LineageOS/android_external_libcxx
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Teach __hash_table how to handle unordered_map's __hash_value_type.

Browse Source 
This patch is fairly large and contains a number of changes. The main change
is teaching '__hash_table' how to handle '__hash_value_type'. Unfortunately
this change is a rampant layering violation, but it's required to make
unordered_map conforming without re-writing all of __hash_table.
After this change 'unordered_map' can delegate to '__hash_table' in almost all cases.

The major changes found in this patch are:

  * Teach __hash_table to differentiate between the true container value type
    and the node value type by introducing the "__container_value_type" and
    "__node_value_type" typedefs. In the case of unordered_map '__container_value_type'
    is 'pair<const Key, Value>' and '__node_value_type' is '__hash_value_type'.
    
  * Switch almost all overloads in '__hash_table' previously taking 'value_type'
    (AKA '__node_value_type) to take  '__container_value_type' instead. Previously
    'pair<K, V>' would be implicitly converted to '__hash_value_type<K, V>' because
    of the function signature.
    
  * Add '__get_key', '__get_value', '__get_ptr', and '__move' static functions to
    '__key_value_types'. These functions allow '__hash_table' to unwrap
    '__node_value_type' objects into '__container_value_type' and its sub-parts.

  * Pass  '__hash_value_type::__value_'  to 'a.construct(p, ...)' instead of
    '__hash_value_type' itself. The C++14 standard requires that 'a.construct()'
    and 'a.destroy()' are only ever instantiated for the containers value type.

  * Remove '__hash_value_type's constructors and destructors. We should never
    construct an instance of this type.
    (TODO this is UB but we already do it in plenty of places).
  
  * Add a generic "try-emplace" function to '__hash_table' called
    '__emplace_unique_key_args(Key const&, Args...)'.

  
The following changes were done as cleanup:

  * Introduce the '_LIBCPP_CXX03_LANG' macro to be used in place of
    '_LIBCPP_HAS_NO_VARIADICS' or '_LIBCPP_HAS_NO_RVALUE_REFERENCE'.
    
  * Cleanup C++11 only overloads that assume an incomplete C++11 implementation.
    For example this patch removes the __construct_node overloads that do
    manual pack expansion.
    
  * Forward 'unordered_map::emplace' to '__hash_table' and remove dead code
    resulting from the change. This includes almost all
    'unordered_map::__construct_node' overloads.


The following changes are planed for future revisions:

  * Fix LWG issue #2469 by delegating 'unordered_map::operator[]' to use
    '__emplace_unique_key_args'.
    
  * Rewrite 'unordered_map::try_emplace' in terms of '__emplace_unique_key_args'.
  
  * Optimize '__emplace_unique' to call '__emplace_unique_key_args' when possible.
    This prevent unneeded allocations when inserting duplicate entries.


The additional follow up work needed after this patch:

  * Respect the lifetime rules for '__hash_value_type' by actually constructing it.
  * Make '__insert_multi' act similar to '__insert_unique' for objects of type
    'T&' and 'T const &&' with 'T = __container_value_type'.
  
  

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@260513 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Eric Fiselier
2016-02-11 11:59:44 +00:00
parent 7bec7e5729
commit 2960ae20e2
9 changed files with 1294 additions and 363 deletions
Download Patch File Download Diff File Expand all files Collapse all files

268
include/unordered_map
View File

@@ -583,8 +583,7 @@ public:
}
};
#if __cplusplus >= 201103L
#ifndef _LIBCPP_CXX03_LANG
template <class _Key, class _Tp>
union __hash_value_type
{
@@ -596,19 +595,6 @@ union __hash_value_type
value_type __cc;
__nc_value_type __nc;
template <class ..._Args>
_LIBCPP_INLINE_VISIBILITY
__hash_value_type(_Args&& ...__args)
: __cc(std::forward<_Args>(__args)...) {}
_LIBCPP_INLINE_VISIBILITY
__hash_value_type(const __hash_value_type& __v)
: __cc(__v.__cc) {}
_LIBCPP_INLINE_VISIBILITY
__hash_value_type(__hash_value_type&& __v)
: __nc(_VSTD::move(__v.__nc)) {}
_LIBCPP_INLINE_VISIBILITY
__hash_value_type& operator=(const __hash_value_type& __v)
{__nc = __v.__cc; return *this;}
@@ -617,8 +603,23 @@ union __hash_value_type
__hash_value_type& operator=(__hash_value_type&& __v)
{__nc = _VSTD::move(__v.__nc); return *this;}
template <class _ValueTp,
class = typename enable_if<
__is_same_uncvref<_ValueTp, value_type>::value
>::type
>
_LIBCPP_INLINE_VISIBILITY
~__hash_value_type() {__cc.~value_type();}
__hash_value_type& operator=(_ValueTp&& __v) {
__nc = _VSTD::forward<_ValueTp>(__v); return *this;
}
private:
__hash_value_type(const __hash_value_type& __v) = delete;
__hash_value_type(__hash_value_type&& __v) = delete;
template <class ..._Args>
explicit __hash_value_type(_Args&& ...__args) = delete;
~__hash_value_type() = delete;
};
#else
@@ -632,18 +633,8 @@ struct __hash_value_type
value_type __cc;
_LIBCPP_INLINE_VISIBILITY
__hash_value_type() {}
template <class _A0>
_LIBCPP_INLINE_VISIBILITY
__hash_value_type(const _A0& __a0)
: __cc(__a0) {}
template <class _A0, class _A1>
_LIBCPP_INLINE_VISIBILITY
__hash_value_type(const _A0& __a0, const _A1& __a1)
: __cc(__a0, __a1) {}
private:
~__hash_value_type();
};
#endif
@@ -780,6 +771,7 @@ private:
__table __table_;
typedef typename __table::_NodeTypes _NodeTypes;
typedef typename __table::__node_pointer __node_pointer;
typedef typename __table::__node_const_pointer __node_const_pointer;
typedef typename __table::__node_traits __node_traits;
@@ -788,6 +780,9 @@ private:
typedef __hash_map_node_destructor<__node_allocator> _Dp;
typedef unique_ptr<__node, _Dp> __node_holder;
typedef allocator_traits<allocator_type> __alloc_traits;
static_assert((is_same<typename __table::__container_value_type, value_type>::value), "");
static_assert((is_same<typename __table::__node_value_type, __value_type>::value), "");
public:
typedef typename __alloc_traits::pointer pointer;
typedef typename __alloc_traits::const_pointer const_pointer;
@@ -913,28 +908,26 @@ public:
_LIBCPP_INLINE_VISIBILITY
const_iterator cend() const _NOEXCEPT {return __table_.end();}
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
#ifndef _LIBCPP_HAS_NO_VARIADICS
#ifndef _LIBCPP_CXX03_LANG
template <class... _Args>
_LIBCPP_INLINE_VISIBILITY
pair<iterator, bool> emplace(_Args&&... __args) {
return __table_.__emplace_unique(_VSTD::forward<_Args>(__args)...);
}
template <class... _Args>
pair<iterator, bool> emplace(_Args&&... __args);
template <class... _Args>
_LIBCPP_INLINE_VISIBILITY
_LIBCPP_INLINE_VISIBILITY
iterator emplace_hint(const_iterator __p, _Args&&... __args) {
#if _LIBCPP_DEBUG_LEVEL >= 2
iterator emplace_hint(const_iterator __p, _Args&&... __args)
{
_LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
"unordered_map::emplace_hint(const_iterator, args...) called with an iterator not"
" referring to this unordered_map");
return __table_.__emplace_unique(_VSTD::forward<_Args>(__args)...).first;
}
#else
iterator emplace_hint(const_iterator, _Args&&... __args)
{return emplace(_VSTD::forward<_Args>(__args)...).first;}
_LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
"unordered_map::emplace_hint(const_iterator, args...) called with an iterator not"
" referring to this unordered_map");
#endif
#endif // _LIBCPP_HAS_NO_VARIADICS
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
return __table_.__emplace_unique(_VSTD::forward<_Args>(__args)...).first;
}
#endif // _LIBCPP_CXX03_LANG
_LIBCPP_INLINE_VISIBILITY
pair<iterator, bool> insert(const value_type& __x)
{return __table_.__insert_unique(__x);}
@@ -1191,17 +1184,9 @@ public:
#endif // _LIBCPP_DEBUG_LEVEL >= 2
private:
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
__node_holder __construct_node();
template <class _A0>
__node_holder
__construct_node(_A0&& __a0);
#ifndef _LIBCPP_CXX03_LANG
__node_holder __construct_node_with_key(key_type&& __k);
#ifndef _LIBCPP_HAS_NO_VARIADICS
template <class _A0, class _A1, class ..._Args>
__node_holder __construct_node(_A0&& __a0, _A1&& __a1, _Args&& ...__args);
#endif // _LIBCPP_HAS_NO_VARIADICS
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
#endif // _LIBCPP_CXX03_LANG
__node_holder __construct_node_with_key(const key_type& __k);
};
@@ -1328,10 +1313,10 @@ unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
if (__a != __u.get_allocator())
{
iterator __i = __u.begin();
while (__u.size() != 0)
__table_.__insert_unique(
_VSTD::move(__u.__table_.remove((__i++).__i_)->__value_)
);
while (__u.size() != 0) {
__table_.__emplace_unique(_VSTD::move(
__u.__table_.remove((__i++).__i_)->__value_.__nc));
}
}
#if _LIBCPP_DEBUG_LEVEL >= 2
else
@@ -1409,33 +1394,7 @@ unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(
#endif // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder
unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__construct_node()
{
__node_allocator& __na = __table_.__node_alloc();
__node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
__node_traits::construct(__na, _VSTD::addressof(__h->__value_));
__h.get_deleter().__first_constructed = true;
__h.get_deleter().__second_constructed = true;
return __h;
}
template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
template <class _A0>
typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder
unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__construct_node(_A0&& __a0)
{
__node_allocator& __na = __table_.__node_alloc();
__node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
__node_traits::construct(__na, _VSTD::addressof(__h->__value_),
_VSTD::forward<_A0>(__a0));
__h.get_deleter().__first_constructed = true;
__h.get_deleter().__second_constructed = true;
return __h;
}
#ifndef _LIBCPP_CXX03_LANG
template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder
@@ -1450,39 +1409,7 @@ unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__construct_node_with_key(key_ty
return __h;
}
#ifndef _LIBCPP_HAS_NO_VARIADICS
template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
template <class _A0, class _A1, class ..._Args>
typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder
unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__construct_node(_A0&& __a0,
_A1&& __a1,
_Args&&... __args)
{
__node_allocator& __na = __table_.__node_alloc();
__node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
__node_traits::construct(__na, _VSTD::addressof(__h->__value_),
_VSTD::forward<_A0>(__a0), _VSTD::forward<_A1>(__a1),
_VSTD::forward<_Args>(__args)...);
__h.get_deleter().__first_constructed = true;
__h.get_deleter().__second_constructed = true;
return __h;
}
template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
template <class... _Args>
pair<typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::iterator, bool>
unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::emplace(_Args&&... __args)
{
__node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
pair<iterator, bool> __r = __table_.__node_insert_unique(__h.get());
if (__r.second)
__h.release();
return __r;
}
#endif // _LIBCPP_HAS_NO_VARIADICS
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
#endif
template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder
@@ -1630,6 +1557,7 @@ private:
__table __table_;
typedef typename __table::_NodeTypes _NodeTypes;
typedef typename __table::__node_traits __node_traits;
typedef typename __table::__node_allocator __node_allocator;
typedef typename __table::__node __node;
@@ -1765,16 +1693,18 @@ public:
_LIBCPP_INLINE_VISIBILITY
const_iterator cend() const _NOEXCEPT {return __table_.end();}
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
#ifndef _LIBCPP_HAS_NO_VARIADICS
#ifndef _LIBCPP_CXX03_LANG
template <class... _Args>
iterator emplace(_Args&&... __args) {
return __table_.__emplace_multi(_VSTD::forward<_Args>(__args)...);
}
template <class... _Args>
iterator emplace(_Args&&... __args);
iterator emplace_hint(const_iterator __p, _Args&&... __args) {
return __table_.__emplace_hint_multi(__p.__i_, _VSTD::forward<_Args>(__args)...);
}
#endif // _LIBCPP_CXX03_LANG
template <class... _Args>
iterator emplace_hint(const_iterator __p, _Args&&... __args);
#endif // _LIBCPP_HAS_NO_VARIADICS
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
_LIBCPP_INLINE_VISIBILITY
iterator insert(const value_type& __x) {return __table_.__insert_multi(__x);}
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
@@ -1888,17 +1818,7 @@ public:
#endif // _LIBCPP_DEBUG_LEVEL >= 2
private:
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
__node_holder __construct_node();
template <class _A0>
__node_holder
__construct_node(_A0&& __a0);
#ifndef _LIBCPP_HAS_NO_VARIADICS
template <class _A0, class _A1, class ..._Args>
__node_holder __construct_node(_A0&& __a0, _A1&& __a1, _Args&& ...__args);
#endif // _LIBCPP_HAS_NO_VARIADICS
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
};
template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
@@ -2027,7 +1947,7 @@ unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
while (__u.size() != 0)
{
__table_.__insert_multi(
_VSTD::move(__u.__table_.remove((__i++).__i_)->__value_)
_VSTD::move(__u.__table_.remove((__i++).__i_)->__value_.__nc)
);
}
}
@@ -2107,77 +2027,7 @@ unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(
#endif // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
typename unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder
unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::__construct_node()
{
__node_allocator& __na = __table_.__node_alloc();
__node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
__node_traits::construct(__na, _VSTD::addressof(__h->__value_));
__h.get_deleter().__first_constructed = true;
__h.get_deleter().__second_constructed = true;
return __h;
}
template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
template <class _A0>
typename unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder
unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::__construct_node(_A0&& __a0)
{
__node_allocator& __na = __table_.__node_alloc();
__node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
__node_traits::construct(__na, _VSTD::addressof(__h->__value_),
_VSTD::forward<_A0>(__a0));
__h.get_deleter().__first_constructed = true;
__h.get_deleter().__second_constructed = true;
return __h;
}
#ifndef _LIBCPP_HAS_NO_VARIADICS
template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
template <class _A0, class _A1, class ..._Args>
typename unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder
unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::__construct_node(
_A0&& __a0, _A1&& __a1, _Args&&... __args)
{
__node_allocator& __na = __table_.__node_alloc();
__node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
__node_traits::construct(__na, _VSTD::addressof(__h->__value_),
_VSTD::forward<_A0>(__a0), _VSTD::forward<_A1>(__a1),
_VSTD::forward<_Args>(__args)...);
__h.get_deleter().__first_constructed = true;
__h.get_deleter().__second_constructed = true;
return __h;
}
template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
template <class... _Args>
typename unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::iterator
unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::emplace(_Args&&... __args)
{
__node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
iterator __r = __table_.__node_insert_multi(__h.get());
__h.release();
return __r;
}
template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
template <class... _Args>
typename unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::iterator
unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::emplace_hint(
const_iterator __p, _Args&&... __args)
{
__node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
iterator __r = __table_.__node_insert_multi(__p.__i_, __h.get());
__h.release();
return __r;
}
#endif // _LIBCPP_HAS_NO_VARIADICS
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
template <class _InputIterator>