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| 1 /* | |
| 2 * This file is part of Adblock Plus <https://adblockplus.org/>, | |
| 3 * Copyright (C) 2006-2016 Eyeo GmbH | |
| 4 * | |
| 5 * Adblock Plus is free software: you can redistribute it and/or modify | |
| 6 * it under the terms of the GNU General Public License version 3 as | |
| 7 * published by the Free Software Foundation. | |
| 8 * | |
| 9 * Adblock Plus is distributed in the hope that it will be useful, | |
| 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 12 * GNU General Public License for more details. | |
| 13 * | |
| 14 * You should have received a copy of the GNU General Public License | |
| 15 * along with Adblock Plus. If not, see <http://www.gnu.org/licenses/>. | |
| 16 */ | |
| 17 | |
| 18 /** | |
| 19 * @fileOverview Downloads a set of URLs in regular time intervals. | |
| 20 */ | |
| 21 | |
| 22 let {Utils} = require("utils"); | |
| 23 | |
| 24 let MILLIS_IN_SECOND = exports.MILLIS_IN_SECOND = 1000; | |
| 25 let MILLIS_IN_MINUTE = exports.MILLIS_IN_MINUTE = 60 * MILLIS_IN_SECOND; | |
| 26 let MILLIS_IN_HOUR = exports.MILLIS_IN_HOUR = 60 * MILLIS_IN_MINUTE; | |
| 27 let MILLIS_IN_DAY = exports.MILLIS_IN_DAY = 24 * MILLIS_IN_HOUR; | |
| 28 | |
| 29 /** | |
| 30 * Creates a new downloader instance. | |
| 31 * @param {Function} dataSource Function that will yield downloadable objects o
n each check | |
| 32 * @param {Integer} initialDelay Number of milliseconds to wait before the firs
t check | |
| 33 * @param {Integer} checkInterval Interval between the checks | |
| 34 * @constructor | |
| 35 */ | |
| 36 let Downloader = exports.Downloader = function Downloader(dataSource, initialDel
ay, checkInterval) | |
| 37 { | |
| 38 this.dataSource = dataSource; | |
| 39 this._timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer); | |
| 40 this._timer.initWithCallback(function() | |
| 41 { | |
| 42 this._timer.delay = checkInterval; | |
| 43 this._doCheck(); | |
| 44 }.bind(this), initialDelay, Ci.nsITimer.TYPE_REPEATING_SLACK); | |
| 45 this._downloading = Object.create(null); | |
| 46 } | |
| 47 Downloader.prototype = | |
| 48 { | |
| 49 /** | |
| 50 * Timer triggering the downloads. | |
| 51 * @type nsITimer | |
| 52 */ | |
| 53 _timer: null, | |
| 54 | |
| 55 /** | |
| 56 * Map containing the URLs of objects currently being downloaded as its keys. | |
| 57 */ | |
| 58 _downloading: null, | |
| 59 | |
| 60 /** | |
| 61 * Function that will yield downloadable objects on each check. | |
| 62 * @type Function | |
| 63 */ | |
| 64 dataSource: null, | |
| 65 | |
| 66 /** | |
| 67 * Maximal time interval that the checks can be left out until the soft | |
| 68 * expiration interval increases. | |
| 69 * @type Integer | |
| 70 */ | |
| 71 maxAbsenceInterval: 1 * MILLIS_IN_DAY, | |
| 72 | |
| 73 /** | |
| 74 * Minimal time interval before retrying a download after an error. | |
| 75 * @type Integer | |
| 76 */ | |
| 77 minRetryInterval: 1 * MILLIS_IN_DAY, | |
| 78 | |
| 79 /** | |
| 80 * Maximal allowed expiration interval, larger expiration intervals will be | |
| 81 * corrected. | |
| 82 * @type Integer | |
| 83 */ | |
| 84 maxExpirationInterval: 14 * MILLIS_IN_DAY, | |
| 85 | |
| 86 /** | |
| 87 * Maximal number of redirects before the download is considered as failed. | |
| 88 * @type Integer | |
| 89 */ | |
| 90 maxRedirects: 5, | |
| 91 | |
| 92 /** | |
| 93 * Called whenever expiration intervals for an object need to be adapted. | |
| 94 * @type Function | |
| 95 */ | |
| 96 onExpirationChange: null, | |
| 97 | |
| 98 /** | |
| 99 * Callback to be triggered whenever a download starts. | |
| 100 * @type Function | |
| 101 */ | |
| 102 onDownloadStarted: null, | |
| 103 | |
| 104 /** | |
| 105 * Callback to be triggered whenever a download finishes successfully. The | |
| 106 * callback can return an error code to indicate that the data is wrong. | |
| 107 * @type Function | |
| 108 */ | |
| 109 onDownloadSuccess: null, | |
| 110 | |
| 111 /** | |
| 112 * Callback to be triggered whenever a download fails. | |
| 113 * @type Function | |
| 114 */ | |
| 115 onDownloadError: null, | |
| 116 | |
| 117 /** | |
| 118 * Checks whether anything needs downloading. | |
| 119 */ | |
| 120 _doCheck: function() | |
| 121 { | |
| 122 let now = Date.now(); | |
| 123 for (let downloadable of this.dataSource()) | |
| 124 { | |
| 125 if (downloadable.lastCheck && now - downloadable.lastCheck > this.maxAbsen
ceInterval) | |
| 126 { | |
| 127 // No checks for a long time interval - user must have been offline, e.g
. | |
| 128 // during a weekend. Increase soft expiration to prevent load peaks on t
he | |
| 129 // server. | |
| 130 downloadable.softExpiration += now - downloadable.lastCheck; | |
| 131 } | |
| 132 downloadable.lastCheck = now; | |
| 133 | |
| 134 // Sanity check: do expiration times make sense? Make sure people changing | |
| 135 // system clock don't get stuck with outdated subscriptions. | |
| 136 if (downloadable.hardExpiration - now > this.maxExpirationInterval) | |
| 137 downloadable.hardExpiration = now + this.maxExpirationInterval; | |
| 138 if (downloadable.softExpiration - now > this.maxExpirationInterval) | |
| 139 downloadable.softExpiration = now + this.maxExpirationInterval; | |
| 140 | |
| 141 // Notify the caller about changes to expiration parameters | |
| 142 if (this.onExpirationChange) | |
| 143 this.onExpirationChange(downloadable); | |
| 144 | |
| 145 // Does that object need downloading? | |
| 146 if (downloadable.softExpiration > now && downloadable.hardExpiration > now
) | |
| 147 continue; | |
| 148 | |
| 149 // Do not retry downloads too often | |
| 150 if (downloadable.lastError && now - downloadable.lastError < this.minRetry
Interval) | |
| 151 continue; | |
| 152 | |
| 153 this._download(downloadable, 0); | |
| 154 } | |
| 155 }, | |
| 156 | |
| 157 /** | |
| 158 * Stops the periodic checks. | |
| 159 */ | |
| 160 cancel: function() | |
| 161 { | |
| 162 this._timer.cancel(); | |
| 163 }, | |
| 164 | |
| 165 /** | |
| 166 * Checks whether an address is currently being downloaded. | |
| 167 */ | |
| 168 isDownloading: function(/**String*/ url) /**Boolean*/ | |
| 169 { | |
| 170 return url in this._downloading; | |
| 171 }, | |
| 172 | |
| 173 /** | |
| 174 * Starts downloading for an object. | |
| 175 */ | |
| 176 download: function(/**Downloadable*/ downloadable) | |
| 177 { | |
| 178 // Make sure to detach download from the current execution context | |
| 179 Utils.runAsync(this._download.bind(this, downloadable, 0)); | |
| 180 }, | |
| 181 | |
| 182 /** | |
| 183 * Generates the real download URL for an object by appending various | |
| 184 * parameters. | |
| 185 */ | |
| 186 getDownloadUrl: function(/**Downloadable*/ downloadable) /** String*/ | |
| 187 { | |
| 188 let {addonName, addonVersion, application, applicationVersion, platform, pla
tformVersion} = require("info"); | |
| 189 let url = downloadable.redirectURL || downloadable.url; | |
| 190 if (url.indexOf("?") >= 0) | |
| 191 url += "&"; | |
| 192 else | |
| 193 url += "?"; | |
| 194 // We limit the download count to 4+ to keep the request anonymized | |
| 195 let downloadCount = downloadable.downloadCount; | |
| 196 if (downloadCount > 4) | |
| 197 downloadCount = "4+"; | |
| 198 url += "addonName=" + encodeURIComponent(addonName) + | |
| 199 "&addonVersion=" + encodeURIComponent(addonVersion) + | |
| 200 "&application=" + encodeURIComponent(application) + | |
| 201 "&applicationVersion=" + encodeURIComponent(applicationVersion) + | |
| 202 "&platform=" + encodeURIComponent(platform) + | |
| 203 "&platformVersion=" + encodeURIComponent(platformVersion) + | |
| 204 "&lastVersion=" + encodeURIComponent(downloadable.lastVersion) + | |
| 205 "&downloadCount=" + encodeURIComponent(downloadCount); | |
| 206 return url; | |
| 207 }, | |
| 208 | |
| 209 _download: function(downloadable, redirects) | |
| 210 { | |
| 211 if (this.isDownloading(downloadable.url)) | |
| 212 return; | |
| 213 | |
| 214 let downloadUrl = this.getDownloadUrl(downloadable); | |
| 215 let request = null; | |
| 216 | |
| 217 let errorCallback = function errorCallback(error) | |
| 218 { | |
| 219 let channelStatus = -1; | |
| 220 try | |
| 221 { | |
| 222 channelStatus = request.channel.status; | |
| 223 } catch (e) {} | |
| 224 | |
| 225 let responseStatus = request.status; | |
| 226 | |
| 227 Cu.reportError("Adblock Plus: Downloading URL " + downloadable.url + " fai
led (" + error + ")\n" + | |
| 228 "Download address: " + downloadUrl + "\n" + | |
| 229 "Channel status: " + channelStatus + "\n" + | |
| 230 "Server response: " + responseStatus); | |
| 231 | |
| 232 if (this.onDownloadError) | |
| 233 { | |
| 234 // Allow one extra redirect if the error handler gives us a redirect URL | |
| 235 let redirectCallback = null; | |
| 236 if (redirects <= this.maxRedirects) | |
| 237 { | |
| 238 redirectCallback = function redirectCallback(url) | |
| 239 { | |
| 240 downloadable.redirectURL = url; | |
| 241 this._download(downloadable, redirects + 1); | |
| 242 }.bind(this); | |
| 243 } | |
| 244 | |
| 245 this.onDownloadError(downloadable, downloadUrl, error, channelStatus, re
sponseStatus, redirectCallback); | |
| 246 } | |
| 247 }.bind(this); | |
| 248 | |
| 249 try | |
| 250 { | |
| 251 request = new XMLHttpRequest(); | |
| 252 request.mozBackgroundRequest = true; | |
| 253 request.open("GET", downloadUrl); | |
| 254 } | |
| 255 catch (e) | |
| 256 { | |
| 257 errorCallback("synchronize_invalid_url"); | |
| 258 return; | |
| 259 } | |
| 260 | |
| 261 try { | |
| 262 request.overrideMimeType("text/plain"); | |
| 263 request.channel.loadFlags = request.channel.loadFlags | | |
| 264 request.channel.INHIBIT_CACHING | | |
| 265 request.channel.VALIDATE_ALWAYS; | |
| 266 | |
| 267 // Override redirect limit from preferences, user might have set it to 1 | |
| 268 if (request.channel instanceof Ci.nsIHttpChannel) | |
| 269 request.channel.redirectionLimit = this.maxRedirects; | |
| 270 } | |
| 271 catch (e) | |
| 272 { | |
| 273 Cu.reportError(e) | |
| 274 } | |
| 275 | |
| 276 request.addEventListener("error", function(event) | |
| 277 { | |
| 278 if (onShutdown.done) | |
| 279 return; | |
| 280 | |
| 281 delete this._downloading[downloadable.url]; | |
| 282 errorCallback("synchronize_connection_error"); | |
| 283 }.bind(this), false); | |
| 284 | |
| 285 request.addEventListener("load", function(event) | |
| 286 { | |
| 287 if (onShutdown.done) | |
| 288 return; | |
| 289 | |
| 290 delete this._downloading[downloadable.url]; | |
| 291 | |
| 292 // Status will be 0 for non-HTTP requests | |
| 293 if (request.status && request.status != 200) | |
| 294 { | |
| 295 errorCallback("synchronize_connection_error"); | |
| 296 return; | |
| 297 } | |
| 298 | |
| 299 downloadable.downloadCount++; | |
| 300 | |
| 301 this.onDownloadSuccess(downloadable, request.responseText, errorCallback,
function redirectCallback(url) | |
| 302 { | |
| 303 if (redirects >= this.maxRedirects) | |
| 304 errorCallback("synchronize_connection_error"); | |
| 305 else | |
| 306 { | |
| 307 downloadable.redirectURL = url; | |
| 308 this._download(downloadable, redirects + 1); | |
| 309 } | |
| 310 }.bind(this)); | |
| 311 }.bind(this), false); | |
| 312 | |
| 313 request.send(null); | |
| 314 | |
| 315 this._downloading[downloadable.url] = true; | |
| 316 if (this.onDownloadStarted) | |
| 317 this.onDownloadStarted(downloadable); | |
| 318 }, | |
| 319 | |
| 320 /** | |
| 321 * Produces a soft and a hard expiration interval for a given supplied | |
| 322 * expiration interval. | |
| 323 * @return {Array} soft and hard expiration interval | |
| 324 */ | |
| 325 processExpirationInterval: function(/**Integer*/ interval) | |
| 326 { | |
| 327 interval = Math.min(Math.max(interval, 0), this.maxExpirationInterval); | |
| 328 let soft = Math.round(interval * (Math.random() * 0.4 + 0.8)); | |
| 329 let hard = interval * 2; | |
| 330 let now = Date.now(); | |
| 331 return [now + soft, now + hard]; | |
| 332 } | |
| 333 }; | |
| 334 | |
| 335 /** | |
| 336 * An object that can be downloaded by the downloadable | |
| 337 * @param {String} url URL that has to be requested for the object | |
| 338 * @constructor | |
| 339 */ | |
| 340 let Downloadable = exports.Downloadable = function Downloadable(url) | |
| 341 { | |
| 342 this.url = url; | |
| 343 } | |
| 344 Downloadable.prototype = | |
| 345 { | |
| 346 /** | |
| 347 * URL that has to be requested for the object. | |
| 348 * @type String | |
| 349 */ | |
| 350 url: null, | |
| 351 | |
| 352 /** | |
| 353 * URL that the download was redirected to if any. | |
| 354 * @type String | |
| 355 */ | |
| 356 redirectURL: null, | |
| 357 | |
| 358 /** | |
| 359 * Time of last download error or 0 if the last download was successful. | |
| 360 * @type Integer | |
| 361 */ | |
| 362 lastError: 0, | |
| 363 | |
| 364 /** | |
| 365 * Time of last check whether the object needs downloading. | |
| 366 * @type Integer | |
| 367 */ | |
| 368 lastCheck: 0, | |
| 369 | |
| 370 /** | |
| 371 * Object version corresponding to the last successful download. | |
| 372 * @type Integer | |
| 373 */ | |
| 374 lastVersion: 0, | |
| 375 | |
| 376 /** | |
| 377 * Soft expiration interval, will increase if no checks are performed for a | |
| 378 * while. | |
| 379 * @type Integer | |
| 380 */ | |
| 381 softExpiration: 0, | |
| 382 | |
| 383 /** | |
| 384 * Hard expiration interval, this is fixed. | |
| 385 * @type Integer | |
| 386 */ | |
| 387 hardExpiration: 0, | |
| 388 | |
| 389 /** | |
| 390 * Number indicating how often the object was downloaded. | |
| 391 * @type Integer | |
| 392 */ | |
| 393 downloadCount: 0, | |
| 394 }; | |
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