dlib C++ Library - hash_table_kernel_abstract.h

// Copyright (C) 2003 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#undef DLIB_HASH_TABLE_KERNEl_ABSTRACT_
#ifdef DLIB_HASH_TABLE_KERNEl_ABSTRACT_
#include "../interfaces/map_pair.h"
#include "../general_hash/general_hash.h"
#include "../interfaces/enumerable.h"
#include "../interfaces/remover.h"
#include "../serialize.h"
#include "../algs.h"
#include <functional>
namespace dlib 
{
 template <
 typename domain,
 typename range,
 typename mem_manager = default_memory_manager,
 typename compare = std::less<domain>
 >
 class hash_table : public enumerable<map_pair<domain,range> >,
 public pair_remover<domain,range>
 {
 /*!
 REQUIREMENTS ON domain
 domain must be comparable by compare where compare is a functor compatible with std::less and
 domain must be hashable by general_hash 
 (general_hash is defined in dlib/general_hash) and 
 domain must be swappable by a global swap() and
 domain must have a default constructor
 REQUIREMENTS ON range
 range must be swappable by a global swap() and
 range must have a default constructor
 REQUIREMENTS ON mem_manager
 must be an implementation of memory_manager/memory_manager_kernel_abstract.h or
 must be an implementation of memory_manager_global/memory_manager_global_kernel_abstract.h or
 must be an implementation of memory_manager_stateless/memory_manager_stateless_kernel_abstract.h 
 mem_manager::type can be set to anything.
 POINTERS AND REFERENCES TO INTERNAL DATA
 swap(), count(), and operator[] functions do 
 not invalidate pointers or references to internal data.
 All other functions have no such guarantee.
 INITIAL VALUE
 size() == 0
 ENUMERATION ORDER
 No order is specified. Only that each element will be visited once
 and only once.
 
 WHAT THIS OBJECT REPRESENTS
 hash_table contains items of type T
 This object represents a data dictionary that is built on top of some 
 kind of hash table. The number of buckets in the hash table is 
 defined by the constructor argument and is some power of 2.
 Also note that unless specified otherwise, no member functions
 of this object throw exceptions.
 
 NOTE:
 definition of equivalent:
 a is equivalent to b if
 a < b == false and
 b < a == false
 !*/
 public:
 typedef domain domain_type;
 typedef range range_type;
 typedef compare compare_type;
 typedef mem_manager mem_manager_type;
 explicit hash_table(
 unsigned long expnum
 );
 /*!
 requires
 - expnum < 32
 ensures 
 - #*this is properly initialized
 - #*this will use 2^expnum as a suggestion for the initial number
 of buckets.
 throws
 - std::bad_alloc or any exception thrown by domain's or range's 
 constructor.
 !*/
 virtual ~hash_table(
 ); 
 /*!
 ensures
 - all memory associated with *this has been released
 !*/
 void clear(
 );
 /*!
 ensures
 - #*this has its initial value
 throws
 - std::bad_alloc or any exception thrown by domain's or range's 
 constructor.
 if this exception is thrown then *this is unusable 
 until clear() is called and succeeds
 !*/
 unsigned long count (
 const domain& d
 ) const;
 /*!
 ensures
 - returns the number of elements in the domain of *this that are 
 equivalent to d
 !*/ 
 void add (
 domain& d,
 range& r
 );
 /*!
 requires
 - &d != &r (i.e. d and r cannot be the same variable)
 ensures 
 - adds a mapping between d and r to *this
 - if (count(d) == 0) then
 - #*(*this)[d] == r
 - else
 - #(*this)[d] != 0
 - #d and #r have initial values for their types
 - #count(d) == count(d) + 1
 - #at_start() == true
 - #size() == size() + 1
 throws 
 - std::bad_alloc or any exception thrown by domain's or range's 
 constructor.
 if add() throws then it has no effect
 !*/
 void remove (
 const domain& d,
 domain& d_copy,
 range& r
 );
 /*!
 requires
 - (*this)[d] != 0 
 - &d != &r (i.e. d and r cannot be the same variable) 
 - &d != &d_copy (i.e. d and d_copy cannot be the same variable) 
 - &r != &d_copy (i.e. r and d_copy cannot be the same variable) 
 ensures
 - some element in the domain of *this that is equivalent to d has
 been removed and swapped into #d_copy. Additionally, its 
 associated range element has been removed and swapped into #r.
 - #count(d) = count(d) - 1
 - #size() == size() - 1
 - #at_start() == true 
 !*/
 void destroy (
 const domain& d
 );
 /*!
 requires
 - (*this)[d] != 0 
 ensures
 - an element in the domain of *this equivalent to d has been removed. 
 The element in the range of *this associated with d has also been 
 removed.
 - #count(d) == count(d) - 1
 - #size() == size() - 1
 - #at_start() == true 
 !*/
 const range* operator[] (
 const domain& d
 ) const;
 /*!
 ensures
 - if (there is an element in the domain equivalent to d) then
 - returns a pointer to an element in the range of *this that
 is associated with an element in the domain of *this 
 equivalent to d.
 - else
 - returns 0
 !*/
 range* operator[] (
 const domain& d
 );
 /*!
 ensures
 - if (there is an element in the domain equivalent to d) then
 - returns a pointer to an element in the range of *this that
 is associated with an element in the domain of *this 
 equivalent to d.
 - else
 - returns 0
 !*/
 void swap (
 hash_table& item
 );
 /*!
 ensures
 - swaps *this and item
 !*/ 
 private:
 // restricted functions
 hash_table(hash_table&); 
 hash_table& operator=(hash_table&);
 };
 template <
 typename domain,
 typename range,
 typename mem_manager
 >
 inline void swap (
 hash_table<domain,range,mem_manager>& a, 
 hash_table<domain,range,mem_manager>& b 
 ) { a.swap(b); }
 /*!
 provides a global swap function
 !*/
 template <
 typename domain,
 typename range,
 typename mem_manager
 >
 void deserialize (
 hash_table<domain,range,mem_manager>& item, 
 std::istream& in
 ); 
 /*!
 provides deserialization support 
 !*/
}
#endif // DLIB_HASH_TABLE_KERNEl_ABSTRACT_