netwerk/dns/IDNBlocklistUtils.cpp

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #include "IDNBlocklistUtils.h"
   6
   7 #include "nsStringFwd.h"
   8
   9 namespace mozilla {
  10 namespace net {
  11
  12 static constexpr char16_t sBlocklistPairs[][2] = {
  13 #include "IDNCharacterBlocklist.inc"
  14 };
  15
  16 void RemoveCharFromBlocklist(char16_t aChar,
  17                              nsTArray<BlocklistRange>& aBlocklist) {
  18   auto pos = aBlocklist.BinaryIndexOf(aChar, BlocklistPairToCharComparator());
  19   if (pos == nsTArray<BlocklistRange>::NoIndex) {
  20     return;
  21   }
  22
  23   auto& pair = aBlocklist[pos];
  24
  25   // If the matched range has a length of one, we can just remove it
  26   if (pair.second == pair.first) {
  27     aBlocklist.RemoveElementAt(pos);
  28     return;
  29   }
  30
  31   // If the character matches the first element in the range, just update
  32   // the range.
  33   if (aChar == pair.first) {
  34     pair.first = pair.first + 1;
  35     return;
  36   }
  37
  38   // Also if it matches the last character in the range, we just update it.
  39   if (aChar == pair.second) {
  40     pair.second = pair.second - 1;
  41     return;
  42   }
  43
  44   // Our character is in the middle of the range, splitting it in two.
  45   // We update the matched range to reflect the values before the character,
  46   // and insert a new range that represents the values after.
  47   char16_t lastElement = pair.second;
  48   pair.second = aChar - 1;
  49   aBlocklist.InsertElementAt(pos + 1,
  50                              std::make_pair(char16_t(aChar + 1), lastElement));
  51 }
  52
  53 void InitializeBlocklist(nsTArray<BlocklistRange>& aBlocklist) {
  54   aBlocklist.Clear();
  55   for (auto const& arr : sBlocklistPairs) {
  56     // The hardcoded pairs are already sorted.
  57     aBlocklist.AppendElement(std::make_pair(arr[0], arr[1]));
  58   }
  59 }
  60
  61 }  // namespace net
  62 }  // namespace mozilla