--- /dev/null
+#ifndef STLPLUS_HASH\r
+#define STLPLUS_HASH\r
+////////////////////////////////////////////////////////////////////////////////\r
+\r
+// Author: Andy Rushton\r
+// Copyright: (c) Southampton University 1999-2004\r
+// (c) Andy Rushton 2004-2009\r
+// License: BSD License, see ../docs/license.html\r
+\r
+// A chained hash table using STL semantics\r
+\r
+////////////////////////////////////////////////////////////////////////////////\r
+#include "containers_fixes.hpp"\r
+#include "exceptions.hpp"\r
+#include "safe_iterator.hpp"\r
+#include <map>\r
+\r
+namespace stlplus\r
+{\r
+\r
+ ////////////////////////////////////////////////////////////////////////////////\r
+ // internals\r
+\r
+ template<typename K, typename T, class H, class E> class hash;\r
+ template<typename K, typename T, class H, class E> class hash_element;\r
+\r
+ ////////////////////////////////////////////////////////////////////////////////\r
+ // iterator class\r
+\r
+ template<typename K, typename T, class H, class E, typename V>\r
+ class hash_iterator : public safe_iterator<hash<K,T,H,E>,hash_element<K,T,H,E> >\r
+ {\r
+ public:\r
+ friend class hash<K,T,H,E>;\r
+\r
+ // local type definitions\r
+ // an iterator points to a value whilst a const_iterator points to a const value\r
+ typedef V value_type;\r
+ typedef hash_iterator<K,T,H,E,std::pair<const K,T> > iterator;\r
+ typedef hash_iterator<K,T,H,E,const std::pair<const K,T> > const_iterator;\r
+ typedef hash_iterator<K,T,H,E,V> this_iterator;\r
+ typedef V& reference;\r
+ typedef V* pointer;\r
+\r
+ // constructor to create a null iterator - you must assign a valid value to this iterator before using it\r
+ // any attempt to dereference or use a null iterator is an error\r
+ // the only valid thing you can do is assign an iterator to it\r
+ hash_iterator(void);\r
+ ~hash_iterator(void);\r
+\r
+ // Type conversion methods allow const_iterator and iterator to be converted\r
+ // convert an iterator/const_iterator to a const_iterator\r
+ const_iterator constify(void) const;\r
+ // convert an iterator/const_iterator to an iterator\r
+ iterator deconstify(void) const;\r
+\r
+ // increment operators used to step through the set of all values in a hash\r
+ // it is only legal to increment a valid iterator\r
+ // there's no decrement - I've only implemented this as a unidirectional iterator\r
+ // pre-increment\r
+ this_iterator& operator ++ (void)\r
+ throw(null_dereference,end_dereference);\r
+ // post-increment\r
+ this_iterator operator ++ (int)\r
+ throw(null_dereference,end_dereference);\r
+\r
+ // test useful for testing whether iteration has completed\r
+ bool operator == (const this_iterator& r) const;\r
+ bool operator != (const this_iterator& r) const;\r
+ bool operator < (const this_iterator& r) const;\r
+\r
+ // access the value - a const_iterator gives you a const value, an iterator a non-const value\r
+ // it is illegal to dereference an invalid (i.e. null or end) iterator\r
+ reference operator*(void) const\r
+ throw(null_dereference,end_dereference);\r
+ pointer operator->(void) const\r
+ throw(null_dereference,end_dereference);\r
+\r
+ private:\r
+ friend class hash_element<K,T,H,E>;\r
+\r
+ // constructor used by hash to create a non-null iterator\r
+ // you cannot create a valid iterator except by calling a hash method that returns one\r
+ explicit hash_iterator(hash_element<K,T,H,E>* element);\r
+ // constructor used to create an end iterator\r
+ explicit hash_iterator(const hash<K,T,H,E>* owner);\r
+ // used to create an alias of an iterator\r
+ explicit hash_iterator(const safe_iterator<hash<K,T,H,E>, hash_element<K,T,H,E> >& iterator);\r
+ };\r
+\r
+ ////////////////////////////////////////////////////////////////////////////////\r
+ // Hash class\r
+ // K = key type\r
+ // T = value type\r
+ // H = hash function object with the profile 'unsigned H(const K&)'\r
+ // E = equal function object with profile 'bool E(const K&, const K&)' defaults to equal_to which in turn calls '=='\r
+\r
+ template<typename K, typename T, class H, class E = std::equal_to<K> >\r
+ class hash\r
+ {\r
+ public:\r
+ typedef unsigned size_type;\r
+ typedef K key_type;\r
+ typedef T data_type;\r
+ typedef T mapped_type;\r
+ typedef std::pair<const K, T> value_type;\r
+ typedef hash_iterator<K,T,H,E,value_type> iterator;\r
+ typedef hash_iterator<K,T,H,E,const value_type> const_iterator;\r
+\r
+ // construct a hash table with specified number of bins\r
+ // the default 0 bins means leave it to the table to decide\r
+ // specifying 0 bins also enables auto-rehashing, otherwise auto-rehashing defaults off\r
+ hash(unsigned bins = 0);\r
+ ~hash(void);\r
+\r
+ // copy and equality copy the data elements but not the size of the copied table\r
+ hash(const hash&);\r
+ hash& operator = (const hash&);\r
+\r
+ // test for an empty table and for the size of a table\r
+ // efficient because the size is stored separately from the table contents\r
+ bool empty(void) const;\r
+ unsigned size(void) const;\r
+\r
+ // test for equality - two hashes are equal if they contain equal values\r
+ bool operator == (const hash&) const;\r
+ bool operator != (const hash&) const;\r
+\r
+ // switch auto-rehash on\r
+ void auto_rehash(void);\r
+ // switch auto-rehash off\r
+ void manual_rehash(void);\r
+ // force a rehash now\r
+ // default of 0 means implement built-in size calculation for rehashing (recommended - it doubles the number of bins)\r
+ void rehash(unsigned bins = 0);\r
+ // test the loading ratio, which is the size divided by the number of bins\r
+ // use this if you are doing your own rehashing\r
+ // the recommendation is to double the bins when the loading exceeds 0.5 which is what auto-rehashing does\r
+ float loading(void) const;\r
+\r
+ // test for the presence of a key\r
+ bool present(const K& key) const;\r
+ // provide map equivalent key count function (0 or 1, as not a multimap)\r
+ size_type count(const K& key) const;\r
+\r
+ // insert a new key/data pair - replaces any previous value for this key\r
+ iterator insert(const K& key, const T& data);\r
+ // insert a copy of the pair into the table (std::map compatible)\r
+ std::pair<iterator, bool> insert(const value_type& value);\r
+ // insert a new key and return the iterator so that the data can be filled in\r
+ iterator insert(const K& key);\r
+\r
+ // remove a key/data pair from the hash table\r
+ bool erase(const K& key);\r
+ // remove all elements from the hash table\r
+ void erase(void);\r
+ // provide the std::map equivalent clear function\r
+ void clear(void);\r
+\r
+ // find a key and return an iterator to it\r
+ // The iterator is like a pointer to a pair<const K,T>\r
+ // end() is returned if the find fails\r
+ const_iterator find(const K& key) const;\r
+ iterator find(const K& key);\r
+\r
+ // returns the data corresponding to the key\r
+ // const version is used for const hashes and cannot change the hash, so failure causes an exception\r
+ // non-const version is for non-const hashes and is like map - it creates a new key/data pair if find fails\r
+ const T& operator[] (const K& key) const throw(std::out_of_range);\r
+ T& operator[] (const K& key);\r
+\r
+ // iterators allow the hash table to be traversed\r
+ // iterators remain valid unless an item is removed or unless a rehash happens\r
+ const_iterator begin(void) const;\r
+ iterator begin(void);\r
+ const_iterator end(void) const;\r
+ iterator end(void);\r
+\r
+ // internals\r
+ private:\r
+ friend class hash_element<K,T,H,E>;\r
+ friend class hash_iterator<K,T,H,E,std::pair<const K,T> >;\r
+ friend class hash_iterator<K,T,H,E,const std::pair<const K,T> >;\r
+\r
+ unsigned m_rehash;\r
+ unsigned m_bins;\r
+ unsigned m_size;\r
+ hash_element<K,T,H,E>** m_values;\r
+ };\r
+\r
+ ////////////////////////////////////////////////////////////////////////////////\r
+\r
+} // end namespace stlplus\r
+\r
+#include "hash.tpp"\r
+#endif\r