Track ascii-ness of data in externalized strings.

src/objects-inl.h

 // Copyright 2006-2008 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 219 matching lines @@
 
 bool StringShape::IsSymbol() {
   ASSERT(valid());
   ASSERT(kSymbolTag != 0);
   return (type_ & kIsSymbolMask) != 0;
 }
 
 
 bool String::IsAsciiRepresentation() {
   uint32_t type = map()->instance_type();
-  if ((type & kStringRepresentationMask) == kConsStringTag &&
-      ConsString::cast(this)->second()->length() == 0) {
-    return ConsString::cast(this)->first()->IsAsciiRepresentation();
-  }
   return (type & kStringEncodingMask) == kAsciiStringTag;
 }
 
 
 bool String::IsTwoByteRepresentation() {
   uint32_t type = map()->instance_type();
-  if ((type & kStringRepresentationMask) == kConsStringTag &&
-             ConsString::cast(this)->second()->length() == 0) {
-    return ConsString::cast(this)->first()->IsTwoByteRepresentation();
-  }
   return (type & kStringEncodingMask) == kTwoByteStringTag;
 }
 
 
-bool String::IsExternalTwoByteStringWithAsciiChars() {
-  if (!IsExternalTwoByteString()) return false;
-  const uc16* data = ExternalTwoByteString::cast(this)->resource()->data();
-  for (int i = 0, len = length(); i < len; i++) {
-    if (data[i] > kMaxAsciiCharCode) return false;
-  }
-  return true;
+bool String::HasAsciiChars() {

[Søren Thygesen Gjesse, 2010/06/10 13:55:46]

HasAsciiChars() -> HasOnlyAsciiChars()?

+  uint32_t type = map()->instance_type();
+  return (type & kStringEncodingMask) == kAsciiStringTag ||
+         (type & kAsciiDataHintMask) == kAsciiDataHintTag;
 }
 
 
 bool StringShape::IsCons() {
   return (type_ & kStringRepresentationMask) == kConsStringTag;
 }
 
 
 bool StringShape::IsExternal() {
   return (type_ & kStringRepresentationMask) == kExternalStringTag;
@@ skipping 2955 matching lines @@
 #undef WRITE_INT_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_