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/*
* (C) 2014,2015 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_ALGO_REGISTRY_H__
#define BOTAN_ALGO_REGISTRY_H__
#include <botan/types.h>
#include <functional>
#include <stdexcept>
#include <mutex>
#include <map>
namespace Botan {
size_t static_provider_weight(const std::string& prov_name);
template<typename T>
class Algo_Registry
{
public:
typedef typename T::Spec Spec;
typedef std::function<T* (const Spec&)> maker_fn;
static Algo_Registry<T>& global_registry()
{
static Algo_Registry<T> g_registry;
return g_registry;
}
void add(const std::string& name, const std::string& provider, maker_fn fn)
{
std::unique_lock<std::mutex> lock(m_mutex);
if(!m_maker_fns[name][provider])
m_maker_fns[name][provider] = fn;
}
T* make(const Spec& spec, const std::string& provider = "")
{
maker_fn maker = find_maker(spec, provider);
try
{
return maker(spec);
}
catch(std::exception& e)
{
throw std::runtime_error("Creating '" + spec.as_string() + "' failed: " + e.what());
}
}
class Add
{
public:
Add(const std::string& basename, maker_fn fn, const std::string& provider = "builtin")
{
Algo_Registry<T>::global_registry().add(basename, provider, fn);
}
Add(bool cond, const std::string& basename, maker_fn fn, const std::string& provider)
{
if(cond)
Algo_Registry<T>::global_registry().add(basename, provider, fn);
}
};
private:
Algo_Registry() {}
maker_fn find_maker(const Spec& spec, const std::string& provider)
{
const std::string basename = spec.algo_name();
std::unique_lock<std::mutex> lock(m_mutex);
auto providers = m_maker_fns.find(basename);
if(providers != m_maker_fns.end() && !providers->second.empty())
{
const std::map<std::string, maker_fn>& prov = providers->second;
if(provider != "")
{
// find one explicit provider requested by user, or fail
auto i = prov.find(provider);
if(i != prov.end())
return i->second;
}
else
{
if(prov.size() == 1)
{
return prov.begin()->second;
}
else if(prov.size() > 1)
{
// TODO choose best of available options (how?)
//throw std::runtime_error("multiple choice not implemented");
return prov.begin()->second;
}
}
}
// Default result is a function producing a null pointer
return [](const Spec&) { return nullptr; };
}
std::mutex m_mutex;
std::map<std::string, std::map<std::string, maker_fn>> m_maker_fns;
};
template<typename T> T*
make_new_T(const typename Algo_Registry<T>::Spec&) { return new T; }
template<typename T, size_t DEF_VAL> T*
make_new_T_1len(const typename Algo_Registry<T>::Spec& spec)
{
return new T(spec.arg_as_integer(0, DEF_VAL));
}
template<typename T, size_t DEF1, size_t DEF2> T*
make_new_T_2len(const typename Algo_Registry<T>::Spec& spec)
{
return new T(spec.arg_as_integer(0, DEF1), spec.arg_as_integer(1, DEF2));
}
template<typename T> T*
make_new_T_1str(const typename Algo_Registry<T>::Spec& spec, const std::string& def)
{
return new T(spec.arg(0, def));
}
#define BOTAN_REGISTER_NAMED_T(T, namestr, type, maker) \
namespace { Algo_Registry<T>::Add g_ ## type ## _reg(namestr, maker); }
#define BOTAN_REGISTER_T(T, name, maker) \
namespace { Algo_Registry<T>::Add g_ ## name ## _reg(#name, maker); }
#define BOTAN_REGISTER_T_NOARGS(T, name) \
namespace { Algo_Registry<T>::Add g_ ## name ## _reg(#name, make_new_T<name>); }
#define BOTAN_REGISTER_T_1LEN(T, name, def) \
namespace { Algo_Registry<T>::Add g_ ## name ## _reg(#name, make_new_T_1len<name, def>); }
#define BOTAN_REGISTER_NAMED_T_NOARGS(T, type, name, provider) \
namespace { Algo_Registry<T>::Add g_ ## type ## _reg(name, make_new_T<type>, provider); }
#define BOTAN_COND_REGISTER_NAMED_T_NOARGS(cond, T, type, name, provider) \
namespace { Algo_Registry<T>::Add g_ ## type ## _reg(cond, name, make_new_T<type>, provider); }
#define BOTAN_REGISTER_NAMED_T_2LEN(T, type, name, provider, len1, len2) \
namespace { Algo_Registry<T>::Add g_ ## type ## _reg(name, make_new_T_2len<type, len1, len2>, provider); }
// TODO move elsewhere:
#define BOTAN_REGISTER_TRANSFORM(name, maker) BOTAN_REGISTER_T(Transform, name, maker)
#define BOTAN_REGISTER_TRANSFORM_NOARGS(name) BOTAN_REGISTER_T_NOARGS(Transform, name)
}
#endif
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