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 nsPtrHashKey<T> and nsVoidPtrHashKey.  */
8 
9 #ifndef nsPointerHashKeys_h
10 #define nsPointerHashKeys_h
11 
12 #include "nscore.h"
13 
14 #include "mozilla/Attributes.h"
15 #include "mozilla/HashFunctions.h"
16 
17 /**
18  * hashkey wrapper using T* KeyType
19  *
20  * @see nsTHashtable::EntryType for specification
21  */
22 template <class T>
23 class nsPtrHashKey : public PLDHashEntryHdr {
24  public:
25   typedef T* KeyType;
26   typedef const T* KeyTypePointer;
27 
nsPtrHashKey(const T * aKey)28   explicit nsPtrHashKey(const T* aKey) : mKey(const_cast<T*>(aKey)) {}
nsPtrHashKey(nsPtrHashKey<T> && aToMove)29   nsPtrHashKey(nsPtrHashKey<T>&& aToMove)
30       : PLDHashEntryHdr(std::move(aToMove)), mKey(std::move(aToMove.mKey)) {}
31   ~nsPtrHashKey() = default;
32 
GetKey()33   KeyType GetKey() const { return mKey; }
KeyEquals(KeyTypePointer aKey)34   bool KeyEquals(KeyTypePointer aKey) const { return aKey == mKey; }
35 
KeyToPointer(KeyType aKey)36   static KeyTypePointer KeyToPointer(KeyType aKey) { return aKey; }
HashKey(KeyTypePointer aKey)37   static PLDHashNumber HashKey(KeyTypePointer aKey) {
38     return mozilla::HashGeneric(aKey);
39   }
40   enum { ALLOW_MEMMOVE = true };
41 
42  protected:
43   T* MOZ_NON_OWNING_REF mKey;
44 };
45 
46 typedef nsPtrHashKey<const void> nsVoidPtrHashKey;
47 
48 #endif  // nsPointerHashKeys_h
49