1 files changed, 51 insertions, 0 deletions
diff --git a/xpcom/ds/nsAtomHashKeys.h b/xpcom/ds/nsAtomHashKeys.h
new file mode 100644
index 0000000000..85aed03bd0
--- /dev/null
+++ b/xpcom/ds/nsAtomHashKeys.h
@@ -0,0 +1,51 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+/* Definitions for nsAtom-related hash keys */
+
+#ifndef nsAtomHashKeys_h
+#define nsAtomHashKeys_h
+
+#include "nsAtom.h"
+#include "nsHashKeys.h"
+
+// TODO(emilio): Consider removing this and specializing AddToHash instead
+// once bug 1849386 is fixed.
+
+// Hash keys suitable for use in nsTHashTable.
+struct nsAtomHashKey : public nsRefPtrHashKey<nsAtom> {
+  using nsRefPtrHashKey::nsRefPtrHashKey;
+  static PLDHashNumber HashKey(KeyTypePointer aKey) {
+    return MOZ_LIKELY(aKey) ? aKey->hash() : 0;
+  }
+};
+
+struct nsWeakAtomHashKey : public nsPtrHashKey<nsAtom> {
+  using nsPtrHashKey::nsPtrHashKey;
+  static PLDHashNumber HashKey(KeyTypePointer aKey) {
+    return nsAtomHashKey::HashKey(aKey);
+  }
+};
+
+// Hash keys suitable for use in mozilla::HashMap.
+namespace mozilla {
+
+struct AtomHashKey {
+  RefPtr<nsAtom> mKey;
+
+  explicit AtomHashKey(nsAtom* aAtom) : mKey(aAtom) {}
+
+  using Lookup = nsAtom*;
+
+  static HashNumber hash(const Lookup& aKey) { return aKey->hash(); }
+  static bool match(const AtomHashKey& aFirst, const Lookup& aSecond) {
+    return aFirst.mKey == aSecond;
+  }
+};
+
+}  // namespace mozilla
+
+#endif  // nsAtomHashKeys_h