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

src/objects-inl.h

Index: src/objects-inl.h
===================================================================
--- src/objects-inl.h	(revision 1251)
+++ src/objects-inl.h	(working copy)
@@ -1639,6 +1639,34 @@
 }
 
 
+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));
 }
@@ -1650,6 +1678,34 @@
 }
 
 
+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);