1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/jdk/nashorn/internal/runtime/linker/BrowserJSObjectLinker.java Thu Aug 21 20:06:48 2014 +0530
1.3 @@ -0,0 +1,199 @@
1.4 +/*
1.5 + * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation. Oracle designates this
1.11 + * particular file as subject to the "Classpath" exception as provided
1.12 + * by Oracle in the LICENSE file that accompanied this code.
1.13 + *
1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 + * version 2 for more details (a copy is included in the LICENSE file that
1.18 + * accompanied this code).
1.19 + *
1.20 + * You should have received a copy of the GNU General Public License version
1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 + *
1.24 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.25 + * or visit www.oracle.com if you need additional information or have any
1.26 + * questions.
1.27 + */
1.28 +
1.29 +package jdk.nashorn.internal.runtime.linker;
1.30 +
1.31 +import static jdk.nashorn.internal.runtime.linker.BrowserJSObjectLinker.JSObjectHandles.*;
1.32 +
1.33 +import java.lang.invoke.MethodHandle;
1.34 +import java.lang.invoke.MethodHandles;
1.35 +import jdk.internal.dynalink.CallSiteDescriptor;
1.36 +import jdk.internal.dynalink.linker.GuardedInvocation;
1.37 +import jdk.internal.dynalink.linker.LinkRequest;
1.38 +import jdk.internal.dynalink.linker.LinkerServices;
1.39 +import jdk.internal.dynalink.linker.TypeBasedGuardingDynamicLinker;
1.40 +import jdk.internal.dynalink.support.CallSiteDescriptorFactory;
1.41 +import jdk.nashorn.internal.lookup.MethodHandleFactory;
1.42 +import jdk.nashorn.internal.lookup.MethodHandleFunctionality;
1.43 +import jdk.nashorn.internal.runtime.JSType;
1.44 +
1.45 +/**
1.46 + * A Dynalink linker to handle web browser built-in JS (DOM etc.) objects.
1.47 + */
1.48 +final class BrowserJSObjectLinker implements TypeBasedGuardingDynamicLinker {
1.49 + private static final ClassLoader myLoader = BrowserJSObjectLinker.class.getClassLoader();
1.50 + private static final String JSOBJECT_CLASS = "netscape.javascript.JSObject";
1.51 + // not final because this is lazily initialized
1.52 + // when we hit a subclass for the first time.
1.53 + private static volatile Class<?> jsObjectClass;
1.54 +
1.55 + @Override
1.56 + public boolean canLinkType(final Class<?> type) {
1.57 + return canLinkTypeStatic(type);
1.58 + }
1.59 +
1.60 + static boolean canLinkTypeStatic(final Class<?> type) {
1.61 + if (jsObjectClass != null && jsObjectClass.isAssignableFrom(type)) {
1.62 + return true;
1.63 + }
1.64 +
1.65 + // check if this class is a subclass of JSObject
1.66 + Class<?> clazz = type;
1.67 + while (clazz != null) {
1.68 + if (clazz.getClassLoader() == myLoader &&
1.69 + clazz.getName().equals(JSOBJECT_CLASS)) {
1.70 + jsObjectClass = clazz;
1.71 + return true;
1.72 + }
1.73 + clazz = clazz.getSuperclass();
1.74 + }
1.75 +
1.76 + return false;
1.77 + }
1.78 +
1.79 + private static void checkJSObjectClass() {
1.80 + assert jsObjectClass != null : JSOBJECT_CLASS + " not found!";
1.81 + }
1.82 +
1.83 + @Override
1.84 + public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices) throws Exception {
1.85 + final LinkRequest requestWithoutContext = request.withoutRuntimeContext(); // Nashorn has no runtime context
1.86 + final Object self = requestWithoutContext.getReceiver();
1.87 + final CallSiteDescriptor desc = requestWithoutContext.getCallSiteDescriptor();
1.88 + checkJSObjectClass();
1.89 +
1.90 + if (desc.getNameTokenCount() < 2 || !"dyn".equals(desc.getNameToken(CallSiteDescriptor.SCHEME))) {
1.91 + // We only support standard "dyn:*[:*]" operations
1.92 + return null;
1.93 + }
1.94 +
1.95 + final GuardedInvocation inv;
1.96 + if (jsObjectClass.isInstance(self)) {
1.97 + inv = lookup(desc);
1.98 + } else {
1.99 + throw new AssertionError(); // Should never reach here.
1.100 + }
1.101 +
1.102 + return Bootstrap.asTypeSafeReturn(inv, linkerServices, desc);
1.103 + }
1.104 +
1.105 + private static GuardedInvocation lookup(final CallSiteDescriptor desc) {
1.106 + final String operator = CallSiteDescriptorFactory.tokenizeOperators(desc).get(0);
1.107 + final int c = desc.getNameTokenCount();
1.108 +
1.109 + switch (operator) {
1.110 + case "getProp":
1.111 + case "getElem":
1.112 + case "getMethod":
1.113 + return c > 2 ? findGetMethod(desc) : findGetIndexMethod();
1.114 + case "setProp":
1.115 + case "setElem":
1.116 + return c > 2 ? findSetMethod(desc) : findSetIndexMethod();
1.117 + default:
1.118 + return null;
1.119 + }
1.120 + }
1.121 +
1.122 + private static GuardedInvocation findGetMethod(final CallSiteDescriptor desc) {
1.123 + final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
1.124 + final MethodHandle getter = MH.insertArguments(JSOBJECT_GETMEMBER, 1, name);
1.125 + return new GuardedInvocation(getter, IS_JSOBJECT_GUARD);
1.126 + }
1.127 +
1.128 + private static GuardedInvocation findGetIndexMethod() {
1.129 + return new GuardedInvocation(JSOBJECTLINKER_GET, IS_JSOBJECT_GUARD);
1.130 + }
1.131 +
1.132 + private static GuardedInvocation findSetMethod(final CallSiteDescriptor desc) {
1.133 + final MethodHandle getter = MH.insertArguments(JSOBJECT_SETMEMBER, 1, desc.getNameToken(2));
1.134 + return new GuardedInvocation(getter, IS_JSOBJECT_GUARD);
1.135 + }
1.136 +
1.137 + private static GuardedInvocation findSetIndexMethod() {
1.138 + return new GuardedInvocation(JSOBJECTLINKER_PUT, IS_JSOBJECT_GUARD);
1.139 + }
1.140 +
1.141 + @SuppressWarnings("unused")
1.142 + private static boolean isJSObject(final Object self) {
1.143 + return jsObjectClass.isInstance(self);
1.144 + }
1.145 +
1.146 + @SuppressWarnings("unused")
1.147 + private static Object get(final Object jsobj, final Object key) throws Throwable {
1.148 + if (key instanceof Integer) {
1.149 + return JSOBJECT_GETSLOT.invokeExact(jsobj, (int)key);
1.150 + } else if (key instanceof Number) {
1.151 + final int index = getIndex((Number)key);
1.152 + if (index > -1) {
1.153 + return JSOBJECT_GETSLOT.invokeExact(jsobj, index);
1.154 + }
1.155 + } else if (key instanceof String) {
1.156 + return JSOBJECT_GETMEMBER.invokeExact(jsobj, (String)key);
1.157 + }
1.158 + return null;
1.159 + }
1.160 +
1.161 + @SuppressWarnings("unused")
1.162 + private static void put(final Object jsobj, final Object key, final Object value) throws Throwable {
1.163 + if (key instanceof Integer) {
1.164 + JSOBJECT_SETSLOT.invokeExact(jsobj, (int)key, value);
1.165 + } else if (key instanceof Number) {
1.166 + JSOBJECT_SETSLOT.invokeExact(jsobj, getIndex((Number)key), value);
1.167 + } else if (key instanceof String) {
1.168 + JSOBJECT_SETMEMBER.invokeExact(jsobj, (String)key, value);
1.169 + }
1.170 + }
1.171 +
1.172 + private static int getIndex(final Number n) {
1.173 + final double value = n.doubleValue();
1.174 + return JSType.isRepresentableAsInt(value) ? (int)value : -1;
1.175 + }
1.176 +
1.177 + private static final MethodHandleFunctionality MH = MethodHandleFactory.getFunctionality();
1.178 + // method handles of the current class
1.179 + private static final MethodHandle IS_JSOBJECT_GUARD = findOwnMH_S("isJSObject", boolean.class, Object.class);
1.180 + private static final MethodHandle JSOBJECTLINKER_GET = findOwnMH_S("get", Object.class, Object.class, Object.class);
1.181 + private static final MethodHandle JSOBJECTLINKER_PUT = findOwnMH_S("put", Void.TYPE, Object.class, Object.class, Object.class);
1.182 +
1.183 + private static MethodHandle findOwnMH_S(final String name, final Class<?> rtype, final Class<?>... types) {
1.184 + return MH.findStatic(MethodHandles.lookup(), BrowserJSObjectLinker.class, name, MH.type(rtype, types));
1.185 + }
1.186 +
1.187 + // method handles of netscape.javascript.JSObject class
1.188 + // These are in separate class as we lazily initialize these
1.189 + // method handles when we hit a subclass of JSObject first time.
1.190 + static class JSObjectHandles {
1.191 + // method handles of JSObject class
1.192 + static final MethodHandle JSOBJECT_GETMEMBER = findJSObjectMH_V("getMember", Object.class, String.class).asType(MH.type(Object.class, Object.class, String.class));
1.193 + static final MethodHandle JSOBJECT_GETSLOT = findJSObjectMH_V("getSlot", Object.class, int.class).asType(MH.type(Object.class, Object.class, int.class));
1.194 + 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));
1.195 + 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));
1.196 +
1.197 + private static MethodHandle findJSObjectMH_V(final String name, final Class<?> rtype, final Class<?>... types) {
1.198 + checkJSObjectClass();
1.199 + return MH.findVirtual(MethodHandles.publicLookup(), jsObjectClass, name, MH.type(rtype, types));
1.200 + }
1.201 + }
1.202 +}
