CasperSecurity
import { default as EventsDispatcher } from '../events/dispatcher';
import { OneOffTimer as Timer } from '../utils/timers';
import { Config } from '../config';
import Logger from '../logger';
import HandshakePayload from './handshake/handshake_payload';
import Connection from './connection';
import Strategy from '../strategies/strategy';
import StrategyRunner from '../strategies/strategy_runner';
import * as Collections from '../utils/collections';
import Timeline from '../timeline/timeline';
import ConnectionManagerOptions from './connection_manager_options';
import Runtime from 'runtime';
import {
ErrorCallbacks,
HandshakeCallbacks,
ConnectionCallbacks
} from './callbacks';
import Action from './protocol/action';
/** Manages connection to Pusher.
*
* Uses a strategy (currently only default), timers and network availability
* info to establish a connection and export its state. In case of failures,
* manages reconnection attempts.
*
* Exports state changes as following events:
* - "state_change", { previous: p, current: state }
* - state
*
* States:
* - initialized - initial state, never transitioned to
* - connecting - connection is being established
* - connected - connection has been fully established
* - disconnected - on requested disconnection
* - unavailable - after connection timeout or when there's no network
* - failed - when the connection strategy is not supported
*
* Options:
* - unavailableTimeout - time to transition to unavailable state
* - activityTimeout - time after which ping message should be sent
* - pongTimeout - time for Pusher to respond with pong before reconnecting
*
* @param {String} key application key
* @param {Object} options
*/
export default class ConnectionManager extends EventsDispatcher {
key: string;
options: ConnectionManagerOptions;
state: string;
connection: Connection;
usingTLS: boolean;
timeline: Timeline;
socket_id: string;
unavailableTimer: Timer;
activityTimer: Timer;
retryTimer: Timer;
activityTimeout: number;
strategy: Strategy;
runner: StrategyRunner;
errorCallbacks: ErrorCallbacks;
handshakeCallbacks: HandshakeCallbacks;
connectionCallbacks: ConnectionCallbacks;
constructor(key: string, options: ConnectionManagerOptions) {
super();
this.state = 'initialized';
this.connection = null;
this.key = key;
this.options = options;
this.timeline = this.options.timeline;
this.usingTLS = this.options.useTLS;
this.errorCallbacks = this.buildErrorCallbacks();
this.connectionCallbacks = this.buildConnectionCallbacks(
this.errorCallbacks
);
this.handshakeCallbacks = this.buildHandshakeCallbacks(this.errorCallbacks);
var Network = Runtime.getNetwork();
Network.bind('online', () => {
this.timeline.info({ netinfo: 'online' });
if (this.state === 'connecting' || this.state === 'unavailable') {
this.retryIn(0);
}
});
Network.bind('offline', () => {
this.timeline.info({ netinfo: 'offline' });
if (this.connection) {
this.sendActivityCheck();
}
});
this.updateStrategy();
}
/** Establishes a connection to Pusher.
*
* Does nothing when connection is already established. See top-level doc
* to find events emitted on connection attempts.
*/
connect() {
if (this.connection || this.runner) {
return;
}
if (!this.strategy.isSupported()) {
this.updateState('failed');
return;
}
this.updateState('connecting');
this.startConnecting();
this.setUnavailableTimer();
}
/** Sends raw data.
*
* @param {String} data
*/
send(data) {
if (this.connection) {
return this.connection.send(data);
} else {
return false;
}
}
/** Sends an event.
*
* @param {String} name
* @param {String} data
* @param {String} [channel]
* @returns {Boolean} whether message was sent or not
*/
send_event(name: string, data: any, channel?: string) {
if (this.connection) {
return this.connection.send_event(name, data, channel);
} else {
return false;
}
}
/** Closes the connection. */
disconnect() {
this.disconnectInternally();
this.updateState('disconnected');
}
isUsingTLS() {
return this.usingTLS;
}
private startConnecting() {
var callback = (error, handshake) => {
if (error) {
this.runner = this.strategy.connect(0, callback);
} else {
if (handshake.action === 'error') {
this.emit('error', {
type: 'HandshakeError',
error: handshake.error
});
this.timeline.error({ handshakeError: handshake.error });
} else {
this.abortConnecting(); // we don't support switching connections yet
this.handshakeCallbacks[handshake.action](handshake);
}
}
};
this.runner = this.strategy.connect(0, callback);
}
private abortConnecting() {
if (this.runner) {
this.runner.abort();
this.runner = null;
}
}
private disconnectInternally() {
this.abortConnecting();
this.clearRetryTimer();
this.clearUnavailableTimer();
if (this.connection) {
var connection = this.abandonConnection();
connection.close();
}
}
private updateStrategy() {
this.strategy = this.options.getStrategy({
key: this.key,
timeline: this.timeline,
useTLS: this.usingTLS
});
}
private retryIn(delay) {
this.timeline.info({ action: 'retry', delay: delay });
if (delay > 0) {
this.emit('connecting_in', Math.round(delay / 1000));
}
this.retryTimer = new Timer(delay || 0, () => {
this.disconnectInternally();
this.connect();
});
}
private clearRetryTimer() {
if (this.retryTimer) {
this.retryTimer.ensureAborted();
this.retryTimer = null;
}
}
private setUnavailableTimer() {
this.unavailableTimer = new Timer(this.options.unavailableTimeout, () => {
this.updateState('unavailable');
});
}
private clearUnavailableTimer() {
if (this.unavailableTimer) {
this.unavailableTimer.ensureAborted();
}
}
private sendActivityCheck() {
this.stopActivityCheck();
this.connection.ping();
// wait for pong response
this.activityTimer = new Timer(this.options.pongTimeout, () => {
this.timeline.error({ pong_timed_out: this.options.pongTimeout });
this.retryIn(0);
});
}
private resetActivityCheck() {
this.stopActivityCheck();
// send ping after inactivity
if (this.connection && !this.connection.handlesActivityChecks()) {
this.activityTimer = new Timer(this.activityTimeout, () => {
this.sendActivityCheck();
});
}
}
private stopActivityCheck() {
if (this.activityTimer) {
this.activityTimer.ensureAborted();
}
}
private buildConnectionCallbacks(
errorCallbacks: ErrorCallbacks
): ConnectionCallbacks {
return Collections.extend<ConnectionCallbacks>({}, errorCallbacks, {
message: message => {
// includes pong messages from server
this.resetActivityCheck();
this.emit('message', message);
},
ping: () => {
this.send_event('pusher:pong', {});
},
activity: () => {
this.resetActivityCheck();
},
error: error => {
// just emit error to user - socket will already be closed by browser
this.emit('error', error);
},
closed: () => {
this.abandonConnection();
if (this.shouldRetry()) {
this.retryIn(1000);
}
}
});
}
private buildHandshakeCallbacks(
errorCallbacks: ErrorCallbacks
): HandshakeCallbacks {
return Collections.extend<HandshakeCallbacks>({}, errorCallbacks, {
connected: (handshake: HandshakePayload) => {
this.activityTimeout = Math.min(
this.options.activityTimeout,
handshake.activityTimeout,
handshake.connection.activityTimeout || Infinity
);
this.clearUnavailableTimer();
this.setConnection(handshake.connection);
this.socket_id = this.connection.id;
this.updateState('connected', { socket_id: this.socket_id });
}
});
}
private buildErrorCallbacks(): ErrorCallbacks {
let withErrorEmitted = callback => {
return (result: Action | HandshakePayload) => {
if (result.error) {
this.emit('error', { type: 'WebSocketError', error: result.error });
}
callback(result);
};
};
return {
tls_only: withErrorEmitted(() => {
this.usingTLS = true;
this.updateStrategy();
this.retryIn(0);
}),
refused: withErrorEmitted(() => {
this.disconnect();
}),
backoff: withErrorEmitted(() => {
this.retryIn(1000);
}),
retry: withErrorEmitted(() => {
this.retryIn(0);
})
};
}
private setConnection(connection) {
this.connection = connection;
for (var event in this.connectionCallbacks) {
this.connection.bind(event, this.connectionCallbacks[event]);
}
this.resetActivityCheck();
}
private abandonConnection() {
if (!this.connection) {
return;
}
this.stopActivityCheck();
for (var event in this.connectionCallbacks) {
this.connection.unbind(event, this.connectionCallbacks[event]);
}
var connection = this.connection;
this.connection = null;
return connection;
}
private updateState(newState: string, data?: any) {
var previousState = this.state;
this.state = newState;
if (previousState !== newState) {
var newStateDescription = newState;
if (newStateDescription === 'connected') {
newStateDescription += ' with new socket ID ' + data.socket_id;
}
Logger.debug(
'State changed',
previousState + ' -> ' + newStateDescription
);
this.timeline.info({ state: newState, params: data });
this.emit('state_change', { previous: previousState, current: newState });
this.emit(newState, data);
}
}
private shouldRetry(): boolean {
return this.state === 'connecting' || this.state === 'connected';
}
}