xpcom/glue/AutoRestore.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.

michael@0 1 /* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
michael@0 2 /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0 3 * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0 4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0 5
michael@0 6 /* functions for restoring saved values at the end of a C++ scope */
michael@0 7
michael@0 8 #ifndef mozilla_AutoRestore_h_
michael@0 9 #define mozilla_AutoRestore_h_
michael@0 10
michael@0 11 #include "mozilla/Attributes.h" // MOZ_STACK_CLASS
michael@0 12 #include "mozilla/GuardObjects.h"
michael@0 13
michael@0 14 namespace mozilla {
michael@0 15
michael@0 16 /**
michael@0 17 * Save the current value of a variable and restore it when the object
michael@0 18 * goes out of scope. For example:
michael@0 19 * {
michael@0 20 * AutoRestore<bool> savePainting(mIsPainting);
michael@0 21 * mIsPainting = true;
michael@0 22 *
michael@0 23 * // ... your code here ...
michael@0 24 *
michael@0 25 * // mIsPainting is reset to its old value at the end of this block
michael@0 26 * }
michael@0 27 */
michael@0 28 template <class T>
michael@0 29 class MOZ_STACK_CLASS AutoRestore
michael@0 30 {
michael@0 31 private:
michael@0 32 T& mLocation;
michael@0 33 T mValue;
michael@0 34 MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
michael@0 35 public:
michael@0 36 AutoRestore(T& aValue MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
michael@0 37 : mLocation(aValue), mValue(aValue)
michael@0 38 {
michael@0 39 MOZ_GUARD_OBJECT_NOTIFIER_INIT;
michael@0 40 }
michael@0 41 ~AutoRestore() { mLocation = mValue; }
michael@0 42 };
michael@0 43
michael@0 44 } // namespace mozilla
michael@0 45
michael@0 46 #endif /* !defined(mozilla_AutoRestore_h_) */

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