C++ HandleValue::isNull方法代码示例

bool ScriptInterface::EnumeratePropertyNamesWithPrefix(JS::HandleValue objVal, const char* prefix, std::vector<std::string>& out)
{
	JSAutoRequest rq(m->m_cx);
	
	if (!objVal.isObjectOrNull())
	{
		LOGERROR("EnumeratePropertyNamesWithPrefix expected object type!");
		return false;
	}
		
	if(objVal.isNull())
		return true; // reached the end of the prototype chain
	
	JS::RootedObject obj(m->m_cx, &objVal.toObject());
	JS::RootedObject it(m->m_cx, JS_NewPropertyIterator(m->m_cx, obj));
	if (!it)
		return false;

	while (true)
	{
		JS::RootedId idp(m->m_cx);
		JS::RootedValue val(m->m_cx);
		if (! JS_NextProperty(m->m_cx, it, idp.address()) || ! JS_IdToValue(m->m_cx, idp, &val))
			return false;

		if (val.isUndefined())
			break; // end of iteration
		if (!val.isString())
			continue; // ignore integer properties

		JS::RootedString name(m->m_cx, val.toString());
		size_t len = strlen(prefix)+1;
		std::vector<char> buf(len);
		size_t prefixLen = strlen(prefix) * sizeof(char);
		JS_EncodeStringToBuffer(m->m_cx, name, &buf[0], prefixLen);
		buf[len-1]= '\0';
		if(0 == strcmp(&buf[0], prefix))
		{
			size_t len;
			const jschar* chars = JS_GetStringCharsAndLength(m->m_cx, name, &len);
			out.push_back(std::string(chars, chars+len));
		}
	}

	// Recurse up the prototype chain
	JS::RootedObject prototype(m->m_cx);
	if (JS_GetPrototype(m->m_cx, obj, &prototype))
	{
		JS::RootedValue prototypeVal(m->m_cx, JS::ObjectOrNullValue(prototype));
		if (! EnumeratePropertyNamesWithPrefix(prototypeVal, prefix, out))
			return false;
	}

	return true;
}

bool
JavaScriptShared::toVariant(JSContext* cx, JS::HandleValue from, JSVariant* to)
{
    switch (JS_TypeOfValue(cx, from)) {
      case JSTYPE_VOID:
        *to = UndefinedVariant();
        return true;

      case JSTYPE_OBJECT:
      case JSTYPE_FUNCTION:
      {
        RootedObject obj(cx, from.toObjectOrNull());
        if (!obj) {
            MOZ_ASSERT(from.isNull());
            *to = NullVariant();
            return true;
        }

        if (xpc_JSObjectIsID(cx, obj)) {
            JSIID iid;
            const nsID* id = xpc_JSObjectToID(cx, obj);
            ConvertID(*id, &iid);
            *to = iid;
            return true;
        }

        ObjectVariant objVar;
        if (!toObjectVariant(cx, obj, &objVar))
            return false;
        *to = objVar;
        return true;
      }

      case JSTYPE_SYMBOL:
      {
        RootedSymbol sym(cx, from.toSymbol());

        SymbolVariant symVar;
        if (!toSymbolVariant(cx, sym, &symVar))
            return false;
        *to = symVar;
        return true;
      }

      case JSTYPE_STRING:
      {
        nsAutoJSString autoStr;
        if (!autoStr.init(cx, from))
            return false;
        *to = autoStr;
        return true;
      }

      case JSTYPE_NUMBER:
        if (from.isInt32())
            *to = double(from.toInt32());
        else
            *to = from.toDouble();
        return true;

      case JSTYPE_BOOLEAN:
        *to = from.toBoolean();
        return true;

      default:
        MOZ_ASSERT(false);
        return false;
    }
}

bool ScriptInterface::EnumeratePropertyNamesWithPrefix(JS::HandleValue objVal, const char* prefix, std::vector<std::string>& out)
{
	JSAutoRequest rq(m->m_cx);
	
	if (!objVal.isObjectOrNull())
	{
		LOGERROR("EnumeratePropertyNamesWithPrefix expected object type!");
		return false;
	}
		
	if (objVal.isNull())
		return true; // reached the end of the prototype chain
	
	JS::RootedObject obj(m->m_cx, &objVal.toObject());
	JS::AutoIdArray props(m->m_cx, JS_Enumerate(m->m_cx, obj));
	if (!props)
		return false;

	for (size_t i = 0; i < props.length(); ++i)
	{
		JS::RootedId id(m->m_cx, props[i]);
		JS::RootedValue val(m->m_cx);
		if (!JS_IdToValue(m->m_cx, id, &val))
			return false;

		if (!val.isString())
			continue; // ignore integer properties

		JS::RootedString name(m->m_cx, val.toString());
		size_t len = strlen(prefix)+1;
		std::vector<char> buf(len);
		size_t prefixLen = strlen(prefix) * sizeof(char);
		JS_EncodeStringToBuffer(m->m_cx, name, &buf[0], prefixLen);
		buf[len-1]= '\0';
		if (0 == strcmp(&buf[0], prefix))
		{
			if (JS_StringHasLatin1Chars(name))
			{
				size_t length;
				JS::AutoCheckCannotGC nogc;
				const JS::Latin1Char* chars = JS_GetLatin1StringCharsAndLength(m->m_cx, nogc, name, &length);
				if (chars)
					out.push_back(std::string(chars, chars+length));
			}
			else
			{
				size_t length;
				JS::AutoCheckCannotGC nogc;
				const char16_t* chars = JS_GetTwoByteStringCharsAndLength(m->m_cx, nogc, name, &length);
				if (chars)
					out.push_back(std::string(chars, chars+length));
			}
		}
	}

	// Recurse up the prototype chain
	JS::RootedObject prototype(m->m_cx);
	if (JS_GetPrototype(m->m_cx, obj, &prototype))
	{
		JS::RootedValue prototypeVal(m->m_cx, JS::ObjectOrNullValue(prototype));
		if (!EnumeratePropertyNamesWithPrefix(prototypeVal, prefix, out))
			return false;
	}

	return true;
}

void CBinarySerializerScriptImpl::HandleScriptVal(JS::HandleValue val)
{
	JSContext* cx = m_ScriptInterface.GetContext();
	JSAutoRequest rq(cx);

	switch (JS_TypeOfValue(cx, val))
	{
	case JSTYPE_VOID:
	{
		m_Serializer.NumberU8_Unbounded("type", SCRIPT_TYPE_VOID);
		break;
	}
	case JSTYPE_NULL: // This type is never actually returned (it's a JS2 feature)
	{
		m_Serializer.NumberU8_Unbounded("type", SCRIPT_TYPE_NULL);
		break;
	}
	case JSTYPE_OBJECT:
	{
		if (val.isNull())
		{
			m_Serializer.NumberU8_Unbounded("type", SCRIPT_TYPE_NULL);
			break;
		}

		JS::RootedObject obj(cx, &val.toObject());

		// If we've already serialized this object, just output a reference to it
		u32 tag = GetScriptBackrefTag(obj);
		if (tag)
		{
			m_Serializer.NumberU8_Unbounded("type", SCRIPT_TYPE_BACKREF);
			m_Serializer.NumberU32_Unbounded("tag", tag);
			break;
		}

		// Arrays are special cases of Object
		if (JS_IsArrayObject(cx, obj))
		{
			m_Serializer.NumberU8_Unbounded("type", SCRIPT_TYPE_ARRAY);
			// TODO: probably should have a more efficient storage format

			// Arrays like [1, 2, ] have an 'undefined' at the end which is part of the
			// length but seemingly isn't enumerated, so store the length explicitly
			uint length = 0;
			if (!JS_GetArrayLength(cx, obj, &length))
				throw PSERROR_Serialize_ScriptError("JS_GetArrayLength failed");
			m_Serializer.NumberU32_Unbounded("array length", length);
		}
		else if (JS_IsTypedArrayObject(obj))
		{
			m_Serializer.NumberU8_Unbounded("type", SCRIPT_TYPE_TYPED_ARRAY);

			m_Serializer.NumberU8_Unbounded("array type", GetArrayType(JS_GetArrayBufferViewType(obj)));
			m_Serializer.NumberU32_Unbounded("byte offset", JS_GetTypedArrayByteOffset(obj));
			m_Serializer.NumberU32_Unbounded("length", JS_GetTypedArrayLength(obj));

			// Now handle its array buffer
			// this may be a backref, since ArrayBuffers can be shared by multiple views
			JS::RootedValue bufferVal(cx, JS::ObjectValue(*JS_GetArrayBufferViewBuffer(cx, obj)));
			HandleScriptVal(bufferVal);
			break;
		}
		else if (JS_IsArrayBufferObject(obj))
		{
			m_Serializer.NumberU8_Unbounded("type", SCRIPT_TYPE_ARRAY_BUFFER);

#if BYTE_ORDER != LITTLE_ENDIAN
#error TODO: need to convert JS ArrayBuffer data to little-endian
#endif

			u32 length = JS_GetArrayBufferByteLength(obj);
			m_Serializer.NumberU32_Unbounded("buffer length", length);
			JS::AutoCheckCannotGC nogc;
			m_Serializer.RawBytes("buffer data", (const u8*)JS_GetArrayBufferData(obj, nogc), length);
			break;
		}
		else
		{
			// Find type of object
			const JSClass* jsclass = JS_GetClass(obj);
			if (!jsclass)
				throw PSERROR_Serialize_ScriptError("JS_GetClass failed");
// TODO: Remove this workaround for upstream API breakage when updating SpiderMonkey
// See https://bugzilla.mozilla.org/show_bug.cgi?id=1236373
#define JSCLASS_CACHED_PROTO_WIDTH js::JSCLASS_CACHED_PROTO_WIDTH
			JSProtoKey protokey = JSCLASS_CACHED_PROTO_KEY(jsclass);
#undef JSCLASS_CACHED_PROTO_WIDTH

			if (protokey == JSProto_Object)
			{
				// Object class - check for user-defined prototype
				JS::RootedObject proto(cx);
				JS_GetPrototype(cx, obj, &proto);
				if (!proto)
					throw PSERROR_Serialize_ScriptError("JS_GetPrototype failed");

				if (m_SerializablePrototypes->empty() || !IsSerializablePrototype(proto))
				{
					// Standard Object prototype
//.........这里部分代码省略.........