gecko-dev/devtools/server/startup/worker.js

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

"use strict";

/* eslint-env mozilla/chrome-worker */
/* global worker, loadSubScript, global */

/*
 * Worker debugger script that listens for requests to start a `DebuggerServer` for a
 * worker in a process.  Loaded into a specific worker during
 * `DebuggerServer.connectToWorker` which is called from the same process as the worker.
 */

// This function is used to do remote procedure calls from the worker to the
// main thread. It is exposed as a built-in global to every module by the
// worker loader. To make sure the worker loader can access it, it needs to be
// defined before loading the worker loader script below.
this.rpc = function(method, ...params) {
  let id = nextId++;

  postMessage(JSON.stringify({
    type: "rpc",
    method: method,
    params: params,
    id: id
  }));

  let deferred = defer();
  rpcDeferreds[id] = deferred;
  return deferred.promise;
};

loadSubScript("resource://devtools/shared/worker/loader.js");

var defer = worker.require("devtools/shared/defer");
var { ActorPool } = worker.require("devtools/server/actors/common");
var { ThreadActor } = worker.require("devtools/server/actors/thread");
var { WebConsoleActor } = worker.require("devtools/server/actors/webconsole");
var { TabSources } = worker.require("devtools/server/actors/utils/TabSources");
var makeDebugger = worker.require("devtools/server/actors/utils/make-debugger");
var { DebuggerServer } = worker.require("devtools/server/main");

DebuggerServer.init();
DebuggerServer.createRootActor = function() {
  throw new Error("Should never get here!");
};

var connections = Object.create(null);
var nextId = 0;
var rpcDeferreds = [];

this.addEventListener("message", function(event) {
  let packet = JSON.parse(event.data);
  switch (packet.type) {
    case "connect":
      // Step 3: Create a connection to the parent.
      let connection = DebuggerServer.connectToParent(packet.id, this);
      connections[packet.id] = {
        connection,
        rpcs: []
      };

      // Step 4: Create a thread actor for the connection to the parent.
      let pool = new ActorPool(connection);
      connection.addActorPool(pool);

      let sources = null;

      let parent = {
        actorID: packet.id,

        makeDebugger: makeDebugger.bind(null, {
          findDebuggees: () => {
            return [this.global];
          },

          shouldAddNewGlobalAsDebuggee: () => {
            return true;
          },
        }),

        get sources() {
          if (sources === null) {
            sources = new TabSources(threadActor);
          }
          return sources;
        },

        window: global
      };

      let threadActor = new ThreadActor(parent, global);
      pool.addActor(threadActor);

      // parentActor.threadActor is needed from the webconsole for grip previewing
      parent.threadActor = threadActor;

      let consoleActor = new WebConsoleActor(connection, parent);
      pool.addActor(consoleActor);

      // Step 5: Send a response packet to the parent to notify
      // it that a connection has been established.
      postMessage(JSON.stringify({
        type: "connected",
        id: packet.id,
        threadActor: threadActor.actorID,
        consoleActor: consoleActor.actorID,
      }));
      break;

    case "disconnect":
      connections[packet.id].connection.close();
      break;

    case "rpc":
      let deferred = rpcDeferreds[packet.id];
      delete rpcDeferreds[packet.id];
      if (packet.error) {
        deferred.reject(packet.error);
      }
      deferred.resolve(packet.result);
      break;
  }
});