Add resource metadata for open files.

sdk/lib/io/io_resource_info.dart

Index: sdk/lib/io/io_resource_info.dart
diff --git a/sdk/lib/io/io_resource_info.dart b/sdk/lib/io/io_resource_info.dart
index 79557b36fefe8d380372ce0f5a62cd507b6b50f0..8c30c646995627e7bead00ebca152a04ef2a87a1 100644
--- a/sdk/lib/io/io_resource_info.dart
+++ b/sdk/lib/io/io_resource_info.dart
@@ -4,10 +4,6 @@
 
 part of dart.io;
 
-const String TCP_STRING = 'TCP';
-const String UDP_STRING = 'UDP';
-
-
 abstract class _IOResourceInfo {
   final String type;
   final int id;
@@ -35,6 +31,9 @@ abstract class _IOResourceInfo {
   static int getNextID() => _count++;
 }
 
+// TODO(ricow): Move stopwatch into this class and use it for both files
+// and sockets (by using setters on totalRead/totalWritten). Also, consider
+// setting readCount and writeCount in those setters.
 abstract class _ReadWriteResourceInfo extends _IOResourceInfo {
   int totalRead;
   int totalWritten;
@@ -70,13 +69,69 @@ abstract class _ReadWriteResourceInfo extends _IOResourceInfo {
   }
 }
 
+class _FileResourceInfo extends _ReadWriteResourceInfo {
+  static const String TYPE = '_file';
+
+  final file;
+
+  static Map<int, _FileResourceInfo> openFiles =
+      new Map<int, _FileResourceInfo>();
+
+  _FileResourceInfo(this.file) : super(TYPE) {
+    FileOpened(this);
+  }
+
+  static FileOpened(_FileResourceInfo info) {
+    assert(!openFiles.containsKey(info.id));
+    openFiles[info.id] = info;
+  }
+
+  static FileClosed(_FileResourceInfo info) {
+    assert(openFiles.containsKey(info.id));
+    openFiles.remove(info.id);
+  }
+
+  static Iterable<Map<String, String>> getOpenFilesList() {
+    return new List.from(openFiles.values.map((e) => e.referenceValueMap));
+  }
+
+  static Future<ServiceExtensionResponse> getOpenFiles(function, params) {
+    assert(function == '__getOpenFiles');
+    var data = {'type': '_openfiles', 'data': getOpenFilesList()};
+    var json = JSON.encode(data);
+    return new Future.value(new ServiceExtensionResponse.result(json));
+  }
+
+  Map<String, String> getFileInfoMap() {
+    var result = fullValueMap;
+    return result;
+  }
+
+  static Future<ServiceExtensionResponse> getFileInfoMapByID(function, params) {
+    assert(params.containsKey('id'));
+    var id = int.parse(params['id']);
+    var result =
+      openFiles.containsKey(id) ? openFiles[id].getFileInfoMap() : {};
+    var json = JSON.encode(result);
+    return new Future.value(new ServiceExtensionResponse.result(json));
+  }
+
+  String get name {
+    return '${file.path}';
+  }
+}
+
 class _SocketResourceInfo extends _ReadWriteResourceInfo {
+  static const String TCP_STRING = 'TCP';
+  static const String UDP_STRING = 'UDP';
+  static const String TYPE = '_socket';
+
   final socket;
 
   static Map<int, _SocketResourceInfo> openSockets =
       new Map<int, _SocketResourceInfo>();
 
-  _SocketResourceInfo(this.socket) : super('_socket') {
+  _SocketResourceInfo(this.socket) : super(TYPE) {
     SocketOpened(this);
   }