xpcom/ds/nsAtomHashKeys.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 /* Definitions for nsAtom-related hash keys */
   8
   9 #ifndef nsAtomHashKeys_h
  10 #define nsAtomHashKeys_h
  11
  12 #include "nsAtom.h"
  13 #include "nsHashKeys.h"
  14
  15 // TODO(emilio): Consider removing this and specializing AddToHash instead
  16 // once bug 1849386 is fixed.
  17
  18 // Hash keys suitable for use in nsTHashTable.
  19 struct nsAtomHashKey : public nsRefPtrHashKey<nsAtom> {
  20   using nsRefPtrHashKey::nsRefPtrHashKey;
  21   static PLDHashNumber HashKey(KeyTypePointer aKey) {
  22     return MOZ_LIKELY(aKey) ? aKey->hash() : 0;
  23   }
  24 };
  25
  26 struct nsWeakAtomHashKey : public nsPtrHashKey<nsAtom> {
  27   using nsPtrHashKey::nsPtrHashKey;
  28   static PLDHashNumber HashKey(KeyTypePointer aKey) {
  29     return nsAtomHashKey::HashKey(aKey);
  30   }
  31 };
  32
  33 // Hash keys suitable for use in mozilla::HashMap.
  34 namespace mozilla {
  35
  36 struct AtomHashKey {
  37   RefPtr<nsAtom> mKey;
  38
  39   explicit AtomHashKey(nsAtom* aAtom) : mKey(aAtom) {}
  40
  41   using Lookup = nsAtom*;
  42
  43   static HashNumber hash(const Lookup& aKey) { return aKey->hash(); }
  44   static bool match(const AtomHashKey& aFirst, const Lookup& aSecond) {
  45     return aFirst.mKey == aSecond;
  46   }
  47 };
  48
  49 }  // namespace mozilla
  50
  51 #endif  // nsAtomHashKeys_h