Optimized scanner to avoid virtual calls for every character read.

src/api.cc

 // Copyright 2010 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 1142 matching lines @@
     EnsureConstructor(this);
   }
   Utils::OpenHandle(this)->set_internal_field_count(i::Smi::FromInt(value));
 }
 
 
 // --- S c r i p t D a t a ---
 
 
 ScriptData* ScriptData::PreCompile(const char* input, int length) {
-  unibrow::Utf8InputBuffer<> buf(input, length);
-  return i::ParserApi::PreParse(i::Handle<i::String>(), &buf, NULL);
+  i::Utf8ToUC16CharacterStream stream(
+      reinterpret_cast<const unsigned char*>(input), length);
+  return i::ParserApi::PreParse(&stream, NULL);
 }
 
 
 ScriptData* ScriptData::PreCompile(v8::Handle<String> source) {
   i::Handle<i::String> str = Utils::OpenHandle(*source);
-  return i::ParserApi::PreParse(str, NULL, NULL);
+  if (str->IsExternalTwoByteString()) {
+    i::ExternalTwoByteStringUC16CharacterStream stream(
+      i::Handle<i::ExternalTwoByteString>::cast(str), 0, str->length());
+    return i::ParserApi::PreParse(&stream, NULL);
+  } else {
+    i::GenericStringUC16CharacterStream stream(str, 0, str->length());
+    return i::ParserApi::PreParse(&stream, NULL);
+  }
 }
 
 
 ScriptData* ScriptData::New(const char* data, int length) {
   // Return an empty ScriptData if the length is obviously invalid.
   if (length % sizeof(unsigned) != 0) {
     return new i::ScriptDataImpl();
   }
 
   // Copy the data to ensure it is properly aligned.
@@ skipping 3840 matching lines @@
 
 
 char* HandleScopeImplementer::Iterate(ObjectVisitor* v, char* storage) {
   HandleScopeImplementer* thread_local =
       reinterpret_cast<HandleScopeImplementer*>(storage);
   thread_local->IterateThis(v);
   return storage + ArchiveSpacePerThread();
 }
 
 } }  // namespace v8::internal