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Refactor suggested_upper_bucket_count/suggested_lower_bucket_count to be independent of the hashtable.

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Ion Gaztañaga
2017-12-09 13:01:49 +01:00
parent 71317671ec
commit 53b1aef2da
1 changed files with 72 additions and 12 deletions
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84
include/boost/intrusive/hashtable.hpp
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@@ -115,26 +115,89 @@ bool priv_algo_is_permutation(ForwardIterator1 first1, ForwardIterator1 last1, F
template<int Dummy = 0>
struct prime_list_holder
{
private:
template <class SizeType> // sizeof(SizeType) < sizeof(std::size_t)
static BOOST_INTRUSIVE_FORCEINLINE SizeType truncate_size_type(std::size_t n, detail::true_)
{
return n < std::size_t(SizeType(-1)) ? static_cast<SizeType>(n) : SizeType(-1);
}
template <class SizeType> // sizeof(SizeType) == sizeof(std::size_t)
static BOOST_INTRUSIVE_FORCEINLINE SizeType truncate_size_type(std::size_t n, detail::false_)
{
return static_cast<SizeType>(n);
}
template <class SizeType> //sizeof(SizeType) > sizeof(std::size_t)
static BOOST_INTRUSIVE_FORCEINLINE SizeType suggested_upper_bucket_count_dispatch(SizeType n, detail::true_)
{
std::size_t const c = n > std::size_t(-1)
? std::size_t(-1)
: suggested_upper_bucket_count_impl(static_cast<std::size_t>(n));
return static_cast<SizeType>(c);
}
template <class SizeType> //sizeof(SizeType) > sizeof(std::size_t)
static BOOST_INTRUSIVE_FORCEINLINE SizeType suggested_lower_bucket_count_dispatch(SizeType n, detail::true_)
{
std::size_t const c = n > std::size_t(-1)
? std::size_t(-1)
: suggested_lower_bucket_count_impl(static_cast<std::size_t>(n));
return static_cast<SizeType>(c);
}
template <class SizeType>
static BOOST_INTRUSIVE_FORCEINLINE SizeType suggested_upper_bucket_count_dispatch(SizeType n, detail::false_)
{
std::size_t const c = suggested_upper_bucket_count_impl(static_cast<std::size_t>(n));
return truncate_size_type<SizeType>(c, detail::bool_<(sizeof(SizeType) < sizeof(std::size_t))>());
}
template <class SizeType>
static BOOST_INTRUSIVE_FORCEINLINE SizeType suggested_lower_bucket_count_dispatch(SizeType n, detail::false_)
{
std::size_t const c = suggested_lower_bucket_count_impl(static_cast<std::size_t>(n));
return truncate_size_type<SizeType>(c, detail::bool_<(sizeof(SizeType) < sizeof(std::size_t))>());
}
static const std::size_t prime_list[];
static const std::size_t prime_list_size;
static std::size_t suggested_upper_bucket_count(std::size_t n)
static std::size_t suggested_lower_bucket_count_impl(std::size_t n)
{
const std::size_t *primes = &prime_list_holder<0>::prime_list[0];
const std::size_t *primes_end = primes + prime_list_holder<0>::prime_list_size;
std::size_t const* bound = std::lower_bound(primes, primes_end, n);
bound -= (bound == primes_end);
//Tables have upper SIZE_MAX, so we must always found an entry
BOOST_INTRUSIVE_INVARIANT_ASSERT(bound != primes_end);
bound -= std::size_t(bound != primes);
return *bound;
}
static std::size_t suggested_lower_bucket_count(std::size_t n)
static std::size_t suggested_upper_bucket_count_impl(std::size_t n)
{
const std::size_t *primes = &prime_list_holder<0>::prime_list[0];
const std::size_t *primes_end = primes + prime_list_holder<0>::prime_list_size;
std::size_t const* bound = std::upper_bound(primes, primes_end, n);
bound -= (bound != primes);
bound -= std::size_t(bound == primes_end);
return *bound;
}
public:
template <class SizeType>
static BOOST_INTRUSIVE_FORCEINLINE SizeType suggested_upper_bucket_count(SizeType n)
{
return (suggested_upper_bucket_count_dispatch)(n, detail::bool_<(sizeof(SizeType) > sizeof(std::size_t))>());
}
template <class SizeType>
static BOOST_INTRUSIVE_FORCEINLINE SizeType suggested_lower_bucket_count(SizeType n)
{
return (suggested_lower_bucket_count_dispatch)(n, detail::bool_<(sizeof(SizeType) > sizeof(std::size_t))>());
}
};
#if !defined(BOOST_INTRUSIVE_DOXYGEN_INVOKED)
@@ -184,9 +247,9 @@ const std::size_t prime_list_holder<Dummy>::prime_list[] = {
BOOST_INTRUSIVE_PRIME_C(432345564227567621), BOOST_INTRUSIVE_PRIME_C(864691128455135207),
BOOST_INTRUSIVE_PRIME_C(1729382256910270481), BOOST_INTRUSIVE_PRIME_C(3458764513820540933),
BOOST_INTRUSIVE_PRIME_C(6917529027641081903), BOOST_INTRUSIVE_PRIME_C(13835058055282163729),
BOOST_INTRUSIVE_PRIME_C(18446744073709551557)
BOOST_INTRUSIVE_PRIME_C(18446744073709551557), BOOST_INTRUSIVE_PRIME_C(18446744073709551615) //Upper limit, just in case
#else
BOOST_INTRUSIVE_PRIME_C(4294967291)
BOOST_INTRUSIVE_PRIME_C(4294967291), BOOST_INTRUSIVE_PRIME_C(4294967295) //Upper limit, just in case
#endif
};
@@ -1476,16 +1539,12 @@ struct hashdata_internal
static BOOST_INTRUSIVE_FORCEINLINE size_type suggested_upper_bucket_count(size_type n)
{
std::size_t c = prime_list_holder<0>::suggested_upper_bucket_count
(sizeof(size_type) > sizeof(std::size_t) && n > std::size_t(-1) ? std::size_t(-1) : static_cast<std::size_t>(n));
return sizeof(size_type) < sizeof(std::size_t) && c > size_type(-1) ? size_type(-1) : static_cast<size_type>(c);
return prime_list_holder<0>::suggested_upper_bucket_count(n);
}
static BOOST_INTRUSIVE_FORCEINLINE size_type suggested_lower_bucket_count(size_type n)
{
std::size_t c = prime_list_holder<0>::suggested_lower_bucket_count
(sizeof(size_type) > sizeof(std::size_t) && n > std::size_t(-1) ? std::size_t(-1) : static_cast<std::size_t>(n));
return sizeof(size_type) < sizeof(std::size_t) && c > size_type(-1) ? size_type(-1) : static_cast<size_type>(c);
return prime_list_holder<0>::suggested_lower_bucket_count(n);
}
const_local_iterator cbegin(size_type n) const
@@ -1497,6 +1556,7 @@ struct hashdata_internal
using internal_type::end;
using internal_type::cend;
local_iterator end(size_type n)
{ return local_iterator(this->priv_bucket_pointer()[n].end(), this->priv_value_traits_ptr()); }