update flutter run --devfs (#4942)

* update flutter run --devfs

* use async; add todo

packages/flutter_tools/lib/src/observatory.dart

@@ -142,14 +142,9 @@ class Observatory {
   // DevFS / VM virtual file system methods
 
   /// Create a new file system.
-  ///
-  /// When you create a file system you provide a fsName parameter. Given the
-  /// [fsName] parameter you can build all the URIs you need with the following
-  /// format:
-  ///
-  ///     dart-devfs://$fsName/$path
-  Future<Response> createDevFS(String fsName) {
-    return sendRequest('_createDevFS', <String, dynamic> { 'fsName': fsName });
+  Future<CreateDevFSResponse> createDevFS(String fsName) async {
+    Response response = await sendRequest('_createDevFS', <String, dynamic> { 'fsName': fsName });
+    return new CreateDevFSResponse(response.response);
   }
 
   /// List the available file systems.
@@ -175,9 +170,7 @@ class Observatory {
   }
 
   // Write multiple files into a file system.
-  Future<Response> writeDevFSFiles(String fsName, {
-    List<DevFSFile> files
-  }) {
+  Future<Response> writeDevFSFiles(String fsName, { List<DevFSFile> files }) {
     assert(files != null);
 
     return sendRequest('_writeDevFSFiles', <String, dynamic> {
@@ -186,13 +179,6 @@ class Observatory {
     });
   }
 
-  // Read one file from a file system.
-  Future<List<int>> readDevFSFile() {
-    return sendRequest('_readDevFSFile').then((Response response) {
-      return BASE64.decode(response.response['fileContents']);
-    });
-  }
-
   /// The complete list of a file system.
   Future<List<String>> listDevFSFiles(String fsName) {
     return sendRequest('_listDevFSFiles', <String, dynamic> {
@@ -229,9 +215,10 @@ class Observatory {
   }
 
   Future<Response> flutterExit(String isolateId) {
-    return peer.sendRequest('ext.flutter.exit', <String, dynamic>{
-      'isolateId': isolateId
-    }).then((dynamic result) => new Response(result));
+    return peer
+      .sendRequest('ext.flutter.exit', <String, dynamic>{ 'isolateId': isolateId })
+      .then((dynamic result) => new Response(result))
+      .timeout(new Duration(seconds: 2), onTimeout: () => null);
   }
 
   void _addIsolate(IsolateRef isolate) {
@@ -278,6 +265,13 @@ class Response {
   String toString() => response.toString();
 }
 
+class CreateDevFSResponse extends Response {
+  CreateDevFSResponse(Map<String, dynamic> response) : super(response);
+
+  String get name => response['name'];
+  String get uri => response['uri'];
+}
+
 class VM extends Response {
   VM(Map<String, dynamic> response) : super(response);
 

packages/flutter_tools/lib/src/run.dart

@@ -267,15 +267,17 @@ class RunAndStayResident {
         });
       }
 
-      ProcessSignal.SIGINT.watch().listen((ProcessSignal signal) {
+      ProcessSignal.SIGINT.watch().listen((ProcessSignal signal) async {
         _resetTerminal();
-        _stopLogger();
-        _stopApp();
+        await _stopLogger();
+        await _stopApp();
+        exit(0);
       });
-      ProcessSignal.SIGTERM.watch().listen((ProcessSignal signal) {
+      ProcessSignal.SIGTERM.watch().listen((ProcessSignal signal) async {
         _resetTerminal();
-        _stopLogger();
-        _stopApp();
+        await _stopLogger();
+        await _stopApp();
+        exit(0);
       });
     }
 
@@ -383,8 +385,8 @@ class RunAndStayResident {
       printStatus('Type "d" to send modified project files to the the client\'s DevFS.');
   }
 
-  void _stopLogger() {
-    _loggingSubscription?.cancel();
+  Future<dynamic> _stopLogger() {
+    return _loggingSubscription?.cancel();
   }
 
   void _resetTerminal() {
@@ -441,9 +443,13 @@ class DevFS {
   final Observatory observatory;
 
   String fsName;
+  String uri;
   Map<String, _DevFSFileEntry> entries = <String, _DevFSFileEntry>{};
 
-  Future<dynamic> init() => observatory.createDevFS(fsName);
+  Future<Null> init() async {
+    CreateDevFSResponse response = await observatory.createDevFS(fsName);
+    uri = response.uri;
+  }
 
   void stageFile(String devPath, File file) {
     entries.putIfAbsent(devPath, () => new _DevFSFileEntry(devPath, file));
@@ -456,7 +462,7 @@ class DevFS {
       .toList();
 
     for (_DevFSFileEntry entry in toSend) {
-      printTrace('sending devfs://$fsName/${entry.devPath}');
+      printTrace('sending to devfs: ${entry.devPath}');
       entry.updateLastModified();
     }
 
@@ -471,7 +477,16 @@ class DevFS {
       List<_DevFSFile> files = toSend.map((_DevFSFileEntry entry) {
         return new _DevFSFile('/${entry.devPath}', entry.file);
       }).toList();
-      await observatory.writeDevFSFiles(fsName, files: files);
+
+      // TODO(devoncarew): Batch this up in larger groups using writeDevFSFiles().
+      // The current implementation leaves dangling service protocol calls on a timeout.
+      await Future.wait(files.map((_DevFSFile file) {
+        return observatory.writeDevFSFile(
+          fsName,
+          path: file.path,
+          fileContents: file.getContents()
+        );
+      })).timeout(new Duration(seconds: 10));
     } finally {
       status.stop(showElapsedTime: true);
     }