Exheredludis/paludis/util/digest_registry.hh
2012-04-15 14:51:19 +01:00

84 lines
2.7 KiB
C++

/* vim: set sw=4 sts=4 et foldmethod=syntax : */
/*
* Copyright (c) 2011, 2012 David Leverton
*
* This file is part of the Paludis package manager. Paludis is free software;
* you can redistribute it and/or modify it under the terms of the GNU General
* Public License version 2, as published by the Free Software Foundation.
*
* Paludis 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.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
* Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef PALUDIS_GUARD_PALUDIS_UTIL_DIGEST_REGISTRY_HH
#define PALUDIS_GUARD_PALUDIS_UTIL_DIGEST_REGISTRY_HH 1
#include <iosfwd>
#include <string>
#include <paludis/util/attributes.hh>
#include <paludis/util/pimp.hh>
#include <paludis/util/singleton.hh>
#include <paludis/util/wrapped_forward_iterator-fwd.hh>
#include <functional>
#include <utility>
namespace paludis
{
class DigestRegistry;
extern template class Pimp<DigestRegistry>;
extern template class PALUDIS_VISIBLE Singleton<DigestRegistry>;
class PALUDIS_VISIBLE DigestRegistry :
public Singleton<DigestRegistry>
{
friend class Singleton<DigestRegistry>;
public:
typedef std::function<std::string (std::istream &)> Function;
Function get(const std::string & algo) const;
struct AlgorithmsConstIteratorTag;
typedef WrappedForwardIterator<AlgorithmsConstIteratorTag, const std::pair<const std::string, Function> > AlgorithmsConstIterator;
AlgorithmsConstIterator begin_algorithms() const PALUDIS_ATTRIBUTE((warn_unused_result));
AlgorithmsConstIterator end_algorithms() const PALUDIS_ATTRIBUTE((warn_unused_result));
template <typename T_>
class Registration
{
public:
Registration(const std::string & algo)
{
get_instance()->register_function(algo, do_digest<T_>);
}
};
private:
DigestRegistry();
~DigestRegistry();
Pimp<DigestRegistry> _imp;
void register_function(const std::string & algo, const Function & func);
template <typename T_>
static std::string
do_digest(std::istream & stream)
{
T_ digest(stream);
return digest.hexsum();
}
};
}
#endif