Canvas2D Performance: fix the bottleneck of hasInstance in JS binding -- TypeChecking Interface

Source/bindings/scripts/v8_types.py

 # Copyright (C) 2013 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 483 matching lines @@
 
 def v8_conversion_is_trivial(idl_type):
     # The conversion is a simple expression that returns the converted value and
     # cannot raise an exception.
     return (idl_type.base_type in TRIVIAL_CONVERSIONS or
             idl_type.is_wrapper_type)
 
 IdlType.v8_conversion_is_trivial = property(v8_conversion_is_trivial)
 
 
-def v8_value_to_cpp_value(idl_type, extended_attributes, v8_value, index, isolate):
+def v8_value_to_cpp_value(idl_type, extended_attributes, v8_value, needs_type_check, index, isolate):
     if idl_type.name == 'void':
         return ''
 
     # Array or sequence types
     native_array_element_type = idl_type.native_array_element_type
     if native_array_element_type:
         return v8_value_to_cpp_value_array_or_sequence(native_array_element_type, v8_value, index)
 
     # Simple types
     idl_type = idl_type.preprocessed_type
@@ skipping 10 matching lines @@
         arguments = v8_value
 
     if base_idl_type in V8_VALUE_TO_CPP_VALUE:
         cpp_expression_format = V8_VALUE_TO_CPP_VALUE[base_idl_type]
     elif idl_type.is_typed_array_element_type:
         cpp_expression_format = (
             '{v8_value}->Is{idl_type}() ? '
             'V8{idl_type}::toImpl(v8::Handle<v8::{idl_type}>::Cast({v8_value})) : 0')
     elif idl_type.is_dictionary:
         cpp_expression_format = 'V8{idl_type}::toImpl({isolate}, {v8_value}, exceptionState)'
+    elif needs_type_check:
+        cpp_expression_format = (
+            'V8{idl_type}::toImplWithTypeCheck({isolate}, {v8_value})')
     else:
         cpp_expression_format = (
-            'V8{idl_type}::toImplWithTypeCheck({isolate}, {v8_value})')
+            'V8{idl_type}::toImpl(v8::Handle<v8::Object>::Cast({v8_value}))')
 
     return cpp_expression_format.format(arguments=arguments, idl_type=base_idl_type, v8_value=v8_value, isolate=isolate)
 
 
 def v8_value_to_cpp_value_array_or_sequence(native_array_element_type, v8_value, index, isolate='info.GetIsolate()'):
     # Index is None for setters, index (starting at 0) for method arguments,
     # and is used to provide a human-readable exception message
     if index is None:
         index = 0  # special case, meaning "setter"
     else:
         index += 1  # human-readable index
     if (native_array_element_type.is_interface_type and
         native_array_element_type.name != 'Dictionary'):
         this_cpp_type = None
         ref_ptr_type = cpp_ptr_type('RefPtr', 'Member', native_array_element_type.gc_type)
         expression_format = '(to{ref_ptr_type}NativeArray<{native_array_element_type}, V8{native_array_element_type}>({v8_value}, {index}, {isolate}, exceptionState))'
         add_includes_for_type(native_array_element_type)
     else:
         ref_ptr_type = None
         this_cpp_type = native_array_element_type.cpp_type
         expression_format = 'toImplArray<{cpp_type}>({v8_value}, {index}, {isolate}, exceptionState)'
     expression = expression_format.format(native_array_element_type=native_array_element_type.name, cpp_type=this_cpp_type, index=index, ref_ptr_type=ref_ptr_type, v8_value=v8_value, isolate=isolate)
     return expression
 
 
-def v8_value_to_local_cpp_value(idl_type, extended_attributes, v8_value, variable_name, index=None, declare_variable=True, isolate='info.GetIsolate()', used_in_private_script=False, return_promise=False):
+def v8_value_to_local_cpp_value(idl_type, extended_attributes, v8_value, variable_name, needs_type_check=True, index=None, declare_variable=True, isolate='info.GetIsolate()', used_in_private_script=False, return_promise=False):
     """Returns an expression that converts a V8 value to a C++ value and stores it as a local value."""
 
     # FIXME: Support union type.
     if idl_type.is_union_type:
         return '/* no V8 -> C++ conversion for IDL union type: %s */' % idl_type.name
 
     this_cpp_type = idl_type.cpp_type_args(extended_attributes=extended_attributes, raw_type=True)
     idl_type = idl_type.preprocessed_type
 
     if idl_type.base_type in ('void', 'object', 'EventHandler', 'EventListener'):
         return '/* no V8 -> C++ conversion for IDL type: %s */' % idl_type.name
 
-    cpp_value = v8_value_to_cpp_value(idl_type, extended_attributes, v8_value, index, isolate)
+    cpp_value = v8_value_to_cpp_value(idl_type, extended_attributes, v8_value, needs_type_check, index, isolate)
     if idl_type.is_string_type or idl_type.v8_conversion_needs_exception_state:
         # Types that need error handling and use one of a group of (C++) macros
         # to take care of this.
 
         args = [variable_name, cpp_value]
 
         if idl_type.v8_conversion_needs_exception_state:
             macro = 'TONATIVE_DEFAULT_EXCEPTIONSTATE' if used_in_private_script else 'TONATIVE_VOID_EXCEPTIONSTATE'
         elif return_promise:
             macro = 'TOSTRING_VOID_EXCEPTIONSTATE'
@@ skipping 277 matching lines @@
 
 
 def is_explicit_nullable(idl_type):
     # Nullable type that isn't implicit nullable (see above.) For such types,
     # we use Nullable<T> or similar explicit ways to represent a null value.
     return idl_type.is_nullable and not idl_type.is_implicit_nullable
 
 IdlTypeBase.is_implicit_nullable = property(is_implicit_nullable)
 IdlUnionType.is_implicit_nullable = False
 IdlTypeBase.is_explicit_nullable = property(is_explicit_nullable)