gears/base/common/url_utils.cc

   1 // Copyright 2007, Google Inc.
   2 //
   3 // Redistribution and use in source and binary forms, with or without
   4 // modification, are permitted provided that the following conditions are met:
   5 //
   6 //  1. Redistributions of source code must retain the above copyright notice,
   7 //     this list of conditions and the following disclaimer.
   8 //  2. Redistributions in binary form must reproduce the above copyright notice,
   9 //     this list of conditions and the following disclaimer in the documentation
  10 //     and/or other materials provided with the distribution.
  11 //  3. Neither the name of Google Inc. nor the names of its contributors may be
  12 //     used to endorse or promote products derived from this software without
  13 //     specific prior written permission.
  14 //
  15 // THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  16 // WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  17 // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
  18 // EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  19 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  20 // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  21 // OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  22 // WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  23 // OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  24 // ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25
  26 #include "gears/base/common/url_utils.h"
  27
  28
  29 bool IsRelativeUrl(const char16 *url) {
  30   // From RFC 2396 (URI Generic Syntax):
  31   // * "Relative URI references are distinguished from absolute URI in that
  32   //    they do not begin with a scheme name."
  33   // * "Scheme names consist of a sequence of characters beginning with a
  34   //    lower case letter and followed by any combination of lower case
  35   //    letters, digits, plus ('+'), period ('.'), or hyphen ('-').  For
  36   //    resiliency, programs interpreting URI should treat upper case letters
  37   //    as equivalent to lower case in scheme names (e.g., allow 'HTTP' as
  38   //    well as 'http')."
  39   // The algorithm below does not support escaped characters.
  40
  41   bool first_is_alpha = (url[0] >= 'a' && url[0] <= 'z') ||
  42                         (url[0] >= 'A' && url[0] <= 'Z');
  43   if (first_is_alpha) {
  44     int i = 1;
  45     while ((url[i] >= 'a' && url[i] <= 'z') ||
  46            (url[i] >= 'A' && url[i] <= 'Z') ||
  47            (url[i] >= '0' && url[i] <= '9') ||
  48            (url[i] == '+') || (url[i] == '.') || (url[i] == '-')) {
  49       ++i;
  50     }
  51     if (url[i] == ':') {
  52       return false;  // absolute URL
  53     }
  54   }
  55   return true;
  56 }