The Tor Browser / file diff

     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/browser/components/sessionstore/src/TabStateCache.jsm	Wed Dec 31 06:09:35 2014 +0100
     1.3 @@ -0,0 +1,82 @@
     1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
     1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this file,
     1.6 + * You can obtain one at http://mozilla.org/MPL/2.0/. */
     1.7 +
     1.8 +"use strict";
     1.9 +
    1.10 +this.EXPORTED_SYMBOLS = ["TabStateCache"];
    1.11 +
    1.12 +/**
    1.13 + * A cache for tabs data.
    1.14 + *
    1.15 + * This cache implements a weak map from tabs (as XUL elements)
    1.16 + * to tab data (as objects).
    1.17 + *
    1.18 + * Note that we should never cache private data, as:
    1.19 + * - that data is used very seldom by SessionStore;
    1.20 + * - caching private data in addition to public data is memory consuming.
    1.21 + */
    1.22 +this.TabStateCache = Object.freeze({
    1.23 +  /**
    1.24 +   * Retrieves cached data for a given |browser|.
    1.25 +   *
    1.26 +   * @param browser (xul:browser)
    1.27 +   *        The browser to retrieve cached data for.
    1.28 +   * @return (object)
    1.29 +   *         The cached data stored for the given |browser|.
    1.30 +   */
    1.31 +  get: function (browser) {
    1.32 +    return TabStateCacheInternal.get(browser);
    1.33 +  },
    1.34 +
    1.35 +  /**
    1.36 +   * Updates cached data for a given |browser|.
    1.37 +   *
    1.38 +   * @param browser (xul:browser)
    1.39 +   *        The browser belonging to the given tab data.
    1.40 +   * @param newData (object)
    1.41 +   *        The new data to be stored for the given |browser|.
    1.42 +   */
    1.43 +  update: function (browser, newData) {
    1.44 +    TabStateCacheInternal.update(browser, newData);
    1.45 +  }
    1.46 +});
    1.47 +
    1.48 +let TabStateCacheInternal = {
    1.49 +  _data: new WeakMap(),
    1.50 +
    1.51 +  /**
    1.52 +   * Retrieves cached data for a given |browser|.
    1.53 +   *
    1.54 +   * @param browser (xul:browser)
    1.55 +   *        The browser to retrieve cached data for.
    1.56 +   * @return (object)
    1.57 +   *         The cached data stored for the given |browser|.
    1.58 +   */
    1.59 +  get: function (browser) {
    1.60 +    return this._data.get(browser.permanentKey);
    1.61 +  },
    1.62 +
    1.63 +  /**
    1.64 +   * Updates cached data for a given |browser|.
    1.65 +   *
    1.66 +   * @param browser (xul:browser)
    1.67 +   *        The browser belonging to the given tab data.
    1.68 +   * @param newData (object)
    1.69 +   *        The new data to be stored for the given |browser|.
    1.70 +   */
    1.71 +  update: function (browser, newData) {
    1.72 +    let data = this._data.get(browser.permanentKey) || {};
    1.73 +
    1.74 +    for (let key of Object.keys(newData)) {
    1.75 +      let value = newData[key];
    1.76 +      if (value === null) {
    1.77 +        delete data[key];
    1.78 +      } else {
    1.79 +        data[key] = value;
    1.80 +      }
    1.81 +    }
    1.82 +
    1.83 +    this._data.set(browser.permanentKey, data);
    1.84 +  }
    1.85 +};