/*
This file implements a static open-address hashtable which uses
double hashing. 
Copyright (C) 2004 The University of Texas at Austin

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.

Email: usman@cs.njit.edu
Mail: Usman Roshan, Department of Computer Sciences, NJIT-CCS, Computer
Science Department, GITC 4400, University Heights, Newark, NJ 07102
*/

/*! \file hashtable2.h
\brief Contains definition for a hash table structure which
uses pointers as keys and void* for values
*/

#ifndef HASHTABLE2
#define HASHTABLE2

typedef unsigned int PTR_TYPE;

typedef struct hashtable2_struct* hashtable2;

typedef struct hashtable2_node_struct* hashtable2_node;

struct hashtable2_node_struct {
  PTR_TYPE key;
  void* value;
};

struct hashtable2_struct { 
  
  /*size is size of table*/
  long size_;
  
  /*number of collisions before empty slot is found*/
  int probelength_;
  
  /* hash sets this value.  it is used in hash1 and hash2
     to avoid calling hash again (efficiency reasons) */
  unsigned long h_;
  
  /*random values used in hash functions.*/
  unsigned long a1_, a2_, b1_, b2_, P_;
  
  hashtable2_node* table_;
};

/*hash functions*/
unsigned int hash_2(hashtable2 ht, PTR_TYPE key);
/*unsigned int hash_2(hashtable2 ht, unsigned int c, unsigned int a, unsigned int b);*/
unsigned long hash2_1 (hashtable2 ht);
unsigned long hash2_2 (hashtable2 ht);

/*dictionary operations*/
void  insert_hashtable2 (hashtable2 ht, PTR_TYPE key, void* value);
void* lookup_hashtable2 (hashtable2 ht, PTR_TYPE key);
void set_value_null_hashtable2 (hashtable2 ht, PTR_TYPE key);
void list_hashtable2_stats(hashtable2 ht);
int probelength_hashtable2(hashtable2 ht);

/*constructor*/
hashtable2 new_hashtable2(long sz);             

/*destructor*/
void del_hashtable2(hashtable2 ht);

#endif