/* Copyright (C) 2002 Christopher Clark <firstname.lastname@cl.cam.ac.uk> */
/* Modifications made by Jack Lange <jarusl@cs.northwestern.edu> */

#ifndef __VMM_HASHTABLE_H__
#define __VMM_HASHTABLE_H__

#ifdef __V3VEE__

struct hashtable;

/* Example of use:
 *
 *      struct hashtable  *h;
 *      struct some_key   *k;
 *      struct some_value *v;
 *
 *      static uint_t         hash_from_key_fn( void *k );
 *      static int                  keys_equal_fn ( void *key1, void *key2 );
 *
 *      h = create_hashtable(16, hash_from_key_fn, keys_equal_fn);
 *      k = (struct some_key *)     malloc(sizeof(struct some_key));
 *      v = (struct some_value *)   malloc(sizeof(struct some_value));
 *
 *      (initialise k and v to suitable values)
 * 
 *      if (! hashtable_insert(h,k,v) )
 *      {     exit(-1);               }
 *
 *      if (NULL == (found = hashtable_search(h,k) ))
 *      {    printf("not found!");                  }
 *
 *      if (NULL == (found = hashtable_remove(h,k) ))
 *      {    printf("Not found\n");                 }
 *
 */

/* Macros may be used to define type-safe(r) hashtable access functions, with
 * methods specialized to take known key and value types as parameters.
 * 
 * Example:
 *
 * Insert this at the start of your file:
 *
 * DEFINE_HASHTABLE_INSERT(insert_some, struct some_key, struct some_value);
 * DEFINE_HASHTABLE_SEARCH(search_some, struct some_key, struct some_value);
 * DEFINE_HASHTABLE_REMOVE(remove_some, struct some_key, struct some_value);
 *
 * This defines the functions 'insert_some', 'search_some' and 'remove_some'.
 * These operate just like hashtable_insert etc., with the same parameters,
 * but their function signatures have 'struct some_key *' rather than
 * 'void *', and hence can generate compile time errors if your program is
 * supplying incorrect data as a key (and similarly for value).
 *
 * Note that the hash and key equality functions passed to create_hashtable
 * still take 'void *' parameters instead of 'some key *'. This shouldn't be
 * a difficult issue as they're only defined and passed once, and the other
 * functions will ensure that only valid keys are supplied to them.
 *
 * The cost for this checking is increased code size and runtime overhead
 * - if performance is important, it may be worth switching back to the
 * unsafe methods once your program has been debugged with the safe methods.
 * This just requires switching to some simple alternative defines - eg:
 * #define insert_some hashtable_insert
 *
 */

ulong_t hash_long(ulong_t val, uint_t bits);
ulong_t hash_buffer(uchar_t * msg, uint_t length);




#define DEFINE_HASHTABLE_INSERT(fnname, keytype, valuetype)		\
  int fnname (struct hashtable * htable, keytype * key, valuetype * value) { \
    return hashtable_insert(htable, key, value);			\
  }

#define DEFINE_HASHTABLE_SEARCH(fnname, keytype, valuetype)		\
  valuetype * fnname (struct hashtable * htable, keytype * key) {	\
    return (valuetype *) (hashtable_search(htable, key));		\
  }

#define DEFINE_HASHTABLE_REMOVE(fnname, keytype, valuetype)		\
  valuetype * fnname (struct hashtable * htable, keytype * key) {	\
    return (valuetype *) (hashtable_remove(htable, key));		\
  }






struct hashtable * create_hashtable(uint_t min_size,
				    uint_t (*hashfunction) (void * key),
				    int (*key_eq_fn) (void * key1, void * key2));

void hashtable_destroy(struct hashtable * htable, int free_values);

/*
 * returns non-zero for successful insertion
 *
 * This function will cause the table to expand if the insertion would take
 * the ratio of entries to table size over the maximum load factor.
 *
 * This function does not check for repeated insertions with a duplicate key.
 * The value returned when using a duplicate key is undefined -- when
 * the hashtable changes size, the order of retrieval of duplicate key
 * entries is reversed.
 * If in doubt, remove before insert.
 */
int hashtable_insert(struct hashtable * htable, void * key, void * value);

int hashtable_change(struct hashtable * htable, void * key, void * value);


// returns the value associated with the key, or NULL if none found
void * hashtable_search(struct hashtable * htable, void * key);

// returns the value associated with the key, or NULL if none found
void * hashtable_remove(struct hashtable * htable, void * key);

uint_t hashtable_count(struct hashtable * htable);

  /* ************ */
 /* ITERATOR API */
/* ************ */

#define DEFINE_HASHTABLE_ITERATOR_SEARCH(fnname, keytype)		\
  int fnname (struct hashtable_itr * iter, struct hashtable * htable, keytype * key) { \
    return (hashtable_iterator_search(iter, htable, key));		\
  }



/*****************************************************************************/
/* This struct is only concrete here to allow the inlining of two of the
 * accessor functions. */
struct hashtable_iter {
  struct hashtable * htable;
  struct hash_entry * entry;
  struct hash_entry * parent;
  uint_t index;
};


struct hashtable_iter * create_hashtable_iterator(struct hashtable * htable);

/* - return the value of the (key,value) pair at the current position */
//extern inline 
void * hashtable_get_iter_key(struct hashtable_iter * iter);
/* {
   return iter->entry->key;
   }
*/


/* value - return the value of the (key,value) pair at the current position */
//extern inline 
void * hashtable_get_iter_value(struct hashtable_iter * iter);
/* {
   return iter->entry->value;
   }
*/



/* returns zero if advanced to end of table */
int hashtable_iterator_advance(struct hashtable_iter * iter);

/* remove current element and advance the iterator to the next element
 *          NB: if you need the value to free it, read it before
 *          removing. ie: beware memory leaks!
 *          returns zero if advanced to end of table 
 */
int hashtable_iterator_remove(struct hashtable_iter * iter);


/* search - overwrite the supplied iterator, to point to the entry
 *          matching the supplied key.
 *          returns zero if not found. */
int hashtable_iterator_search(struct hashtable_iter * iter, struct hashtable * htable, void * key);




#endif // ! __V3VEE__


#endif /* __VMM_HASHTABLE_H__ */






































/*
 * Copyright (c) 2002, Christopher Clark
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 
 * * Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * 
 * * Neither the name of the original author; nor the names of any contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 * 
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/