hashtable.h

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/*
 * Vega Strike
 * Copyright (C) 2001-2002 Alan Shieh
 *
 * http://vegastrike.sourceforge.net/
 *
 * This program 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
 * of the License, or (at your option) any later version.
 *
 * This program 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 program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#ifndef _HASHTABLE_H_
#define _HASHTABLE_H_
#include "config.h"
#include "gnuhash.h"
#include <math.h>
#include <string>
#include <vector>
#include <algorithm>
#include <utility>
#define HASH_INTSIZE (sizeof (int)*8)
#define HASH_SALT_0 0x7EF92C3B
#define HASH_SALT_1 0x9B
class Unit;
//const int hashsize = 1001;
//Hashtable doesn't grow
template < class KEY, class VALUE, int SIZ >
class Hashtable : public vsUMap< KEY, VALUE* >
{
    typedef std::pair< KEY, VALUE* >HashElement;
    typedef vsUMap< KEY, VALUE* >   supertype;
public:
    static int hash( const int key )
    {
        unsigned int k = key;
        k %= SIZ;
        return k;
    }
    static int hash( const char *key )
    {
        unsigned int k = 0;
        for (const char *start = key; *start != '\0'; ++start) {
            k ^= (*start&HASH_SALT_1);
            k ^= HASH_SALT_0;
            k  = ( ( (k>>4)&0xF )|( k<<(HASH_INTSIZE-4) ) );
            k ^= *start;
        }
        k %= SIZ;
        return k;
    }
    static int hash( const std::string &key )
    {
        unsigned int k = 0;
        for (typename std::string::const_iterator start = key.begin(); start != key.end(); ++start) {
            k ^= (*start&HASH_SALT_1);
            k ^= HASH_SALT_0;
            k  = ( ( (k>>4)&0xF )|( k<<(HASH_INTSIZE-4) ) );
            k ^= *start;
        }
        k %= SIZ;
        return k;
    }
    std::vector< VALUE* >GetAll() const
    {
        std::vector< VALUE* >retval( this->size() );
        typename supertype::const_iterator iter = this->begin();
        typename supertype::const_iterator end  = this->end();
        size_t i = 0;
        for (; iter != end; ++iter, ++i)
            retval[i] = iter->second;
        return retval;
    }

    VALUE * Get( const KEY &key ) const
    {
        typename supertype::const_iterator iter = this->find( key );
        typename supertype::const_iterator end  = this->end();
        if (iter != end) return iter->second;
        return NULL;
    }

    void Put( const KEY &key, VALUE *value )
    {
        (*this)[key] = value;
    }

    void Delete( const KEY &key )
    {
        typename supertype::iterator iter = this->find( key );
        if ( iter == this->end() )
//fprintf(stderr,"failed to remove item in hash_map\n");
            return;
        this->erase( iter );
    }
};

#endif