From 6de7dc5879b3605a180dafa05f792f132eafdcaa Mon Sep 17 00:00:00 2001 From: Daniel Stenberg Date: Thu, 3 Jan 2002 10:22:59 +0000 Subject: Sterling Hughes' provided initial DNS cache source code. --- lib/hash.c | 271 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 271 insertions(+) create mode 100644 lib/hash.c (limited to 'lib/hash.c') diff --git a/lib/hash.c b/lib/hash.c new file mode 100644 index 000000000..c0680e488 --- /dev/null +++ b/lib/hash.c @@ -0,0 +1,271 @@ +/***************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) 2001, Daniel Stenberg, , et al + * + * In order to be useful for every potential user, curl and libcurl are + * dual-licensed under the MPL and the MIT/X-derivate licenses. + * + * 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 MPL or the MIT/X-derivate + * licenses. You may pick one of these licenses. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + * $Id$ + *****************************************************************************/ + +#include "setup.h" + +#include + +#include "hash.h" +#include "llist.h" + +#ifdef MALLOCDEBUG +/* this must be the last include file */ +#include "memdebug.h" +#endif + + +static unsigned long +curl_hash_str(const char *key, unsigned int key_length) +{ + register unsigned long h = 0; + register unsigned long g; + register char *p = (char *) key; + register char *end = (char *) key + key_length; + + while (p < end) { + h = (h << 4) + *p++; + if ((g = (h & 0xF0000000))) { + h = h ^ (g >> 24); + h = h ^ g; + } + } + + return h; +} + +static unsigned long +curl_hash_num(unsigned long key) +{ + key += ~(key << 15); + key ^= (key >> 10); + key += (key << 3); + key ^= (key >> 6); + key += (key << 11); + key ^= (key >> 16); + + return key; +} + +static void +hash_element_dtor(void *u, void *ele) +{ + curl_hash_element *e = (curl_hash_element *) ele; + curl_hash *h = (curl_hash *) u; + + if (e->key.type == CURL_HASH_KEY_IS_STRING) { + free(e->key.value.str.val); + } + h->dtor(e->ptr); + + free(e); + e = NULL; +} + +void +curl_hash_init(curl_hash *h, int slots, curl_hash_dtor dtor) +{ + int i; + + h->dtor = dtor; + h->size = 0; + h->slots = slots; + + h->table = (curl_llist **) malloc(slots * sizeof(curl_llist *)); + for (i = 0; i < h->slots; ++i) { + h->table[i] = curl_llist_alloc((curl_llist_dtor) hash_element_dtor); + } +} + +curl_hash * +curl_hash_alloc(int slots, curl_hash_dtor dtor) +{ + curl_hash *h; + + h = malloc(sizeof(curl_hash)); + curl_hash_init(h, slots, dtor); + + return h; +} + +#define FIND_SLOT(__h, __s_key, __s_key_len, __n_key) \ + ((__s_key ? curl_hash_str(__s_key, __s_key_len) : curl_hash_num(__n_key)) % (__h)->slots) + +#define KEY_CREATE(__k, __s_key, __s_key_len, __n_key, __dup) \ + if (__s_key) { \ + if (__dup) { \ + (__k)->value.str.val = (char *) malloc(__s_key_len); \ + memcpy((__k)->value.str.val, __s_key, __s_key_len); \ + } else { \ + (__k)->value.str.val = __s_key; \ + } \ + (__k)->value.str.len = __s_key_len; \ + (__k)->type = CURL_HASH_KEY_IS_STRING; \ + } else { \ + (__k)->value.num = __n_key; \ + (__k)->type = CURL_HASH_KEY_IS_NUM; \ + } + +#define MIN(a, b) (a > b ? b : a) + +static int +curl_hash_key_compare(curl_hash_key *key1, curl_hash_key *key2) +{ + if (key1->type == CURL_HASH_KEY_IS_NUM) { + if (key2->type == CURL_HASH_KEY_IS_STRING) + return 0; + + if (key1->value.num == key2->value.num) + return 1; + } else { + if (key2->type == CURL_HASH_KEY_IS_NUM) + return 0; + + if (memcmp(key1->value.str.val, key2->value.str.val, + MIN(key1->value.str.len, key2->value.str.len)) == 0) + return 1; + } + + return 0; +} + +int +curl_hash_add_or_update(curl_hash *h, char *str_key, unsigned int str_key_len, + unsigned long num_key, const void *p) +{ + curl_hash_element *e; + curl_hash_key tmp; + curl_llist *l; + curl_llist_element *le; + int slot; + + slot = FIND_SLOT(h, str_key, str_key_len, num_key); + l = h->table[slot]; + KEY_CREATE(&tmp, str_key, str_key_len, num_key, 0); + for (le = CURL_LLIST_HEAD(l); le != NULL; le = CURL_LLIST_NEXT(le)) { + if (curl_hash_key_compare(&tmp, &((curl_hash_element *) CURL_LLIST_VALP(le))->key)) { + curl_hash_element *to_update = CURL_LLIST_VALP(le); + h->dtor(to_update->ptr); + to_update->ptr = (void *) p; + return 1; + } + } + + e = (curl_hash_element *) malloc(sizeof(curl_hash_element)); + KEY_CREATE(&e->key, str_key, str_key_len, num_key, 1); + e->ptr = (void *) p; + + if (curl_llist_insert_next(l, CURL_LLIST_TAIL(l), e)) { + ++h->size; + return 1; + } else { + return 0; + } +} + +int +curl_hash_extended_delete(curl_hash *h, char *str_key, unsigned int str_key_len, + unsigned long num_key) +{ + curl_llist *l; + curl_llist_element *le; + curl_hash_key tmp; + int slot; + + slot = FIND_SLOT(h, str_key, str_key_len, num_key); + l = h->table[slot]; + + KEY_CREATE(&tmp, str_key, str_key_len, num_key, 0); + for (le = CURL_LLIST_HEAD(l); le != NULL; le = CURL_LLIST_NEXT(le)) { + if (curl_hash_key_compare(&tmp, &((curl_hash_element *) CURL_LLIST_VALP(le))->key)) { + curl_llist_remove(l, le, (void *) h); + --h->size; + return 1; + } + } + + return 0; +} + +int +curl_hash_extended_find(curl_hash *h, char *str_key, unsigned int str_key_len, + unsigned long num_key, void **p) +{ + curl_llist *l; + curl_llist_element *le; + curl_hash_key tmp; + int slot; + + slot = FIND_SLOT(h, str_key, str_key_len, num_key); + l = h->table[slot]; + + KEY_CREATE(&tmp, str_key, str_key_len, num_key, 0); + for (le = CURL_LLIST_HEAD(l); le != NULL; le = CURL_LLIST_NEXT(le)) { + if (curl_hash_key_compare(&tmp, &((curl_hash_element *) CURL_LLIST_VALP(le))->key)) { + *p = ((curl_hash_element *) CURL_LLIST_VALP(le))->ptr; + return 1; + } + } + + return 0; +} + +void +curl_hash_apply(curl_hash *h, void *user, void (*cb)(void *, curl_hash_element *)) +{ + curl_llist_element *le; + int i; + + for (i = 0; i < h->slots; ++i) { + for (le = CURL_LLIST_HEAD(h->table[i]); le != NULL; le = CURL_LLIST_NEXT(le)) { + cb(user, (curl_hash_element *) CURL_LLIST_VALP(le)); + } + } +} + +void +curl_hash_clean(curl_hash *h) +{ + int i; + + for (i = 0; i < h->slots; ++i) { + curl_llist_destroy(h->table[i], (void *) h); + } + + free(h->table); + h->table = NULL; +} + +void +curl_hash_destroy(curl_hash *h) +{ + curl_hash_clean(h); + free(h); +} + +/* + * local variables: + * eval: (load-file "../curl-mode.el") + * end: + * vim600: fdm=marker + * vim: et sw=2 ts=2 sts=2 tw=78 + */ -- cgit v1.2.3