BrowserJSObjectLinker.java revision 1805:7caf1f762f1d 
1/*
2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package jdk.nashorn.internal.runtime.linker;
27
28import static jdk.nashorn.internal.runtime.JSType.isString;
29import static jdk.nashorn.internal.runtime.linker.BrowserJSObjectLinker.JSObjectHandles.JSOBJECT_CALL;
30import static jdk.nashorn.internal.runtime.linker.BrowserJSObjectLinker.JSObjectHandles.JSOBJECT_GETMEMBER;
31import static jdk.nashorn.internal.runtime.linker.BrowserJSObjectLinker.JSObjectHandles.JSOBJECT_GETSLOT;
32import static jdk.nashorn.internal.runtime.linker.BrowserJSObjectLinker.JSObjectHandles.JSOBJECT_SETMEMBER;
33import static jdk.nashorn.internal.runtime.linker.BrowserJSObjectLinker.JSObjectHandles.JSOBJECT_SETSLOT;
34
35import java.lang.invoke.MethodHandle;
36import java.lang.invoke.MethodHandles;
37import jdk.dynalink.CallSiteDescriptor;
38import jdk.dynalink.linker.GuardedInvocation;
39import jdk.dynalink.linker.LinkRequest;
40import jdk.dynalink.linker.LinkerServices;
41import jdk.dynalink.linker.TypeBasedGuardingDynamicLinker;
42import jdk.nashorn.internal.lookup.MethodHandleFactory;
43import jdk.nashorn.internal.lookup.MethodHandleFunctionality;
44import jdk.nashorn.internal.runtime.JSType;
45
46/**
47 * A Dynalink linker to handle web browser built-in JS (DOM etc.) objects.
48 */
49final class BrowserJSObjectLinker implements TypeBasedGuardingDynamicLinker {
50    private static final String JSOBJECT_CLASS = "netscape.javascript.JSObject";
51    private static final Class<?> jsObjectClass = findBrowserJSObjectClass();
52    private final NashornBeansLinker nashornBeansLinker;
53
54    BrowserJSObjectLinker(final NashornBeansLinker nashornBeansLinker) {
55        this.nashornBeansLinker = nashornBeansLinker;
56    }
57
58    @Override
59    public boolean canLinkType(final Class<?> type) {
60        return canLinkTypeStatic(type);
61    }
62
63    static boolean canLinkTypeStatic(final Class<?> type) {
64        return jsObjectClass != null && jsObjectClass.isAssignableFrom(type);
65    }
66
67    private static void checkJSObjectClass() {
68        assert jsObjectClass != null : JSOBJECT_CLASS + " not found!";
69    }
70
71    @Override
72    public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices) throws Exception {
73        final Object self = request.getReceiver();
74        final CallSiteDescriptor desc = request.getCallSiteDescriptor();
75        checkJSObjectClass();
76
77        assert jsObjectClass.isInstance(self);
78
79        GuardedInvocation inv = lookup(desc, request, linkerServices);
80        inv = inv.replaceMethods(linkerServices.filterInternalObjects(inv.getInvocation()), inv.getGuard());
81
82        return Bootstrap.asTypeSafeReturn(inv, linkerServices, desc);
83    }
84
85    private GuardedInvocation lookup(final CallSiteDescriptor desc, final LinkRequest request, final LinkerServices linkerServices) throws Exception {
86        GuardedInvocation inv;
87        try {
88            inv = nashornBeansLinker.getGuardedInvocation(request, linkerServices);
89        } catch (final Throwable th) {
90            inv = null;
91        }
92
93        final String name = NashornCallSiteDescriptor.getOperand(desc);
94        switch (NashornCallSiteDescriptor.getStandardOperation(desc)) {
95        case GET:
96            return name != null ? findGetMethod(name, inv) : findGetIndexMethod(inv);
97        case SET:
98            return name != null ? findSetMethod(name, inv) : findSetIndexMethod();
99        case CALL:
100            return findCallMethod(desc);
101        default:
102            return null;
103        }
104    }
105
106    private static GuardedInvocation findGetMethod(final String name, final GuardedInvocation inv) {
107        if (inv != null) {
108            return inv;
109        }
110        final MethodHandle getter = MH.insertArguments(JSOBJECT_GETMEMBER, 1, name);
111        return new GuardedInvocation(getter, IS_JSOBJECT_GUARD);
112    }
113
114    private static GuardedInvocation findGetIndexMethod(final GuardedInvocation inv) {
115        final MethodHandle getter = MH.insertArguments(JSOBJECTLINKER_GET, 0, inv.getInvocation());
116        return inv.replaceMethods(getter, inv.getGuard());
117    }
118
119    private static GuardedInvocation findSetMethod(final String name, final GuardedInvocation inv) {
120        if (inv != null) {
121            return inv;
122        }
123        final MethodHandle getter = MH.insertArguments(JSOBJECT_SETMEMBER, 1, name);
124        return new GuardedInvocation(getter, IS_JSOBJECT_GUARD);
125    }
126
127    private static GuardedInvocation findSetIndexMethod() {
128        return new GuardedInvocation(JSOBJECTLINKER_PUT, IS_JSOBJECT_GUARD);
129    }
130
131    private static GuardedInvocation findCallMethod(final CallSiteDescriptor desc) {
132        final MethodHandle call = MH.insertArguments(JSOBJECT_CALL, 1, "call");
133        return new GuardedInvocation(MH.asCollector(call, Object[].class, desc.getMethodType().parameterCount() - 1), IS_JSOBJECT_GUARD);
134    }
135
136    @SuppressWarnings("unused")
137    private static boolean isJSObject(final Object self) {
138        return jsObjectClass.isInstance(self);
139    }
140
141    @SuppressWarnings("unused")
142    private static Object get(final MethodHandle fallback, final Object jsobj, final Object key) throws Throwable {
143        if (key instanceof Integer) {
144            return JSOBJECT_GETSLOT.invokeExact(jsobj, (int)key);
145        } else if (key instanceof Number) {
146            final int index = getIndex((Number)key);
147            if (index > -1) {
148                return JSOBJECT_GETSLOT.invokeExact(jsobj, index);
149            }
150        } else if (isString(key)) {
151            final String name = key.toString();
152            if (name.indexOf('(') != -1) {
153                return fallback.invokeExact(jsobj, (Object) name);
154            }
155            return JSOBJECT_GETMEMBER.invokeExact(jsobj, name);
156        }
157        return null;
158    }
159
160    @SuppressWarnings("unused")
161    private static void put(final Object jsobj, final Object key, final Object value) throws Throwable {
162        if (key instanceof Integer) {
163            JSOBJECT_SETSLOT.invokeExact(jsobj, (int)key, value);
164        } else if (key instanceof Number) {
165            JSOBJECT_SETSLOT.invokeExact(jsobj, getIndex((Number)key), value);
166        } else if (isString(key)) {
167            JSOBJECT_SETMEMBER.invokeExact(jsobj, key.toString(), value);
168        }
169    }
170
171    private static int getIndex(final Number n) {
172        final double value = n.doubleValue();
173        return JSType.isRepresentableAsInt(value) ? (int)value : -1;
174    }
175
176    private static final MethodHandleFunctionality MH = MethodHandleFactory.getFunctionality();
177    // method handles of the current class
178    private static final MethodHandle IS_JSOBJECT_GUARD  = findOwnMH_S("isJSObject", boolean.class, Object.class);
179    private static final MethodHandle JSOBJECTLINKER_GET = findOwnMH_S("get", Object.class, MethodHandle.class, Object.class, Object.class);
180    private static final MethodHandle JSOBJECTLINKER_PUT = findOwnMH_S("put", Void.TYPE, Object.class, Object.class, Object.class);
181
182    private static MethodHandle findOwnMH_S(final String name, final Class<?> rtype, final Class<?>... types) {
183            return MH.findStatic(MethodHandles.lookup(), BrowserJSObjectLinker.class, name, MH.type(rtype, types));
184    }
185
186    // method handles of netscape.javascript.JSObject class
187    // These are in separate class as we lazily initialize these
188    // method handles when we hit a subclass of JSObject first time.
189    static class JSObjectHandles {
190        // method handles of JSObject class
191        static final MethodHandle JSOBJECT_GETMEMBER     = findJSObjectMH_V("getMember", Object.class, String.class).asType(MH.type(Object.class, Object.class, String.class));
192        static final MethodHandle JSOBJECT_GETSLOT       = findJSObjectMH_V("getSlot", Object.class, int.class).asType(MH.type(Object.class, Object.class, int.class));
193        static final MethodHandle JSOBJECT_SETMEMBER     = findJSObjectMH_V("setMember", Void.TYPE, String.class, Object.class).asType(MH.type(Void.TYPE, Object.class, String.class, Object.class));
194        static final MethodHandle JSOBJECT_SETSLOT       = findJSObjectMH_V("setSlot", Void.TYPE, int.class, Object.class).asType(MH.type(Void.TYPE, Object.class, int.class, Object.class));
195        static final MethodHandle JSOBJECT_CALL          = findJSObjectMH_V("call", Object.class, String.class, Object[].class).asType(MH.type(Object.class, Object.class, String.class, Object[].class));
196
197        private static MethodHandle findJSObjectMH_V(final String name, final Class<?> rtype, final Class<?>... types) {
198            checkJSObjectClass();
199            return MH.findVirtual(MethodHandles.publicLookup(), jsObjectClass, name, MH.type(rtype, types));
200        }
201    }
202
203    private static Class<?> findBrowserJSObjectClass() {
204        ClassLoader extLoader;
205        extLoader = BrowserJSObjectLinker.class.getClassLoader();
206        // in case nashorn is loaded as bootstrap!
207        if (extLoader == null) {
208            extLoader = ClassLoader.getSystemClassLoader().getParent();
209        }
210        try {
211            return Class.forName(JSOBJECT_CLASS, false, extLoader);
212        } catch (final ClassNotFoundException e) {
213            return null;
214        }
215    }
216}
217