LibJS: Make TypedArray::element_name return FlyString instead of String

This ensures that comparison between TypedArray names will be essentially free (just a pointer comparison), which will allow us to efficiently implement specification steps like: "24. If srcType is the same as targetType, then" efficiently.
orospakr · Feb 8, 2022 · c7a8902 · c7a8902
1 parent 9839e2e
commit c7a8902
Show file tree

Hide file tree

Showing 3 changed files with 5 additions and 5 deletions.
diff --git a/Userland/Libraries/LibJS/Runtime/AtomicsObject.cpp b/Userland/Libraries/LibJS/Runtime/AtomicsObject.cpp
@@ -28,14 +28,14 @@ static ThrowCompletionOr<ArrayBuffer*> validate_integer_typed_array(GlobalObject
  auto* buffer = typed_array.viewed_array_buffer();
 
  // 4. Let typeName be typedArray.[[TypedArrayName]].
- auto type_name = typed_array.element_name();
+ auto const& type_name = typed_array.element_name();
 
  // 5. Let type be the Element Type value in Table 72 for typeName.
 
  // 6. If waitable is true, then
  if (waitable) {
  // a. If typeName is not "Int32Array" or "BigInt64Array", throw a TypeError exception.
- if ((type_name != "Int32Array"sv) && (type_name != "BigInt64Array"sv))
+ if ((type_name != vm.names.Int32Array.as_string()) && (type_name != vm.names.BigInt64Array.as_string()))
  return vm.throw_completion<TypeError>(global_object, ErrorType::TypedArrayTypeIsNot, type_name, "Int32 or BigInt64"sv);
  }
  // 7. Else,

diff --git a/Userland/Libraries/LibJS/Runtime/TypedArray.cpp b/Userland/Libraries/LibJS/Runtime/TypedArray.cpp
@@ -395,7 +395,7 @@ void TypedArrayBase::visit_edges(Visitor& visitor)
  \
  ClassName::~ClassName() { } \
  \
- String ClassName::element_name() const  \
+ FlyString const& ClassName::element_name() const \
  { \
  return vm().names.ClassName.as_string(); \
  } \

diff --git a/Userland/Libraries/LibJS/Runtime/TypedArray.h b/Userland/Libraries/LibJS/Runtime/TypedArray.h
@@ -44,7 +44,7 @@ class TypedArrayBase : public Object {
  void set_viewed_array_buffer(ArrayBuffer* array_buffer) { m_viewed_array_buffer = array_buffer; }
 
  virtual size_t element_size() const = 0;
- virtual String element_name() const = 0;
+ virtual FlyString const& element_name() const = 0;
 
  // 25.1.2.6 IsUnclampedIntegerElementType ( type ), https://tc39.es/ecma262/#sec-isunclampedintegerelementtype
  virtual bool is_unclamped_integer_element_type() const = 0;
@@ -482,7 +482,7 @@ ThrowCompletionOr<TypedArrayBase*> typed_array_create(GlobalObject& global_objec
  static ThrowCompletionOr<ClassName*> create(GlobalObject&, u32 length); \
  static ClassName* create(GlobalObject&, u32 length, ArrayBuffer& buffer); \
  ClassName(Object& prototype, u32 length, ArrayBuffer& array_buffer); \
- virtual String element_name() const override;  \
+ virtual FlyString const& element_name() const override; \
  }; \
  class PrototypeName final : public Object { \
  JS_OBJECT(PrototypeName, Object); \