reactos/include/c++/stlport/stl/_hashtable.c

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/*
* Copyright (c) 1994
* Hewlett-Packard Company
*
* Copyright (c) 1996,1997
* Silicon Graphics Computer Systems, Inc.
*
* Copyright (c) 1997
* Moscow Center for SPARC Technology
*
* Copyright (c) 1999
* Boris Fomitchev
*
* This material is provided "as is", with absolutely no warranty expressed
* or implied. Any use is at your own risk.
*
* Permission to use or copy this software for any purpose is hereby granted
* without fee, provided the above notices are retained on all copies.
* Permission to modify the code and to distribute modified code is granted,
* provided the above notices are retained, and a notice that the code was
* modified is included with the above copyright notice.
*
*/
#ifndef _STLP_HASHTABLE_C
#define _STLP_HASHTABLE_C
#ifndef _STLP_INTERNAL_HASHTABLE_H
# include <stl/_hashtable.h>
#endif
_STLP_BEGIN_NAMESPACE
#if defined (_STLP_EXPOSE_GLOBALS_IMPLEMENTATION)
_STLP_MOVE_TO_PRIV_NAMESPACE
# define __PRIME_LIST_BODY { \
7ul, 23ul, \
53ul, 97ul, 193ul, 389ul, 769ul, \
1543ul, 3079ul, 6151ul, 12289ul, 24593ul, \
49157ul, 98317ul, 196613ul, 393241ul, 786433ul, \
1572869ul, 3145739ul, 6291469ul, 12582917ul, 25165843ul, \
50331653ul, 100663319ul, 201326611ul, 402653189ul, 805306457ul,\
1610612741ul, 3221225473ul, 4294967291ul \
}
template <class _Dummy>
const size_t* _STLP_CALL
_Stl_prime<_Dummy>::_S_primes(size_t &__size) {
static const size_t _list[] = __PRIME_LIST_BODY;
# ifndef __MWERKS__
__size = sizeof(_list) / sizeof(_list[0]);
# else
__size = 30;
# endif
return _list;
}
template <class _Dummy>
size_t _STLP_CALL
_Stl_prime<_Dummy>::_S_max_nb_buckets() {
size_t __size;
const size_t* __first = _S_primes(__size);
return *(__first + __size - 1);
}
template <class _Dummy>
size_t _STLP_CALL
_Stl_prime<_Dummy>::_S_next_size(size_t __n) {
size_t __size;
const size_t* __first = _S_primes(__size);
const size_t* __last = __first + __size;
const size_t* pos = __lower_bound(__first, __last, __n,
__less((size_t*)0), __less((size_t*)0), (ptrdiff_t*)0);
return (pos == __last ? *(__last - 1) : *pos);
}
template <class _Dummy>
void _STLP_CALL
_Stl_prime<_Dummy>::_S_prev_sizes(size_t __n, size_t const*&__begin, size_t const*&__pos) {
size_t __size;
__begin = _S_primes(__size);
const size_t* __last = __begin + __size;
__pos = __lower_bound(__begin, __last, __n,
__less((size_t*)0), __less((size_t*)0), (ptrdiff_t*)0);
if (__pos== __last)
--__pos;
else if (*__pos == __n) {
if (__pos != __begin)
--__pos;
}
}
# undef __PRIME_LIST_BODY
_STLP_MOVE_TO_STD_NAMESPACE
#endif
#if defined (_STLP_DEBUG)
# define hashtable _STLP_NON_DBG_NAME(hashtable)
_STLP_MOVE_TO_PRIV_NAMESPACE
#endif
// fbp: these defines are for outline methods definitions.
// needed to definitions to be portable. Should not be used in method bodies.
#if defined ( _STLP_NESTED_TYPE_PARAM_BUG )
# define __size_type__ size_t
# define size_type size_t
# define value_type _Val
# define key_type _Key
# define __reference__ _Val&
# define __iterator__ _Ht_iterator<_Val, _STLP_HEADER_TYPENAME _Traits::_NonConstTraits, \
_Key, _HF, _ExK, _EqK, _All>
# define __const_iterator__ _Ht_iterator<_Val, _STLP_HEADER_TYPENAME _Traits::_ConstTraits, \
_Key, _HF, _ExK, _EqK, _All>
#else
# define __size_type__ _STLP_TYPENAME_ON_RETURN_TYPE hashtable<_Val, _Key, _HF, _Traits, _ExK, _EqK, _All>::size_type
# define __reference__ _STLP_TYPENAME_ON_RETURN_TYPE hashtable<_Val, _Key, _HF, _Traits, _ExK, _EqK, _All>::reference
# define __iterator__ _STLP_TYPENAME_ON_RETURN_TYPE hashtable<_Val, _Key, _HF, _Traits, _ExK, _EqK, _All>::iterator
# define __const_iterator__ _STLP_TYPENAME_ON_RETURN_TYPE hashtable<_Val, _Key, _HF, _Traits, _ExK, _EqK, _All>::const_iterator
#endif
/*
* This method is too difficult to implement for hashtable that do not
* require a sorted operation on the stored type.
template <class _Val, class _Key, class _HF,
class _Traits, class _ExK, class _EqK, class _All>
bool hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>::_M_equal(
const hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>& __ht1,
const hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>& __ht2) {
return __ht1._M_buckets == __ht2._M_buckets &&
__ht1._M_elems == __ht2._M_elems;
}
*/
/* Returns the iterator before the first iterator of the bucket __n and set
* __n to the first previous bucket having the same first iterator as bucket
* __n.
*/
template <class _Val, class _Key, class _HF,
class _Traits, class _ExK, class _EqK, class _All>
__iterator__
hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>
::_M_before_begin(size_type &__n) const {
return _S_before_begin(_M_elems, _M_buckets, __n);
}
template <class _Val, class _Key, class _HF,
class _Traits, class _ExK, class _EqK, class _All>
__iterator__
hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>
::_S_before_begin(const _ElemsCont& __elems, const _BucketVector& __buckets,
size_type &__n) {
_ElemsCont &__mutable_elems = __CONST_CAST(_ElemsCont&, __elems);
typename _BucketVector::const_iterator __bpos(__buckets.begin() + __n);
_ElemsIte __pos(*__bpos);
if (__pos == __mutable_elems.begin()) {
__n = 0;
return __mutable_elems.before_begin();
}
typename _BucketVector::const_iterator __bcur(__bpos);
_BucketType *__pos_node = __pos._M_node;
for (--__bcur; __pos_node == *__bcur; --__bcur);
__n = __bcur - __buckets.begin() + 1;
_ElemsIte __cur(*__bcur);
_ElemsIte __prev = __cur++;
for (; __cur != __pos; ++__prev, ++__cur);
return __prev;
}
template <class _Val, class _Key, class _HF,
class _Traits, class _ExK, class _EqK, class _All>
__iterator__
hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>
::_M_insert_noresize(size_type __n, const value_type& __obj) {
//We always insert this element as 1st in the bucket to not break
//the elements order as equal elements must be kept next to each other.
size_type __prev = __n;
_ElemsIte __pos = _M_before_begin(__prev)._M_ite;
fill(_M_buckets.begin() + __prev, _M_buckets.begin() + __n + 1,
_M_elems.insert_after(__pos, __obj)._M_node);
++_M_num_elements;
return iterator(_ElemsIte(_M_buckets[__n]));
}
template <class _Val, class _Key, class _HF,
class _Traits, class _ExK, class _EqK, class _All>
pair<__iterator__, bool>
hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>
::insert_unique_noresize(const value_type& __obj) {
const size_type __n = _M_bkt_num(__obj);
_ElemsIte __cur(_M_buckets[__n]);
_ElemsIte __last(_M_buckets[__n + 1]);
if (__cur != __last) {
for (; __cur != __last; ++__cur) {
if (_M_equals(_M_get_key(*__cur), _M_get_key(__obj))) {
//We check that equivalent keys have equals hash code as otherwise, on resize,
//equivalent value might not be in the same bucket
_STLP_ASSERT(_M_hash(_M_get_key(*__cur)) == _M_hash(_M_get_key(__obj)))
return pair<iterator, bool>(iterator(__cur), false);
}
}
/* Here we do not rely on the _M_insert_noresize method as we know
* that we cannot break element orders, elements are unique, and
* insertion after the first bucket element is faster than what is
* done in _M_insert_noresize.
*/
__cur = _M_elems.insert_after(_ElemsIte(_M_buckets[__n]), __obj);
++_M_num_elements;
return pair<iterator, bool>(iterator(__cur), true);
}
return pair<iterator, bool>(_M_insert_noresize(__n, __obj), true);
}
template <class _Val, class _Key, class _HF,
class _Traits, class _ExK, class _EqK, class _All>
__iterator__
hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>
::insert_equal_noresize(const value_type& __obj) {
const size_type __n = _M_bkt_num(__obj);
{
_ElemsIte __cur(_M_buckets[__n]);
_ElemsIte __last(_M_buckets[__n + 1]);
for (; __cur != __last; ++__cur) {
if (_M_equals(_M_get_key(*__cur), _M_get_key(__obj))) {
//We check that equivalent keys have equals hash code as otherwise, on resize,
//equivalent value might not be in the same bucket
_STLP_ASSERT(_M_hash(_M_get_key(*__cur)) == _M_hash(_M_get_key(__obj)))
++_M_num_elements;
return _M_elems.insert_after(__cur, __obj);
}
}
}
return _M_insert_noresize(__n, __obj);
}
template <class _Val, class _Key, class _HF,
class _Traits, class _ExK, class _EqK, class _All>
__reference__
hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>
::_M_insert(const value_type& __obj) {
_M_enlarge(_M_num_elements + 1);
return *insert_unique_noresize(__obj).first;
}
template <class _Val, class _Key, class _HF,
class _Traits, class _ExK, class _EqK, class _All>
__size_type__
hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>
::erase(const key_type& __key) {
const size_type __n = _M_bkt_num_key(__key);
_ElemsIte __cur(_M_buckets[__n]);
_ElemsIte __last(_M_buckets[__n + 1]);
if (__cur == __last)
return 0;
size_type __erased = 0;
if (_M_equals(_M_get_key(*__cur), __key)) {
//We look for the pos before __cur:
size_type __prev_b = __n;
_ElemsIte __prev = _M_before_begin(__prev_b)._M_ite;
do {
__cur = _M_elems.erase_after(__prev);
++__erased;
} while ((__cur != __last) && _M_equals(_M_get_key(*__cur), __key));
fill(_M_buckets.begin() + __prev_b, _M_buckets.begin() + __n + 1, __cur._M_node);
}
else {
_ElemsIte __prev = __cur++;
for (; __cur != __last; ++__prev, ++__cur) {
if (_M_equals(_M_get_key(*__cur), __key)) {
do {
__cur = _M_elems.erase_after(__prev);
++__erased;
} while ((__cur != __last) && _M_equals(_M_get_key(*__cur), __key));
break;
}
}
}
_M_num_elements -= __erased;
_M_reduce();
return __erased;
}
template <class _Val, class _Key, class _HF,
class _Traits, class _ExK, class _EqK, class _All>
void hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>
::erase(const_iterator __it) {
const size_type __n = _M_bkt_num(*__it);
_ElemsIte __cur(_M_buckets[__n]);
size_type __erased = 0;
if (__cur == __it._M_ite) {
size_type __prev_b = __n;
_ElemsIte __prev = _M_before_begin(__prev_b)._M_ite;
fill(_M_buckets.begin() + __prev_b, _M_buckets.begin() + __n + 1,
_M_elems.erase_after(__prev)._M_node);
++__erased;
}
else {
_ElemsIte __prev = __cur++;
_ElemsIte __last(_M_buckets[__n + 1]);
for (; __cur != __last; ++__prev, ++__cur) {
if (__cur == __it._M_ite) {
_M_elems.erase_after(__prev);
++__erased;
break;
}
}
}
_M_num_elements -= __erased;
_M_reduce();
}
template <class _Val, class _Key, class _HF,
class _Traits, class _ExK, class _EqK, class _All>
void hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>
::erase(const_iterator __first, const_iterator __last) {
if (__first == __last)
return;
size_type __f_bucket = _M_bkt_num(*__first);
size_type __l_bucket = __last != end() ? _M_bkt_num(*__last) : (_M_buckets.size() - 1);
_ElemsIte __cur(_M_buckets[__f_bucket]);
_ElemsIte __prev;
if (__cur == __first._M_ite) {
__prev = _M_before_begin(__f_bucket)._M_ite;
}
else {
_ElemsIte __last(_M_buckets[++__f_bucket]);
__prev = __cur++;
for (; (__cur != __last) && (__cur != __first._M_ite); ++__prev, ++__cur);
}
size_type __erased = 0;
//We do not use the slist::erase_after method taking a range to count the
//number of erased elements:
while (__cur != __last._M_ite) {
__cur = _M_elems.erase_after(__prev);
++__erased;
}
fill(_M_buckets.begin() + __f_bucket, _M_buckets.begin() + __l_bucket + 1, __cur._M_node);
_M_num_elements -= __erased;
_M_reduce();
}
template <class _Val, class _Key, class _HF,
class _Traits, class _ExK, class _EqK, class _All>
void hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>
::rehash(size_type __num_buckets_hint) {
if (bucket_count() >= __num_buckets_hint) {
// We are trying to reduce number of buckets, we have to validate it:
size_type __limit_num_buckets = (size_type)((float)size() / max_load_factor());
if (__num_buckets_hint < __limit_num_buckets) {
// Targetted number of buckets __num_buckets_hint would break
// load_factor() <= max_load_factor() rule.
return;
}
}
_M_rehash(__num_buckets_hint);
}
template <class _Val, class _Key, class _HF,
class _Traits, class _ExK, class _EqK, class _All>
void hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>
::_M_enlarge(size_type __to_size) {
size_type __num_buckets = bucket_count();
size_type __num_buckets_hint = (size_type)((float)__to_size / max_load_factor());
if (__num_buckets_hint <= __num_buckets) {
return;
}
__num_buckets = _STLP_PRIV _Stl_prime_type::_S_next_size(__num_buckets_hint);
_M_rehash(__num_buckets);
}
template <class _Val, class _Key, class _HF,
class _Traits, class _ExK, class _EqK, class _All>
void hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>
::_M_reduce() {
size_type __num_buckets = bucket_count();
// We only try to reduce the hashtable if the theorical load factor
// is lower than a fraction of the max load factor:
// 4 factor is coming from the fact that prime number list is almost a
// geometrical suite with reason 2, as we try to jump 2 levels is means
// a 4 factor.
if ((float)size() / (float)__num_buckets > max_load_factor() / 4.0f)
return;
const size_type *__first;
const size_type *__prev;
_STLP_PRIV _Stl_prime_type::_S_prev_sizes(__num_buckets, __first, __prev);
/* We are only going to reduce number of buckets if moving to yet the previous number
* of buckets in the prime numbers would respect the load rule. Otherwise algorithm
* successively removing and adding an element would each time perform an expensive
* rehash operation. */
const size_type *__prev_prev = __prev;
if (__prev_prev != __first) {
--__prev_prev;
if ((float)size() / (float)*__prev_prev > max_load_factor())
return;
}
else {
if (*__prev >= __num_buckets)
return;
}
// Can we reduce further:
while (__prev_prev != __first) {
--__prev_prev;
if ((float)size() / (float)*__prev_prev > max_load_factor())
// We cannot reduce further.
break;
--__prev;
}
_M_rehash(*__prev);
}
template <class _Val, class _Key, class _HF,
class _Traits, class _ExK, class _EqK, class _All>
void hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>
::_M_resize() {
if (load_factor() > max_load_factor()) {
// We have to enlarge
_M_enlarge(size());
}
else {
// We can try to reduce size:
_M_reduce();
}
}
template <class _Val, class _Key, class _HF,
class _Traits, class _ExK, class _EqK, class _All>
void hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>
::_M_rehash(size_type __num_buckets) {
#if defined (_STLP_DEBUG)
_M_check();
#endif
_ElemsCont __tmp_elems(_M_elems.get_allocator());
_BucketVector __tmp(__num_buckets + 1, __STATIC_CAST(_BucketType*, 0), _M_buckets.get_allocator());
_ElemsIte __cur, __last(_M_elems.end());
while (!_M_elems.empty()) {
__cur = _M_elems.begin();
size_type __new_bucket = _M_bkt_num(*__cur, __num_buckets);
_ElemsIte __ite(__cur), __before_ite(__cur);
for (++__ite;
__ite != __last && _M_equals(_M_get_key(*__cur), _M_get_key(*__ite));
++__ite, ++__before_ite);
size_type __prev_bucket = __new_bucket;
_ElemsIte __prev = _S_before_begin(__tmp_elems, __tmp, __prev_bucket)._M_ite;
__tmp_elems.splice_after(__prev, _M_elems, _M_elems.before_begin(), __before_ite);
fill(__tmp.begin() + __prev_bucket, __tmp.begin() + __new_bucket + 1, __cur._M_node);
}
_M_elems.swap(__tmp_elems);
_M_buckets.swap(__tmp);
}
#if defined (_STLP_DEBUG)
template <class _Val, class _Key, class _HF,
class _Traits, class _ExK, class _EqK, class _All>
void hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>::_M_check() const {
//We check that hash code of stored keys haven't change and also that equivalent
//relation hasn't been modified
size_t __num_buckets = bucket_count();
for (size_t __b = 0; __b < __num_buckets; ++__b) {
_ElemsIte __cur(_M_buckets[__b]), __last(_M_buckets[__b + 1]);
_ElemsIte __fst(__cur), __snd(__cur);
for (; __cur != __last; ++__cur) {
_STLP_ASSERT( _M_bkt_num(*__cur, __num_buckets) == __b )
_STLP_ASSERT( !_M_equals(_M_get_key(*__fst), _M_get_key(*__cur)) || _M_equals(_M_get_key(*__snd), _M_get_key(*__cur)) )
if (__fst != __snd)
++__fst;
if (__snd != __cur)
++__snd;
}
}
}
#endif
template <class _Val, class _Key, class _HF,
class _Traits, class _ExK, class _EqK, class _All>
void hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>::clear() {
_M_elems.clear();
_M_buckets.assign(_M_buckets.size(), __STATIC_CAST(_BucketType*, 0));
_M_num_elements = 0;
}
template <class _Val, class _Key, class _HF,
class _Traits, class _ExK, class _EqK, class _All>
void hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>
::_M_copy_from(const hashtable<_Val,_Key,_HF,_Traits,_ExK,_EqK,_All>& __ht) {
_M_elems.clear();
_M_elems.insert(_M_elems.end(), __ht._M_elems.begin(), __ht._M_elems.end());
_M_buckets.resize(__ht._M_buckets.size());
_ElemsConstIte __src(__ht._M_elems.begin()), __src_end(__ht._M_elems.end());
_ElemsIte __dst(_M_elems.begin());
typename _BucketVector::const_iterator __src_b(__ht._M_buckets.begin()),
__src_end_b(__ht._M_buckets.end());
typename _BucketVector::iterator __dst_b(_M_buckets.begin()), __dst_end_b(_M_buckets.end());
for (; __src != __src_end; ++__src, ++__dst) {
for (; __src_b != __src_end_b; ++__src_b, ++__dst_b) {
if (*__src_b == __src._M_node) {
*__dst_b = __dst._M_node;
}
else
break;
}
}
fill(__dst_b, __dst_end_b, __STATIC_CAST(_BucketType*, 0));
_M_num_elements = __ht._M_num_elements;
_M_max_load_factor = __ht._M_max_load_factor;
}
#undef __iterator__
#undef const_iterator
#undef __size_type__
#undef __reference__
#undef size_type
#undef value_type
#undef key_type
#undef __stl_num_primes
#if defined (_STLP_DEBUG)
# undef hashtable
_STLP_MOVE_TO_STD_NAMESPACE
#endif
_STLP_END_NAMESPACE
#endif /* _STLP_HASHTABLE_C */
// Local Variables:
// mode:C++
// End: