v8 typed arrays: add DataView type

src/objects-inl.h

 // Copyright 2012 the V8 project authors. 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 in the documentation and/or other materials provided
@@ skipping 664 matching lines @@
 
 
 bool Object::IsBoolean() {
   return IsOddball() &&
       ((Oddball::cast(this)->kind() & Oddball::kNotBooleanMask) == 0);
 }
 
 
 TYPE_CHECKER(JSArray, JS_ARRAY_TYPE)
 TYPE_CHECKER(JSArrayBuffer, JS_ARRAY_BUFFER_TYPE)
+TYPE_CHECKER(JSDataView, JS_DATA_VIEW_TYPE)
 TYPE_CHECKER(JSTypedArray, JS_TYPED_ARRAY_TYPE)
 TYPE_CHECKER(JSRegExp, JS_REGEXP_TYPE)
 
 
 template <> inline bool Is<JSArray>(Object* obj) {
   return obj->IsJSArray();
 }
 
 
 bool Object::IsHashTable() {
@@ skipping 942 matching lines @@
     case JS_FUNCTION_TYPE:
       return JSFunction::kSize;
     case JS_VALUE_TYPE:
       return JSValue::kSize;
     case JS_DATE_TYPE:
       return JSDate::kSize;
     case JS_ARRAY_TYPE:
       return JSArray::kSize;
     case JS_ARRAY_BUFFER_TYPE:
       return JSArrayBuffer::kSize;
+    case JS_DATA_VIEW_TYPE:
+      return JSDataView::kSize;
     case JS_TYPED_ARRAY_TYPE:
       return JSTypedArray::kSize;
     case JS_SET_TYPE:
       return JSSet::kSize;
     case JS_MAP_TYPE:
       return JSMap::kSize;
     case JS_WEAK_MAP_TYPE:
       return JSWeakMap::kSize;
     case JS_REGEXP_TYPE:
       return JSRegExp::kSize;
@@ skipping 884 matching lines @@
 CAST_ACCESSOR(SharedFunctionInfo)
 CAST_ACCESSOR(Map)
 CAST_ACCESSOR(JSFunction)
 CAST_ACCESSOR(GlobalObject)
 CAST_ACCESSOR(JSGlobalProxy)
 CAST_ACCESSOR(JSGlobalObject)
 CAST_ACCESSOR(JSBuiltinsObject)
 CAST_ACCESSOR(Code)
 CAST_ACCESSOR(JSArray)
 CAST_ACCESSOR(JSArrayBuffer)
+CAST_ACCESSOR(JSDataView)
 CAST_ACCESSOR(JSTypedArray)
 CAST_ACCESSOR(JSRegExp)
 CAST_ACCESSOR(JSProxy)
 CAST_ACCESSOR(JSFunctionProxy)
 CAST_ACCESSOR(JSSet)
 CAST_ACCESSOR(JSMap)
 CAST_ACCESSOR(JSWeakMap)
 CAST_ACCESSOR(Foreign)
 CAST_ACCESSOR(ByteArray)
 CAST_ACCESSOR(FreeSpace)
@@ skipping 2753 matching lines @@
 bool JSArrayBuffer::is_external() {
   return BooleanBit::get(flag(), kIsExternalBit);
 }
 
 
 void JSArrayBuffer::set_is_external(bool value) {
   set_flag(BooleanBit::set(flag(), kIsExternalBit, value));
 }
 
 
+ACCESSORS(JSDataView, buffer, Object, kBufferOffset)
+ACCESSORS(JSDataView, byte_offset, Object, kByteOffsetOffset)
+ACCESSORS(JSDataView, byte_length, Object, kByteLengthOffset)
+
+
+template <typename TypeName>
+TypeName JSDataView::Get(size_t byte_offset, bool little_endian) {
+  size_t byte_length = static_cast<size_t>(this->byte_length()->Number());

[Dmitry Lomov (no reviews), 2013/06/03 13:09:04]

Use NumberToSize

[bnoordhuis, 2013/06/03 13:48:12]

I copied that from ArrayBuffer actually, to keep friction as low as possible.
:-)

Want me to update that as well? 

[Dmitry Lomov (no reviews), 2013/06/03 14:42:49]

Use NumberToSize here, do not update usages in code you have not touched (to
minimize churn)

+  if (byte_offset + sizeof(TypeName) > byte_length) return 0;
+  if (byte_offset + sizeof(TypeName) < byte_offset) return 0;  // Overflow.
+  Handle<JSArrayBuffer> buffer(JSArrayBuffer::cast(this->buffer()));
+  const char* data = static_cast<const char*>(buffer->backing_store()) +
+                     static_cast<size_t>(this->byte_offset()->Number()) +
+                     byte_offset;
+  TypeName value;
+  OS::MemCopy(&value, data, sizeof(value));
+  if (sizeof(TypeName) > 1 && little_endian ^ IsLittleEndian()) {
+    Swizzle(&value);
+  }
+  return value;
+}
+
+
+template <typename TypeName>
+void JSDataView::Set(size_t byte_offset, TypeName value, bool little_endian) {
+  size_t byte_length = static_cast<size_t>(this->byte_length()->Number());

[Dmitry Lomov (no reviews), 2013/06/03 13:09:04]

Use NumberToSize.

+  if (byte_offset + sizeof(TypeName) > byte_length) return;
+  if (byte_offset + sizeof(TypeName) < byte_offset) return;  // Overflow.
+  Handle<JSArrayBuffer> buffer(JSArrayBuffer::cast(this->buffer()));
+  char* data = static_cast<char*>(buffer->backing_store()) +
+               static_cast<size_t>(this->byte_offset()->Number()) +
+               byte_offset;
+  if (sizeof(TypeName) > 1 && little_endian ^ IsLittleEndian()) {
+    Swizzle(&value);
+  }
+  OS::MemCopy(data, &value, sizeof(value));
+}
+
+
 ACCESSORS(JSTypedArray, buffer, Object, kBufferOffset)
 ACCESSORS(JSTypedArray, byte_offset, Object, kByteOffsetOffset)
 ACCESSORS(JSTypedArray, byte_length, Object, kByteLengthOffset)
 ACCESSORS(JSTypedArray, length, Object, kLengthOffset)
 
 ACCESSORS(JSRegExp, data, Object, kDataOffset)
 
 
 JSRegExp::Type JSRegExp::TypeTag() {
   Object* data = this->data();
@@ skipping 883 matching lines @@
 #undef WRITE_UINT32_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_