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 (04da00a61c6d)

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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680
/* 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";

const EXPORTED_SYMBOLS = ["FaviconLoader"];

const { XPCOMUtils } = ChromeUtils.import(
  "resource://gre/modules/XPCOMUtils.jsm"
);
const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");

XPCOMUtils.defineLazyGlobalGetters(this, ["Blob", "FileReader"]);

ChromeUtils.defineModuleGetter(
  this,
  "DeferredTask",
  "resource://gre/modules/DeferredTask.jsm"
);
ChromeUtils.defineModuleGetter(
  this,
  "PromiseUtils",
  "resource://gre/modules/PromiseUtils.jsm"
);

const STREAM_SEGMENT_SIZE = 4096;
const PR_UINT32_MAX = 0xffffffff;

const BinaryInputStream = Components.Constructor(
  "@mozilla.org/binaryinputstream;1",
  "nsIBinaryInputStream",
  "setInputStream"
);
const StorageStream = Components.Constructor(
  "@mozilla.org/storagestream;1",
  "nsIStorageStream",
  "init"
);
const BufferedOutputStream = Components.Constructor(
  "@mozilla.org/network/buffered-output-stream;1",
  "nsIBufferedOutputStream",
  "init"
);

const SIZES_TELEMETRY_ENUM = {
  NO_SIZES: 0,
  ANY: 1,
  DIMENSION: 2,
  INVALID: 3,
};

const FAVICON_PARSING_TIMEOUT = 100;
const FAVICON_RICH_ICON_MIN_WIDTH = 96;
const PREFERRED_WIDTH = 16;

// URL schemes that we don't want to load and convert to data URLs.
const LOCAL_FAVICON_SCHEMES = ["chrome", "about", "resource", "data"];

const MAX_FAVICON_EXPIRATION = 7 * 24 * 60 * 60 * 1000;
const MAX_ICON_SIZE = 2048;

const TYPE_ICO = "image/x-icon";
const TYPE_SVG = "image/svg+xml";

function promiseBlobAsDataURL(blob) {
  return new Promise((resolve, reject) => {
    let reader = new FileReader();
    reader.addEventListener("load", () => resolve(reader.result));
    reader.addEventListener("error", reject);
    reader.readAsDataURL(blob);
  });
}

function promiseBlobAsOctets(blob) {
  return new Promise((resolve, reject) => {
    let reader = new FileReader();
    reader.addEventListener("load", () => {
      resolve(Array.from(reader.result).map(c => c.charCodeAt(0)));
    });
    reader.addEventListener("error", reject);
    reader.readAsBinaryString(blob);
  });
}

function promiseImage(stream, type) {
  return new Promise((resolve, reject) => {
    let imgTools = Cc["@mozilla.org/image/tools;1"].getService(Ci.imgITools);

    imgTools.decodeImageAsync(
      stream,
      type,
      (image, result) => {
        if (!Components.isSuccessCode(result)) {
          reject();
          return;
        }

        resolve(image);
      },
      Services.tm.currentThread
    );
  });
}

class FaviconLoad {
  constructor(iconInfo) {
    this.icon = iconInfo;

    this.channel = Services.io.newChannelFromURI(
      iconInfo.iconUri,
      iconInfo.node,
      iconInfo.node.nodePrincipal,
      iconInfo.node.nodePrincipal,
      Ci.nsILoadInfo.SEC_ALLOW_CROSS_ORIGIN_DATA_INHERITS |
        Ci.nsILoadInfo.SEC_ALLOW_CHROME |
        Ci.nsILoadInfo.SEC_DISALLOW_SCRIPT,
      Ci.nsIContentPolicy.TYPE_INTERNAL_IMAGE_FAVICON
    );

    this.channel.loadFlags |=
      Ci.nsIRequest.LOAD_BACKGROUND |
      Ci.nsIRequest.VALIDATE_NEVER |
      Ci.nsIRequest.LOAD_FROM_CACHE;
    // Sometimes node is a document and sometimes it is an element. This is
    // the easiest single way to get to the load group in both those cases.
    this.channel.loadGroup =
      iconInfo.node.ownerGlobal.document.documentLoadGroup;
    this.channel.notificationCallbacks = this;

    if (this.channel instanceof Ci.nsIHttpChannel) {
      try {
        let acceptHeader = Services.prefs.getCharPref("image.http.accept");
        this.channel.setRequestHeader("Accept", acceptHeader, false);
      } catch (e) {
        // Failing to get the pref or set the header is ignorable.
      }
    }

    if (this.channel instanceof Ci.nsIHttpChannelInternal) {
      this.channel.blockAuthPrompt = true;
    }

    if (
      Services.prefs.getBoolPref("network.http.tailing.enabled", true) &&
      this.channel instanceof Ci.nsIClassOfService
    ) {
      this.channel.addClassFlags(
        Ci.nsIClassOfService.Tail | Ci.nsIClassOfService.Throttleable
      );
    }
  }

  load() {
    this._deferred = PromiseUtils.defer();

    // Clear the references when we succeed or fail.
    let cleanup = () => {
      this.channel = null;
      this.dataBuffer = null;
      this.stream = null;
    };
    this._deferred.promise.then(cleanup, cleanup);

    this.dataBuffer = new StorageStream(STREAM_SEGMENT_SIZE, PR_UINT32_MAX);

    // storage streams do not implement writeFrom so wrap it with a buffered stream.
    this.stream = new BufferedOutputStream(
      this.dataBuffer.getOutputStream(0),
      STREAM_SEGMENT_SIZE * 2
    );

    try {
      this.channel.asyncOpen(this);
    } catch (e) {
      this._deferred.reject(e);
    }

    return this._deferred.promise;
  }

  cancel() {
    if (!this.channel) {
      return;
    }

    this.channel.cancel(Cr.NS_BINDING_ABORTED);
  }

  onStartRequest(request) {}

  onDataAvailable(request, inputStream, offset, count) {
    this.stream.writeFrom(inputStream, count);
  }

  asyncOnChannelRedirect(oldChannel, newChannel, flags, callback) {
    if (oldChannel == this.channel) {
      this.channel = newChannel;
    }

    callback.onRedirectVerifyCallback(Cr.NS_OK);
  }

  async onStopRequest(request, statusCode) {
    if (request != this.channel) {
      // Indicates that a redirect has occurred. We don't care about the result
      // of the original channel.
      return;
    }

    this.stream.close();
    this.stream = null;

    if (!Components.isSuccessCode(statusCode)) {
      if (statusCode == Cr.NS_BINDING_ABORTED) {
        this._deferred.reject(
          Components.Exception(
            `Favicon load from ${this.icon.iconUri.spec} was cancelled.`,
            statusCode
          )
        );
      } else {
        this._deferred.reject(
          Components.Exception(
            `Favicon at "${this.icon.iconUri.spec}" failed to load.`,
            statusCode
          )
        );
      }
      return;
    }

    if (this.channel instanceof Ci.nsIHttpChannel) {
      if (!this.channel.requestSucceeded) {
        this._deferred.reject(
          Components.Exception(
            `Favicon at "${this.icon.iconUri.spec}" failed to load: ${
              this.channel.responseStatusText
            }.`,
            Cr.NS_ERROR_FAILURE
          )
        );
        return;
      }
    }

    // Attempt to get an expiration time from the cache.  If this fails, we'll
    // use this default.
    let expiration = Date.now() + MAX_FAVICON_EXPIRATION;

    // This stuff isn't available after onStopRequest returns (so don't start
    // any async operations before this!).
    if (this.channel instanceof Ci.nsICacheInfoChannel) {
      try {
        expiration = Math.min(
          this.channel.cacheTokenExpirationTime * 1000,
          expiration
        );
      } catch (e) {
        // Ignore failures to get the expiration time.
      }
    }

    try {
      let stream = new BinaryInputStream(this.dataBuffer.newInputStream(0));
      let buffer = new ArrayBuffer(this.dataBuffer.length);
      stream.readArrayBuffer(buffer.byteLength, buffer);

      let type = this.channel.contentType;
      let blob = new Blob([buffer], { type });

      if (type != "image/svg+xml") {
        let octets = await promiseBlobAsOctets(blob);
        let sniffer = Cc["@mozilla.org/image/loader;1"].createInstance(
          Ci.nsIContentSniffer
        );
        type = sniffer.getMIMETypeFromContent(
          this.channel,
          octets,
          octets.length
        );

        if (!type) {
          throw Components.Exception(
            `Favicon at "${
              this.icon.iconUri.spec
            }" did not match a known mimetype.`,
            Cr.NS_ERROR_FAILURE
          );
        }

        blob = blob.slice(0, blob.size, type);

        let image;
        try {
          image = await promiseImage(this.dataBuffer.newInputStream(0), type);
        } catch (e) {
          throw Components.Exception(
            `Favicon at "${this.icon.iconUri.spec}" could not be decoded.`,
            Cr.NS_ERROR_FAILURE
          );
        }

        if (image.width > MAX_ICON_SIZE || image.height > MAX_ICON_SIZE) {
          throw Components.Exception(
            `Favicon at "${this.icon.iconUri.spec}" is too large.`,
            Cr.NS_ERROR_FAILURE
          );
        }
      }

      let dataURL = await promiseBlobAsDataURL(blob);

      this._deferred.resolve({
        expiration,
        dataURL,
      });
    } catch (e) {
      this._deferred.reject(e);
    }
  }

  getInterface(iid) {
    if (iid.equals(Ci.nsIChannelEventSink)) {
      return this;
    }
    throw Cr.NS_ERROR_NO_INTERFACE;
  }
}

/*
 * Extract the icon width from the size attribute. It also sends the telemetry
 * about the size type and size dimension info.
 *
 * @param {Array} aSizes An array of strings about size.
 * @return {Number} A width of the icon in pixel.
 */
function extractIconSize(aSizes) {
  let width = -1;
  let sizesType;
  const re = /^([1-9][0-9]*)x[1-9][0-9]*$/i;

  if (aSizes.length) {
    for (let size of aSizes) {
      if (size.toLowerCase() == "any") {
        sizesType = SIZES_TELEMETRY_ENUM.ANY;
        break;
      } else {
        let values = re.exec(size);
        if (values && values.length > 1) {
          sizesType = SIZES_TELEMETRY_ENUM.DIMENSION;
          width = parseInt(values[1]);
          break;
        } else {
          sizesType = SIZES_TELEMETRY_ENUM.INVALID;
          break;
        }
      }
    }
  } else {
    sizesType = SIZES_TELEMETRY_ENUM.NO_SIZES;
  }

  // Telemetry probes for measuring the sizes attribute
  // usage and available dimensions.
  Services.telemetry
    .getHistogramById("LINK_ICON_SIZES_ATTR_USAGE")
    .add(sizesType);
  if (width > 0) {
    Services.telemetry
      .getHistogramById("LINK_ICON_SIZES_ATTR_DIMENSION")
      .add(width);
  }

  return width;
}

/*
 * Get link icon URI from a link dom node.
 *
 * @param {DOMNode} aLink A link dom node.
 * @return {nsIURI} A uri of the icon.
 */
function getLinkIconURI(aLink) {
  let targetDoc = aLink.ownerDocument;
  let uri = Services.io.newURI(aLink.href, targetDoc.characterSet);
  try {
    uri = uri
      .mutate()
      .setUserPass("")
      .finalize();
  } catch (e) {
    // some URIs are immutable
  }
  return uri;
}

/**
 * Guess a type for an icon based on its declared type or file extension.
 */
function guessType(icon) {
  // No type with no icon
  if (!icon) {
    return "";
  }

  // Use the file extension to guess at a type we're interested in
  if (!icon.type) {
    let extension = icon.iconUri.filePath.split(".").pop();
    switch (extension) {
      case "ico":
        return TYPE_ICO;
      case "svg":
        return TYPE_SVG;
    }
  }

  // Fuzzily prefer the type or fall back to the declared type
  return icon.type == "image/vnd.microsoft.icon" ? TYPE_ICO : icon.type || "";
}

/*
 * Selects the best rich icon and tab icon from a list of IconInfo objects.
 *
 * @param {Array} iconInfos A list of IconInfo objects.
 * @param {integer} preferredWidth The preferred width for tab icons.
 */
function selectIcons(iconInfos, preferredWidth) {
  if (!iconInfos.length) {
    return {
      richIcon: null,
      tabIcon: null,
    };
  }

  let preferredIcon;
  let bestSizedIcon;
  // Other links with the "icon" tag are the default icons
  let defaultIcon;
  // Rich icons are either apple-touch or fluid icons, or the ones of the
  // dimension 96x96 or greater
  let largestRichIcon;

  for (let icon of iconInfos) {
    if (!icon.isRichIcon) {
      // First check for svg. If it's not available check for an icon with a
      // size adapt to the current resolution. If both are not available, prefer
      // ico files. When multiple icons are in the same set, the latest wins.
      if (guessType(icon) == TYPE_SVG) {
        preferredIcon = icon;
      } else if (
        icon.width == preferredWidth &&
        guessType(preferredIcon) != TYPE_SVG
      ) {
        preferredIcon = icon;
      } else if (
        guessType(icon) == TYPE_ICO &&
        (!preferredIcon || guessType(preferredIcon) == TYPE_ICO)
      ) {
        preferredIcon = icon;
      }

      // Check for an icon larger yet closest to preferredWidth, that can be
      // downscaled efficiently.
      if (
        icon.width >= preferredWidth &&
        (!bestSizedIcon || bestSizedIcon.width >= icon.width)
      ) {
        bestSizedIcon = icon;
      }
    }

    // Note that some sites use hi-res icons without specifying them as
    // apple-touch or fluid icons.
    if (icon.isRichIcon || icon.width >= FAVICON_RICH_ICON_MIN_WIDTH) {
      if (!largestRichIcon || largestRichIcon.width < icon.width) {
        largestRichIcon = icon;
      }
    } else {
      defaultIcon = icon;
    }
  }

  // Now set the favicons for the page in the following order:
  // 1. Set the best rich icon if any.
  // 2. Set the preferred one if any, otherwise check if there's a better
  //    sized fit.
  // This order allows smaller icon frames to eventually override rich icon
  // frames.

  let tabIcon = null;
  if (preferredIcon) {
    tabIcon = preferredIcon;
  } else if (bestSizedIcon) {
    tabIcon = bestSizedIcon;
  } else if (defaultIcon) {
    tabIcon = defaultIcon;
  }

  return {
    richIcon: largestRichIcon,
    tabIcon,
  };
}

class IconLoader {
  constructor(mm) {
    this.mm = mm;
  }

  async load(iconInfo) {
    if (this._loader) {
      this._loader.cancel();
    }

    if (LOCAL_FAVICON_SCHEMES.includes(iconInfo.iconUri.scheme)) {
      // We need to do a manual security check because the channel won't do
      // it for us.
      try {
        Services.scriptSecurityManager.checkLoadURIWithPrincipal(
          iconInfo.node.nodePrincipal,
          iconInfo.iconUri,
          Services.scriptSecurityManager.ALLOW_CHROME
        );
      } catch (ex) {
        return;
      }
      this.mm.sendAsyncMessage("Link:SetIcon", {
        pageURL: iconInfo.pageUri.spec,
        originalURL: iconInfo.iconUri.spec,
        canUseForTab: !iconInfo.isRichIcon,
        expiration: undefined,
        iconURL: iconInfo.iconUri.spec,
      });
      return;
    }

    // Let the main process that a tab icon is possibly coming.
    this.mm.sendAsyncMessage("Link:LoadingIcon", {
      originalURL: iconInfo.iconUri.spec,
      canUseForTab: !iconInfo.isRichIcon,
    });

    try {
      this._loader = new FaviconLoad(iconInfo);
      let { dataURL, expiration } = await this._loader.load();

      this.mm.sendAsyncMessage("Link:SetIcon", {
        pageURL: iconInfo.pageUri.spec,
        originalURL: iconInfo.iconUri.spec,
        canUseForTab: !iconInfo.isRichIcon,
        expiration,
        iconURL: dataURL,
      });
    } catch (e) {
      if (e.result != Cr.NS_BINDING_ABORTED) {
        Cu.reportError(e);

        // Used mainly for tests currently.
        this.mm.sendAsyncMessage("Link:SetFailedIcon", {
          originalURL: iconInfo.iconUri.spec,
          canUseForTab: !iconInfo.isRichIcon,
        });
      }
    } finally {
      this._loader = null;
    }
  }

  cancel() {
    if (!this._loader) {
      return;
    }

    this._loader.cancel();
    this._loader = null;
  }
}

class FaviconLoader {
  constructor(mm) {
    this.mm = mm;
    this.iconInfos = [];

    // For every page we attempt to find a rich icon and a tab icon. These
    // objects take care of the load process for each.
    this.richIconLoader = new IconLoader(mm);
    this.tabIconLoader = new IconLoader(mm);

    this.iconTask = new DeferredTask(
      () => this.loadIcons(),
      FAVICON_PARSING_TIMEOUT
    );
  }

  loadIcons() {
    // If the page is unloaded immediately after the DeferredTask's timer fires
    // we can still attempt to load icons, which will fail since the content
    // window is no longer available. Checking if iconInfos has been cleared
    // allows us to bail out early in this case.
    if (!this.iconInfos.length) {
      return;
    }

    let preferredWidth =
      PREFERRED_WIDTH * Math.ceil(this.mm.content.devicePixelRatio);
    let { richIcon, tabIcon } = selectIcons(this.iconInfos, preferredWidth);
    this.iconInfos = [];

    if (richIcon) {
      this.richIconLoader.load(richIcon);
    }

    if (tabIcon) {
      this.tabIconLoader.load(tabIcon);
    }
  }

  addIconFromLink(aLink, aIsRichIcon) {
    let iconInfo = makeFaviconFromLink(aLink, aIsRichIcon);
    if (iconInfo) {
      this.iconInfos.push(iconInfo);
      this.iconTask.arm();
      return true;
    }
    return false;
  }

  addDefaultIcon(pageUri) {
    // Currently ImageDocuments will just load the default favicon, see bug
    // 403651 for discussion.
    this.iconInfos.push({
      pageUri,
      iconUri: pageUri
        .mutate()
        .setPathQueryRef("/favicon.ico")
        .finalize(),
      width: -1,
      isRichIcon: false,
      type: TYPE_ICO,
      node: this.mm.content.document,
    });
    this.iconTask.arm();
  }

  onPageShow() {
    // We're likely done with icon parsing so load the pending icons now.
    if (this.iconTask.isArmed) {
      this.iconTask.disarm();
      this.loadIcons();
    }
  }

  onPageHide() {
    this.richIconLoader.cancel();
    this.tabIconLoader.cancel();

    this.iconTask.disarm();
    this.iconInfos = [];
  }
}

function makeFaviconFromLink(aLink, aIsRichIcon) {
  let iconUri = getLinkIconURI(aLink);
  if (!iconUri) {
    return null;
  }

  // Extract the size type and width.
  let width = extractIconSize(aLink.sizes);

  return {
    pageUri: aLink.ownerDocument.documentURIObject,
    iconUri,
    width,
    isRichIcon: aIsRichIcon,
    type: aLink.type,
    node: aLink,
  };
}