genode/repos/os/src/server/nic_router/size_guard.h

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C++

/*
* \brief Utility to ensure that a size value doesn't exceed a limit
* \author Martin Stein
* \date 2016-08-24
*/
/*
* Copyright (C) 2016-2017 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU Affero General Public License version 3.
*/
#ifndef _SIZE_GUARD_H_
#define _SIZE_GUARD_H_
/* Genode includes */
#include <base/stdint.h>
namespace Genode {
template <size_t MAX, typename EXCEPTION>
class Size_guard_tpl;
}
template <Genode::size_t MAX, typename EXCEPTION>
class Genode::Size_guard_tpl
{
private:
size_t _curr { 0 };
public:
void add(size_t size)
{
size_t const new_size = _curr + size;
if (new_size > MAX) { throw EXCEPTION(); }
_curr = new_size;
}
size_t curr() const { return _curr; }
};
#endif /* _SIZE_GUARD_H_ */