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Rhino is an open-source implementation of JavaScript written entirely in Java.
It is typically embedded into Java applications to provide scripting to end users.
Full jar including tools, excluding the JSR-223 Script Engine wrapper.
/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.javascript;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.util.WeakHashMap;
/**
* This is an implementation of the ES6 WeakMap class. As per the spec, keys must be
* ordinary objects. Since there is no defined "equality" for objects, comparisions
* are done strictly by object equality. Both ES6 and the java.util.WeakHashMap class
* have the same basic structure -- entries are removed automatically when the sole
* remaining reference to the key is a weak reference. Therefore, we can use
* WeakHashMap as the basis of this implementation and preserve the same semantics.
*/
public class NativeWeakMap
extends IdScriptableObject
{
private static final Object MAP_TAG = "WeakMap";
private boolean instanceOfWeakMap = false;
private transient WeakHashMap map = new WeakHashMap<>();
private static final Object NULL_VALUE = new Object();
static void init(Scriptable scope, boolean sealed) {
NativeWeakMap m = new NativeWeakMap();
m.exportAsJSClass(MAX_PROTOTYPE_ID, scope, sealed);
}
@Override
public String getClassName() {
return "WeakMap";
}
@Override
public Object execIdCall(IdFunctionObject f, Context cx, Scriptable scope,
Scriptable thisObj, Object[] args) {
if (!f.hasTag(MAP_TAG)) {
return super.execIdCall(f, cx, scope, thisObj, args);
}
int id = f.methodId();
switch (id) {
case Id_constructor:
if (thisObj == null) {
NativeWeakMap nm = new NativeWeakMap();
nm.instanceOfWeakMap = true;
if (args.length > 0) {
NativeMap.loadFromIterable(cx, scope, nm, args[0]);
}
return nm;
}
throw ScriptRuntime.typeError1("msg.no.new", "WeakMap");
case Id_delete:
return realThis(thisObj, f).js_delete(args.length > 0 ? args[0] : Undefined.instance);
case Id_get:
return realThis(thisObj, f).js_get(args.length > 0 ? args[0] : Undefined.instance);
case Id_has:
return realThis(thisObj, f).js_has(args.length > 0 ? args[0] : Undefined.instance);
case Id_set:
return realThis(thisObj, f).js_set(
args.length > 0 ? args[0] : Undefined.instance,
args.length > 1 ? args[1] : Undefined.instance);
}
throw new IllegalArgumentException("WeakMap.prototype has no method: " + f.getFunctionName());
}
private Object js_delete(Object key) {
if (!ScriptRuntime.isObject(key)) {
return false;
}
final Object oldVal = map.remove(key);
return (oldVal != null);
}
private Object js_get(Object key) {
if (!ScriptRuntime.isObject(key)) {
return Undefined.instance;
}
Object result = map.get(key);
if (result == null) {
return Undefined.instance;
} else if (result == NULL_VALUE) {
return null;
}
return result;
}
private Object js_has(Object key) {
if (!ScriptRuntime.isObject(key)) {
return false;
}
return map.containsKey(key);
}
private Object js_set(Object key, Object v) {
// As the spec says, only a true "Object" can be the key to a WeakMap.
// Use the default object equality here. ScriptableObject does not override
// equals or hashCode, which means that in effect we are only keying on object identity.
// This is all correct according to the ECMAscript spec.
if (!ScriptRuntime.isObject(key)) {
throw ScriptRuntime.typeError1("msg.arg.not.object", ScriptRuntime.typeof(key));
}
// Map.get() does not distinguish between "not found" and a null value. So,
// replace true null here with a marker so that we can re-convert in "get".
final Object value = (v == null ? NULL_VALUE : v);
map.put((Scriptable)key, value);
return this;
}
private NativeWeakMap realThis(Scriptable thisObj, IdFunctionObject f) {
if (thisObj == null) {
throw incompatibleCallError(f);
}
try {
final NativeWeakMap nm = (NativeWeakMap)thisObj;
if (!nm.instanceOfWeakMap) {
// Check for "Map internal data tag"
throw incompatibleCallError(f);
}
return nm;
} catch (ClassCastException cce) {
throw incompatibleCallError(f);
}
}
@Override
protected void initPrototypeId(int id) {
if (id == SymbolId_toStringTag) {
initPrototypeValue(SymbolId_toStringTag, SymbolKey.TO_STRING_TAG,
getClassName(), DONTENUM | READONLY);
return;
}
String s, fnName = null;
int arity;
switch (id) {
case Id_constructor: arity = 0; s = "constructor"; break;
case Id_delete: arity = 1; s = "delete"; break;
case Id_get: arity = 1; s = "get"; break;
case Id_has: arity = 1; s = "has"; break;
case Id_set: arity = 2; s = "set"; break;
default: throw new IllegalArgumentException(String.valueOf(id));
}
initPrototypeMethod(MAP_TAG, id, s, fnName, arity);
}
@Override
protected int findPrototypeId(Symbol k)
{
if (SymbolKey.TO_STRING_TAG.equals(k)) {
return SymbolId_toStringTag;
}
return 0;
}
// #string_id_map#
@Override
protected int findPrototypeId(String s) {
int id;
// #generated# Last update: 2018-08-24 15:27:45 PDT
L0: { id = 0; String X = null; int c;
int s_length = s.length();
if (s_length==3) {
c=s.charAt(0);
if (c=='g') { if (s.charAt(2)=='t' && s.charAt(1)=='e') {id=Id_get; break L0;} }
else if (c=='h') { if (s.charAt(2)=='s' && s.charAt(1)=='a') {id=Id_has; break L0;} }
else if (c=='s') { if (s.charAt(2)=='t' && s.charAt(1)=='e') {id=Id_set; break L0;} }
}
else if (s_length==6) { X="delete";id=Id_delete; }
else if (s_length==11) { X="constructor";id=Id_constructor; }
if (X!=null && X!=s && !X.equals(s)) id = 0;
break L0;
}
// #/generated#
return id;
}
private static final int
Id_constructor = 1,
Id_delete = 2,
Id_get = 3,
Id_has = 4,
Id_set = 5,
SymbolId_toStringTag = 6,
MAX_PROTOTYPE_ID = SymbolId_toStringTag;
// #/string_id_map#
private void readObject(ObjectInputStream stream)
throws IOException, ClassNotFoundException
{
stream.defaultReadObject();
map = new WeakHashMap<>();
}
}