Allow the morphing of strings to external strings to avoid having to...

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 1621 matching lines @@
   return *reinterpret_cast<Resource**>(FIELD_ADDR(this, kResourceOffset));
 }
 
 
 void ExternalAsciiString::set_resource(
     ExternalAsciiString::Resource* resource) {
   *reinterpret_cast<Resource**>(FIELD_ADDR(this, kResourceOffset)) = resource;
 }
 
 
+Map* ExternalAsciiString::StringMap(int length) {
+  Map* map;
+  // Number of characters: determines the map.
+  if (length <= String::kMaxShortStringSize) {
+    map = Heap::short_external_ascii_string_map();
+  } else if (length <= String::kMaxMediumStringSize) {
+    map = Heap::medium_external_ascii_string_map();
+  } else {
+    map = Heap::long_external_ascii_string_map();
+  }
+  return map;
+}
+
+
+Map* ExternalAsciiString::SymbolMap(int length) {
+  Map* map;
+  // Number of characters: determines the map.
+  if (length <= String::kMaxShortStringSize) {
+    map = Heap::short_external_ascii_symbol_map();
+  } else if (length <= String::kMaxMediumStringSize) {
+    map = Heap::medium_external_ascii_symbol_map();
+  } else {
+    map = Heap::long_external_ascii_symbol_map();
+  }
+  return map;
+}
+
+
 ExternalTwoByteString::Resource* ExternalTwoByteString::resource() {
   return *reinterpret_cast<Resource**>(FIELD_ADDR(this, kResourceOffset));
 }
 
 
 void ExternalTwoByteString::set_resource(
     ExternalTwoByteString::Resource* resource) {
   *reinterpret_cast<Resource**>(FIELD_ADDR(this, kResourceOffset)) = resource;
 }
 
 
+Map* ExternalTwoByteString::StringMap(int length) {
+  Map* map;
+  // Number of characters: determines the map.
+  if (length <= String::kMaxShortStringSize) {
+    map = Heap::short_external_string_map();
+  } else if (length <= String::kMaxMediumStringSize) {
+    map = Heap::medium_external_string_map();
+  } else {
+    map = Heap::long_external_string_map();
+  }
+  return map;
+}
+
+
+Map* ExternalTwoByteString::SymbolMap(int length) {
+  Map* map;
+  // Number of characters: determines the map.
+  if (length <= String::kMaxShortStringSize) {
+    map = Heap::short_external_symbol_map();
+  } else if (length <= String::kMaxMediumStringSize) {
+    map = Heap::medium_external_symbol_map();
+  } else {
+    map = Heap::long_external_symbol_map();
+  }
+  return map;
+}
+
+
 byte ByteArray::get(int index) {
   ASSERT(index >= 0 && index < this->length());
   return READ_BYTE_FIELD(this, kHeaderSize + index * kCharSize);
 }
 
 
 void ByteArray::set(int index, byte value) {
   ASSERT(index >= 0 && index < this->length());
   WRITE_BYTE_FIELD(this, kHeaderSize + index * kCharSize, value);
 }
@@ skipping 833 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_