curl/lib/hash.c

340 строки
7.7 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at http://curl.haxx.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
#include "setup.h"
#include "hash.h"
#include "llist.h"
#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>
#include "curl_memory.h"
/* The last #include file should be: */
#include "memdebug.h"
static void
hash_element_dtor(void *user, void *element)
{
struct curl_hash *h = (struct curl_hash *) user;
struct curl_hash_element *e = (struct curl_hash_element *) element;
if(e->key)
free(e->key);
if(e->ptr)
h->dtor(e->ptr);
free(e);
}
/* return 1 on error, 0 is fine */
int
Curl_hash_init(struct curl_hash *h,
int slots,
hash_function hfunc,
comp_function comparator,
curl_hash_dtor dtor)
{
int i;
if(!slots || !hfunc || !comparator ||!dtor) {
return 1; /* failure */
}
h->hash_func = hfunc;
h->comp_func = comparator;
h->dtor = dtor;
h->size = 0;
h->slots = slots;
h->table = malloc(slots * sizeof(struct curl_llist *));
if(h->table) {
for(i = 0; i < slots; ++i) {
h->table[i] = Curl_llist_alloc((curl_llist_dtor) hash_element_dtor);
if(!h->table[i]) {
while(i--)
Curl_llist_destroy(h->table[i], NULL);
free(h->table);
return 1; /* failure */
}
}
return 0; /* fine */
}
else
return 1; /* failure */
}
struct curl_hash *
Curl_hash_alloc(int slots,
hash_function hfunc,
comp_function comparator,
curl_hash_dtor dtor)
{
struct curl_hash *h;
if(!slots || !hfunc || !comparator ||!dtor) {
return NULL; /* failure */
}
h = malloc(sizeof(struct curl_hash));
if(h) {
if(Curl_hash_init(h, slots, hfunc, comparator, dtor)) {
/* failure */
free(h);
h = NULL;
}
}
return h;
}
static struct curl_hash_element *
mk_hash_element(const void *key, size_t key_len, const void *p)
{
struct curl_hash_element *he = malloc(sizeof(struct curl_hash_element));
if(he) {
void *dupkey = malloc(key_len);
if(dupkey) {
/* copy the key */
memcpy(dupkey, key, key_len);
he->key = dupkey;
he->key_len = key_len;
he->ptr = (void *) p;
}
else {
/* failed to duplicate the key, free memory and fail */
free(he);
he = NULL;
}
}
return he;
}
#define FETCH_LIST(x,y,z) x->table[x->hash_func(y, z, x->slots)]
/* Insert the data in the hash. If there already was a match in the hash,
* that data is replaced.
*
* @unittest: 1305
*/
void *
Curl_hash_add(struct curl_hash *h, void *key, size_t key_len, void *p)
{
struct curl_hash_element *he;
struct curl_llist_element *le;
struct curl_llist *l = FETCH_LIST (h, key, key_len);
for(le = l->head; le; le = le->next) {
he = (struct curl_hash_element *) le->ptr;
if(h->comp_func(he->key, he->key_len, key, key_len)) {
Curl_llist_remove(l, le, (void *)h);
--h->size;
break;
}
}
he = mk_hash_element(key, key_len, p);
if(he) {
if(Curl_llist_insert_next(l, l->tail, he)) {
++h->size;
return p; /* return the new entry */
}
/*
* Couldn't insert it, destroy the 'he' element and the key again. We
* don't call hash_element_dtor() since that would also call the
* "destructor" for the actual data 'p'. When we fail, we shall not touch
* that data.
*/
free(he->key);
free(he);
}
return NULL; /* failure */
}
/* remove the identified hash entry, returns non-zero on failure */
int Curl_hash_delete(struct curl_hash *h, void *key, size_t key_len)
{
struct curl_llist_element *le;
struct curl_hash_element *he;
struct curl_llist *l = FETCH_LIST(h, key, key_len);
for(le = l->head; le; le = le->next) {
he = le->ptr;
if(h->comp_func(he->key, he->key_len, key, key_len)) {
Curl_llist_remove(l, le, (void *) h);
return 0;
}
}
return 1;
}
void *
Curl_hash_pick(struct curl_hash *h, void *key, size_t key_len)
{
struct curl_llist_element *le;
struct curl_hash_element *he;
struct curl_llist *l = FETCH_LIST(h, key, key_len);
for(le = l->head; le; le = le->next) {
he = le->ptr;
if(h->comp_func(he->key, he->key_len, key, key_len)) {
return he->ptr;
}
}
return NULL;
}
#if defined(DEBUGBUILD) && defined(AGGRESIVE_TEST)
void
Curl_hash_apply(curl_hash *h, void *user,
void (*cb)(void *user, void *ptr))
{
struct curl_llist_element *le;
int i;
for(i = 0; i < h->slots; ++i) {
for(le = (h->table[i])->head;
le;
le = le->next) {
curl_hash_element *el = le->ptr;
cb(user, el->ptr);
}
}
}
#endif
void
Curl_hash_clean(struct curl_hash *h)
{
int i;
for(i = 0; i < h->slots; ++i) {
Curl_llist_destroy(h->table[i], (void *) h);
h->table[i] = NULL;
}
free(h->table);
}
void
Curl_hash_clean_with_criterium(struct curl_hash *h, void *user,
int (*comp)(void *, void *))
{
struct curl_llist_element *le;
struct curl_llist_element *lnext;
struct curl_llist *list;
int i;
for(i = 0; i < h->slots; ++i) {
list = h->table[i];
le = list->head; /* get first list entry */
while(le) {
struct curl_hash_element *he = le->ptr;
lnext = le->next;
/* ask the callback function if we shall remove this entry or not */
if(comp(user, he->ptr)) {
Curl_llist_remove(list, le, (void *) h);
--h->size; /* one less entry in the hash now */
}
le = lnext;
}
}
}
void
Curl_hash_destroy(struct curl_hash *h)
{
if(!h)
return;
Curl_hash_clean(h);
free(h);
}
size_t Curl_hash_str(void* key, size_t key_length, size_t slots_num)
{
const char* key_str = (const char *) key;
const char *end = key_str + key_length;
unsigned long h = 5381;
while(key_str < end) {
h += h << 5;
h ^= (unsigned long) *key_str++;
}
return (h % slots_num);
}
size_t Curl_str_key_compare(void*k1, size_t key1_len, void*k2, size_t key2_len)
{
char *key1 = (char *)k1;
char *key2 = (char *)k2;
if(key1_len == key2_len &&
*key1 == *key2 &&
memcmp(key1, key2, key1_len) == 0) {
return 1;
}
return 0;
}
#if 0 /* useful function for debugging hashes and their contents */
void Curl_hash_print(struct curl_hash *h,
void (*func)(void *))
{
int i;
struct curl_llist_element *le;
struct curl_llist *list;
struct curl_hash_element *he;
if(!h)
return;
fprintf(stderr, "=Hash dump=\n");
for(i = 0; i < h->slots; i++) {
list = h->table[i];
le = list->head; /* get first list entry */
if(le) {
fprintf(stderr, "index %d:", i);
while(le) {
he = le->ptr;
if(func)
func(he->ptr);
else
fprintf(stderr, " [%p]", he->ptr);
le = le->next;
}
fprintf(stderr, "\n");
}
}
}
#endif