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/*
* Copyright (C) 2008 Stig Venaas <venaas@uninett.no>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*/
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include "list.h"
#include "hash.h"
/* allocates and initialises hash structure; returns NULL if malloc fails */
struct hash *hash_create() {
struct hash *h = malloc(sizeof(struct hash));
if (!h)
return NULL;
h->hashlist = list_create();
if (!h->hashlist) {
free(h);
return NULL;
}
pthread_mutex_init(&h->mutex, NULL);
return h;
}
/* frees all memory associated with the hash */
void hash_destroy(struct hash *h) {
struct list_node *ln;
if (!h)
return;
for (ln = list_first(h->hashlist); ln; ln = list_next(ln)) {
free(((struct hash_entry *)ln->data)->key);
free(((struct hash_entry *)ln->data)->data);
}
list_destroy(h->hashlist);
pthread_mutex_destroy(&h->mutex);
}
/* insert entry in hash; returns 1 if ok, 0 if malloc fails */
int hash_insert(struct hash *h, void *key, uint32_t keylen, void *data) {
struct hash_entry *e;
if (!h)
return 0;
e = malloc(sizeof(struct hash_entry));
if (!e)
return 0;
memset(e, 0, sizeof(struct hash_entry));
e->key = malloc(keylen);
if (!e->key) {
free(e);
return 0;
}
memcpy(e->key, key, keylen);
e->keylen = keylen;
e->data = data;
pthread_mutex_lock(&h->mutex);
if (!list_push(h->hashlist, e)) {
pthread_mutex_unlock(&h->mutex);
free(e->key);
free(e);
return 0;
}
pthread_mutex_unlock(&h->mutex);
return 1;
}
/* reads entry from hash */
void *hash_read(struct hash *h, void *key, uint32_t keylen) {
struct list_node *ln;
struct hash_entry *e;
if (!h)
return 0;
pthread_mutex_lock(&h->mutex);
for (ln = list_first(h->hashlist); ln; ln = list_next(ln)) {
e = (struct hash_entry *)ln->data;
if (e->keylen == keylen && !memcmp(e->key, key, keylen)) {
pthread_mutex_unlock(&h->mutex);
return e->data;
}
}
pthread_mutex_unlock(&h->mutex);
return NULL;
}
/* extracts entry from hash */
void *hash_extract(struct hash *h, void *key, uint32_t keylen) {
struct list_node *ln;
struct hash_entry *e;
if (!h)
return 0;
pthread_mutex_lock(&h->mutex);
for (ln = list_first(h->hashlist); ln; ln = list_next(ln)) {
e = (struct hash_entry *)ln->data;
if (e->keylen == keylen && !memcmp(e->key, key, keylen)) {
free(e->key);
list_removedata(h->hashlist, e);
free(e);
pthread_mutex_unlock(&h->mutex);
return e->data;
}
}
pthread_mutex_unlock(&h->mutex);
return NULL;
}
/* returns first entry */
struct hash_entry *hash_first(struct hash *hash) {
struct list_node *ln;
struct hash_entry *e;
if (!hash || !((ln = list_first(hash->hashlist))))
return NULL;
e = (struct hash_entry *)ln->data;
e->next = ln->next;
return e;
}
/* returns the next node after the argument */
struct hash_entry *hash_next(struct hash_entry *entry) {
struct hash_entry *e;
if (!entry || !entry->next)
return NULL;
e = (struct hash_entry *)entry->next->data;
e->next = (struct list_node *)entry->next->next;
return e;
}
/* Local Variables: */
/* c-file-style: "stroustrup" */
/* End: */
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