = " + foo.x); // prints 42
+
+// now bind a mirror object to an object
+var obj = loadWithNewGlobal({
+ name: "test",
+ script: "obj = { x: 33, y: 'hello' }"
+});
+
+Object.bindProperties(this, obj);
+print("x = " + x); // prints 33
+print("y = " + y); // prints "hello"
+
+x = Math.PI; // changes obj.x to Math.PI
+print("obj.x = " +obj.x); // prints Math.PI
+
+obj.y = 32;
+print("y = " + y); // should print 32
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/test/script/basic/JDK-8014785.js.EXPECTED Tue Jul 09 17:37:46 2013 +0530
@@ -0,0 +1,8 @@
+foo.x = 34
+obj.x = hello
+obj.x = 42
+foo.x = 42
+x = 33
+y = hello
+obj.x = 3.141592653589793
+y = 32