/work/obj-fuzz/dist/include/nsJSThingHashtable.h
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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 nsJSThingHashtable_h__ |
8 | | #define nsJSThingHashtable_h__ |
9 | | |
10 | | #include "nsHashKeys.h" |
11 | | #include "nsBaseHashtable.h" |
12 | | |
13 | | namespace JS { |
14 | | template<class T> |
15 | | class Heap; |
16 | | } /* namespace JS */ |
17 | | |
18 | | /** |
19 | | * A wrapper for hash keys that sets ALLOW_MEMMOVE to false. |
20 | | * |
21 | | * This is used in the implementation of nsJSThingHashtable and is not intended |
22 | | * to be used directly. |
23 | | * |
24 | | * It is necessary for hash tables containing JS::Heap<T> values as these must |
25 | | * be copied rather than memmoved. |
26 | | */ |
27 | | template<class T> |
28 | | class nsHashKeyDisallowMemmove : public T |
29 | | { |
30 | | public: |
31 | 0 | explicit nsHashKeyDisallowMemmove(const typename T::KeyTypePointer aKey) : T(aKey) {} |
32 | | enum { ALLOW_MEMMOVE = false }; |
33 | | }; |
34 | | |
35 | | |
36 | | /** |
37 | | * Templated hashtable class for use on the heap where the values are JS GC things. |
38 | | * |
39 | | * Storing JS GC thing pointers on the heap requires wrapping them in a |
40 | | * JS::Heap<T>, and this class takes care of that while presenting an interface |
41 | | * in terms of the wrapped type T. |
42 | | * |
43 | | * For example, to store a hashtable mapping strings to JSObject pointers, you |
44 | | * can declare a data member like this: |
45 | | * |
46 | | * nsJSThingHashtable<nsStringHashKey, JSObject*> mStringToObjectMap; |
47 | | * |
48 | | * See nsBaseHashtable for complete declaration |
49 | | * @param KeyClass a wrapper-class for the hashtable key, see nsHashKeys.h |
50 | | * for a complete specification. |
51 | | * @param DataType the datatype being wrapped, must be a JS GC thing. |
52 | | * @see nsInterfaceHashtable, nsClassHashtable |
53 | | */ |
54 | | template<class KeyClass, class DataType> |
55 | | class nsJSThingHashtable |
56 | | : public nsBaseHashtable<nsHashKeyDisallowMemmove<KeyClass>, |
57 | | JS::Heap<DataType>, DataType> |
58 | | { |
59 | | }; |
60 | | |
61 | | #endif // nsJSThingHashtable_h__ |