DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (d38398e5144e)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254
/* 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";

this.EXPORTED_SYMBOLS = ["ExtensionStorage"];

const Ci = Components.interfaces;
const Cc = Components.classes;
const Cu = Components.utils;
const Cr = Components.results;

Cu.import("resource://gre/modules/XPCOMUtils.jsm");
Cu.import("resource://gre/modules/Services.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "OS",
                                  "resource://gre/modules/osfile.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "AsyncShutdown",
                                  "resource://gre/modules/AsyncShutdown.jsm");

/**
 * Helper function used to sanitize the objects that have to be saved in the ExtensionStorage.
 *
 * @param {BaseContext} context
 *   The current extension context.
 * @param {string} key
 *   The key of the current JSON property.
 * @param {any} value
 *   The value of the current JSON property.
 *
 * @returns {any}
 *   The sanitized value of the property.
 */
function jsonReplacer(context, key, value) {
  switch (typeof(value)) {
    // Serialize primitive types as-is.
    case "string":
    case "number":
    case "boolean":
      return value;

    case "object":
      if (value === null) {
        return value;
      }

      switch (Cu.getClassName(value, true)) {
        // Serialize arrays and ordinary objects as-is.
        case "Array":
        case "Object":
          return value;

        // Serialize Date objects and regular expressions as their
        // string representations.
        case "Date":
        case "RegExp":
          return String(value);
      }
      break;
  }

  if (!key) {
    // If this is the root object, and we can't serialize it, serialize
    // the value to an empty object.
    return new context.cloneScope.Object();
  }

  // Everything else, omit entirely.
  return undefined;
}

this.ExtensionStorage = {
  cache: new Map(),
  listeners: new Map(),

  /**
   * Sanitizes the given value, and returns a JSON-compatible
   * representation of it, based on the privileges of the given global.
   *
   * @param {value} value
   *        The value to sanitize.
   * @param {Context} context
   *        The extension context in which to sanitize the value
   * @returns {value}
   *        The sanitized value.
   */
  sanitize(value, context) {
    let json = context.jsonStringify(value, jsonReplacer.bind(null, context));
    return JSON.parse(json);
  },

  getExtensionDir(extensionId) {
    return OS.Path.join(this.extensionDir, extensionId);
  },

  getStorageFile(extensionId) {
    return OS.Path.join(this.extensionDir, extensionId, "storage.js");
  },

  read(extensionId) {
    if (this.cache.has(extensionId)) {
      return this.cache.get(extensionId);
    }

    let path = this.getStorageFile(extensionId);
    let decoder = new TextDecoder();
    let promise = OS.File.read(path);
    promise = promise.then(array => {
      return JSON.parse(decoder.decode(array));
    }).catch((error) => {
      if (!error.becauseNoSuchFile) {
        Cu.reportError("Unable to parse JSON data for extension storage.");
      }
      return {};
    });
    this.cache.set(extensionId, promise);
    return promise;
  },

  write(extensionId) {
    let promise = this.read(extensionId).then(extData => {
      let encoder = new TextEncoder();
      let array = encoder.encode(JSON.stringify(extData));
      let path = this.getStorageFile(extensionId);
      OS.File.makeDir(this.getExtensionDir(extensionId), {
        ignoreExisting: true,
        from: OS.Constants.Path.profileDir,
      });
      let promise = OS.File.writeAtomic(path, array);
      return promise;
    }).catch(() => {
      // Make sure this promise is never rejected.
      Cu.reportError("Unable to write JSON data for extension storage.");
    });

    AsyncShutdown.profileBeforeChange.addBlocker(
      "ExtensionStorage: Finish writing extension data",
      promise);

    return promise.then(() => {
      AsyncShutdown.profileBeforeChange.removeBlocker(promise);
    });
  },

  set(extensionId, items, context) {
    return this.read(extensionId).then(extData => {
      let changes = {};
      for (let prop in items) {
        let item = this.sanitize(items[prop], context);
        changes[prop] = {oldValue: extData[prop], newValue: item};
        extData[prop] = item;
      }

      this.notifyListeners(extensionId, changes);

      return this.write(extensionId);
    });
  },

  remove(extensionId, items) {
    return this.read(extensionId).then(extData => {
      let changes = {};
      for (let prop of [].concat(items)) {
        changes[prop] = {oldValue: extData[prop]};
        delete extData[prop];
      }

      this.notifyListeners(extensionId, changes);

      return this.write(extensionId);
    });
  },

  clear(extensionId) {
    return this.read(extensionId).then(extData => {
      let changes = {};
      for (let prop of Object.keys(extData)) {
        changes[prop] = {oldValue: extData[prop]};
        delete extData[prop];
      }

      this.notifyListeners(extensionId, changes);

      return this.write(extensionId);
    });
  },

  get(extensionId, keys) {
    return this.read(extensionId).then(extData => {
      let result = {};
      if (keys === null) {
        Object.assign(result, extData);
      } else if (typeof(keys) == "object" && !Array.isArray(keys)) {
        for (let prop in keys) {
          if (prop in extData) {
            result[prop] = extData[prop];
          } else {
            result[prop] = keys[prop];
          }
        }
      } else {
        for (let prop of [].concat(keys)) {
          if (prop in extData) {
            result[prop] = extData[prop];
          }
        }
      }

      return result;
    });
  },

  addOnChangedListener(extensionId, listener) {
    let listeners = this.listeners.get(extensionId) || new Set();
    listeners.add(listener);
    this.listeners.set(extensionId, listeners);
  },

  removeOnChangedListener(extensionId, listener) {
    let listeners = this.listeners.get(extensionId);
    listeners.delete(listener);
  },

  notifyListeners(extensionId, changes) {
    let listeners = this.listeners.get(extensionId);
    if (listeners) {
      for (let listener of listeners) {
        listener(changes);
      }
    }
  },

  init() {
    if (Services.appinfo.processType != Services.appinfo.PROCESS_TYPE_DEFAULT) {
      return;
    }
    Services.obs.addObserver(this, "extension-invalidate-storage-cache", false);
    Services.obs.addObserver(this, "xpcom-shutdown", false);
  },

  observe(subject, topic, data) {
    if (topic == "xpcom-shutdown") {
      Services.obs.removeObserver(this, "extension-invalidate-storage-cache");
      Services.obs.removeObserver(this, "xpcom-shutdown");
    } else if (topic == "extension-invalidate-storage-cache") {
      this.cache.clear();
    }
  },
};

XPCOMUtils.defineLazyGetter(ExtensionStorage, "extensionDir",
  () => OS.Path.join(OS.Constants.Path.profileDir, "browser-extension-data"));

ExtensionStorage.init();