/*
THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
SOFTWARE CORPORATION ("PARALLAX").  PARALLAX, IN DISTRIBUTING THE CODE TO
END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
IN USING, DISPLAYING,  AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
FREE PURPOSES.  IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES.  THE END-USER UNDERSTANDS
AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.  
COPYRIGHT 1993-1999 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
*/

#pragma off (unreferenced)
static char rcsid[] = "$Id: hash.c 2.2 1995/08/17 11:32:54 matt Exp $";
#pragma on (unreferenced)

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "error.h"
#include "hash.h"
	
int hashtable_init( hashtable *ht, int size )	{
	int i;

	ht->size=0;

	for (i=1; i<13; i++ )	{
		if ( (1<<i) >= size )	{
			ht->bitsize = i;
			ht->size = 1<<i;
			break;
		}
	}
	size = ht->size;
	ht->and_mask = ht->size - 1;
	if (ht->size==0)
		Error( "Hashtable has size of 0" );

	ht->key = (char **)malloc( size * sizeof(char *) );
	if (ht->key==NULL)
		Error( "Not enough memory to create a hash table of size %d", size );

	for (i=0; i<size; i++ )
		ht->key[i] = NULL;

	// Use calloc cause we want zero'd array.
	ht->value = malloc( size*sizeof(int) );
	if (ht->value==NULL)	{
		free(ht->key);
		Error( "Not enough memory to create a hash table of size %d\n", size );
	}

	ht->nitems = 0;

	return 0;
}

void hashtable_free( hashtable *ht )	{
	if (ht->key != NULL )
		free( ht->key );
	if (ht->value != NULL )
		free( ht->value );
	ht->size = 0;
}

int hashtable_getkey( char *key )	{
	int k = 0, i=0;

	while( *key )	{
		k^=((int)(*key++))<<i;
		i++;
	}
	return k;
}

int hashtable_search( hashtable *ht, char *key )	{
	int i,j,k;

	strlwr( key );

	k = hashtable_getkey( key );
	i = 0;
	
	while(i < ht->size )	{
		j = (k+(i++)) & ht->and_mask;
		if ( ht->key[j] == NULL )
			return -1;
		if (!stricmp(ht->key[j], key ))
			return ht->value[j];
	}
	return -1;
}

void hashtable_insert( hashtable *ht, char *key, int value )	{
	int i,j,k;

	strlwr( key );
	k = hashtable_getkey( key );
	i = 0;

	while(i < ht->size)	{
		j = (k+(i++)) & ht->and_mask;
		if ( ht->key[j] == NULL )	{
			ht->nitems++;
			ht->key[j] = key;
			ht->value[j] = value;
			return;
		} else if (!stricmp( key, ht->key[j] ))	{
			return;
		}
	}
	Error( "Out of hash slots\n" );
}