Add Dart_IsExternalString and Dart_ExternalStringGetPeer to the dart

runtime/vm/dart_api_impl.cc

 // Copyright (c) 2011, 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 "include/dart_api.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/dart.h"
@@ skipping 1116 matching lines @@
 
 
 DART_EXPORT Dart_Handle Dart_NewString32(const uint32_t* codepoints,
                                          intptr_t length) {
   DARTSCOPE(Isolate::Current());
   const String& obj = String::Handle(String::New(codepoints, length));
   return Api::NewLocalHandle(obj);
 }
 
 
+DART_EXPORT bool Dart_IsExternalString(Dart_Handle object) {
+  DARTSCOPE(Isolate::Current());
+  const String& str = Api::UnwrapStringHandle(object);
+  if (str.IsNull()) {
+    return false;
+  }
+  return str.IsExternal();
+}
+
+
+DART_EXPORT Dart_Handle Dart_ExternalStringGetPeer(Dart_Handle object,
+                                                   void** peer) {
+  DARTSCOPE(Isolate::Current());
+  const String& str = Api::UnwrapStringHandle(object);
+  if (str.IsNull()) {
+    RETURN_TYPE_ERROR(object, String);
+  }
+  if (!str.IsExternal()) {
+    return Api::Error("%s expects argument 'object' to be an external String.",
+                      CURRENT_FUNC);
+  }
+  if (peer == NULL) {
+    return Api::Error("%s expects argument 'peer' to be non-NULL.",
+                      CURRENT_FUNC);
+  }
+  *peer = str.GetPeer();
+  return Api::Success();
+}
+
+
 DART_EXPORT Dart_Handle Dart_NewExternalString8(const uint8_t* codepoints,
                                                 intptr_t length,
                                                 void* peer,
                                                 Dart_PeerFinalizer callback) {
   DARTSCOPE(Isolate::Current());
   const String& obj =
       String::Handle(String::NewExternal(codepoints, length, peer, callback));
   return Api::NewLocalHandle(obj);
 }
 
@@ skipping 1230 matching lines @@
     }
     delete debug_region;
   } else {
     *buffer = NULL;
     *buffer_size = 0;
   }
 }
 
 
 }  // namespace dart