/*
* Copyright (c) 2014, 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. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* 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.
*
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package jdk.nashorn.internal.runtime.linker;
import static jdk.nashorn.internal.runtime.JSType.isString;
import static jdk.nashorn.internal.runtime.linker.BrowserJSObjectLinker.JSObjectHandles.JSOBJECT_CALL;
import static jdk.nashorn.internal.runtime.linker.BrowserJSObjectLinker.JSObjectHandles.JSOBJECT_GETMEMBER;
import static jdk.nashorn.internal.runtime.linker.BrowserJSObjectLinker.JSObjectHandles.JSOBJECT_GETSLOT;
import static jdk.nashorn.internal.runtime.linker.BrowserJSObjectLinker.JSObjectHandles.JSOBJECT_SETMEMBER;
import static jdk.nashorn.internal.runtime.linker.BrowserJSObjectLinker.JSObjectHandles.JSOBJECT_SETSLOT;
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import jdk.dynalink.CallSiteDescriptor;
import jdk.dynalink.linker.GuardedInvocation;
import jdk.dynalink.linker.LinkRequest;
import jdk.dynalink.linker.LinkerServices;
import jdk.dynalink.linker.TypeBasedGuardingDynamicLinker;
import jdk.nashorn.internal.lookup.MethodHandleFactory;
import jdk.nashorn.internal.lookup.MethodHandleFunctionality;
import jdk.nashorn.internal.runtime.JSType;
/**
* A Dynalink linker to handle web browser built-in JS (DOM etc.) objects.
*/
final class BrowserJSObjectLinker implements TypeBasedGuardingDynamicLinker {
private static final String JSOBJECT_CLASS = "netscape.javascript.JSObject";
private static final Class<?> jsObjectClass = findBrowserJSObjectClass();
private final NashornBeansLinker nashornBeansLinker;
BrowserJSObjectLinker(final NashornBeansLinker nashornBeansLinker) {
this.nashornBeansLinker = nashornBeansLinker;
}
@Override
public boolean canLinkType(final Class<?> type) {
return canLinkTypeStatic(type);
}
static boolean canLinkTypeStatic(final Class<?> type) {
return jsObjectClass != null && jsObjectClass.isAssignableFrom(type);
}
private static void checkJSObjectClass() {
assert jsObjectClass != null : JSOBJECT_CLASS + " not found!";
}
@Override
public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices) throws Exception {
final Object self = request.getReceiver();
final CallSiteDescriptor desc = request.getCallSiteDescriptor();
checkJSObjectClass();
assert jsObjectClass.isInstance(self);
GuardedInvocation inv = lookup(desc, request, linkerServices);
inv = inv.replaceMethods(linkerServices.filterInternalObjects(inv.getInvocation()), inv.getGuard());
return Bootstrap.asTypeSafeReturn(inv, linkerServices, desc);
}
private GuardedInvocation lookup(final CallSiteDescriptor desc, final LinkRequest request, final LinkerServices linkerServices) throws Exception {
GuardedInvocation inv;
try {
inv = nashornBeansLinker.getGuardedInvocation(request, linkerServices);
} catch (final Throwable th) {
inv = null;
}
final String name = NashornCallSiteDescriptor.getOperand(desc);
switch (NashornCallSiteDescriptor.getStandardOperation(desc)) {
case GET:
return name != null ? findGetMethod(name, inv) : findGetIndexMethod(inv);
case SET:
return name != null ? findSetMethod(name, inv) : findSetIndexMethod();
case CALL:
return findCallMethod(desc);
default:
return null;
}
}
private static GuardedInvocation findGetMethod(final String name, final GuardedInvocation inv) {
if (inv != null) {
return inv;
}
final MethodHandle getter = MH.insertArguments(JSOBJECT_GETMEMBER, 1, name);
return new GuardedInvocation(getter, IS_JSOBJECT_GUARD);
}
private static GuardedInvocation findGetIndexMethod(final GuardedInvocation inv) {
final MethodHandle getter = MH.insertArguments(JSOBJECTLINKER_GET, 0, inv.getInvocation());
return inv.replaceMethods(getter, inv.getGuard());
}
private static GuardedInvocation findSetMethod(final String name, final GuardedInvocation inv) {
if (inv != null) {
return inv;
}
final MethodHandle getter = MH.insertArguments(JSOBJECT_SETMEMBER, 1, name);
return new GuardedInvocation(getter, IS_JSOBJECT_GUARD);
}
private static GuardedInvocation findSetIndexMethod() {
return new GuardedInvocation(JSOBJECTLINKER_PUT, IS_JSOBJECT_GUARD);
}
private static GuardedInvocation findCallMethod(final CallSiteDescriptor desc) {
final MethodHandle call = MH.insertArguments(JSOBJECT_CALL, 1, "call");
return new GuardedInvocation(MH.asCollector(call, Object[].class, desc.getMethodType().parameterCount() - 1), IS_JSOBJECT_GUARD);
}
@SuppressWarnings("unused")
private static boolean isJSObject(final Object self) {
return jsObjectClass.isInstance(self);
}
@SuppressWarnings("unused")
private static Object get(final MethodHandle fallback, final Object jsobj, final Object key) throws Throwable {
if (key instanceof Integer) {
return JSOBJECT_GETSLOT.invokeExact(jsobj, (int)key);
} else if (key instanceof Number) {
final int index = getIndex((Number)key);
if (index > -1) {
return JSOBJECT_GETSLOT.invokeExact(jsobj, index);
}
} else if (isString(key)) {
final String name = key.toString();
if (name.indexOf('(') != -1) {
return fallback.invokeExact(jsobj, (Object) name);
}
return JSOBJECT_GETMEMBER.invokeExact(jsobj, name);
}
return null;
}
@SuppressWarnings("unused")
private static void put(final Object jsobj, final Object key, final Object value) throws Throwable {
if (key instanceof Integer) {
JSOBJECT_SETSLOT.invokeExact(jsobj, (int)key, value);
} else if (key instanceof Number) {
JSOBJECT_SETSLOT.invokeExact(jsobj, getIndex((Number)key), value);
} else if (isString(key)) {
JSOBJECT_SETMEMBER.invokeExact(jsobj, key.toString(), value);
}
}
private static int getIndex(final Number n) {
final double value = n.doubleValue();
return JSType.isRepresentableAsInt(value) ? (int)value : -1;
}
private static final MethodHandleFunctionality MH = MethodHandleFactory.getFunctionality();
// method handles of the current class
private static final MethodHandle IS_JSOBJECT_GUARD = findOwnMH_S("isJSObject", boolean.class, Object.class);
private static final MethodHandle JSOBJECTLINKER_GET = findOwnMH_S("get", Object.class, MethodHandle.class, Object.class, Object.class);
private static final MethodHandle JSOBJECTLINKER_PUT = findOwnMH_S("put", Void.TYPE, Object.class, Object.class, Object.class);
private static MethodHandle findOwnMH_S(final String name, final Class<?> rtype, final Class<?>... types) {
return MH.findStatic(MethodHandles.lookup(), BrowserJSObjectLinker.class, name, MH.type(rtype, types));
}
// method handles of netscape.javascript.JSObject class
// These are in separate class as we lazily initialize these
// method handles when we hit a subclass of JSObject first time.
static class JSObjectHandles {
// method handles of JSObject class
static final MethodHandle JSOBJECT_GETMEMBER = findJSObjectMH_V("getMember", Object.class, String.class).asType(MH.type(Object.class, Object.class, String.class));
static final MethodHandle JSOBJECT_GETSLOT = findJSObjectMH_V("getSlot", Object.class, int.class).asType(MH.type(Object.class, Object.class, int.class));
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));
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));
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));
private static MethodHandle findJSObjectMH_V(final String name, final Class<?> rtype, final Class<?>... types) {
checkJSObjectClass();
return MH.findVirtual(MethodHandles.publicLookup(), jsObjectClass, name, MH.type(rtype, types));
}
}
private static Class<?> findBrowserJSObjectClass() {
ClassLoader extLoader;
extLoader = BrowserJSObjectLinker.class.getClassLoader();
// in case nashorn is loaded as bootstrap!
if (extLoader == null) {
extLoader = ClassLoader.getSystemClassLoader().getParent();
}
try {
return Class.forName(JSOBJECT_CLASS, false, extLoader);
} catch (final ClassNotFoundException e) {
return null;
}
}
}