nashorn/src/jdk/nashorn/internal/runtime/linker/JSObjectLinker.java - platform/libcore - Git at Google

 /*
  * 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.  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.
  *
  * 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.
  */

 package jdk.nashorn.internal.runtime.linker;

 import jdk.nashorn.internal.lookup.MethodHandleFunctionality;
 import jdk.nashorn.internal.lookup.MethodHandleFactory;
 import java.lang.invoke.MethodHandle;
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.MethodType;
 import java.util.Objects;
 import jdk.internal.dynalink.CallSiteDescriptor;
 import jdk.internal.dynalink.linker.GuardedInvocation;
 import jdk.internal.dynalink.linker.LinkRequest;
 import jdk.internal.dynalink.linker.LinkerServices;
 import jdk.internal.dynalink.linker.TypeBasedGuardingDynamicLinker;
 import jdk.internal.dynalink.support.CallSiteDescriptorFactory;
 import jdk.nashorn.internal.runtime.JSType;
 import jdk.nashorn.api.scripting.JSObject;

 /**
  * A Dynalink linker to handle web browser built-in JS (DOM etc.) objects as well
  * as ScriptObjects from other Nashorn contexts.
  */
 final class JSObjectLinker implements TypeBasedGuardingDynamicLinker {
    /**
      * Instances of this class are used to represent a method member of a JSObject
      */
     private static final class JSObjectMethod {
         // The name of the JSObject method property
         private final String name;

         JSObjectMethod(final String name) {
             this.name = name;
         }

         String getName() {
             return name;
         }

         static GuardedInvocation lookup(final CallSiteDescriptor desc) {
             final String operator = CallSiteDescriptorFactory.tokenizeOperators(desc).get(0);
             switch (operator) {
                 case "call": {
                     // collect everything except the first two - JSObjectMethod instance and the actual 'self'
                     final int paramCount = desc.getMethodType().parameterCount();
                     final MethodHandle caller = MH.asCollector(JSOBJECTMETHOD_CALL, Object[].class, paramCount - 2);
                     return new GuardedInvocation(caller, null, IS_JSOBJECTMETHOD_GUARD);
                 }
                 default:
                     return null;
             }
         }
     }

     @Override
     public boolean canLinkType(final Class<?> type) {
         return canLinkTypeStatic(type);
     }

     static boolean canLinkTypeStatic(final Class<?> type) {
         // can link JSObject and JSObjectMethod
         return JSObject.class.isAssignableFrom(type) || JSObjectMethod.class.isAssignableFrom(type);
     }

     @Override
     public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices) throws Exception {
         final LinkRequest requestWithoutContext = request.withoutRuntimeContext(); // Nashorn has no runtime context
         final Object self = requestWithoutContext.getReceiver();
         final CallSiteDescriptor desc = requestWithoutContext.getCallSiteDescriptor();

         if (desc.getNameTokenCount() < 2 || !"dyn".equals(desc.getNameToken(CallSiteDescriptor.SCHEME))) {
             // We only support standard "dyn:*[:*]" operations
             return null;
         }

         final GuardedInvocation inv;
         if (self instanceof JSObject) {
             inv = lookup(desc);
         } else if (self instanceof JSObjectMethod) {
             inv = JSObjectMethod.lookup(desc);
         } else {
             throw new AssertionError(); // Should never reach here.
         }

         return Bootstrap.asType(inv, linkerServices, desc);
     }

     private static GuardedInvocation lookup(final CallSiteDescriptor desc) {
         final String operator = CallSiteDescriptorFactory.tokenizeOperators(desc).get(0);
         final int c = desc.getNameTokenCount();
         switch (operator) {
             case "getProp":
             case "getElem":
             case "getMethod":
                 return c > 2 ? findGetMethod(desc, operator) : findGetIndexMethod();
             case "setProp":
             case "setElem":
                 return c > 2 ? findSetMethod(desc) : findSetIndexMethod();
             case "call":
             case "callMethod":
                 return findCallMethod(desc, operator);
             case "new":
             default:
                 return null;
         }
     }

     private static GuardedInvocation findGetMethod(final CallSiteDescriptor desc, final String operator) {
         // if "getMethod" then return JSObjectMethod object - which just holds the name of the method
         // subsequently, link on dyn:call for JSObjectMethod will actually call that method
         final MethodHandle getter = MH.insertArguments("getMethod".equals(operator)? JSOBJECT_GETMETHOD : JSOBJECT_GET, 1, desc.getNameToken(2));
         return new GuardedInvocation(getter, null, IS_JSOBJECT_GUARD);
     }

     private static GuardedInvocation findGetIndexMethod() {
         return new GuardedInvocation(JSOBJECT_GET, null, IS_JSOBJECT_GUARD);
     }

     private static GuardedInvocation findSetMethod(final CallSiteDescriptor desc) {
         final MethodHandle getter = MH.insertArguments(JSOBJECT_PUT, 1, desc.getNameToken(2));
         return new GuardedInvocation(getter, null, IS_JSOBJECT_GUARD);
     }

     private static GuardedInvocation findSetIndexMethod() {
         return new GuardedInvocation(JSOBJECT_PUT, null, IS_JSOBJECT_GUARD);
     }

     private static GuardedInvocation findCallMethod(final CallSiteDescriptor desc, final String operator) {
         // if operator is "call", then 'self' is a JSObject function object already. Use 'call' as the method name
         final String methodName = "callMethod".equals(operator)? desc.getNameToken(2) : "call";
         MethodHandle func = MH.insertArguments(JSOBJECT_CALL, 1, methodName);
         func = MH.asCollector(func, Object[].class, desc.getMethodType().parameterCount() - 1);
         return new GuardedInvocation(func, null, IS_JSOBJECT_GUARD);
     }

     @SuppressWarnings("unused")
     private static boolean isJSObjectMethod(final Object self) {
         return self instanceof JSObjectMethod;
     }

     @SuppressWarnings("unused")
     private static boolean isJSObject(final Object self) {
         return self instanceof JSObject;
     }


     @SuppressWarnings("unused")
     private static Object getMethod(final Object jsobj, final Object key) {
         return new JSObjectMethod(Objects.toString(key));
     }

     @SuppressWarnings("unused")
     private static Object get(final Object jsobj, final Object key) {
         if (key instanceof String) {
             return ((JSObject)jsobj).getMember((String)key);
         } else if (key instanceof Number) {
             final int index = getIndex((Number)key);
             if (index > -1) {
                 return ((JSObject)jsobj).getSlot(index);
             }
         }
         return null;
     }

     @SuppressWarnings("unused")
     private static void put(final Object jsobj, final Object key, final Object value) {
         if (key instanceof String) {
             ((JSObject)jsobj).setMember((String)key, value);
         } else if (key instanceof Number) {
             ((JSObject)jsobj).setSlot(getIndex((Number)key), value);
         }
     }

     @SuppressWarnings("unused")
     private static Object call(final Object jsobj, final Object method, final Object... args) {
         return ((JSObject)jsobj).call(Objects.toString(method), args);
     }

     @SuppressWarnings("unused")
     private static Object jsObjectMethodCall(final Object jsObjMethod, final Object jsobj, final Object... args) {
         // we have JSObjectMethod, JSObject and args. Get method name from JSObjectMethod instance
         final String methodName = ((JSObjectMethod)jsObjMethod).getName();
         // call the method on JSObject
         return ((JSObject)jsobj).call(methodName, args);
     }

     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();

     private static final MethodHandle IS_JSOBJECTMETHOD_GUARD = findOwnMH("isJSObjectMethod", boolean.class, Object.class);
     private static final MethodHandle IS_JSOBJECT_GUARD = findOwnMH("isJSObject", boolean.class, Object.class);
     private static final MethodHandle JSOBJECT_GETMETHOD = findOwnMH("getMethod", Object.class, Object.class, Object.class);
     private static final MethodHandle JSOBJECT_GET = findOwnMH("get", Object.class, Object.class, Object.class);
     private static final MethodHandle JSOBJECT_PUT = findOwnMH("put", Void.TYPE, Object.class, Object.class, Object.class);
     private static final MethodHandle JSOBJECT_CALL = findOwnMH("call", Object.class, Object.class, Object.class, Object[].class);
     private static final MethodHandle JSOBJECTMETHOD_CALL = findOwnMH("jsObjectMethodCall", Object.class, Object.class, Object.class, Object[].class);

     private static MethodHandle findOwnMH(final String name, final Class<?> rtype, final Class<?>... types) {
         final Class<?>   own = JSObjectLinker.class;
         final MethodType mt  = MH.type(rtype, types);
         try {
             return MH.findStatic(MethodHandles.lookup(), own, name, mt);
         } catch (final MethodHandleFactory.LookupException e) {
             return MH.findVirtual(MethodHandles.lookup(), own, name, mt);
         }
     }
 }
	/*
	* 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. 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.
	*
	* 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.
	*/

	package jdk.nashorn.internal.runtime.linker;

	import jdk.nashorn.internal.lookup.MethodHandleFunctionality;
	import jdk.nashorn.internal.lookup.MethodHandleFactory;
	import java.lang.invoke.MethodHandle;
	import java.lang.invoke.MethodHandles;
	import java.lang.invoke.MethodType;
	import java.util.Objects;
	import jdk.internal.dynalink.CallSiteDescriptor;
	import jdk.internal.dynalink.linker.GuardedInvocation;
	import jdk.internal.dynalink.linker.LinkRequest;
	import jdk.internal.dynalink.linker.LinkerServices;
	import jdk.internal.dynalink.linker.TypeBasedGuardingDynamicLinker;
	import jdk.internal.dynalink.support.CallSiteDescriptorFactory;
	import jdk.nashorn.internal.runtime.JSType;
	import jdk.nashorn.api.scripting.JSObject;

	/**
	* A Dynalink linker to handle web browser built-in JS (DOM etc.) objects as well
	* as ScriptObjects from other Nashorn contexts.
	*/
	final class JSObjectLinker implements TypeBasedGuardingDynamicLinker {
	/**
	* Instances of this class are used to represent a method member of a JSObject
	*/
	private static final class JSObjectMethod {
	// The name of the JSObject method property
	private final String name;

	JSObjectMethod(final String name) {
	this.name = name;
	}

	String getName() {
	return name;
	}

	static GuardedInvocation lookup(final CallSiteDescriptor desc) {
	final String operator = CallSiteDescriptorFactory.tokenizeOperators(desc).get(0);
	switch (operator) {
	case "call": {
	// collect everything except the first two - JSObjectMethod instance and the actual 'self'
	final int paramCount = desc.getMethodType().parameterCount();
	final MethodHandle caller = MH.asCollector(JSOBJECTMETHOD_CALL, Object[].class, paramCount - 2);
	return new GuardedInvocation(caller, null, IS_JSOBJECTMETHOD_GUARD);
	}
	default:
	return null;
	}
	}
	}

	@Override
	public boolean canLinkType(final Class<?> type) {
	return canLinkTypeStatic(type);
	}

	static boolean canLinkTypeStatic(final Class<?> type) {
	// can link JSObject and JSObjectMethod
	return JSObject.class.isAssignableFrom(type) \|\| JSObjectMethod.class.isAssignableFrom(type);
	}

	@Override
	public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices) throws Exception {
	final LinkRequest requestWithoutContext = request.withoutRuntimeContext(); // Nashorn has no runtime context
	final Object self = requestWithoutContext.getReceiver();
	final CallSiteDescriptor desc = requestWithoutContext.getCallSiteDescriptor();

	if (desc.getNameTokenCount() < 2 \|\| !"dyn".equals(desc.getNameToken(CallSiteDescriptor.SCHEME))) {
	// We only support standard "dyn:[:]" operations
	return null;
	}

	final GuardedInvocation inv;
	if (self instanceof JSObject) {
	inv = lookup(desc);
	} else if (self instanceof JSObjectMethod) {
	inv = JSObjectMethod.lookup(desc);
	} else {
	throw new AssertionError(); // Should never reach here.
	}

	return Bootstrap.asType(inv, linkerServices, desc);
	}

	private static GuardedInvocation lookup(final CallSiteDescriptor desc) {
	final String operator = CallSiteDescriptorFactory.tokenizeOperators(desc).get(0);
	final int c = desc.getNameTokenCount();
	switch (operator) {
	case "getProp":
	case "getElem":
	case "getMethod":
	return c > 2 ? findGetMethod(desc, operator) : findGetIndexMethod();
	case "setProp":
	case "setElem":
	return c > 2 ? findSetMethod(desc) : findSetIndexMethod();
	case "call":
	case "callMethod":
	return findCallMethod(desc, operator);
	case "new":
	default:
	return null;
	}
	}

	private static GuardedInvocation findGetMethod(final CallSiteDescriptor desc, final String operator) {
	// if "getMethod" then return JSObjectMethod object - which just holds the name of the method
	// subsequently, link on dyn:call for JSObjectMethod will actually call that method
	final MethodHandle getter = MH.insertArguments("getMethod".equals(operator)? JSOBJECT_GETMETHOD : JSOBJECT_GET, 1, desc.getNameToken(2));
	return new GuardedInvocation(getter, null, IS_JSOBJECT_GUARD);
	}

	private static GuardedInvocation findGetIndexMethod() {
	return new GuardedInvocation(JSOBJECT_GET, null, IS_JSOBJECT_GUARD);
	}

	private static GuardedInvocation findSetMethod(final CallSiteDescriptor desc) {
	final MethodHandle getter = MH.insertArguments(JSOBJECT_PUT, 1, desc.getNameToken(2));
	return new GuardedInvocation(getter, null, IS_JSOBJECT_GUARD);
	}

	private static GuardedInvocation findSetIndexMethod() {
	return new GuardedInvocation(JSOBJECT_PUT, null, IS_JSOBJECT_GUARD);
	}

	private static GuardedInvocation findCallMethod(final CallSiteDescriptor desc, final String operator) {
	// if operator is "call", then 'self' is a JSObject function object already. Use 'call' as the method name
	final String methodName = "callMethod".equals(operator)? desc.getNameToken(2) : "call";
	MethodHandle func = MH.insertArguments(JSOBJECT_CALL, 1, methodName);
	func = MH.asCollector(func, Object[].class, desc.getMethodType().parameterCount() - 1);
	return new GuardedInvocation(func, null, IS_JSOBJECT_GUARD);
	}

	@SuppressWarnings("unused")
	private static boolean isJSObjectMethod(final Object self) {
	return self instanceof JSObjectMethod;
	}

	@SuppressWarnings("unused")
	private static boolean isJSObject(final Object self) {
	return self instanceof JSObject;
	}


	@SuppressWarnings("unused")
	private static Object getMethod(final Object jsobj, final Object key) {
	return new JSObjectMethod(Objects.toString(key));
	}

	@SuppressWarnings("unused")
	private static Object get(final Object jsobj, final Object key) {
	if (key instanceof String) {
	return ((JSObject)jsobj).getMember((String)key);
	} else if (key instanceof Number) {
	final int index = getIndex((Number)key);
	if (index > -1) {
	return ((JSObject)jsobj).getSlot(index);
	}
	}
	return null;
	}

	@SuppressWarnings("unused")
	private static void put(final Object jsobj, final Object key, final Object value) {
	if (key instanceof String) {
	((JSObject)jsobj).setMember((String)key, value);
	} else if (key instanceof Number) {
	((JSObject)jsobj).setSlot(getIndex((Number)key), value);
	}
	}

	@SuppressWarnings("unused")
	private static Object call(final Object jsobj, final Object method, final Object... args) {
	return ((JSObject)jsobj).call(Objects.toString(method), args);
	}

	@SuppressWarnings("unused")
	private static Object jsObjectMethodCall(final Object jsObjMethod, final Object jsobj, final Object... args) {
	// we have JSObjectMethod, JSObject and args. Get method name from JSObjectMethod instance
	final String methodName = ((JSObjectMethod)jsObjMethod).getName();
	// call the method on JSObject
	return ((JSObject)jsobj).call(methodName, args);
	}

	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();

	private static final MethodHandle IS_JSOBJECTMETHOD_GUARD = findOwnMH("isJSObjectMethod", boolean.class, Object.class);
	private static final MethodHandle IS_JSOBJECT_GUARD = findOwnMH("isJSObject", boolean.class, Object.class);
	private static final MethodHandle JSOBJECT_GETMETHOD = findOwnMH("getMethod", Object.class, Object.class, Object.class);
	private static final MethodHandle JSOBJECT_GET = findOwnMH("get", Object.class, Object.class, Object.class);
	private static final MethodHandle JSOBJECT_PUT = findOwnMH("put", Void.TYPE, Object.class, Object.class, Object.class);
	private static final MethodHandle JSOBJECT_CALL = findOwnMH("call", Object.class, Object.class, Object.class, Object[].class);
	private static final MethodHandle JSOBJECTMETHOD_CALL = findOwnMH("jsObjectMethodCall", Object.class, Object.class, Object.class, Object[].class);

	private static MethodHandle findOwnMH(final String name, final Class<?> rtype, final Class<?>... types) {
	final Class<?> own = JSObjectLinker.class;
	final MethodType mt = MH.type(rtype, types);
	try {
	return MH.findStatic(MethodHandles.lookup(), own, name, mt);
	} catch (final MethodHandleFactory.LookupException e) {
	return MH.findVirtual(MethodHandles.lookup(), own, name, mt);
	}
	}
	}