feedc0de/boost_unordered
1
0
Fork 0
forked from boostorg/unordered
Code Pull Requests Activity

Clean up dummy_groups and groups allocation

Browse Source
This commit is contained in:
Christian Mazakas
2023-09-06 12:42:22 -07:00
parent 2cab340749
commit 675e30bd95
1 changed files with 56 additions and 40 deletions
Download Patch File Download Diff File Expand all files Collapse all files

52
include/boost/unordered/detail/foa/core.hpp
View File

@@ -920,8 +920,8 @@ inline unsigned int unchecked_countr_zero(int x)
* allocators. * allocators.
*/ */
template<typename GroupPtr,std::size_t Size> template<typename Group,std::size_t Size>
GroupPtr dummy_groups() Group* dummy_groups()
{ {
/* Dummy storage initialized as if in an empty container (actually, each /* Dummy storage initialized as if in an empty container (actually, each
* of its groups is initialized like a separate empty container). * of its groups is initialized like a separate empty container).
@@ -931,15 +931,11 @@ GroupPtr dummy_groups()
* insertion as the container's capacity is precisely zero. * insertion as the container's capacity is precisely zero.
*/ */
using pointer_traits=boost::pointer_traits<GroupPtr>; static constexpr typename Group::dummy_group_type
using group_type=typename pointer_traits::element_type; storage[Size]={typename Group::dummy_group_type(),};
static constexpr typename group_type::dummy_group_type return reinterpret_cast<Group*>(
storage[Size]={typename group_type::dummy_group_type(),}; const_cast<typename Group::dummy_group_type*>(storage));
group_type* pg=reinterpret_cast<group_type*>(
const_cast<typename group_type::dummy_group_type*>(storage));
return pointer_traits::pointer_to(*pg);
} }
template<typename Value,typename Group,typename SizePolicy,typename Allocator> template<typename Value,typename Group,typename SizePolicy,typename Allocator>
@@ -964,18 +960,19 @@ struct table_arrays
value_type* elements()const noexcept{return boost::to_address(elements_);} value_type* elements()const noexcept{return boost::to_address(elements_);}
group_type* groups()const noexcept{return boost::to_address(groups_);} group_type* groups()const noexcept{return boost::to_address(groups_);}
static table_arrays new_(allocator_type al,std::size_t n) static void set_arrays(table_arrays& arrays,allocator_type al,std::size_t n)
{
return set_arrays(
arrays,al,n,std::is_same<group_type*,group_type_pointer>{});
}
static void set_arrays(
table_arrays& arrays,allocator_type al,std::size_t,std::false_type /* always allocate */)
{ {
using storage_traits=boost::allocator_traits<allocator_type>; using storage_traits=boost::allocator_traits<allocator_type>;
auto groups_size_index=arrays.groups_size_index;
auto groups_size_index=size_index_for<group_type,size_policy>(n);
auto groups_size=size_policy::size(groups_size_index); auto groups_size=size_policy::size(groups_size_index);
table_arrays arrays{groups_size_index,groups_size-1,nullptr,nullptr};
if(!n&&std::is_same<group_type*,group_type_pointer>::value){
arrays.groups_=dummy_groups<group_type_pointer,size_policy::min_size()>();
}
else{
auto sal=allocator_type(al); auto sal=allocator_type(al);
arrays.elements_=storage_traits::allocate(sal,buffer_size(groups_size)); arrays.elements_=storage_traits::allocate(sal,buffer_size(groups_size));
@@ -1001,6 +998,25 @@ struct table_arrays
>{}); >{});
arrays.groups()[groups_size-1].set_sentinel(); arrays.groups()[groups_size-1].set_sentinel();
} }
static void set_arrays(
table_arrays& arrays,allocator_type al,std::size_t n,std::true_type /* optimize for n==0*/)
{
if(!n){
arrays.groups_=dummy_groups<group_type,size_policy::min_size()>();
}
else{
set_arrays(arrays,al,n,std::false_type{});
}
}
static table_arrays new_(allocator_type al,std::size_t n)
{
auto groups_size_index=size_index_for<group_type,size_policy>(n);
auto groups_size=size_policy::size(groups_size_index);
table_arrays arrays{groups_size_index,groups_size-1,nullptr,nullptr};
set_arrays(arrays,al,n);
return arrays; return arrays;
} }