implement client heartbeat #460.

client/src/neko/base.ts

@@ -20,6 +20,7 @@ export interface BaseEvents {
 
 export abstract class BaseClient extends EventEmitter<BaseEvents> {
   protected _ws?: WebSocket
+  protected _ws_heartbeat?: number
   protected _peer?: RTCPeerConnection
   protected _channel?: RTCDataChannel
   protected _timeout?: number
@@ -82,6 +83,11 @@ export abstract class BaseClient extends EventEmitter<BaseEvents> {
       this._timeout = undefined
     }
 
+    if (this._ws_heartbeat) {
+      clearInterval(this._ws_heartbeat)
+      this._ws_heartbeat = undefined
+    }
+
     if (this._ws) {
       // reset all events
       this._ws.onmessage = () => {}

client/src/neko/events.ts

@@ -14,6 +14,9 @@ export const EVENT = {
     DISCONNECT: 'system/disconnect',
     ERROR: 'system/error',
   },
+  CLIENT: {
+    HEARTBEAT: 'client/heartbeat'
+  },
   SIGNAL: {
     OFFER: 'signal/offer',
     ANSWER: 'signal/answer',
@@ -69,6 +72,7 @@ export type Events = typeof EVENT
 
 export type WebSocketEvents =
   | SystemEvents
+  | ClientEvents
   | ControlEvents
   | MemberEvents
   | SignalEvents
@@ -87,6 +91,7 @@ export type ControlEvents =
   | typeof EVENT.CONTROL.KEYBOARD
 
 export type SystemEvents = typeof EVENT.SYSTEM.DISCONNECT
+export type ClientEvents = typeof EVENT.CLIENT.HEARTBEAT
 export type MemberEvents = typeof EVENT.MEMBER.LIST | typeof EVENT.MEMBER.CONNECTED | typeof EVENT.MEMBER.DISCONNECTED
 
 export type SignalEvents =

client/src/neko/index.ts

@@ -134,7 +134,7 @@ export class NekoClient extends BaseClient implements EventEmitter<NekoEvents> {
   /////////////////////////////
   // System Events
   /////////////////////////////
-  protected [EVENT.SYSTEM.INIT]({ implicit_hosting, locks, file_transfer }: SystemInitPayload) {
+  protected [EVENT.SYSTEM.INIT]({ implicit_hosting, locks, file_transfer, heartbeat_interval }: SystemInitPayload) {
     this.$accessor.remote.setImplicitHosting(implicit_hosting)
     this.$accessor.remote.setFileTransfer(file_transfer)
 
@@ -145,6 +145,11 @@ export class NekoClient extends BaseClient implements EventEmitter<NekoEvents> {
         id: locks[resource],
       })
     }
+
+    if (heartbeat_interval > 0) {
+      if (this._ws_heartbeat) clearInterval(this._ws_heartbeat)
+      this._ws_heartbeat = window.setInterval(() => this.sendMessage(EVENT.CLIENT.HEARTBEAT), heartbeat_interval * 1000)
+    }
   }
 
   protected [EVENT.SYSTEM.DISCONNECT]({ message }: SystemMessagePayload) {

client/src/neko/messages.ts

@@ -61,6 +61,7 @@ export interface SystemInitPayload {
   implicit_hosting: boolean
   locks: Record<string, string>
   file_transfer: boolean
+  heartbeat_interval: number
 }
 
 // system/disconnect