Implement external strings.

runtime/include/dart_api.h

Index: runtime/include/dart_api.h
diff --git a/runtime/include/dart_api.h b/runtime/include/dart_api.h
index c8faf4fbde751742299289e6213915e9d902c68a..1d914a63f1a3b818cc7e12c74e0d1331f0e44ad3 100755
--- a/runtime/include/dart_api.h
+++ b/runtime/include/dart_api.h
@@ -98,6 +98,13 @@ typedef Dart_Result (*Dart_LibraryTagHandler)(Dart_LibraryTag tag,
                                               Dart_Handle library,
                                               Dart_Handle url);
 
+typedef void (*Dart_ExternalString8Finalizer)(uint8_t* codepoints,

[Anton Muhin, 2011/10/26 14:11:53]

I think codepoints may go away---embedder should be able to restore codepoints
from peer if need be.

+                                              void* peer);
+typedef void (*Dart_ExternalString16Finalizer)(uint16_t* codepoints,
+                                               void* peer);
+typedef void (*Dart_ExternalString32Finalizer)(uint32_t* codepoints,
+                                               void* peer);
+
 // TODO(iposva): This is a placeholder for the eventual external Dart API.
 
 // Return value handling after a Dart API call.
@@ -293,6 +300,23 @@ DART_EXPORT Dart_Handle Dart_NewString16(const uint16_t* codepoints,
 DART_EXPORT Dart_Handle Dart_NewString32(const uint32_t* codepoints,
                                          intptr_t length);
 
+DART_EXPORT Dart_Handle Dart_NewExternalString8(
+    uint8_t* codepoints,
+    intptr_t length,
+    void* peer,
+    Dart_ExternalString8Finalizer finalizer);
+DART_EXPORT Dart_Handle Dart_NewExternalString16(
+    uint16_t* codepoints,
+    intptr_t length,
+    void* peer,
+    Dart_ExternalString16Finalizer finalizer);
+DART_EXPORT Dart_Handle Dart_NewExternalString32(
+    uint32_t* codepoints,
+    intptr_t length,
+    void* peer,
+    Dart_ExternalString32Finalizer finalizer);
+
+
 // The functions below test whether the object is a String and its codepoints
 // all fit into 8 or 16 bits respectively.
 DART_EXPORT bool Dart_IsString8(Dart_Handle object);