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Diffstat (limited to 'boost/uuid/detail/random_provider.hpp')
-rw-r--r-- | boost/uuid/detail/random_provider.hpp | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/boost/uuid/detail/random_provider.hpp b/boost/uuid/detail/random_provider.hpp new file mode 100644 index 0000000000..03d8f26f95 --- /dev/null +++ b/boost/uuid/detail/random_provider.hpp @@ -0,0 +1,75 @@ +// +// Copyright (c) 2017 James E. King III +// +// Distributed under the Boost Software License, Version 1.0. +// (See accompanying file LICENSE_1_0.txt or copy at +// http://www.boost.org/LICENCE_1_0.txt) +// +// Platform-specific random entropy provider +// + +#ifndef BOOST_UUID_DETAIL_RANDOM_PROVIDER_HPP +#define BOOST_UUID_DETAIL_RANDOM_PROVIDER_HPP + +#include <boost/core/noncopyable.hpp> +#include <boost/cstdint.hpp> +#include <boost/limits.hpp> +#include <boost/static_assert.hpp> +#include <boost/type_traits/is_integral.hpp> +#include <boost/type_traits/is_unsigned.hpp> +#include <boost/uuid/entropy_error.hpp> +#include <climits> +#include <iterator> + +// Detection of the platform is separated from inclusion of the correct +// header to facilitate mock testing of the provider implementations. + +#include <boost/uuid/detail/random_provider_detect_platform.hpp> +#include <boost/uuid/detail/random_provider_include_platform.hpp> + + +namespace boost { +namespace uuids { +namespace detail { + +//! \brief Contains code common to all random_provider implementations. +//! \note random_provider_base is required to provide this method: +//! void get_random_bytes(void *buf, size_t siz); +//! \note noncopyable because of some base implementations so +//! this makes it uniform across platforms to avoid any +//! porting surprises +class random_provider + : public detail::random_provider_base, + public noncopyable +{ +public: + //! Leverage the provider as a SeedSeq for + //! PseudoRandomNumberGeneration seeing. + //! \note: See Boost.Random documentation for more details + template<class Iter> + void generate(Iter first, Iter last) + { + typedef typename std::iterator_traits<Iter>::value_type value_type; + BOOST_STATIC_ASSERT(is_integral<value_type>::value); + BOOST_STATIC_ASSERT(is_unsigned<value_type>::value); + BOOST_STATIC_ASSERT(sizeof(value_type) * CHAR_BIT >= 32); + + for (; first != last; ++first) + { + get_random_bytes(&*first, sizeof(*first)); + *first &= (std::numeric_limits<boost::uint32_t>::max)(); + } + } + + //! Return the name of the selected provider + const char * name() const + { + return BOOST_UUID_RANDOM_PROVIDER_STRINGIFY(BOOST_UUID_RANDOM_PROVIDER_NAME); + } +}; + +} // detail +} // uuids +} // boost + +#endif // BOOST_UUID_DETAIL_RANDOM_PROVIDER_HPP |