📄 stl_hashtable.h
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/* * Copyright (c) 1996,1997 * Silicon Graphics Computer Systems, Inc. * * Permission to use, copy, modify, distribute and sell this software * and its documentation for any purpose is hereby granted without fee, * provided that the above copyright notice appear in all copies and * that both that copyright notice and this permission notice appear * in supporting documentation. Silicon Graphics makes no * representations about the suitability of this software for any * purpose. It is provided "as is" without express or implied warranty. * * * Copyright (c) 1994 * Hewlett-Packard Company * * Permission to use, copy, modify, distribute and sell this software * and its documentation for any purpose is hereby granted without fee, * provided that the above copyright notice appear in all copies and * that both that copyright notice and this permission notice appear * in supporting documentation. Hewlett-Packard Company makes no * representations about the suitability of this software for any * purpose. It is provided "as is" without express or implied warranty. * *//* NOTE: This is an internal header file, included by other STL headers. * You should not attempt to use it directly. */#ifndef __SGI_STL_INTERNAL_HASHTABLE_H#define __SGI_STL_INTERNAL_HASHTABLE_H// Hashtable class, used to implement the hashed associative containers// hash_set, hash_map, hash_multiset, and hash_multimap.#include <bits/stl_algobase.h>#include <bits/stl_alloc.h>#include <bits/stl_construct.h>#include <bits/stl_tempbuf.h>#include <bits/stl_algo.h>#include <bits/stl_uninitialized.h>#include <bits/stl_function.h>#include <bits/stl_vector.h>#include <ext/stl_hash_fun.h>namespace std{template <class _Val>struct _Hashtable_node{ _Hashtable_node* _M_next; _Val _M_val;}; template <class _Val, class _Key, class _HashFcn, class _ExtractKey, class _EqualKey, class _Alloc = alloc>class hashtable;template <class _Val, class _Key, class _HashFcn, class _ExtractKey, class _EqualKey, class _Alloc>struct _Hashtable_iterator;template <class _Val, class _Key, class _HashFcn, class _ExtractKey, class _EqualKey, class _Alloc>struct _Hashtable_const_iterator;template <class _Val, class _Key, class _HashFcn, class _ExtractKey, class _EqualKey, class _Alloc>struct _Hashtable_iterator { typedef hashtable<_Val,_Key,_HashFcn,_ExtractKey,_EqualKey,_Alloc> _Hashtable; typedef _Hashtable_iterator<_Val, _Key, _HashFcn, _ExtractKey, _EqualKey, _Alloc> iterator; typedef _Hashtable_const_iterator<_Val, _Key, _HashFcn, _ExtractKey, _EqualKey, _Alloc> const_iterator; typedef _Hashtable_node<_Val> _Node; typedef forward_iterator_tag iterator_category; typedef _Val value_type; typedef ptrdiff_t difference_type; typedef size_t size_type; typedef _Val& reference; typedef _Val* pointer; _Node* _M_cur; _Hashtable* _M_ht; _Hashtable_iterator(_Node* __n, _Hashtable* __tab) : _M_cur(__n), _M_ht(__tab) {} _Hashtable_iterator() {} reference operator*() const { return _M_cur->_M_val; } pointer operator->() const { return &(operator*()); } iterator& operator++(); iterator operator++(int); bool operator==(const iterator& __it) const { return _M_cur == __it._M_cur; } bool operator!=(const iterator& __it) const { return _M_cur != __it._M_cur; }};template <class _Val, class _Key, class _HashFcn, class _ExtractKey, class _EqualKey, class _Alloc>struct _Hashtable_const_iterator { typedef hashtable<_Val,_Key,_HashFcn,_ExtractKey,_EqualKey,_Alloc> _Hashtable; typedef _Hashtable_iterator<_Val,_Key,_HashFcn, _ExtractKey,_EqualKey,_Alloc> iterator; typedef _Hashtable_const_iterator<_Val, _Key, _HashFcn, _ExtractKey, _EqualKey, _Alloc> const_iterator; typedef _Hashtable_node<_Val> _Node; typedef forward_iterator_tag iterator_category; typedef _Val value_type; typedef ptrdiff_t difference_type; typedef size_t size_type; typedef const _Val& reference; typedef const _Val* pointer; const _Node* _M_cur; const _Hashtable* _M_ht; _Hashtable_const_iterator(const _Node* __n, const _Hashtable* __tab) : _M_cur(__n), _M_ht(__tab) {} _Hashtable_const_iterator() {} _Hashtable_const_iterator(const iterator& __it) : _M_cur(__it._M_cur), _M_ht(__it._M_ht) {} reference operator*() const { return _M_cur->_M_val; } pointer operator->() const { return &(operator*()); } const_iterator& operator++(); const_iterator operator++(int); bool operator==(const const_iterator& __it) const { return _M_cur == __it._M_cur; } bool operator!=(const const_iterator& __it) const { return _M_cur != __it._M_cur; }};// Note: assumes long is at least 32 bits.enum { __stl_num_primes = 28 };static const unsigned long __stl_prime_list[__stl_num_primes] ={ 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};inline unsigned long __stl_next_prime(unsigned long __n){ const unsigned long* __first = __stl_prime_list; const unsigned long* __last = __stl_prime_list + (int)__stl_num_primes; const unsigned long* pos = lower_bound(__first, __last, __n); return pos == __last ? *(__last - 1) : *pos;}// Forward declaration of operator==.template <class _Val, class _Key, class _HF, class _Ex, class _Eq, class _All>class hashtable;template <class _Val, class _Key, class _HF, class _Ex, class _Eq, class _All>bool operator==(const hashtable<_Val,_Key,_HF,_Ex,_Eq,_All>& __ht1, const hashtable<_Val,_Key,_HF,_Ex,_Eq,_All>& __ht2);// Hashtables handle allocators a bit differently than other containers// do. If we're using standard-conforming allocators, then a hashtable// unconditionally has a member variable to hold its allocator, even if// it so happens that all instances of the allocator type are identical.// This is because, for hashtables, this extra storage is negligible. // Additionally, a base class wouldn't serve any other purposes; it // wouldn't, for example, simplify the exception-handling code.template <class _Val, class _Key, class _HashFcn, class _ExtractKey, class _EqualKey, class _Alloc>class hashtable {public: typedef _Key key_type; typedef _Val value_type; typedef _HashFcn hasher; typedef _EqualKey key_equal; typedef size_t size_type; typedef ptrdiff_t difference_type; typedef value_type* pointer; typedef const value_type* const_pointer; typedef value_type& reference; typedef const value_type& const_reference; hasher hash_funct() const { return _M_hash; } key_equal key_eq() const { return _M_equals; }private: typedef _Hashtable_node<_Val> _Node;public: typedef typename _Alloc_traits<_Val,_Alloc>::allocator_type allocator_type; allocator_type get_allocator() const { return _M_node_allocator; }private: typename _Alloc_traits<_Node, _Alloc>::allocator_type _M_node_allocator; _Node* _M_get_node() { return _M_node_allocator.allocate(1); } void _M_put_node(_Node* __p) { _M_node_allocator.deallocate(__p, 1); }private: hasher _M_hash; key_equal _M_equals; _ExtractKey _M_get_key; vector<_Node*,_Alloc> _M_buckets; size_type _M_num_elements;public: typedef _Hashtable_iterator<_Val,_Key,_HashFcn,_ExtractKey,_EqualKey,_Alloc> iterator; typedef _Hashtable_const_iterator<_Val,_Key,_HashFcn,_ExtractKey,_EqualKey, _Alloc> const_iterator; friend struct _Hashtable_iterator<_Val,_Key,_HashFcn,_ExtractKey,_EqualKey,_Alloc>; friend struct _Hashtable_const_iterator<_Val,_Key,_HashFcn,_ExtractKey,_EqualKey,_Alloc>;public: hashtable(size_type __n, const _HashFcn& __hf, const _EqualKey& __eql, const _ExtractKey& __ext, const allocator_type& __a = allocator_type()) : _M_node_allocator(__a), _M_hash(__hf), _M_equals(__eql), _M_get_key(__ext), _M_buckets(__a), _M_num_elements(0) { _M_initialize_buckets(__n); } hashtable(size_type __n, const _HashFcn& __hf, const _EqualKey& __eql, const allocator_type& __a = allocator_type()) : _M_node_allocator(__a), _M_hash(__hf), _M_equals(__eql), _M_get_key(_ExtractKey()), _M_buckets(__a), _M_num_elements(0) { _M_initialize_buckets(__n); } hashtable(const hashtable& __ht) : _M_node_allocator(__ht.get_allocator()), _M_hash(__ht._M_hash), _M_equals(__ht._M_equals), _M_get_key(__ht._M_get_key), _M_buckets(__ht.get_allocator()), _M_num_elements(0) { _M_copy_from(__ht); } hashtable& operator= (const hashtable& __ht) { if (&__ht != this) { clear(); _M_hash = __ht._M_hash; _M_equals = __ht._M_equals; _M_get_key = __ht._M_get_key; _M_copy_from(__ht); } return *this; } ~hashtable() { clear(); } size_type size() const { return _M_num_elements; } size_type max_size() const { return size_type(-1); } bool empty() const { return size() == 0; } void swap(hashtable& __ht) { std::swap(_M_hash, __ht._M_hash); std::swap(_M_equals, __ht._M_equals); std::swap(_M_get_key, __ht._M_get_key); _M_buckets.swap(__ht._M_buckets); std::swap(_M_num_elements, __ht._M_num_elements); } iterator begin() { for (size_type __n = 0; __n < _M_buckets.size(); ++__n) if (_M_buckets[__n]) return iterator(_M_buckets[__n], this); return end(); } iterator end() { return iterator(0, this); } const_iterator begin() const { for (size_type __n = 0; __n < _M_buckets.size(); ++__n) if (_M_buckets[__n]) return const_iterator(_M_buckets[__n], this); return end(); } const_iterator end() const { return const_iterator(0, this); } template <class _Vl, class _Ky, class _HF, class _Ex, class _Eq, class _Al> friend bool operator== (const hashtable<_Vl, _Ky, _HF, _Ex, _Eq, _Al>&, const hashtable<_Vl, _Ky, _HF, _Ex, _Eq, _Al>&);public: size_type bucket_count() const { return _M_buckets.size(); } size_type max_bucket_count() const { return __stl_prime_list[(int)__stl_num_primes - 1]; } size_type elems_in_bucket(size_type __bucket) const { size_type __result = 0; for (_Node* __cur = _M_buckets[__bucket]; __cur; __cur = __cur->_M_next) __result += 1; return __result; } pair<iterator, bool> insert_unique(const value_type& __obj) { resize(_M_num_elements + 1); return insert_unique_noresize(__obj); } iterator insert_equal(const value_type& __obj) { resize(_M_num_elements + 1); return insert_equal_noresize(__obj); } pair<iterator, bool> insert_unique_noresize(const value_type& __obj); iterator insert_equal_noresize(const value_type& __obj); template <class _InputIterator> void insert_unique(_InputIterator __f, _InputIterator __l) { insert_unique(__f, __l, __iterator_category(__f)); } template <class _InputIterator> void insert_equal(_InputIterator __f, _InputIterator __l) { insert_equal(__f, __l, __iterator_category(__f)); } template <class _InputIterator> void insert_unique(_InputIterator __f, _InputIterator __l, input_iterator_tag) { for ( ; __f != __l; ++__f) insert_unique(*__f); } template <class _InputIterator> void insert_equal(_InputIterator __f, _InputIterator __l, input_iterator_tag) { for ( ; __f != __l; ++__f) insert_equal(*__f); } template <class _ForwardIterator> void insert_unique(_ForwardIterator __f, _ForwardIterator __l, forward_iterator_tag) { size_type __n = 0; distance(__f, __l, __n); resize(_M_num_elements + __n); for ( ; __n > 0; --__n, ++__f) insert_unique_noresize(*__f); } template <class _ForwardIterator> void insert_equal(_ForwardIterator __f, _ForwardIterator __l, forward_iterator_tag) { size_type __n = 0; distance(__f, __l, __n); resize(_M_num_elements + __n); for ( ; __n > 0; --__n, ++__f) insert_equal_noresize(*__f); } reference find_or_insert(const value_type& __obj); iterator find(const key_type& __key) { size_type __n = _M_bkt_num_key(__key); _Node* __first; for ( __first = _M_buckets[__n]; __first && !_M_equals(_M_get_key(__first->_M_val), __key); __first = __first->_M_next) {} return iterator(__first, this); } const_iterator find(const key_type& __key) const { size_type __n = _M_bkt_num_key(__key); const _Node* __first; for ( __first = _M_buckets[__n]; __first && !_M_equals(_M_get_key(__first->_M_val), __key); __first = __first->_M_next) {} return const_iterator(__first, this); } size_type count(const key_type& __key) const { const size_type __n = _M_bkt_num_key(__key); size_type __result = 0; for (const _Node* __cur = _M_buckets[__n]; __cur; __cur = __cur->_M_next) if (_M_equals(_M_get_key(__cur->_M_val), __key)) ++__result; return __result; } pair<iterator, iterator> equal_range(const key_type& __key); pair<const_iterator, const_iterator> equal_range(const key_type& __key) const; size_type erase(const key_type& __key); void erase(const iterator& __it); void erase(iterator __first, iterator __last); void erase(const const_iterator& __it); void erase(const_iterator __first, const_iterator __last); void resize(size_type __num_elements_hint); void clear();private: size_type _M_next_size(size_type __n) const { return __stl_next_prime(__n); } void _M_initialize_buckets(size_type __n) { const size_type __n_buckets = _M_next_size(__n); _M_buckets.reserve(__n_buckets); _M_buckets.insert(_M_buckets.end(), __n_buckets, (_Node*) 0); _M_num_elements = 0; } size_type _M_bkt_num_key(const key_type& __key) const { return _M_bkt_num_key(__key, _M_buckets.size()); }
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