mirror of
https://github.com/telegramdesktop/tdesktop
synced 2024-12-12 17:34:51 +00:00
84 lines
2.4 KiB
C++
84 lines
2.4 KiB
C++
/*
|
|
This file is part of Telegram Desktop,
|
|
the official desktop version of Telegram messaging app, see https://telegram.org
|
|
|
|
Telegram Desktop is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
It is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
In addition, as a special exception, the copyright holders give permission
|
|
to link the code of portions of this program with the OpenSSL library.
|
|
|
|
Full license: https://github.com/telegramdesktop/tdesktop/blob/master/LICENSE
|
|
Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
|
|
*/
|
|
#pragma once
|
|
|
|
namespace Data {
|
|
|
|
// This module suggests a way to hold global data structures, that are
|
|
// created on demand and deleted at the end of the app launch.
|
|
//
|
|
// Usage:
|
|
//
|
|
// class MyData : public Data::AbstractStruct { .. data .. };
|
|
// Data::GlobalStructurePointer<MyData> myData;
|
|
// .. somewhere when needed ..
|
|
// myData.createIfNull();
|
|
|
|
class AbstractStructure {
|
|
public:
|
|
virtual ~AbstractStructure() = 0;
|
|
};
|
|
inline AbstractStructure::~AbstractStructure() = default;
|
|
|
|
namespace internal {
|
|
|
|
void registerAbstractStructure(AbstractStructure **p);
|
|
|
|
} // namespace
|
|
|
|
// Must be created in global scope!
|
|
// Structure is derived from AbstractStructure.
|
|
template <typename Structure>
|
|
class GlobalStructurePointer {
|
|
public:
|
|
GlobalStructurePointer() = default;
|
|
GlobalStructurePointer(const GlobalStructurePointer<Structure> &other) = delete;
|
|
GlobalStructurePointer &operator=(const GlobalStructurePointer<Structure> &other) = delete;
|
|
|
|
void createIfNull() {
|
|
if (!_p) {
|
|
_p = new Structure();
|
|
internal::registerAbstractStructure(&_p);
|
|
}
|
|
}
|
|
Structure *operator->() {
|
|
t_assert(_p != nullptr);
|
|
return static_cast<Structure*>(_p);
|
|
}
|
|
const Structure *operator->() const {
|
|
t_assert(_p != nullptr);
|
|
return static_cast<const Structure*>(_p);
|
|
}
|
|
explicit operator bool() const {
|
|
return _p != nullptr;
|
|
}
|
|
|
|
private:
|
|
AbstractStructure *_p;
|
|
|
|
};
|
|
|
|
// This method should be called at the end of the app launch.
|
|
// It will destroy all data structures created by Data::GlobalStructurePointer.
|
|
void clearGlobalStructures();
|
|
|
|
} // namespace Data
|