clixon/lib/src/clixon_hash.c
Olof hagsand f511cb0030 Split config into multiple sub-files on mount-point boundaries and dont write clean subfiles
Added CLICON_XMLDB_MULTI option, added cl:xmldb-split extension
2024-04-25 14:58:14 +02:00

405 lines
9.8 KiB
C

/*
*
***** BEGIN LICENSE BLOCK *****
Copyright (C) 2009-2016 Olof Hagsand and Benny Holmgren
Copyright (C) 2017-2019 Olof Hagsand
Copyright (C) 2020-2022 Olof Hagsand and Rubicon Communications, LLC(Netgate)
This file is part of CLIXON.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Alternatively, the contents of this file may be used under the terms of
the GNU General Public License Version 3 or later (the "GPL"),
in which case the provisions of the GPL are applicable instead
of those above. If you wish to allow use of your version of this file only
under the terms of the GPL, and not to allow others to
use your version of this file under the terms of Apache License version 2,
indicate your decision by deleting the provisions above and replace them with
the notice and other provisions required by the GPL. If you do not delete
the provisions above, a recipient may use your version of this file under
the terms of any one of the Apache License version 2 or the GPL.
***** END LICENSE BLOCK *****
*/
/*
* A simple implementation of a associative array style data store. Keys
* are always strings while values can be some arbitrary data referenced
* by void*.
*
* XXX: functions such as hash_keys(), hash_value() etc are currently returning
* pointers to the actual data storage. Should probably make copies.
*
* Example usage:
*
* int main()
* {
* char **s;
* int n;
* size_t slen;
* clicon_hash_t *hash = hash_init();
*
* n = 234;
* hash_add(hash, "APA", &n, sizeof(n));
* hash_dump(hash, stdout);
*
* puts("----");
*
* hash_add(hash, "BEPA", "hoppla Polle!", strlen("hoppla Polle!")+1);
* puts((char *)hash_value(hash, "BEPA", NULL));
* hash_dump(hash, stdout);
*
* puts("----");
*
* n = 33;
* hash_add(hash, "CEPA", &n, sizeof(n));
* hash_dump(hash, stdout);
*
* puts("----");
*
* hash_del(hash, "APA");
* hash_dump(hash, stdout);
*
* hash_free(hash);
*
* return 0;
* }
*/
#ifdef HAVE_CONFIG_H
#include "clixon_config.h" /* generated by config & autoconf */
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <inttypes.h>
/* cligen */
#include <cligen/cligen.h>
/* clixon */
#include "clixon_queue.h"
#include "clixon_hash.h"
#include "clixon_handle.h"
#include "clixon_yang.h"
#include "clixon_xml.h"
#include "clixon_err.h"
#define HASH_SIZE 1031 /* Number of hash buckets. Should be a prime */
#define align4(s) (((s)/4)*4 + 4)
/*! A very simplistic algorithm to calculate a hash bucket index
*/
static uint32_t
hash_bucket(const char *str)
{
uint32_t n = 0;
while(*str)
n += (uint32_t)*str++;
return n % HASH_SIZE;
}
/*! Initialize hash table.
*
* @retval hash Pointer to new hash table.
* @retval NULL Error
* @see hash_free For freeing the hash-table
*/
clicon_hash_t *
clicon_hash_init(void)
{
clicon_hash_t *hash;
if ((hash = (clicon_hash_t *)malloc(sizeof(clicon_hash_t) * HASH_SIZE)) == NULL){
clixon_err(OE_UNIX, errno, "malloc");
return NULL;
}
memset(hash, 0, sizeof(clicon_hash_t)*HASH_SIZE);
return hash;
}
/*! Free hash table.
*
* @param[in] hash Hash table
* @retval 0 OK
* @retval -1 Error
*/
int
clicon_hash_free(clicon_hash_t *hash)
{
int i;
clicon_hash_t tmp;
for (i = 0; i < HASH_SIZE; i++) {
while (hash[i]) {
tmp = hash[i];
DELQ(tmp, hash[i], clicon_hash_t);
free(tmp->h_key);
free(tmp->h_val);
free(tmp);
}
}
free(hash);
return 0;
}
/*! Find hash key.
*
* @param[in] hash Hash table
* @param[in] key Variable name
* @retval variable Hash variable structure on success
* @retval NULL Not found
*/
clicon_hash_t
clicon_hash_lookup(clicon_hash_t *hash,
const char *key)
{
uint32_t bkt;
clicon_hash_t h;
bkt = hash_bucket(key);
h = hash[bkt];
if (h) {
do {
if (!strcmp(h->h_key, key))
return h;
h = NEXTQ(clicon_hash_t, h);
} while (h != hash[bkt]);
}
return NULL;
}
/*! Get value of hash
*
* @param[in] hash Hash table
* @param[in] key Variable name
* @param[out] vlen Length of value (as returned by function if != NULL)
* @retval value Hash value, length given in vlen
* @retval NULL Key not found or value NULL
*/
void *
clicon_hash_value(clicon_hash_t *hash,
const char *key,
size_t *vlen)
{
clicon_hash_t h;
if (hash == NULL){
clixon_err(OE_UNIX, EINVAL, "hash is NULL");
return NULL;
}
h = clicon_hash_lookup(hash, key);
if (h == NULL)
return NULL; /* OK, key not found */
if (vlen)
*vlen = h->h_vlen;
return h->h_val;
}
/*! Copy value and add hash entry.
*
* @param[in] hash Hash table
* @param[in] key Variable name
* @param[in] val Variable value (pointer to)
* @param[in] vlen Length of variable value
* @retval hash New hash structure on success
* @retval NULL Error
* @note special case val is NULL and vlen==0
*/
clicon_hash_t
clicon_hash_add(clicon_hash_t *hash,
const char *key,
void *val,
size_t vlen)
{
void *newval = NULL;
clicon_hash_t h;
clicon_hash_t new = NULL;
if (hash == NULL){
clixon_err(OE_UNIX, EINVAL, "hash is NULL");
return NULL;
}
/* Check NULL case */
if ((val == NULL && vlen != 0) ||
(val != NULL && vlen == 0)){
clixon_err(OE_UNIX, EINVAL, "Mismatch in value and length, only one is zero");
goto catch;
}
/* If variable exist, don't allocate a new. just replace value */
h = clicon_hash_lookup(hash, key);
if (h == NULL) {
if ((new = (clicon_hash_t)malloc(sizeof(*new))) == NULL){
clixon_err(OE_UNIX, errno, "malloc");
goto catch;
}
memset(new, 0, sizeof(*new));
new->h_key = strdup(key);
if (new->h_key == NULL){
clixon_err(OE_UNIX, errno, "strdup");
goto catch;
}
h = new;
}
if (vlen){
/* Make copy of value. aligned */
newval = malloc(align4(vlen+3));
if (newval == NULL){
clixon_err(OE_UNIX, errno, "malloc");
goto catch;
}
memcpy(newval, val, vlen);
}
/* Free old value if existing variable */
if (h->h_val)
free(h->h_val);
h->h_val = newval;
h->h_vlen = vlen;
/* Add to list only if new variable */
if (new)
INSQ(h, hash[hash_bucket(key)]);
return h;
catch:
if (new) {
if (new->h_key)
free(new->h_key);
free(new);
}
return NULL;
}
/*! Delete hash entry.
*
* @param[in] hash Hash table
* @param[in] key Variable name
* @retval 0 OK
* @retval -1 Key not found
*/
int
clicon_hash_del(clicon_hash_t *hash,
const char *key)
{
clicon_hash_t h;
if (hash == NULL){
clixon_err(OE_UNIX, EINVAL, "hash is NULL");
return -1;
}
h = clicon_hash_lookup(hash, key);
if (h == NULL)
return -1;
DELQ(h, hash[hash_bucket(key)], clicon_hash_t);
free(h->h_key);
free(h->h_val);
free(h);
return 0;
}
/*! Return vector of keys in hash table
*
* @param[in] hash Hash table
* @param[out] vector Vector of keys, NULL if not found
* @param[out] nkeys Size of key vector
* @retval 0 OK
* @retval -1 Error
* @note: vector needs to be deallocated with free
*/
int
clicon_hash_keys(clicon_hash_t *hash,
char ***vector,
size_t *nkeys)
{
int retval = -1;
int bkt;
clicon_hash_t h;
char **tmp;
char **keys = NULL;
if (hash == NULL){
clixon_err(OE_UNIX, EINVAL, "hash is NULL");
return -1;
}
*nkeys = 0;
for (bkt = 0; bkt < HASH_SIZE; bkt++) {
h = hash[bkt];
do {
if (h == NULL)
break;
tmp = realloc(keys, ((*nkeys)+1) * sizeof(char *));
if (tmp == NULL){
clixon_err(OE_UNIX, errno, "realloc");
goto catch;
}
keys = tmp;
keys[*nkeys] = h->h_key;
(*nkeys)++;
h = NEXTQ(clicon_hash_t, h);
} while (h != hash[bkt]);
}
if (vector){
*vector = keys;
keys = NULL;
}
retval = 0;
catch:
if (keys)
free(keys);
return retval;
}
/*! Dump contents of hash to FILE pointer.
*
* @param[in] hash Hash structure
* @param[in] f FILE pointer for print output
* @retval 0 OK
* @retval -1 Error
*/
int
clicon_hash_dump(clicon_hash_t *hash,
FILE *f)
{
int retval = -1;
int i;
char **keys = NULL;
void *val;
size_t klen;
size_t vlen;
if (hash == NULL)
goto ok;
if (clicon_hash_keys(hash, &keys, &klen) < 0)
goto done;
for(i = 0; i < klen; i++) {
val = clicon_hash_value(hash, keys[i], &vlen);
printf("%s =\t 0x%p , length %zu\n", keys[i], val, vlen);
}
ok:
retval = 0;
done:
if (keys)
free(keys);
return retval;
}