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 #ifndef vm_PropertyKey_h 8 #define vm_PropertyKey_h 9 10 #include "mozilla/HashFunctions.h" // mozilla::HashGeneric 11 12 #include "NamespaceImports.h" // js::PropertyKey 13 14 #include "js/HashTable.h" // js::DefaultHasher 15 #include "js/Id.h" // JS::PropertyKey 16 #include "vm/StringType.h" // JSAtom::hash 17 #include "vm/SymbolType.h" // JS::Symbol::hash 18 19 namespace js { 20 HashPropertyKey(PropertyKey key)21static MOZ_ALWAYS_INLINE js::HashNumber HashPropertyKey(PropertyKey key) { 22 // HashGeneric alone would work, but bits of atom and symbol addresses 23 // could then be recovered from the hash code. See bug 1330769. 24 if (MOZ_LIKELY(key.isAtom())) { 25 return key.toAtom()->hash(); 26 } 27 if (key.isSymbol()) { 28 return key.toSymbol()->hash(); 29 } 30 return mozilla::HashGeneric(key.asBits); 31 } 32 33 } // namespace js 34 35 namespace mozilla { 36 37 template <> 38 struct DefaultHasher<JS::PropertyKey> { 39 using Lookup = JS::PropertyKey; 40 static HashNumber hash(JS::PropertyKey key) { 41 return js::HashPropertyKey(key); 42 } 43 static bool match(JS::PropertyKey key1, JS::PropertyKey key2) { 44 return key1 == key2; 45 } 46 }; 47 48 } // namespace mozilla 49 50 #endif /* vm_PropertyKey_h */ 51