Add appengine/gcloud/mustache dependencies.

pkg/appengine/lib/api/logging.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 appengine.api.logging;
+
+import 'dart:async';
+
+import 'package:gcloud/service_scope.dart' as ss;
+
+class LogLevel {
+  static const LogLevel CRITICAL = const LogLevel._('Critical', 4);
+  static const LogLevel ERROR = const LogLevel._('Error', 3);
+  static const LogLevel WARNING = const LogLevel._('Warning', 2);
+  static const LogLevel INFO = const LogLevel._('Info', 1);
+  static const LogLevel DEBUG = const LogLevel._('Debug', 0);
+
+  final String name;
+  final int level;
+
+  const LogLevel._(this.name, this.level);
+
+  String toString() => name;
+}
+
+abstract class Logging {
+  void critical(String string, {DateTime timestamp}) {
+    log(LogLevel.CRITICAL, string, timestamp: timestamp);
+  }
+
+  void error(String string, {DateTime timestamp}) {
+    log(LogLevel.ERROR, string, timestamp: timestamp);
+  }
+
+  void warning(String string, {DateTime timestamp}) {
+    log(LogLevel.WARNING, string, timestamp: timestamp);
+  }
+
+  void info(String string, {DateTime timestamp}) {
+    log(LogLevel.INFO, string, timestamp: timestamp);
+  }
+
+  void debug(String string, {DateTime timestamp}) {
+    log(LogLevel.DEBUG, string, timestamp: timestamp);
+  }
+
+  void log(LogLevel level, String message, {DateTime timestamp});
+
+  Future flush();
+}
+
+/**
+ * Register a new [Logging] object.
+ *
+ * Calling this outside of a service scope or calling it more than once inside
+ * the same service scope will result in an error.
+ *
+ * See the `package:gcloud/service_scope.dart` library for more information.
+ */
+void registerLoggingService(Logging service) {
+  ss.register(#_appengine.logging, service);
+}
+
+/**
+ * The logging service.
+ *
+ * Request handlers will be run inside a service scope which contains the
+ * modules service.
+ */
+Logging get loggingService => ss.lookup(#_appengine.logging);