diff --git a/src/lib/cloud-provider.js b/src/lib/cloud-provider.js
index 8116813ebd17c98549b3fc55565944747f19054d..1e6fb2adeca3635939aa9bf7c0e987bb2363ece2 100644
--- a/src/lib/cloud-provider.js
+++ b/src/lib/cloud-provider.js
@@ -16,24 +16,26 @@ class CloudProvider {
this.vm = vm;
this.username = username;
this.projectId = projectId;
+ this.cloudHost = cloudHost;
- // Open a websocket connection to the clouddata server
- this.openConnection(cloudHost);
+ this.connectionAttempts = 0;
+
+ this.openConnection();
}
/**
* Open a new websocket connection to the clouddata server.
* @param {string} cloudHost The cloud data server to connect to.
*/
- openConnection (cloudHost) {
- if (window.WebSocket === null) {
- log.warn('Websocket support is not available in this browser');
+ openConnection () {
+ try {
+ this.connection = new WebSocket((location.protocol === 'http:' ? 'ws://' : 'wss://') + this.cloudHost);
+ } catch (e) {
+ log.warn('Websocket support is not available in this browser', e);
this.connection = null;
return;
}
- this.connection = new WebSocket((location.protocol === 'http:' ? 'ws://' : 'wss://') + cloudHost);
-
this.connection.onerror = this.onError.bind(this);
this.connection.onmessage = this.onMessage.bind(this);
this.connection.onopen = this.onOpen.bind(this);
@@ -42,8 +44,7 @@ class CloudProvider {
onError (event) {
log.error(`Websocket connection error: ${JSON.stringify(event)}`);
- // TODO Add re-connection attempt logic here
- this.clear();
+ // Error is always followed by close, which handles reconnect logic.
}
onMessage (event) {
@@ -57,12 +58,31 @@ class CloudProvider {
}
onOpen () {
+ this.connectionAttempts = 1; // Reset because we successfully connected
this.writeToServer('handshake');
log.info(`Successfully connected to clouddata server.`);
}
onClose () {
log.info(`Closed connection to websocket`);
+ const exponentialTimeout = (Math.pow(2, this.connectionAttempts) - 1) * 1000;
+ const randomizedTimeout = this.randomizeDuration(exponentialTimeout);
+ this.setTimeout(this.reconnectNow.bind(this), randomizedTimeout);
+ }
+
+ reconnectNow () {
+ // Max connection attempts at 5, so timeout will max out in range [0, 31s]
+ this.connectionAttempts = Math.min(this.connectionAttempts + 1, 5);
+ this.openConnection();
+ }
+
+ randomizeDuration (t) {
+ return Math.random() * t;
+ }
+
+ setTimeout (fn, time) {
+ log.info(`Reconnecting in ${time}ms, attempt ${this.connectionAttempts}`);
+ this._connectionTimeout = window.setTimeout(fn, time);
}
parseMessage (message) {
@@ -148,7 +168,7 @@ class CloudProvider {
if (this.connection &&
this.connection.readyState !== WebSocket.CLOSING &&
this.connection.readyState !== WebSocket.CLOSED) {
-
+ this.connection.onclose = () => {}; // Remove close listener to prevent reconnect
this.connection.close();
}
this.clear();
@@ -163,6 +183,10 @@ class CloudProvider {
this.vm = null;
this.username = null;
this.projectId = null;
+ if (this._connectionTimeout) {
+ clearTimeout(this._connectionTimeout);
+ this._connectionTimeout = null;
+ }
}
}
diff --git a/test/unit/util/cloud-provider.test.js b/test/unit/util/cloud-provider.test.js
index c81588ddeccad21e2e7e9116f9ae9d5ce7f081a2..d5f8a711222f7e3034a3069bca05a3a1fd47557f 100644
--- a/test/unit/util/cloud-provider.test.js
+++ b/test/unit/util/cloud-provider.test.js
@@ -1,33 +1,51 @@
import CloudProvider from '../../../src/lib/cloud-provider';
-// Disable window.WebSocket
-global.WebSocket = null;
+let websocketConstructorCount = 0;
+
+// Stub the global websocket so we can call open/close/error/send on it
+global.WebSocket = function (url) {
+ this._url = url;
+ this._sentMessages = [];
+
+ // These are not real websocket methods, but used to trigger callbacks
+ this._open = () => this.onopen();
+ this._error = e => this.onerror(e);
+ this._receive = msg => this.onmessage(msg);
+
+ // Stub the real websocket.send to store sent messages
+ this.send = msg => this._sentMessages.push(msg);
+ this.close = () => this.onclose();
+
+ websocketConstructorCount++;
+};
+global.WebSocket.CLOSING = 'CLOSING';
+global.WebSocket.CLOSED = 'CLOSED';
describe('CloudProvider', () => {
let cloudProvider = null;
- let sentMessage = null;
let vmIOData = [];
-
+ let timeout = 0;
beforeEach(() => {
vmIOData = [];
cloudProvider = new CloudProvider();
- // Stub connection
- cloudProvider.connection = {
- send: msg => {
- sentMessage = msg;
- }
- };
// Stub vm
cloudProvider.vm = {
postIOData: (_namespace, data) => {
vmIOData.push(data);
}
};
+ // Stub setTimeout so this can run instantly.
+ cloudProvider.setTimeout = (fn, after) => {
+ timeout = after;
+ fn();
+ };
+ // Stub randomize to make it consistent for testing.
+ cloudProvider.randomizeDuration = t => t;
});
test('updateVariable', () => {
cloudProvider.updateVariable('hello', 1);
- const obj = JSON.parse(sentMessage);
+ const obj = JSON.parse(cloudProvider.connection._sentMessages[0]);
expect(obj.method).toEqual('set');
expect(obj.name).toEqual('hello');
expect(obj.value).toEqual(1);
@@ -35,7 +53,7 @@ describe('CloudProvider', () => {
test('updateVariable with falsey value', () => {
cloudProvider.updateVariable('hello', 0);
- const obj = JSON.parse(sentMessage);
+ const obj = JSON.parse(cloudProvider.connection._sentMessages[0]);
expect(obj.method).toEqual('set');
expect(obj.name).toEqual('hello');
expect(obj.value).toEqual(0);
@@ -43,7 +61,7 @@ describe('CloudProvider', () => {
test('writeToServer with falsey index value', () => {
cloudProvider.writeToServer('method', 'name', 5, 0);
- const obj = JSON.parse(sentMessage);
+ const obj = JSON.parse(cloudProvider.connection._sentMessages[0]);
expect(obj.method).toEqual('method');
expect(obj.name).toEqual('name');
expect(obj.value).toEqual(5);
@@ -55,7 +73,7 @@ describe('CloudProvider', () => {
method: 'ack',
name: 'name'
});
- cloudProvider.onMessage({data: msg});
+ cloudProvider.connection._receive({data: msg});
expect(vmIOData[0].varCreate.name).toEqual('name');
});
@@ -65,7 +83,7 @@ describe('CloudProvider', () => {
name: 'name',
value: 'value'
});
- cloudProvider.onMessage({data: msg});
+ cloudProvider.connection._receive({data: msg});
expect(vmIOData[0].varUpdate.name).toEqual('name');
expect(vmIOData[0].varUpdate.value).toEqual('value');
});
@@ -80,8 +98,60 @@ describe('CloudProvider', () => {
method: 'ack',
name: 'name2'
});
- cloudProvider.onMessage({data: `${msg1}\n${msg2}`});
+ cloudProvider.connection._receive({data: `${msg1}\n${msg2}`});
expect(vmIOData[0].varUpdate.name).toEqual('name1');
expect(vmIOData[1].varCreate.name).toEqual('name2');
});
+
+ test('connecting sets connnection attempts back to 1', () => {
+ expect(cloudProvider.connectionAttempts).toBe(0);
+ cloudProvider.connectionAttempts = 10;
+ cloudProvider.connection._open();
+ expect(cloudProvider.connectionAttempts).toBe(1);
+ });
+
+ test('disconnect waits for a period equal to 2^k-1 before trying again', () => {
+ websocketConstructorCount = 1; // This is global, so set it back to 1 to start
+
+ // Connection attempts should still be 0 because connection hasn't opened yet
+ expect(cloudProvider.connectionAttempts).toBe(0);
+ cloudProvider.connection._open();
+ expect(cloudProvider.connectionAttempts).toBe(1);
+
+ cloudProvider.connection.close();
+ expect(timeout).toEqual(1 * 1000); // 2^1 - 1
+ expect(websocketConstructorCount).toBe(2);
+ expect(cloudProvider.connectionAttempts).toBe(2);
+
+ cloudProvider.connection.close();
+ expect(timeout).toEqual(3 * 1000); // 2^2 - 1
+ expect(websocketConstructorCount).toBe(3);
+ expect(cloudProvider.connectionAttempts).toBe(3);
+
+ cloudProvider.connection.close();
+ expect(timeout).toEqual(7 * 1000); // 2^3 - 1
+ expect(websocketConstructorCount).toBe(4);
+ expect(cloudProvider.connectionAttempts).toBe(4);
+
+ cloudProvider.connection.close();
+ expect(timeout).toEqual(15 * 1000); // 2^4 - 1
+ expect(websocketConstructorCount).toBe(5);
+ expect(cloudProvider.connectionAttempts).toBe(5);
+
+ cloudProvider.connection.close();
+ expect(timeout).toEqual(31 * 1000); // 2^5 - 1
+ expect(websocketConstructorCount).toBe(6);
+ expect(cloudProvider.connectionAttempts).toBe(5); // Maxed at 5
+
+ cloudProvider.connection.close();
+ expect(timeout).toEqual(31 * 1000); // maxed out at 2^5 - 1
+ expect(websocketConstructorCount).toBe(7);
+ expect(cloudProvider.connectionAttempts).toBe(5); // Maxed at 5
+ });
+
+ test('requestCloseConnection does not try to reconnect', () => {
+ websocketConstructorCount = 1; // This is global, so set it back to 1 to start
+ cloudProvider.requestCloseConnection();
+ expect(websocketConstructorCount).toBe(1); // No reconnection attempts
+ });
});