- Represent strings internally in UTF-16 format, this makes it

runtime/vm/symbols.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/symbols.h"
 
 #include "vm/isolate.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
 #include "vm/raw_object.h"
@@ skipping 76 matching lines @@
   // Should only be run by the vm isolate.
   ASSERT(Isolate::Current() == Dart::vm_isolate());
   intptr_t hash = str.Hash();
   intptr_t index = FindIndex(symbol_table, str, 0, str.Length(), hash);
   ASSERT(symbol_table.At(index) == String::null());
   InsertIntoSymbolTable(symbol_table, str, index);
 }
 
 
 RawString* Symbols::New(const char* str) {
-  intptr_t width = 0;
-  intptr_t len = Utf8::CodePointCount(str, &width);
+  ASSERT(str != NULL);
+  Utf8::Type type;
+  intptr_t str_len = strlen(str);
+  const uint8_t* utf8_array = reinterpret_cast<const uint8_t*>(str);
+  intptr_t len = Utf8::CodePointCount(utf8_array, str_len, &type);
   Zone* zone = Isolate::Current()->current_zone();
   if (len == 0) {
     return Symbols::New(reinterpret_cast<uint8_t*>(NULL), 0);
-  } else if (width == 1) {
+  }
+  if (type == Utf8::kAscii) {
     uint8_t* characters = zone->Alloc<uint8_t>(len);
-    Utf8::Decode(str, characters, len);
-    return New(characters, len);
-  } else if (width == 2) {
-    uint16_t* characters = zone->Alloc<uint16_t>(len);
-    Utf8::Decode(str, characters, len);
+    Utf8::DecodeToAscii(utf8_array, str_len, characters, len);
     return New(characters, len);
   }
-  ASSERT(width == 4);
-  uint32_t* characters = zone->Alloc<uint32_t>(len);
-  Utf8::Decode(str, characters, len);
+  ASSERT((type == Utf8::kBMP) || (type == Utf8::kSMP));
+  uint16_t* characters = zone->Alloc<uint16_t>(len);
+  Utf8::DecodeToUTF16(utf8_array, str_len, characters, len);
   return New(characters, len);
 }
 
 
 template<typename T>
 RawString* Symbols::New(const T* characters, intptr_t len) {
   Isolate* isolate = Isolate::Current();
   ASSERT(isolate != Dart::vm_isolate());
   String& symbol = String::Handle(isolate, String::null());
   Array& symbol_table = Array::Handle(isolate, Array::null());
@@ skipping 188 matching lines @@
 }
 
 
 RawObject* Symbols::GetVMSymbol(intptr_t object_id) {
   ASSERT(IsVMSymbolId(object_id));
   intptr_t i = (object_id - kMaxPredefinedObjectIds);
   return (i > 0 && i < Symbols::kMaxId) ? predefined_[i] : Object::null();
 }
 
 }  // namespace dart