xpcom/glue/nsIWeakReferenceUtils.h@97036ab72558
xpcom/glue/nsIWeakReferenceUtils.h
Tue, 06 Jan 2015 21:39:09 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Tue, 06 Jan 2015 21:39:09 +0100
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
- permissions
- -rw-r--r--
Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
1 /* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 /* This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6 #ifndef nsIWeakReferenceUtils_h__
7 #define nsIWeakReferenceUtils_h__
9 #include "nsCOMPtr.h"
10 #include "nsIWeakReference.h"
12 typedef nsCOMPtr<nsIWeakReference> nsWeakPtr;
14 /**
15 *
16 */
18 // a type-safe shortcut for calling the |QueryReferent()| member function
19 // T must inherit from nsIWeakReference, but the cast may be ambiguous.
20 template <class T, class DestinationType>
21 inline
22 nsresult
23 CallQueryReferent( T* aSource, DestinationType** aDestination )
24 {
25 NS_PRECONDITION(aSource, "null parameter");
26 NS_PRECONDITION(aDestination, "null parameter");
28 return aSource->QueryReferent(NS_GET_TEMPLATE_IID(DestinationType),
29 reinterpret_cast<void**>(aDestination));
30 }
33 class NS_COM_GLUE nsQueryReferent : public nsCOMPtr_helper
34 {
35 public:
36 nsQueryReferent( nsIWeakReference* aWeakPtr, nsresult* error )
37 : mWeakPtr(aWeakPtr),
38 mErrorPtr(error)
39 {
40 // nothing else to do here
41 }
43 virtual nsresult NS_FASTCALL operator()( const nsIID& aIID, void** ) const;
45 private:
46 nsIWeakReference* mWeakPtr;
47 nsresult* mErrorPtr;
48 };
50 inline
51 const nsQueryReferent
52 do_QueryReferent( nsIWeakReference* aRawPtr, nsresult* error = 0 )
53 {
54 return nsQueryReferent(aRawPtr, error);
55 }
58 /**
59 * Deprecated, use |do_GetWeakReference| instead.
60 */
61 extern NS_COM_GLUE
62 nsIWeakReference*
63 NS_GetWeakReference( nsISupports* , nsresult* aResult=0 );
65 /**
66 * |do_GetWeakReference| is a convenience function that bundles up all the work needed
67 * to get a weak reference to an arbitrary object, i.e., the |QueryInterface|, test, and
68 * call through to |GetWeakReference|, and put it into your |nsCOMPtr|.
69 * It is specifically designed to cooperate with |nsCOMPtr| (or |nsWeakPtr|) like so:
70 * |nsWeakPtr myWeakPtr = do_GetWeakReference(aPtr);|.
71 */
72 inline
73 already_AddRefed<nsIWeakReference>
74 do_GetWeakReference( nsISupports* aRawPtr, nsresult* error = 0 )
75 {
76 return dont_AddRef(NS_GetWeakReference(aRawPtr, error));
77 }
79 inline
80 void
81 do_GetWeakReference( nsIWeakReference* aRawPtr, nsresult* error = 0 )
82 {
83 // This signature exists solely to _stop_ you from doing a bad thing.
84 // Saying |do_GetWeakReference()| on a weak reference itself,
85 // is very likely to be a programmer error.
86 }
88 template <class T>
89 inline
90 void
91 do_GetWeakReference( already_AddRefed<T>& )
92 {
93 // This signature exists solely to _stop_ you from doing the bad thing.
94 // Saying |do_GetWeakReference()| on a pointer that is not otherwise owned by
95 // someone else is an automatic leak. See <http://bugzilla.mozilla.org/show_bug.cgi?id=8221>.
96 }
98 template <class T>
99 inline
100 void
101 do_GetWeakReference( already_AddRefed<T>&, nsresult* )
102 {
103 // This signature exists solely to _stop_ you from doing the bad thing.
104 // Saying |do_GetWeakReference()| on a pointer that is not otherwise owned by
105 // someone else is an automatic leak. See <http://bugzilla.mozilla.org/show_bug.cgi?id=8221>.
106 }
108 #endif
