《STL源碼剖析》---stl_hash_map.h閱讀筆記

標籤：stl   源碼   c++   hash_map   hash_multimap   

SGI STL中的map底層以紅/黑樹狀結構實現，hash_map以hash table實現。

hash_map不允許插入重新鍵值，hash_multimap允許插入重複鍵值。這兩者的關係就像map和multimap的關係。底層的hash table提供的大部分的操作，hash_map(hash_multimap)大部分都是直接調用hash table的函數。

G++ 2.91.57，cygnus\cygwin-b20\include\g++\stl_hash_map.h 完整列表/* * Copyright (c) 1996 * 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_HASH_MAP_H#define __SGI_STL_INTERNAL_HASH_MAP_H__STL_BEGIN_NAMESPACE#if defined(__sgi) && !defined(__GNUC__) && (_MIPS_SIM != _MIPS_SIM_ABI32)#pragma set woff 1174#endif#ifndef __STL_LIMITED_DEFAULT_TEMPLATES// hash<> 是個 function object，定義於 <stl_hash_fun.h> 中// 例：hash<int>::operator()(int x) const { return x; }template <class Key, class T, class HashFcn = hash<Key>,          class EqualKey = equal_to<Key>,          class Alloc = alloc>#elsetemplate <class Key, class T, class HashFcn, class EqualKey,           class Alloc = alloc>#endifclass hash_map{private:  // 以下使用的 select1st<> 定義於 <stl_function.h> 中。  typedef hashtable<pair<const Key, T>, Key, HashFcn,                    select1st<pair<const Key, T> >, EqualKey, Alloc> ht;  ht rep;// 底層以 hash table 完成public:  typedef typename ht::key_type key_type;  typedef T data_type;  typedef T mapped_type;  typedef typename ht::value_type value_type;  typedef typename ht::hasher hasher;  typedef typename ht::key_equal key_equal;  typedef typename ht::size_type size_type;  typedef typename ht::difference_type difference_type;  typedef typename ht::pointer pointer;  typedef typename ht::const_pointer const_pointer;  typedef typename ht::reference reference;  typedef typename ht::const_reference const_reference;  typedef typename ht::iterator iterator;  typedef typename ht::const_iterator const_iterator;  hasher hash_funct() const { return rep.hash_funct(); }  key_equal key_eq() const { return rep.key_eq(); }public:  //預設使用100的 vector buckets,將有 hash table調整為大於100的質數  hash_map() : rep(100, hasher(), key_equal()) {}  explicit hash_map(size_type n) : rep(n, hasher(), key_equal()) {}  hash_map(size_type n, const hasher& hf) : rep(n, hf, key_equal()) {}  hash_map(size_type n, const hasher& hf, const key_equal& eql)    : rep(n, hf, eql) {}#ifdef __STL_MEMBER_TEMPLATES  // 以下，插入全部使用 insert_unique()，不允許索引值重複。  template <class InputIterator>  hash_map(InputIterator f, InputIterator l)    : rep(100, hasher(), key_equal()) { rep.insert_unique(f, l); }  template <class InputIterator>  hash_map(InputIterator f, InputIterator l, size_type n)    : rep(n, hasher(), key_equal()) { rep.insert_unique(f, l); }  template <class InputIterator>  hash_map(InputIterator f, InputIterator l, size_type n,           const hasher& hf)    : rep(n, hf, key_equal()) { rep.insert_unique(f, l); }  template <class InputIterator>  hash_map(InputIterator f, InputIterator l, size_type n,           const hasher& hf, const key_equal& eql)    : rep(n, hf, eql) { rep.insert_unique(f, l); }#else  hash_map(const value_type* f, const value_type* l)    : rep(100, hasher(), key_equal()) { rep.insert_unique(f, l); }  hash_map(const value_type* f, const value_type* l, size_type n)    : rep(n, hasher(), key_equal()) { rep.insert_unique(f, l); }  hash_map(const value_type* f, const value_type* l, size_type n,           const hasher& hf)    : rep(n, hf, key_equal()) { rep.insert_unique(f, l); }  hash_map(const value_type* f, const value_type* l, size_type n,           const hasher& hf, const key_equal& eql)    : rep(n, hf, eql) { rep.insert_unique(f, l); }  hash_map(const_iterator f, const_iterator l)    : rep(100, hasher(), key_equal()) { rep.insert_unique(f, l); }  hash_map(const_iterator f, const_iterator l, size_type n)    : rep(n, hasher(), key_equal()) { rep.insert_unique(f, l); }  hash_map(const_iterator f, const_iterator l, size_type n,           const hasher& hf)    : rep(n, hf, key_equal()) { rep.insert_unique(f, l); }  hash_map(const_iterator f, const_iterator l, size_type n,           const hasher& hf, const key_equal& eql)    : rep(n, hf, eql) { rep.insert_unique(f, l); }#endif /*__STL_MEMBER_TEMPLATES */public:  // 所有操作幾乎都有 hash table 對應的版本，直接調用即可。  size_type size() const { return rep.size(); }  size_type max_size() const { return rep.max_size(); }  bool empty() const { return rep.empty(); }  void swap(hash_map& hs) { rep.swap(hs.rep); }  friend bool  operator== __STL_NULL_TMPL_ARGS (const hash_map&, const hash_map&);  iterator begin() { return rep.begin(); }  iterator end() { return rep.end(); }  const_iterator begin() const { return rep.begin(); }  const_iterator end() const { return rep.end(); }public:  pair<iterator, bool> insert(const value_type& obj)    { return rep.insert_unique(obj); }#ifdef __STL_MEMBER_TEMPLATES  template <class InputIterator>  void insert(InputIterator f, InputIterator l) { rep.insert_unique(f,l); }#else  void insert(const value_type* f, const value_type* l) {    rep.insert_unique(f,l);  }  void insert(const_iterator f, const_iterator l) { rep.insert_unique(f, l); }#endif /*__STL_MEMBER_TEMPLATES */  pair<iterator, bool> insert_noresize(const value_type& obj)    { return rep.insert_unique_noresize(obj); }      iterator find(const key_type& key) { return rep.find(key); }  const_iterator find(const key_type& key) const { return rep.find(key); }  T& operator[](const key_type& key) {    return rep.find_or_insert(value_type(key, T())).second;  }  size_type count(const key_type& key) const { return rep.count(key); }    pair<iterator, iterator> equal_range(const key_type& key)    { return rep.equal_range(key); }  pair<const_iterator, const_iterator> equal_range(const key_type& key) const    { return rep.equal_range(key); }  size_type erase(const key_type& key) {return rep.erase(key); }  void erase(iterator it) { rep.erase(it); }  void erase(iterator f, iterator l) { rep.erase(f, l); }  void clear() { rep.clear(); }public:  void resize(size_type hint) { rep.resize(hint); }  size_type bucket_count() const { return rep.bucket_count(); }  size_type max_bucket_count() const { return rep.max_bucket_count(); }  size_type elems_in_bucket(size_type n) const    { return rep.elems_in_bucket(n); }};template <class Key, class T, class HashFcn, class EqualKey, class Alloc>inline bool operator==(const hash_map<Key, T, HashFcn, EqualKey, Alloc>& hm1,                       const hash_map<Key, T, HashFcn, EqualKey, Alloc>& hm2){  return hm1.rep == hm2.rep;}#ifdef __STL_FUNCTION_TMPL_PARTIAL_ORDERtemplate <class Key, class T, class HashFcn, class EqualKey, class Alloc>inline void swap(hash_map<Key, T, HashFcn, EqualKey, Alloc>& hm1,                 hash_map<Key, T, HashFcn, EqualKey, Alloc>& hm2){  hm1.swap(hm2);}#endif /* __STL_FUNCTION_TMPL_PARTIAL_ORDER */#ifndef __STL_LIMITED_DEFAULT_TEMPLATEStemplate <class Key, class T, class HashFcn = hash<Key>,          class EqualKey = equal_to<Key>,          class Alloc = alloc>#elsetemplate <class Key, class T, class HashFcn, class EqualKey,          class Alloc = alloc>#endif//和hash_map幾乎完全一樣，只是允許插入重複索引值class hash_multimap{private:  typedef hashtable<pair<const Key, T>, Key, HashFcn,                    select1st<pair<const Key, T> >, EqualKey, Alloc> ht;  ht rep;public:  typedef typename ht::key_type key_type;  typedef T data_type;  typedef T mapped_type;  typedef typename ht::value_type value_type;  typedef typename ht::hasher hasher;  typedef typename ht::key_equal key_equal;  typedef typename ht::size_type size_type;  typedef typename ht::difference_type difference_type;  typedef typename ht::pointer pointer;  typedef typename ht::const_pointer const_pointer;  typedef typename ht::reference reference;  typedef typename ht::const_reference const_reference;  typedef typename ht::iterator iterator;  typedef typename ht::const_iterator const_iterator;  hasher hash_funct() const { return rep.hash_funct(); }  key_equal key_eq() const { return rep.key_eq(); }public:  hash_multimap() : rep(100, hasher(), key_equal()) {}  explicit hash_multimap(size_type n) : rep(n, hasher(), key_equal()) {}  hash_multimap(size_type n, const hasher& hf) : rep(n, hf, key_equal()) {}  hash_multimap(size_type n, const hasher& hf, const key_equal& eql)    : rep(n, hf, eql) {}#ifdef __STL_MEMBER_TEMPLATES// 以下，插入全部使用 insert_equal()，允許索引值重複。  template <class InputIterator>  hash_multimap(InputIterator f, InputIterator l)    : rep(100, hasher(), key_equal()) { rep.insert_equal(f, l); }  template <class InputIterator>  hash_multimap(InputIterator f, InputIterator l, size_type n)    : rep(n, hasher(), key_equal()) { rep.insert_equal(f, l); }  template <class InputIterator>  hash_multimap(InputIterator f, InputIterator l, size_type n,                const hasher& hf)    : rep(n, hf, key_equal()) { rep.insert_equal(f, l); }  template <class InputIterator>  hash_multimap(InputIterator f, InputIterator l, size_type n,                const hasher& hf, const key_equal& eql)    : rep(n, hf, eql) { rep.insert_equal(f, l); }#else  hash_multimap(const value_type* f, const value_type* l)    : rep(100, hasher(), key_equal()) { rep.insert_equal(f, l); }  hash_multimap(const value_type* f, const value_type* l, size_type n)    : rep(n, hasher(), key_equal()) { rep.insert_equal(f, l); }  hash_multimap(const value_type* f, const value_type* l, size_type n,                const hasher& hf)    : rep(n, hf, key_equal()) { rep.insert_equal(f, l); }  hash_multimap(const value_type* f, const value_type* l, size_type n,                const hasher& hf, const key_equal& eql)    : rep(n, hf, eql) { rep.insert_equal(f, l); }  hash_multimap(const_iterator f, const_iterator l)    : rep(100, hasher(), key_equal()) { rep.insert_equal(f, l); }  hash_multimap(const_iterator f, const_iterator l, size_type n)    : rep(n, hasher(), key_equal()) { rep.insert_equal(f, l); }  hash_multimap(const_iterator f, const_iterator l, size_type n,                const hasher& hf)    : rep(n, hf, key_equal()) { rep.insert_equal(f, l); }  hash_multimap(const_iterator f, const_iterator l, size_type n,                const hasher& hf, const key_equal& eql)    : rep(n, hf, eql) { rep.insert_equal(f, l); }#endif /*__STL_MEMBER_TEMPLATES */public:  size_type size() const { return rep.size(); }  size_type max_size() const { return rep.max_size(); }  bool empty() const { return rep.empty(); }  void swap(hash_multimap& hs) { rep.swap(hs.rep); }  friend bool  operator== __STL_NULL_TMPL_ARGS (const hash_multimap&, const hash_multimap&);  iterator begin() { return rep.begin(); }  iterator end() { return rep.end(); }  const_iterator begin() const { return rep.begin(); }  const_iterator end() const { return rep.end(); }public:  iterator insert(const value_type& obj) { return rep.insert_equal(obj); }#ifdef __STL_MEMBER_TEMPLATES  template <class InputIterator>  void insert(InputIterator f, InputIterator l) { rep.insert_equal(f,l); }#else  void insert(const value_type* f, const value_type* l) {    rep.insert_equal(f,l);  }  void insert(const_iterator f, const_iterator l) { rep.insert_equal(f, l); }#endif /*__STL_MEMBER_TEMPLATES */  iterator insert_noresize(const value_type& obj)    { return rep.insert_equal_noresize(obj); }      iterator find(const key_type& key) { return rep.find(key); }  const_iterator find(const key_type& key) const { return rep.find(key); }  size_type count(const key_type& key) const { return rep.count(key); }    pair<iterator, iterator> equal_range(const key_type& key)    { return rep.equal_range(key); }  pair<const_iterator, const_iterator> equal_range(const key_type& key) const    { return rep.equal_range(key); }  size_type erase(const key_type& key) {return rep.erase(key); }  void erase(iterator it) { rep.erase(it); }  void erase(iterator f, iterator l) { rep.erase(f, l); }  void clear() { rep.clear(); }public:  void resize(size_type hint) { rep.resize(hint); }  size_type bucket_count() const { return rep.bucket_count(); }  size_type max_bucket_count() const { return rep.max_bucket_count(); }  size_type elems_in_bucket(size_type n) const    { return rep.elems_in_bucket(n); }};template <class Key, class T, class HF, class EqKey, class Alloc>inline bool operator==(const hash_multimap<Key, T, HF, EqKey, Alloc>& hm1,                       const hash_multimap<Key, T, HF, EqKey, Alloc>& hm2){  return hm1.rep == hm2.rep;}#ifdef __STL_FUNCTION_TMPL_PARTIAL_ORDERtemplate <class Key, class T, class HashFcn, class EqualKey, class Alloc>inline void swap(hash_multimap<Key, T, HashFcn, EqualKey, Alloc>& hm1,                 hash_multimap<Key, T, HashFcn, EqualKey, Alloc>& hm2){  hm1.swap(hm2);}#endif /* __STL_FUNCTION_TMPL_PARTIAL_ORDER */#if defined(__sgi) && !defined(__GNUC__) && (_MIPS_SIM != _MIPS_SIM_ABI32)#pragma reset woff 1174#endif__STL_END_NAMESPACE#endif /* __SGI_STL_INTERNAL_HASH_MAP_H */// Local Variables:// mode:C++// End: