116 lines
3.5 KiB
C
116 lines
3.5 KiB
C
|
|
/* Author : Stephen Smalley, <stephen.smalley.work@gmail.com> */
|
|
|
|
/* FLASK */
|
|
|
|
/*
|
|
* A hash table (hashtab) maintains associations between
|
|
* key values and datum values. The type of the key values
|
|
* and the type of the datum values is arbitrary. The
|
|
* functions for hash computation and key comparison are
|
|
* provided by the creator of the table.
|
|
*/
|
|
|
|
#ifndef _NEWROLE_HASHTAB_H_
|
|
#define _NEWROLE_HASHTAB_H_
|
|
|
|
#include <stdint.h>
|
|
#include <errno.h>
|
|
#include <stdio.h>
|
|
|
|
typedef char *hashtab_key_t; /* generic key type */
|
|
typedef const char *const_hashtab_key_t; /* constant generic key type */
|
|
typedef void *hashtab_datum_t; /* generic datum type */
|
|
|
|
typedef struct hashtab_node *hashtab_ptr_t;
|
|
|
|
typedef struct hashtab_node {
|
|
hashtab_key_t key;
|
|
hashtab_datum_t datum;
|
|
hashtab_ptr_t next;
|
|
} hashtab_node_t;
|
|
|
|
typedef struct hashtab_val {
|
|
hashtab_ptr_t *htable; /* hash table */
|
|
unsigned int size; /* number of slots in hash table */
|
|
uint32_t nel; /* number of elements in hash table */
|
|
unsigned int (*hash_value) (struct hashtab_val * h, const_hashtab_key_t key); /* hash function */
|
|
int (*keycmp) (struct hashtab_val * h, const_hashtab_key_t key1, const_hashtab_key_t key2); /* key comparison function */
|
|
} hashtab_val_t;
|
|
|
|
typedef hashtab_val_t *hashtab_t;
|
|
|
|
/* Define status codes for hash table functions */
|
|
#define HASHTAB_SUCCESS 0
|
|
#define HASHTAB_OVERFLOW -ENOMEM
|
|
#define HASHTAB_PRESENT -EEXIST
|
|
#define HASHTAB_MISSING -ENOENT
|
|
|
|
/*
|
|
Creates a new hash table with the specified characteristics.
|
|
|
|
Returns NULL if insufficient space is available or
|
|
the new hash table otherwise.
|
|
*/
|
|
extern hashtab_t hashtab_create(unsigned int (*hash_value) (hashtab_t h,
|
|
const_hashtab_key_t
|
|
key),
|
|
int (*keycmp) (hashtab_t h,
|
|
const_hashtab_key_t key1,
|
|
const_hashtab_key_t key2),
|
|
unsigned int size);
|
|
/*
|
|
Inserts the specified (key, datum) pair into the specified hash table.
|
|
|
|
Returns HASHTAB_OVERFLOW if insufficient space is available or
|
|
HASHTAB_PRESENT if there is already an entry with the same key or
|
|
HASHTAB_SUCCESS otherwise.
|
|
*/
|
|
extern int hashtab_insert(hashtab_t h, hashtab_key_t k, hashtab_datum_t d);
|
|
|
|
/*
|
|
Removes the entry with the specified key from the hash table.
|
|
Applies the specified destroy function to (key,datum,args) for
|
|
the entry.
|
|
|
|
Returns HASHTAB_MISSING if no entry has the specified key or
|
|
HASHTAB_SUCCESS otherwise.
|
|
*/
|
|
extern int hashtab_remove(hashtab_t h, hashtab_key_t k,
|
|
void (*destroy) (hashtab_key_t k,
|
|
hashtab_datum_t d,
|
|
void *args), void *args);
|
|
|
|
/*
|
|
Searches for the entry with the specified key in the hash table.
|
|
|
|
Returns NULL if no entry has the specified key or
|
|
the datum of the entry otherwise.
|
|
*/
|
|
extern hashtab_datum_t hashtab_search(hashtab_t h, const_hashtab_key_t k);
|
|
|
|
/*
|
|
Destroys the specified hash table.
|
|
*/
|
|
extern void hashtab_destroy(hashtab_t h);
|
|
|
|
/*
|
|
Applies the specified apply function to (key,datum,args)
|
|
for each entry in the specified hash table.
|
|
|
|
The order in which the function is applied to the entries
|
|
is dependent upon the internal structure of the hash table.
|
|
|
|
If apply returns a non-zero status, then hashtab_map will cease
|
|
iterating through the hash table and will propagate the error
|
|
return to its caller.
|
|
*/
|
|
extern int hashtab_map(hashtab_t h,
|
|
int (*apply) (hashtab_key_t k,
|
|
hashtab_datum_t d,
|
|
void *args), void *args);
|
|
|
|
extern void hashtab_hash_eval(hashtab_t h, char *tag);
|
|
|
|
#endif
|