added cluster helper functions

js/server/modules/org/arangodb/cluster.js

@@ -0,0 +1,80 @@
+/*jslint indent: 2, nomen: true, maxlen: 100, sloppy: true, vars: true, white: true, plusplus: true */
+/*global ArangoAgency, ArangoServerState, exports */
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief JavaScript cluster functionality
+///
+/// @file
+///
+/// DISCLAIMER
+///
+/// Copyright 2012 triagens GmbH, Cologne, Germany
+///
+/// Licensed under the Apache License, Version 2.0 (the "License");
+/// you may not use this file except in compliance with the License.
+/// You may obtain a copy of the License at
+///
+///     http://www.apache.org/licenses/LICENSE-2.0
+///
+/// Unless required by applicable law or agreed to in writing, software
+/// distributed under the License is distributed on an "AS IS" BASIS,
+/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+/// See the License for the specific language governing permissions and
+/// limitations under the License.
+///
+/// Copyright holder is triAGENS GmbH, Cologne, Germany
+///
+/// @author Jan Steemann
+/// @author Copyright 2012, triAGENS GmbH, Cologne, Germany
+////////////////////////////////////////////////////////////////////////////////
+
+var isCluster = function () {
+  return (typeof ArangoServerState !== "undefined");
+};
+
+var isCoordinator = function () {
+  if (! isCluster()) {
+    return false;
+  }
+
+  return ArangoServerState.isCoordinator();
+};
+
+var role = function () {
+  if (! isCluster()) {
+    return undefined;
+  }
+
+  return ArangoServerState.role();
+};
+
+var status = function () {
+  if (! isCluster()) {
+    return undefined;
+  }
+
+  return ArangoServerState.status();
+};
+
+var isCoordinatorRequest = function (req) {
+  if (! req || ! req.hasOwnProperty("headers")) {
+    return false;
+  }
+
+  return req.headers.hasOwnProperty("x-arango-coordinator");
+};
+
+exports.isCluster            = isCluster;
+exports.isCoordinator        = isCoordinator;
+exports.role                 = role;
+exports.status               = status;
+exports.isCoordinatorRequest = isCoordinatorRequest;
+
+// -----------------------------------------------------------------------------
+// --SECTION--                                                       END-OF-FILE
+// -----------------------------------------------------------------------------
+
+// Local Variables:
+// mode: outline-minor
+// outline-regexp: "\\(/// @brief\\|/// @addtogroup\\|// --SECTION--\\|/// @page\\|/// @\\}\\)"
+// End: