hashtable.h

mpeg4 video codec mpeg4 video codec

// Hashtable implementation used by containers -*- C++ -*-

// Copyright (C) 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.

// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.

/*
 * 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.
 *
 */

/** @file ext/hashtable.h
 *  This file is a GNU extension to the Standard C++ Library (possibly
 *  containing extensions from the HP/SGI STL subset).
 */

#ifndef _HASHTABLE_H
#define _HASHTABLE_H 1

// Hashtable class, used to implement the hashed associative containers
// hash_set, hash_map, hash_multiset, and hash_multimap.

#include "vector"
#include "iterator"
#include "algorithm"
#include "functional"
#include "hash_fun.h"

#pragma warning(push)
#pragma warning(disable:4127)

# define try      if (true)
# define catch(X) if (false)
# define __throw_exception_again

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 = std::allocator<_Val> >
    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 { _S_num_primes = 28 };

  static const unsigned long __stl_prime_list[_S_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)_S_num_primes;
    const unsigned long* pos = std::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::template rebind<value_type>::other allocator_type;
      allocator_type
      get_allocator() const
      { return _M_node_allocator; }

    private:
      typedef typename _Alloc::template rebind<_Node>::other _Node_Alloc;
      typedef typename _Alloc::template rebind<_Node*>::other _Nodeptr_Alloc;
      typedef vector<_Node*, _Nodeptr_Alloc> _Vector_type;

      _Node_Alloc _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_type          _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);