First round of changes to the file interface.

runtime/bin/file.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 "bin/file.h"
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
 
 #include "include/dart_api.h"
 
 
-static const int kFileFieldIndex = 0;
-
-
 bool File::ReadFully(void* buffer, int64_t num_bytes) {
   int64_t remaining = num_bytes;
   char* current_buffer = reinterpret_cast<char*>(buffer);
   while (remaining > 0) {
     int bytes_read = Read(current_buffer, remaining);
     if (bytes_read <= 0) {
       return false;
     }
     remaining -= bytes_read;  // Reduce the number of remaining bytes.
     current_buffer += bytes_read;  // Move the buffer forward.
@@ skipping 11 matching lines @@
       return false;
     }
     remaining -= bytes_read;  // Reduce the number of remaining bytes.
     current_buffer += bytes_read;  // Move the buffer forward.
   }
   return true;
 }
 
 
 static File* GetFileHandle(Dart_Handle fileobj) {
-  intptr_t value = 0;
-  Dart_Handle result = Dart_GetNativeInstanceField(fileobj, kFileFieldIndex,
-                                                   &value);
-  ASSERT(Dart_IsValid(result));
+  intptr_t value =
+      DartUtils::GetIntegerInstanceField(fileobj, DartUtils::kIdFieldName);
   File* file = reinterpret_cast<File*>(value);
   return file;
 }
 
 
 void FUNCTION_NAME(File_OpenFile)(Dart_NativeArguments args) {
   Dart_EnterScope();
   Dart_Handle fileobj = Dart_GetNativeArgument(args, 0);
   const char* filename =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 1));
   bool writable = DartUtils::GetBooleanValue(Dart_GetNativeArgument(args, 2));
   File* file = File::OpenFile(filename, writable);
-  Dart_SetNativeInstanceField(fileobj,
-                              kFileFieldIndex,
-                              reinterpret_cast<intptr_t>(file));
+  DartUtils::SetIntegerInstanceField(fileobj,
+                                     DartUtils::kIdFieldName,
+                                     reinterpret_cast<intptr_t>(file));
   Dart_SetReturnValue(args, Dart_NewBoolean(file != NULL));
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_Exists)(Dart_NativeArguments args) {
   Dart_EnterScope();
   const char* filename =
-      DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
+      DartUtils::GetStringValue(Dart_GetNativeArgument(args, 1));
   bool exists = File::FileExists(filename);
   Dart_SetReturnValue(args, Dart_NewBoolean(exists));
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_Close)(Dart_NativeArguments args) {
   Dart_EnterScope();
   intptr_t return_value = -1;
   Dart_Handle fileobj = Dart_GetNativeArgument(args, 0);
   File* file = GetFileHandle(fileobj);
   if (file != NULL) {
-    Dart_SetNativeInstanceField(fileobj,
-                                kFileFieldIndex,
-                                NULL);
+    DartUtils::SetIntegerInstanceField(fileobj, DartUtils::kIdFieldName, 0);
     delete file;
     return_value = 0;
   }
   Dart_SetReturnValue(args, Dart_NewInteger(return_value));
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_ReadByte)(Dart_NativeArguments args) {
   Dart_EnterScope();
@@ skipping 138 matching lines @@
   Dart_EnterScope();
   intptr_t return_value = -1;
   File* file = GetFileHandle(Dart_GetNativeArgument(args, 0));
   if (file != NULL) {
     file->Flush();
     return_value = 0;
   }
   Dart_SetReturnValue(args, Dart_NewInteger(return_value));
   Dart_ExitScope();
 }