Merge pull request #51 from arunoda/sockjs-info-support

SockJs info support

Author: emgee3

README.markdown

@@ -45,12 +45,17 @@ var ddpclient = new DDPClient({
   // All properties optional, defaults shown
   host : "localhost",
   port : 3000,
-  path : "websocket",
   ssl  : false,
   autoReconnect : true,
   autoReconnectTimer : 500,
   maintainCollections : true,
-  ddpVersion : '1'  // ['1', 'pre2', 'pre1'] available
+  ddpVersion : '1',  // ['1', 'pre2', 'pre1'] available
+  // uses the SockJs protocol to create the connection
+  // this still uses websockets, but allows to get the benefits
+  // from projects like meteorhacks:cluster
+  // (for load balancing and service discovery)
+  // do not use `path` option when you are using useSockJs
+  useSockJs: true
 });
 
 /*
@@ -173,6 +178,22 @@ ddpclient.on('socket-error', function(error) {
 var oid = new ddpclient.EJSON.ObjectID();
 ```
 
+SockJS Mode
+===============
+
+By using the `useSockJs` option like below, DDP connection will use [SockJs](https://github.com/sockjs) protocol to establish the WebSocket connection.
+
+```js
+var ddpClient = new DDPClient({ useSockJs: true });
+```
+
+Meteor server uses SockJs to implement it's DDP server. With this mode, we can get the benefits provided by [meteorhacks:cluster](https://github.com/meteorhacks/cluster). Some of those are load balancing and service discovery.
+
+* For load balancing you don't need to anything.
+* For service discovery, just use the `path` option to identify the service you are referring to.
+
+> With this mode, `path` option has a special meaning. So, thing twice before using `path` option when you are using this option.
+
 Unimplemented Features
 ====
 The node DDP client does not implement ordered collections, something that while in the DDP spec has not been implemented in Meteor yet.

examples/example-meteor-server/.meteor/.finished-upgraders

@@ -0,0 +1,7 @@
+# This file contains information which helps Meteor properly upgrade your
+# app when you run 'meteor update'. You should check it into version control
+# with your project.
+
+notices-for-0.9.0
+notices-for-0.9.1
+0.9.4-platform-file

examples/example-meteor-server/.meteor/.id

@@ -0,0 +1,7 @@
+# This file contains a token that is unique to your project.
+# Check it into your repository along with the rest of this directory.
+# It can be used for purposes such as:
+#   - ensuring you don't accidentally deploy one app on top of another
+#   - providing package authors with aggregated statistics
+
+16h678x1r5dkr01i9xj33

examples/example-meteor-server/.meteor/platforms

@@ -0,0 +1,2 @@
+server
+browser

examples/example-meteor-server/.meteor/versions

@@ -0,0 +1,53 @@
+[email protected]
+[email protected]
+[email protected]
+[email protected]
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+[email protected]
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+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+meteorhacks:[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]
+[email protected]

examples/example.js

@@ -6,12 +6,17 @@ var ddpclient = new DDPClient({
   // All properties optional, defaults shown
   host : "localhost",
   port : 3000,
-  path : "websocket",
   ssl  : false,
   autoReconnect : true,
   autoReconnectTimer : 500,
   maintainCollections : true,
-  ddpVersion : "1"  // ["1", "pre2", "pre1"] available
+  ddpVersion : "1",  // ["1", "pre2", "pre1"] available,
+  // uses the sockJs protocol to create the connection
+  // this still uses websockets, but allows to get the benefits
+  // from projects like meteorhacks:cluster
+  // (load balancing and service discovery)
+  // do not use `path` option when you are using useSockJs
+  useSockJs: true
 });
 
 /*

lib/ddp-client.js

@@ -4,6 +4,8 @@ var util = require("util");
 var events = require("events");
 var WebSocket = require("faye-websocket");
 var EJSON = require("ddp-ejson");
+var request = require('request');
+var pathJoin = require('path').join;
 var _ = require("ddp-underscore-patched");
 
 var DDPClient = function(opts) {
@@ -21,8 +23,9 @@ var DDPClient = function(opts) {
   // default arguments
   self.host = opts.host || "localhost";
   self.port = opts.port || 3000;
-  self.path = opts.path || "websocket";
+  self.path = opts.path;
   self.ssl  = opts.ssl  || self.port === 443;
+  self.useSockJs = opts.useSockJs || false;
   self.autoReconnect = ("autoReconnect" in opts) ? opts.autoReconnect : true;
   self.autoReconnectTimer = ("autoReconnectTimer" in opts) ? opts.autoReconnectTimer : 500;
   self.maintainCollections = ("maintainCollections" in opts) ? opts.maintainCollections : true;
@@ -309,12 +312,66 @@ DDPClient.prototype.connect = function(connected) {
     });
   }
 
-  // websocket
+  if (self.useSockJs) {
+    self._makeSockJSConnection();
+  } else {
+    var url = self._buildWsUrl();
+    self._makeWebSocketConnection(url);
+  }
+};
+
+DDPClient.prototype._makeSockJSConnection = function() {
+  var self = this;
+
+  // do the info hit
+  var protocol = self.ssl ? "https://" : "http://";
+  var randomValue = "" + Math.ceil(Math.random() * 9999999);
+  var path = pathJoin("/", self.path || "", "sockjs/info");
+  var url = protocol + self.host + ":" + self.port + path;
+
+  request.get(url, function(err, res, body) {
+    if (err) {
+      self._recoverNetworkError();
+    } else if (body) {
+      var info = JSON.parse(body);
+      if(!info.base_url) {
+        // no base_url, then use pure WS handling
+        var url = self._buildWsUrl();
+        self._makeWebSocketConnection(url);
+      } else if (info.base_url.indexOf("http") === 0) {
+        // base url for a different host
+        var url = info.base_url + "/websocket";
+        url = url.replace(/^http/, "ws");
+        self._makeWebSocketConnection(url);
+      } else {
+        // base url for the same host
+        var path = info.base_url + "/websocket";
+        var url = self._buildWsUrl(path);
+        self._makeWebSocketConnection(url);
+      }
+    } else {
+      // no body. weird. use pure WS handling
+      var url = self._buildWsUrl();
+      self._makeWebSocketConnection(url);
+    }
+  });
+};
+
+DDPClient.prototype._buildWsUrl = function(path) {
+  var self = this;
+  path = path || self.path || "websocket";
   var protocol = self.ssl ? "wss://" : "ws://";
-  self.socket = new WebSocket.Client(protocol + self.host + ":" + self.port + "/" + self.path);
-  self._prepareHandlers();
+  var url = protocol + self.host + ":" + self.port;
+  url += (path.indexOf("/") === 0)? path : "/" + path;
+
+  return url;
 };
 
+DDPClient.prototype._makeWebSocketConnection = function(url) {
+  var self = this;
+  self.socket = new WebSocket.Client(url);
+  self._prepareHandlers();
+};
 
 DDPClient.prototype.close = function() {
   var self = this;

package.json

@@ -26,7 +26,8 @@
   "dependencies": {
     "ddp-underscore-patched": "0.8.1-2",
     "ddp-ejson": "0.8.1-3",
-    "faye-websocket": "~0.7.1"
+    "faye-websocket": "~0.7.1",
+    "request": "2.53.x"
   },
   "devDependencies": {
     "mocha": "1.9.x",

test/ddp-client.js

@@ -266,3 +266,146 @@ describe('Collection maintenance and observation', function() {
     assert.equal(oldval.value, true);
   });
 });
+
+
+describe("SockJS", function() {
+  it("should use direct WS connection if there is a path", function() {
+    var ddpclient = new DDPClient();
+    ddpclient._makeWebSocketConnection = sinon.stub();
+    ddpclient.connect();
+
+    assert.ok(ddpclient._makeWebSocketConnection.called);
+  });
+
+  it("should fallback to sockjs if there useSockJS option", function() {
+    var ddpclient = new DDPClient({ useSockJs: true });
+    ddpclient._makeSockJSConnection = sinon.stub();
+    ddpclient.connect();
+
+    assert.ok(ddpclient._makeSockJSConnection.called);
+  });
+
+  describe("after info hit", function() {
+    var request = require("request");
+    it("should connect to the correct url", function(done) {
+      var get = function(url, callback) {
+        assert.equal(url, "http://the-host:9000/sockjs/info");
+        done();
+      };
+
+      WithRequestGet(get, function() {
+        var opts = {
+          host: "the-host",
+          port: 9000
+        };
+        var ddpclient = new DDPClient(opts);
+        ddpclient._makeSockJSConnection();
+      });
+    });
+
+    it("should support custom paths", function(done) {
+      var get = function(url, callback) {
+        assert.equal(url, "http://the-host:9000/search/sockjs/info");
+        done();
+      };
+
+      WithRequestGet(get, function() {
+        var opts = {
+          host: "the-host",
+          port: 9000,
+          path: "search"
+        };
+        var ddpclient = new DDPClient(opts);
+        ddpclient._makeSockJSConnection();
+      });
+    });
+
+    it("should retry if there is an error", function() {
+      var error = { message: "error" };
+      var get = function(url, callback) {
+        callback(error);
+      };
+
+      WithRequestGet(get, function() {
+        var ddpclient = new DDPClient();
+        ddpclient._recoverNetworkError = sinon.stub();
+        ddpclient._makeSockJSConnection();
+        assert.ok(ddpclient._recoverNetworkError.called);
+      });
+    });
+
+    it("should use direct WS if there is no body", function() {
+      var info = null;
+      var get = function(url, callback) {
+        callback(null, null, info);
+      };
+
+      WithRequestGet(get, function() {
+        var ddpclient = new DDPClient();
+        ddpclient._makeWebSocketConnection = sinon.stub();
+        ddpclient._makeSockJSConnection();
+
+        var wsUrl = "ws://localhost:3000/websocket";
+        assert.ok(ddpclient._makeWebSocketConnection.calledWith(wsUrl));
+      });
+    });
+
+    it("should use direct WS if there is no base_url", function() {
+      var info = '{}';
+      var get = function(url, callback) {
+        callback(null, null, info);
+      };
+
+      WithRequestGet(get, function() {
+        var ddpclient = new DDPClient();
+        ddpclient._makeWebSocketConnection = sinon.stub();
+        ddpclient._makeSockJSConnection();
+
+        var wsUrl = "ws://localhost:3000/websocket";
+        assert.ok(ddpclient._makeWebSocketConnection.calledWith(wsUrl));
+      });
+    });
+
+    it("should use full base url if it's starts with http", function() {
+      var info = '{"base_url": "https://somepath"}';
+      var get = function(url, callback) {
+        callback(null, null, info);
+      };
+
+      WithRequestGet(get, function() {
+        var ddpclient = new DDPClient();
+        ddpclient._makeWebSocketConnection = sinon.stub();
+        ddpclient._makeSockJSConnection();
+
+        var wsUrl = "wss://somepath/websocket";
+        assert.ok(ddpclient._makeWebSocketConnection.calledWith(wsUrl));
+      });
+    });
+
+    it("should compute url based on the base_url if it's not starts with http", function() {
+      var info = '{"base_url": "/somepath"}';
+      var get = function(url, callback) {
+        callback(null, null, info);
+      };
+
+      WithRequestGet(get, function() {
+        var ddpclient = new DDPClient();
+        ddpclient._makeWebSocketConnection = sinon.stub();
+        ddpclient._makeSockJSConnection();
+
+        var wsUrl = "ws://localhost:3000/somepath/websocket";
+        assert.ok(ddpclient._makeWebSocketConnection.calledWith(wsUrl));
+      });
+    });
+  });
+});
+
+function WithRequestGet(getFn, fn) {
+  var request = require("request");
+  var originalGet = request.get;
+  request.get = getFn;
+
+  fn();
+
+  request.get = originalGet;
+}