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Diffstat (limited to 'stlport/stlport/stl/_hashtable.c')
| -rw-r--r-- | stlport/stlport/stl/_hashtable.c | 553 |
1 files changed, 553 insertions, 0 deletions
diff --git a/stlport/stlport/stl/_hashtable.c b/stlport/stlport/stl/_hashtable.c new file mode 100644 index 0000000..ddc21bb --- /dev/null +++ b/stlport/stlport/stl/_hashtable.c @@ -0,0 +1,553 @@ +/* + * 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: |