dart:io | Add asynchronous versions of the methods of FileSystemEntity and Link.

runtime/bin/file.cc

 // Copyright (c) 2013, 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 "bin/io_buffer.h"
 #include "bin/thread.h"
@@ skipping 1043 matching lines @@
   if (File::CreateLink(link_name.CString(), target_name.CString())) {
     return CObject::True();
   } else {
     return CObject::NewOSError();
   }
 }
 
 
 static CObject* FileDeleteLinkRequest(const CObjectArray& request) {
   if (request.Length() == 2 && request[1]->IsString()) {
-    CObjectString filename(request[1]);
-    bool result = File::DeleteLink(filename.CString());
+    CObjectString link_path(request[1]);
+    bool result = File::DeleteLink(link_path.CString());
     if (result) {
       return CObject::True();
     } else {
       return CObject::NewOSError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
+static CObject* FileLinkTargetRequest(const CObjectArray& request) {
+  if (request.Length() == 2 && request[1]->IsString()) {
+    CObjectString link_path(request[1]);
+    char* target = File::LinkTarget(link_path.CString());
+    if (target != NULL) {
+      CObject* result = new CObjectString(CObject::NewString(target));
+      free(target);
+      return result;
+    } else {
+      return CObject::NewOSError();
+    }
+  }
+  return CObject::IllegalArgumentError();
+}
+
+
 static void FileService(Dart_Port dest_port_id,
                  Dart_Port reply_port_id,
                  Dart_CObject* message) {
   CObject* response = CObject::IllegalArgumentError();
   CObjectArray request(message);
   if (message->type == Dart_CObject::kArray) {
     if (request.Length() > 1 && request[0]->IsInt32()) {
       CObjectInt32 requestType(request[0]);
       switch (requestType.Value()) {
         case File::kExistsRequest:
@@ skipping 52 matching lines @@
           break;
         case File::kWriteFromRequest:
           response = FileWriteFromRequest(request);
           break;
         case File::kDeleteLinkRequest:
           response = FileDeleteLinkRequest(request);
           break;
         case File::kCreateLinkRequest:
           response = FileCreateLinkRequest(request);
           break;
+        case File::kLinkTargetRequest:
+          response = FileLinkTargetRequest(request);
+          break;
         default:
           UNREACHABLE();
       }
     }
   }
 
   Dart_PostCObject(reply_port_id, response->AsApiCObject());
 }
 
 
 Dart_Port File::GetServicePort() {
   return file_service_.GetServicePort();
 }
 
 
 void FUNCTION_NAME(File_NewServicePort)(Dart_NativeArguments args) {
   Dart_EnterScope();
   Dart_SetReturnValue(args, Dart_Null());
   Dart_Port service_port = File::GetServicePort();
   if (service_port != ILLEGAL_PORT) {
     // Return a send port for the service port.
     Dart_Handle send_port = Dart_NewSendPort(service_port);
     Dart_SetReturnValue(args, send_port);
   }
   Dart_ExitScope();
 }
 
 }  // namespace bin
 }  // namespace dart