gcc/libstdc++-v3/include/bits/unordered_map.h
François Dumont da29608a7a re PR libstdc++/41975 ([C++0x] [DR579] unordered_set::erase performs worse when nearly empty)
2011-11-23  François Dumont <fdumont@gcc.gnu.org>

	PR libstdc++/41975
	* include/bits/hashtable.h (_Hashtable<>): Major data model
	modification to limit performance impact of empty buckets in
	erase(iterator) implementation.
	* include/bits/hashtable_policy.h (_Hashtable_iterator,
	_Hashtable_const_iterator): Remove not used anymore.
	* include/bits/hashtable_policy.h (_Prime_rehash_policy): Remove
	_M_grow_factor, just use natural evolution of prime numbers. Add
	_M_prev_size to know when the number of buckets can be reduced.
	* include/bits/unordered_set.h (__unordered_set<>,
	__unordered_multiset<>), unordered_map.h (__unordered_map<>,
	__unordered_multimap<>): Change default value of cache hash code
	template parameter, false for integral types with noexcept hash
	functor, true otherwise.
	* include/debug/unordered_map, unordered_set: Adapt transformation
	from iterator/const_iterator to respectively
	local_iterator/const_local_iterator.
	* testsuite/performance/23_containers/copy_construct/unordered_set.cc:
	New.
	* testsuite/23_containers/unordered_set/instantiation_neg.cc: New.
	* testsuite/23_containers/unordered_set/hash_policy/rehash.cc: New.
	* testsuite/23_containers/unordered_multiset/cons/copy.cc: New.
	* testsuite/23_containers/unordered_multiset/erase/1.cc,
	24061-multiset.cc: Add checks on the number of bucket elements.
	* testsuite/23_containers/unordered_multiset/insert/multiset_range.cc,
	multiset_single.cc, multiset_single_move.cc: Likewise.

From-SVN: r181677
2011-11-23 20:30:18 +00:00

414 lines
15 KiB
C++

// unordered_map implementation -*- C++ -*-
// Copyright (C) 2010, 2011 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/** @file bits/unordered_map.h
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{unordered_map}
*/
#ifndef _UNORDERED_MAP_H
#define _UNORDERED_MAP_H
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_CONTAINER
// NB: When we get typedef templates these class definitions
// will be unnecessary.
template<class _Key, class _Tp,
class _Hash = hash<_Key>,
class _Pred = std::equal_to<_Key>,
class _Alloc = std::allocator<std::pair<const _Key, _Tp> >,
bool __cache_hash_code =
__not_<__and_<is_integral<_Key>,
__detail::__is_noexcept_hash<_Key, _Hash>>>::value>
class __unordered_map
: public _Hashtable<_Key, std::pair<const _Key, _Tp>, _Alloc,
std::_Select1st<std::pair<const _Key, _Tp> >, _Pred,
_Hash, __detail::_Mod_range_hashing,
__detail::_Default_ranged_hash,
__detail::_Prime_rehash_policy,
__cache_hash_code, false, true>
{
typedef _Hashtable<_Key, std::pair<const _Key, _Tp>, _Alloc,
std::_Select1st<std::pair<const _Key, _Tp> >, _Pred,
_Hash, __detail::_Mod_range_hashing,
__detail::_Default_ranged_hash,
__detail::_Prime_rehash_policy,
__cache_hash_code, false, true>
_Base;
public:
typedef typename _Base::value_type value_type;
typedef typename _Base::size_type size_type;
typedef typename _Base::hasher hasher;
typedef typename _Base::key_equal key_equal;
typedef typename _Base::allocator_type allocator_type;
explicit
__unordered_map(size_type __n = 10,
const hasher& __hf = hasher(),
const key_equal& __eql = key_equal(),
const allocator_type& __a = allocator_type())
: _Base(__n, __hf, __detail::_Mod_range_hashing(),
__detail::_Default_ranged_hash(),
__eql, std::_Select1st<std::pair<const _Key, _Tp> >(), __a)
{ }
template<typename _InputIterator>
__unordered_map(_InputIterator __f, _InputIterator __l,
size_type __n = 0,
const hasher& __hf = hasher(),
const key_equal& __eql = key_equal(),
const allocator_type& __a = allocator_type())
: _Base(__f, __l, __n, __hf, __detail::_Mod_range_hashing(),
__detail::_Default_ranged_hash(),
__eql, std::_Select1st<std::pair<const _Key, _Tp> >(), __a)
{ }
__unordered_map(initializer_list<value_type> __l,
size_type __n = 0,
const hasher& __hf = hasher(),
const key_equal& __eql = key_equal(),
const allocator_type& __a = allocator_type())
: _Base(__l.begin(), __l.end(), __n, __hf,
__detail::_Mod_range_hashing(),
__detail::_Default_ranged_hash(),
__eql, std::_Select1st<std::pair<const _Key, _Tp> >(), __a)
{ }
__unordered_map&
operator=(initializer_list<value_type> __l)
{
this->clear();
this->insert(__l.begin(), __l.end());
return *this;
}
};
template<class _Key, class _Tp,
class _Hash = hash<_Key>,
class _Pred = std::equal_to<_Key>,
class _Alloc = std::allocator<std::pair<const _Key, _Tp> >,
bool __cache_hash_code =
__not_<__and_<is_integral<_Key>,
__detail::__is_noexcept_hash<_Key, _Hash>>>::value>
class __unordered_multimap
: public _Hashtable<_Key, std::pair<const _Key, _Tp>,
_Alloc,
std::_Select1st<std::pair<const _Key, _Tp> >, _Pred,
_Hash, __detail::_Mod_range_hashing,
__detail::_Default_ranged_hash,
__detail::_Prime_rehash_policy,
__cache_hash_code, false, false>
{
typedef _Hashtable<_Key, std::pair<const _Key, _Tp>,
_Alloc,
std::_Select1st<std::pair<const _Key, _Tp> >, _Pred,
_Hash, __detail::_Mod_range_hashing,
__detail::_Default_ranged_hash,
__detail::_Prime_rehash_policy,
__cache_hash_code, false, false>
_Base;
public:
typedef typename _Base::value_type value_type;
typedef typename _Base::size_type size_type;
typedef typename _Base::hasher hasher;
typedef typename _Base::key_equal key_equal;
typedef typename _Base::allocator_type allocator_type;
explicit
__unordered_multimap(size_type __n = 10,
const hasher& __hf = hasher(),
const key_equal& __eql = key_equal(),
const allocator_type& __a = allocator_type())
: _Base(__n, __hf, __detail::_Mod_range_hashing(),
__detail::_Default_ranged_hash(),
__eql, std::_Select1st<std::pair<const _Key, _Tp> >(), __a)
{ }
template<typename _InputIterator>
__unordered_multimap(_InputIterator __f, _InputIterator __l,
size_type __n = 0,
const hasher& __hf = hasher(),
const key_equal& __eql = key_equal(),
const allocator_type& __a = allocator_type())
: _Base(__f, __l, __n, __hf, __detail::_Mod_range_hashing(),
__detail::_Default_ranged_hash(),
__eql, std::_Select1st<std::pair<const _Key, _Tp> >(), __a)
{ }
__unordered_multimap(initializer_list<value_type> __l,
size_type __n = 0,
const hasher& __hf = hasher(),
const key_equal& __eql = key_equal(),
const allocator_type& __a = allocator_type())
: _Base(__l.begin(), __l.end(), __n, __hf,
__detail::_Mod_range_hashing(),
__detail::_Default_ranged_hash(),
__eql, std::_Select1st<std::pair<const _Key, _Tp> >(), __a)
{ }
__unordered_multimap&
operator=(initializer_list<value_type> __l)
{
this->clear();
this->insert(__l.begin(), __l.end());
return *this;
}
};
template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc,
bool __cache_hash_code>
inline void
swap(__unordered_map<_Key, _Tp, _Hash, _Pred,
_Alloc, __cache_hash_code>& __x,
__unordered_map<_Key, _Tp, _Hash, _Pred,
_Alloc, __cache_hash_code>& __y)
{ __x.swap(__y); }
template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc,
bool __cache_hash_code>
inline void
swap(__unordered_multimap<_Key, _Tp, _Hash, _Pred,
_Alloc, __cache_hash_code>& __x,
__unordered_multimap<_Key, _Tp, _Hash, _Pred,
_Alloc, __cache_hash_code>& __y)
{ __x.swap(__y); }
template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc,
bool __cache_hash_code>
inline bool
operator==(const __unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc,
__cache_hash_code>& __x,
const __unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc,
__cache_hash_code>& __y)
{ return __x._M_equal(__y); }
template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc,
bool __cache_hash_code>
inline bool
operator!=(const __unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc,
__cache_hash_code>& __x,
const __unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc,
__cache_hash_code>& __y)
{ return !(__x == __y); }
template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc,
bool __cache_hash_code>
inline bool
operator==(const __unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc,
__cache_hash_code>& __x,
const __unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc,
__cache_hash_code>& __y)
{ return __x._M_equal(__y); }
template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc,
bool __cache_hash_code>
inline bool
operator!=(const __unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc,
__cache_hash_code>& __x,
const __unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc,
__cache_hash_code>& __y)
{ return !(__x == __y); }
/**
* @brief A standard container composed of unique keys (containing
* at most one of each key value) that associates values of another type
* with the keys.
*
* @ingroup unordered_associative_containers
*
* Meets the requirements of a <a href="tables.html#65">container</a>, and
* <a href="tables.html#xx">unordered associative container</a>
*
* @param Key Type of key objects.
* @param Tp Type of mapped objects.
* @param Hash Hashing function object type, defaults to hash<Value>.
* @param Pred Predicate function object type, defaults to equal_to<Value>.
* @param Alloc Allocator type, defaults to allocator<Key>.
*
* The resulting value type of the container is std::pair<const Key, Tp>.
*/
template<class _Key, class _Tp,
class _Hash = hash<_Key>,
class _Pred = std::equal_to<_Key>,
class _Alloc = std::allocator<std::pair<const _Key, _Tp> > >
class unordered_map
: public __unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>
{
typedef __unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc> _Base;
public:
typedef typename _Base::value_type value_type;
typedef typename _Base::size_type size_type;
typedef typename _Base::hasher hasher;
typedef typename _Base::key_equal key_equal;
typedef typename _Base::allocator_type allocator_type;
explicit
unordered_map(size_type __n = 10,
const hasher& __hf = hasher(),
const key_equal& __eql = key_equal(),
const allocator_type& __a = allocator_type())
: _Base(__n, __hf, __eql, __a)
{ }
template<typename _InputIterator>
unordered_map(_InputIterator __f, _InputIterator __l,
size_type __n = 0,
const hasher& __hf = hasher(),
const key_equal& __eql = key_equal(),
const allocator_type& __a = allocator_type())
: _Base(__f, __l, __n, __hf, __eql, __a)
{ }
unordered_map(initializer_list<value_type> __l,
size_type __n = 0,
const hasher& __hf = hasher(),
const key_equal& __eql = key_equal(),
const allocator_type& __a = allocator_type())
: _Base(__l.begin(), __l.end(), __n, __hf, __eql, __a)
{ }
unordered_map&
operator=(initializer_list<value_type> __l)
{
this->clear();
this->insert(__l.begin(), __l.end());
return *this;
}
};
/**
* @brief A standard container composed of equivalent keys
* (possibly containing multiple of each key value) that associates
* values of another type with the keys.
*
* @ingroup unordered_associative_containers
*
* Meets the requirements of a <a href="tables.html#65">container</a>, and
* <a href="tables.html#xx">unordered associative container</a>
*
* @param Key Type of key objects.
* @param Tp Type of mapped objects.
* @param Hash Hashing function object type, defaults to hash<Value>.
* @param Pred Predicate function object type, defaults to equal_to<Value>.
* @param Alloc Allocator type, defaults to allocator<Key>.
*
* The resulting value type of the container is std::pair<const Key, Tp>.
*/
template<class _Key, class _Tp,
class _Hash = hash<_Key>,
class _Pred = std::equal_to<_Key>,
class _Alloc = std::allocator<std::pair<const _Key, _Tp> > >
class unordered_multimap
: public __unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>
{
typedef __unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc> _Base;
public:
typedef typename _Base::value_type value_type;
typedef typename _Base::size_type size_type;
typedef typename _Base::hasher hasher;
typedef typename _Base::key_equal key_equal;
typedef typename _Base::allocator_type allocator_type;
explicit
unordered_multimap(size_type __n = 10,
const hasher& __hf = hasher(),
const key_equal& __eql = key_equal(),
const allocator_type& __a = allocator_type())
: _Base(__n, __hf, __eql, __a)
{ }
template<typename _InputIterator>
unordered_multimap(_InputIterator __f, _InputIterator __l,
size_type __n = 0,
const hasher& __hf = hasher(),
const key_equal& __eql = key_equal(),
const allocator_type& __a = allocator_type())
: _Base(__f, __l, __n, __hf, __eql, __a)
{ }
unordered_multimap(initializer_list<value_type> __l,
size_type __n = 0,
const hasher& __hf = hasher(),
const key_equal& __eql = key_equal(),
const allocator_type& __a = allocator_type())
: _Base(__l.begin(), __l.end(), __n, __hf, __eql, __a)
{ }
unordered_multimap&
operator=(initializer_list<value_type> __l)
{
this->clear();
this->insert(__l.begin(), __l.end());
return *this;
}
};
template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
inline void
swap(unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
{ __x.swap(__y); }
template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
inline void
swap(unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
{ __x.swap(__y); }
template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
inline bool
operator==(const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
{ return __x._M_equal(__y); }
template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
inline bool
operator!=(const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
{ return !(__x == __y); }
template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
inline bool
operator==(const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
{ return __x._M_equal(__y); }
template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
inline bool
operator!=(const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
{ return !(__x == __y); }
_GLIBCXX_END_NAMESPACE_CONTAINER
} // namespace std
#endif /* _UNORDERED_MAP_H */