hashtable.h

一个学习SNMP项目：tmoerlan.

/* snap-1.0. Copyright (C) 2000 by Jonathan T. Moore and Michael Hicks.
 *
 * hashtable.h : basic hash table library, used for managing the
 *   node-resident service namespace
 *
 * $Id: hashtable.h,v 1.2 2003/09/17 11:26:10 tmoerlan Exp $
 */
#include "list.h"

typedef struct {
  void *key;
  void *value;
} pair_t;

typedef struct {
  int (*cmp)(const void *,const void *);	/* for comparing the keys */
  int (*hash)(void *);		/* for hashing the key */	
  int max_len; 			/* max length of bucket list before resize */
  list_t **tab;			/* the table: an array of lists of pairs */
  int tab_sz;			/* size of the table */
} hash_table_t;

/* set to 1 when ht_lookup fails */
int ht_errno;

/* access functions */
hash_table_t *ht_create(int sz,
			int (*cmp)(const void *,const void *),
			int (*hash)(void *));
void ht_insert(hash_table_t *t, void *key, void *val);
void *ht_lookup(hash_table_t *t, void *key);
void ht_remove(hash_table_t * t, void *key);

/* useful for tables indexed by strings */
int hash_string(char *s);