Add watch and modify/delete support to MemoryFile.

pkg/analysis_server/lib/src/resource.dart

 // Copyright (c) 2014, 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.
 
 library resource;
 
 import 'dart:async';
 import 'dart:io' as io;
 
 import 'package:analyzer/src/generated/engine.dart' show TimestampedData;
@@ skipping 226 matching lines @@
     _provider._pathToResource.forEach((path, resource) {
       if (posix.dirname(path) == _path) {
         children.add(resource);
       }
     });
     return children;
   }
 
   @override
   Stream<WatchEvent> get changes {
-    // TODO(paulberry): implement.
-    return new StreamController<WatchEvent>().stream;
+    if (_provider._pathToWatcher.containsKey(_path)) {
+      // Two clients watching the same path is not yet supported.
+      // TODO(paulberry): add support for this if needed.
+      throw new StateError('Path "$_path" is already being watched for changes');
+    }
+    var streamController = new StreamController<WatchEvent>();

[scheglov, 2014/05/28 18:22:28]

AFAIK we use type annotations.

[Paul Berry, 2014/05/28 20:16:22]

Done.

+    _provider._pathToWatcher[_path] = streamController;
+    streamController.done.then((_) {
+      _provider._pathToWatcher.remove(_path);
+    });
+    return streamController.stream;
   }
 }
 
 
 /**
  * An in-memory implementation of [ResourceProvider].
  * Use `/` as a path separator.
  */
 class MemoryResourceProvider implements ResourceProvider {
   final Map<String, _MemoryResource> _pathToResource = <String, _MemoryResource>{};
   final Map<String, String> _pathToContent = <String, String>{};
   final Map<String, int> _pathToTimestamp = <String, int>{};
+  final Map<String, StreamController<WatchEvent>> _pathToWatcher =
+      <String, StreamController<WatchEvent>>{};
   int nextStamp = 0;
 
   @override
   Resource getResource(String path) {
     path = posix.normalize(path);
     Resource resource = _pathToResource[path];
     if (resource == null) {
       resource = new _MemoryFile(this, path);
     }
     return resource;
@@ skipping 28 matching lines @@
     return folder;
   }
 
   File newFile(String path, String content) {
     path = posix.normalize(path);
     newFolder(posix.dirname(path));
     _MemoryFile file = new _MemoryFile(this, path);
     _pathToResource[path] = file;
     _pathToContent[path] = content;
     _pathToTimestamp[path] = nextStamp++;
+    _notifyWatchers(path, ChangeType.ADD);
     return file;
   }
+
+  void _notifyWatchers(String path, changeType) {

[scheglov, 2014/05/28 18:22:28]

Type annotation for "changeType".

[Paul Berry, 2014/05/28 20:16:22]

Done.

+    _pathToWatcher.forEach((watcherPath, streamController) {

[scheglov, 2014/05/28 18:22:28]

I'm not 100% sure, but AFAIK we should put type annotation here too.

[Paul Berry, 2014/05/28 20:16:22]

Done.

+      if (posix.isWithin(watcherPath, path)) {
+        streamController.add(new WatchEvent(changeType, path));
+      }
+    });
+  }
+
+  void modifyFile(String path, String content) {
+    _checkFileAtPath(path);
+    _pathToContent[path] = content;
+    _pathToTimestamp[path] = nextStamp++;
+    _notifyWatchers(path, ChangeType.MODIFY);
+  }
+
+  void _checkFileAtPath(String path) {
+    var resource = _pathToResource[path];
+    if (resource is! _MemoryFile) {
+      throw new ArgumentError(
+          'File expected at "$path" but ${resource.runtimeType} found');
+    }
+  }
+
+  void deleteFile(String path) {
+    _checkFileAtPath(path);
+    _pathToResource.remove(path);
+    _pathToContent.remove(path);
+    _pathToTimestamp.remove(path);
+    _notifyWatchers(path, ChangeType.REMOVE);
+  }
 }
 
 
 /**
  * A `dart:io` based implementation of [File].
  */
 class _PhysicalFile extends _PhysicalResource implements File {
   _PhysicalFile(io.File file) : super(file);
 
   @override
@@ skipping 76 matching lines @@
   Resource getResource(String path) {
     if (io.FileSystemEntity.isDirectorySync(path)) {
       io.Directory directory = new io.Directory(path);
       return new _PhysicalFolder(directory);
     } else {
       io.File file = new io.File(path);
       return new _PhysicalFile(file);
     }
   }
 }