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curl-w32/lib/hash.c

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/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 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 https://curl.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.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
#include "curl_setup.h"
#include <curl/curl.h>
#include "hash.h"
#include "llist.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->ptr) {
h->dtor(e->ptr);
e->ptr = NULL;
}
e->key_len = 0;
free(e);
}
/* Initializes a hash structure.
* Return 1 on error, 0 is fine.
*
* @unittest: 1602
* @unittest: 1603
*/
void
Curl_hash_init(struct Curl_hash *h,
int slots,
hash_function hfunc,
comp_function comparator,
Curl_hash_dtor dtor)
{
DEBUGASSERT(h);
DEBUGASSERT(slots);
DEBUGASSERT(hfunc);
DEBUGASSERT(comparator);
DEBUGASSERT(dtor);
h->table = NULL;
h->hash_func = hfunc;
h->comp_func = comparator;
h->dtor = dtor;
h->size = 0;
h->slots = slots;
}
static struct Curl_hash_element *
mk_hash_element(const void *key, size_t key_len, const void *p)
{
/* allocate the struct plus memory after it to store the key */
struct Curl_hash_element *he = malloc(sizeof(struct Curl_hash_element) +
key_len);
if(he) {
/* copy the key */
memcpy(he->key, key, key_len);
he->key_len = key_len;
he->ptr = (void *) p;
}
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. This function also "lazily" allocates the table if
* needed, as it isn't done in the _init function (anymore).
*
* @unittest: 1305
* @unittest: 1602
* @unittest: 1603
*/
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;
DEBUGASSERT(h);
DEBUGASSERT(h->slots);
if(!h->table) {
int i;
h->table = malloc(h->slots * sizeof(struct Curl_llist));
if(!h->table)
return NULL; /* OOM */
for(i = 0; i < h->slots; ++i)
Curl_llist_init(&h->table[i], hash_element_dtor);
}
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) {
Curl_llist_insert_next(l, l->tail, he, &he->list);
++h->size;
return p; /* return the new entry */
}
return NULL; /* failure */
}
/* Remove the identified hash entry.
* Returns non-zero on failure.
*
* @unittest: 1603
*/
int Curl_hash_delete(struct Curl_hash *h, void *key, size_t key_len)
{
struct Curl_llist_element *le;
struct Curl_llist *l;
DEBUGASSERT(h);
DEBUGASSERT(h->slots);
if(h->table) {
l = FETCH_LIST(h, key, key_len);
for(le = l->head; le; le = le->next) {
struct Curl_hash_element *he = le->ptr;
if(h->comp_func(he->key, he->key_len, key, key_len)) {
Curl_llist_remove(l, le, (void *) h);
--h->size;
return 0;
}
}
}
return 1;
}
/* Retrieves a hash element.
*
* @unittest: 1603
*/
void *
Curl_hash_pick(struct Curl_hash *h, void *key, size_t key_len)
{
struct Curl_llist_element *le;
struct Curl_llist *l;
DEBUGASSERT(h);
if(h->table) {
DEBUGASSERT(h->slots);
l = FETCH_LIST(h, key, key_len);
for(le = l->head; le; le = le->next) {
struct Curl_hash_element *he = le->ptr;
if(h->comp_func(he->key, he->key_len, key, key_len)) {
return he->ptr;
}
}
}
return NULL;
}
#if defined(DEBUGBUILD) && defined(AGGRESSIVE_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
/* Destroys all the entries in the given hash and resets its attributes,
* prepping the given hash for [static|dynamic] deallocation.
*
* @unittest: 1305
* @unittest: 1602
* @unittest: 1603
*/
void
Curl_hash_destroy(struct Curl_hash *h)
{
if(h->table) {
int i;
for(i = 0; i < h->slots; ++i) {
Curl_llist_destroy(&h->table[i], (void *) h);
}
Curl_safefree(h->table);
}
h->size = 0;
h->slots = 0;
}
/* Removes all the entries in the given hash.
*
* @unittest: 1602
*/
void
Curl_hash_clean(struct Curl_hash *h)
{
Curl_hash_clean_with_criterium(h, NULL, NULL);
}
/* Cleans all entries that pass the comp function criteria. */
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;
if(!h || !h->table)
return;
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 || comp(user, he->ptr)) {
Curl_llist_remove(list, le, (void *) h);
--h->size; /* one less entry in the hash now */
}
le = lnext;
}
}
}
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;
size_t h = 5381;
while(key_str < end) {
h += h << 5;
h ^= *key_str++;
}
return (h % slots_num);
}
size_t Curl_str_key_compare(void *k1, size_t key1_len,
void *k2, size_t key2_len)
{
if((key1_len == key2_len) && !memcmp(k1, k2, key1_len))
return 1;
return 0;
}
void Curl_hash_start_iterate(struct Curl_hash *hash,
struct Curl_hash_iterator *iter)
{
iter->hash = hash;
iter->slot_index = 0;
iter->current_element = NULL;
}
struct Curl_hash_element *
Curl_hash_next_element(struct Curl_hash_iterator *iter)
{
struct Curl_hash *h = iter->hash;
if(!h->table)
return NULL; /* empty hash, nothing to return */
/* Get the next element in the current list, if any */
if(iter->current_element)
iter->current_element = iter->current_element->next;
/* If we have reached the end of the list, find the next one */
if(!iter->current_element) {
int i;
for(i = iter->slot_index; i < h->slots; i++) {
if(h->table[i].head) {
iter->current_element = h->table[i].head;
iter->slot_index = i + 1;
break;
}
}
}
if(iter->current_element) {
struct Curl_hash_element *he = iter->current_element->ptr;
return he;
}
return NULL;
}
#if 0 /* useful function for debugging hashes and their contents */
void Curl_hash_print(struct Curl_hash *h,
void (*func)(void *))
{
struct Curl_hash_iterator iter;
struct Curl_hash_element *he;
int last_index = -1;
if(!h)
return;
fprintf(stderr, "=Hash dump=\n");
Curl_hash_start_iterate(h, &iter);
he = Curl_hash_next_element(&iter);
while(he) {
if(iter.slot_index != last_index) {
fprintf(stderr, "index %d:", iter.slot_index);
if(last_index >= 0) {
fprintf(stderr, "\n");
}
last_index = iter.slot_index;
}
if(func)
func(he->ptr);
else
fprintf(stderr, " [%p]", (void *)he->ptr);
he = Curl_hash_next_element(&iter);
}
fprintf(stderr, "\n");
}
#endif
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