devtools/shared/transport/worker-transport.js

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 "use strict";
   6
   7 // Each worker debugger supports only a single connection to the main thread.
   8 // However, its theoretically possible for multiple servers to connect to the
   9 // same worker. Consequently, each transport has a connection id, to allow
  10 // messages from multiple connections to be multiplexed on a single channel.
  11
  12 /**
  13  * A transport that uses a WorkerDebugger to send packets from the main
  14  * thread to a worker thread.
  15  */
  16 class MainThreadWorkerDebuggerTransport {
  17   constructor(dbg, id) {
  18     this._dbg = dbg;
  19     this._id = id;
  20
  21     this._dbgListener = {
  22       onMessage: this._onMessage.bind(this),
  23     };
  24   }
  25
  26   ready() {
  27     this._dbg.addListener(this._dbgListener);
  28   }
  29
  30   close() {
  31     if (this._dbgListener) {
  32       this._dbg.removeListener(this._dbgListener);
  33     }
  34     this._dbgListener = null;
  35     this.hooks?.onTransportClosed();
  36   }
  37
  38   send(packet) {
  39     this._dbg.postMessage(
  40       JSON.stringify({
  41         type: "message",
  42         id: this._id,
  43         message: packet,
  44       })
  45     );
  46   }
  47
  48   startBulkSend() {
  49     throw new Error("Can't send bulk data from worker threads!");
  50   }
  51
  52   _onMessage(message) {
  53     const packet = JSON.parse(message);
  54     if (packet.type !== "message" || packet.id !== this._id || !this.hooks) {
  55       return;
  56     }
  57
  58     this.hooks.onPacket(packet.message);
  59   }
  60 }
  61
  62 exports.MainThreadWorkerDebuggerTransport = MainThreadWorkerDebuggerTransport;
  63
  64 /**
  65  * A transport that uses a WorkerDebuggerGlobalScope to send packets from a
  66  * worker thread to the main thread.
  67  */
  68 function WorkerThreadWorkerDebuggerTransport(scope, id) {
  69   this._scope = scope;
  70   this._id = id;
  71   this._onMessage = this._onMessage.bind(this);
  72 }
  73
  74 WorkerThreadWorkerDebuggerTransport.prototype = {
  75   constructor: WorkerThreadWorkerDebuggerTransport,
  76
  77   ready() {
  78     this._scope.addEventListener("message", this._onMessage);
  79   },
  80
  81   close() {
  82     this._scope.removeEventListener("message", this._onMessage);
  83     this.hooks?.onTransportClosed();
  84   },
  85
  86   send(packet) {
  87     this._scope.postMessage(
  88       JSON.stringify({
  89         type: "message",
  90         id: this._id,
  91         message: packet,
  92       })
  93     );
  94   },
  95
  96   startBulkSend() {
  97     throw new Error("Can't send bulk data from worker threads!");
  98   },
  99
 100   _onMessage(event) {
 101     const packet = JSON.parse(event.data);
 102     if (packet.type !== "message" || packet.id !== this._id) {
 103       return;
 104     }
 105
 106     if (this.hooks) {
 107       this.hooks.onPacket(packet.message);
 108     }
 109   },
 110 };
 111
 112 exports.WorkerThreadWorkerDebuggerTransport =
 113   WorkerThreadWorkerDebuggerTransport;