tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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symbol.js (2996B)

      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 const { Actor } = require("resource://devtools/shared/protocol.js");
      8 const { symbolSpec } = require("resource://devtools/shared/specs/symbol.js");
      9 loader.lazyRequireGetter(
     10  this,
     11  "createValueGrip",
     12  "resource://devtools/server/actors/object/utils.js",
     13  true
     14 );
     15 
     16 /**
     17 * Creates an actor for the specified symbol.
     18 *
     19 * @param {ThreadActor} threadActor: The related thread actor.
     20 * @param {symbol} symbol: The symbol we want to create an actor for.
     21 */
     22 class SymbolActor extends Actor {
     23  constructor(threadActor, symbol) {
     24    super(threadActor.conn, symbolSpec);
     25    this.threadActor = threadActor;
     26    this.symbol = symbol;
     27 
     28    // Align with Object Actor interface
     29    // (this is used from eval-with-debugger)
     30    this.rawObj = this.symbol;
     31  }
     32 
     33  destroy() {
     34    // Because symbolActors is not a weak map, we won't automatically leave
     35    // it so we need to manually leave on destroy so that we don't leak
     36    // memory.
     37    this._releaseActor();
     38    super.destroy();
     39 
     40    this.threadActor = null;
     41  }
     42 
     43  /**
     44   * Returns a grip for this actor for returning in a protocol message.
     45   */
     46  form() {
     47    const form = {
     48      type: this.typeName,
     49      actor: this.actorID,
     50    };
     51    const name = getSymbolName(this.symbol);
     52    if (name !== undefined) {
     53      // Create a grip for the name because it might be a longString.
     54      form.name = createValueGrip(this.threadActor, name, this.getParent());
     55    }
     56    return form;
     57  }
     58 
     59  /**
     60   * Handle a request to release this SymbolActor instance.
     61   */
     62  release() {
     63    // TODO: also check if this.getParent() === threadActor.threadLifetimePool
     64    // when the web console moves away from manually releasing pause-scoped
     65    // actors.
     66    this._releaseActor();
     67    this.destroy();
     68    return {};
     69  }
     70 
     71  _releaseActor() {
     72    const parent = this.getParent();
     73    if (parent && parent.symbolActors) {
     74      delete parent.symbolActors[this.symbol];
     75    }
     76  }
     77 }
     78 
     79 const symbolProtoToString = Symbol.prototype.toString;
     80 
     81 function getSymbolName(symbol) {
     82  const name = symbolProtoToString.call(symbol).slice("Symbol(".length, -1);
     83  return name || undefined;
     84 }
     85 
     86 /**
     87 * Create a grip for the given symbol.
     88 *
     89 * @param threadActor ThreadActor
     90 *        The related Thread Actor
     91 * @param sym Symbol
     92 *        The symbol we are creating a grip for.
     93 * @param pool Pool
     94 *        The actor pool where the new actor will be added.
     95 */
     96 function symbolGrip(threadActor, sym, pool) {
     97  if (!pool.symbolActors) {
     98    pool.symbolActors = Object.create(null);
     99  }
    100 
    101  if (sym in pool.symbolActors) {
    102    return pool.symbolActors[sym].form();
    103  }
    104 
    105  const actor = new SymbolActor(threadActor, sym);
    106  pool.manage(actor);
    107  pool.symbolActors[sym] = actor;
    108  return actor.form();
    109 }
    110 
    111 module.exports = {
    112  SymbolActor,
    113  symbolGrip,
    114 };