API/APICallbackFunction.h

   1 /*
   2  * Copyright (C) 2013 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef APICallbackFunction_h
  27 #define APICallbackFunction_h
  28
  29 #include "APICast.h"
  30 #include "Error.h"
  31 #include "JSCallbackConstructor.h"
  32 #include "JSLock.h"
  33 #include <wtf/Vector.h>
  34
  35 namespace JSC {
  36
  37 struct APICallbackFunction {
  38
  39 template <typename T> static EncodedJSValue JSC_HOST_CALL call(ExecState*);
  40 template <typename T> static EncodedJSValue JSC_HOST_CALL construct(ExecState*);
  41
  42 };
  43
  44 template <typename T>
  45 EncodedJSValue JSC_HOST_CALL APICallbackFunction::call(ExecState* exec)
  46 {
  47     JSContextRef execRef = toRef(exec);
  48     JSObjectRef functionRef = toRef(exec->callee());
  49     JSObjectRef thisObjRef = toRef(jsCast<JSObject*>(exec->thisValue().toThis(exec, NotStrictMode)));
  50
  51     int argumentCount = static_cast<int>(exec->argumentCount());
  52     Vector<JSValueRef, 16> arguments;
  53     arguments.reserveInitialCapacity(argumentCount);
  54     for (int i = 0; i < argumentCount; i++)
  55         arguments.uncheckedAppend(toRef(exec, exec->uncheckedArgument(i)));
  56
  57     JSValueRef exception = 0;
  58     JSValueRef result;
  59     {
  60         JSLock::DropAllLocks dropAllLocks(exec);
  61         result = jsCast<T*>(toJS(functionRef))->functionCallback()(execRef, functionRef, thisObjRef, argumentCount, arguments.data(), &exception);
  62     }
  63     if (exception)
  64         exec->vm().throwException(exec, toJS(exec, exception));
  65
  66     // result must be a valid JSValue.
  67     if (!result)
  68         return JSValue::encode(jsUndefined());
  69
  70     return JSValue::encode(toJS(exec, result));
  71 }
  72
  73 template <typename T>
  74 EncodedJSValue JSC_HOST_CALL APICallbackFunction::construct(ExecState* exec)
  75 {
  76     JSObject* constructor = exec->callee();
  77     JSContextRef ctx = toRef(exec);
  78     JSObjectRef constructorRef = toRef(constructor);
  79
  80     JSObjectCallAsConstructorCallback callback = jsCast<T*>(constructor)->constructCallback();
  81     if (callback) {
  82         size_t argumentCount = exec->argumentCount();
  83         Vector<JSValueRef, 16> arguments;
  84         arguments.reserveInitialCapacity(argumentCount);
  85         for (size_t i = 0; i < argumentCount; ++i)
  86             arguments.uncheckedAppend(toRef(exec, exec->uncheckedArgument(i)));
  87
  88         JSValueRef exception = 0;
  89         JSObjectRef result;
  90         {
  91             JSLock::DropAllLocks dropAllLocks(exec);
  92             result = callback(ctx, constructorRef, argumentCount, arguments.data(), &exception);
  93         }
  94         if (exception) {
  95             exec->vm().throwException(exec, toJS(exec, exception));
  96             return JSValue::encode(toJS(exec, exception));
  97         }
  98         // result must be a valid JSValue.
  99         if (!result)
 100             return throwVMTypeError(exec);
 101         return JSValue::encode(toJS(result));
 102     }
 103
 104     return JSValue::encode(toJS(JSObjectMake(ctx, jsCast<JSCallbackConstructor*>(constructor)->classRef(), 0)));
 105 }
 106
 107 } // namespace JSC
 108
 109 #endif // APICallbackFunction_h