340 lines
		
	
	
		
			7.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			340 lines
		
	
	
		
			7.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /***************************************************************************
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|  *                                  _   _ ____  _
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|  *  Project                     ___| | | |  _ \| |
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|  *                             / __| | | | |_) | |
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|  *                            | (__| |_| |  _ <| |___
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|  *                             \___|\___/|_| \_\_____|
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|  *
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|  * Copyright (C) 1998 - 2008, Daniel Stenberg, <daniel@haxx.se>, et al.
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|  *
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|  * This software is licensed as described in the file COPYING, which
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|  * you should have received as part of this distribution. The terms
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|  * are also available at http://curl.haxx.se/docs/copyright.html.
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|  *
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|  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
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|  * copies of the Software, and permit persons to whom the Software is
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|  * furnished to do so, under the terms of the COPYING file.
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|  *
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|  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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|  * KIND, either express or implied.
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|  *
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|  * $Id: hash.c,v 1.39 2008-10-27 05:29:17 yangtse Exp $
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|  ***************************************************************************/
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| 
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| #include "setup.h"
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| 
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| #include <string.h>
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| #include <stdlib.h>
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| 
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| #include "hash.h"
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| #include "llist.h"
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| 
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| #define _MPRINTF_REPLACE /* use our functions only */
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| #include <curl/mprintf.h>
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| 
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| #include "memory.h"
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| /* The last #include file should be: */
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| #include "memdebug.h"
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| 
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| static void
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| hash_element_dtor(void *user, void *element)
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| {
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|   struct curl_hash *h = (struct curl_hash *) user;
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|   struct curl_hash_element *e = (struct curl_hash_element *) element;
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| 
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|   if(e->key)
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|     free(e->key);
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| 
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|   if(e->ptr)
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|     h->dtor(e->ptr);
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| 
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|   free(e);
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| }
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| 
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| /* return 1 on error, 0 is fine */
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| int
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| Curl_hash_init(struct curl_hash *h,
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|                int slots,
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|                hash_function hfunc,
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|                comp_function comparator,
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|                curl_hash_dtor dtor)
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| {
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|   int i;
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| 
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|   if(!slots || !hfunc || !comparator ||!dtor) {
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|     return 1; /* failure */
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|   }
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| 
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|   h->hash_func = hfunc;
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|   h->comp_func = comparator;
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|   h->dtor = dtor;
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|   h->size = 0;
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|   h->slots = slots;
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| 
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|   h->table = malloc(slots * sizeof(struct curl_llist *));
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|   if(h->table) {
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|     for (i = 0; i < slots; ++i) {
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|       h->table[i] = Curl_llist_alloc((curl_llist_dtor) hash_element_dtor);
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|       if(!h->table[i]) {
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|         while(i--)
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|           Curl_llist_destroy(h->table[i], NULL);
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|         free(h->table);
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|         return 1; /* failure */
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|       }
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|     }
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|     return 0; /* fine */
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|   }
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|   else
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|     return 1; /* failure */
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| }
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| 
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| struct curl_hash *
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| Curl_hash_alloc(int slots,
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|                 hash_function hfunc,
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|                 comp_function comparator,
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|                 curl_hash_dtor dtor)
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| {
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|   struct curl_hash *h;
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| 
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|   if(!slots || !hfunc || !comparator ||!dtor) {
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|     return NULL; /* failure */
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|   }
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| 
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|   h = malloc(sizeof(struct curl_hash));
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|   if(h) {
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|     if(Curl_hash_init(h, slots, hfunc, comparator, dtor)) {
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|       /* failure */
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|       free(h);
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|       h = NULL;
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|     }
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|   }
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| 
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|   return h;
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| }
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| 
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| 
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| 
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| static struct curl_hash_element *
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| mk_hash_element(const void *key, size_t key_len, const void *p)
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| {
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|   struct curl_hash_element *he = malloc(sizeof(struct curl_hash_element));
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| 
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|   if(he) {
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|     void *dupkey = malloc(key_len);
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|     if(dupkey) {
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|       /* copy the key */
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|       memcpy(dupkey, key, key_len);
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| 
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|       he->key = dupkey;
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|       he->key_len = key_len;
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|       he->ptr = (void *) p;
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|     }
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|     else {
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|       /* failed to duplicate the key, free memory and fail */
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|       free(he);
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|       he = NULL;
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|     }
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|   }
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|   return he;
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| }
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| 
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| #define FETCH_LIST(x,y,z) x->table[x->hash_func(y, z, x->slots)]
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| 
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| /* Return the data in the hash. If there already was a match in the hash,
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|    that data is returned. */
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| void *
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| Curl_hash_add(struct curl_hash *h, void *key, size_t key_len, void *p)
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| {
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|   struct curl_hash_element  *he;
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|   struct curl_llist_element *le;
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|   struct curl_llist *l = FETCH_LIST (h, key, key_len);
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| 
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|   for (le = l->head; le; le = le->next) {
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|     he = (struct curl_hash_element *) le->ptr;
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|     if(h->comp_func(he->key, he->key_len, key, key_len)) {
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|       h->dtor(p);     /* remove the NEW entry */
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|       return he->ptr; /* return the EXISTING entry */
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|     }
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|   }
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| 
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|   he = mk_hash_element(key, key_len, p);
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|   if(he) {
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|     if(Curl_llist_insert_next(l, l->tail, he)) {
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|       ++h->size;
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|       return p; /* return the new entry */
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|     }
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|     /*
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|      * Couldn't insert it, destroy the 'he' element and the key again. We
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|      * don't call hash_element_dtor() since that would also call the
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|      * "destructor" for the actual data 'p'. When we fail, we shall not touch
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|      * that data.
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|      */
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|     free(he->key);
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|     free(he);
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|   }
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| 
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|   return NULL; /* failure */
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| }
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| 
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| /* remove the identified hash entry, returns non-zero on failure */
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| int Curl_hash_delete(struct curl_hash *h, void *key, size_t key_len)
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| {
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|   struct curl_llist_element *le;
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|   struct curl_hash_element  *he;
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|   struct curl_llist *l = FETCH_LIST(h, key, key_len);
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| 
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|   for (le = l->head; le; le = le->next) {
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|     he = le->ptr;
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|     if(h->comp_func(he->key, he->key_len, key, key_len)) {
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|       Curl_llist_remove(l, le, (void *) h);
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|       return 0;
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|     }
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|   }
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|   return 1;
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| }
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| 
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| void *
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| Curl_hash_pick(struct curl_hash *h, void *key, size_t key_len)
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| {
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|   struct curl_llist_element *le;
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|   struct curl_hash_element  *he;
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|   struct curl_llist *l = FETCH_LIST(h, key, key_len);
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| 
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|   for (le = l->head; le; le = le->next) {
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|     he = le->ptr;
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|     if(h->comp_func(he->key, he->key_len, key, key_len)) {
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|       return he->ptr;
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|     }
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|   }
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| 
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|   return NULL;
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| }
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| 
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| #if defined(CURLDEBUG) && defined(AGGRESIVE_TEST)
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| void
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| Curl_hash_apply(curl_hash *h, void *user,
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|                 void (*cb)(void *user, void *ptr))
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| {
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|   struct curl_llist_element  *le;
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|   int                  i;
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| 
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|   for (i = 0; i < h->slots; ++i) {
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|     for (le = (h->table[i])->head;
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|          le;
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|          le = le->next) {
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|       curl_hash_element *el = le->ptr;
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|       cb(user, el->ptr);
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|     }
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|   }
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| }
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| #endif
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| 
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| void
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| Curl_hash_clean(struct curl_hash *h)
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| {
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|   int i;
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| 
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|   for (i = 0; i < h->slots; ++i) {
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|     Curl_llist_destroy(h->table[i], (void *) h);
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|     h->table[i] = NULL;
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|   }
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| 
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|   free(h->table);
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| }
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| 
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| void
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| Curl_hash_clean_with_criterium(struct curl_hash *h, void *user,
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|                                int (*comp)(void *, void *))
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| {
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|   struct curl_llist_element *le;
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|   struct curl_llist_element *lnext;
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|   struct curl_llist *list;
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|   int i;
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| 
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|   for (i = 0; i < h->slots; ++i) {
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|     list = h->table[i];
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|     le = list->head; /* get first list entry */
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|     while(le) {
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|       struct curl_hash_element *he = le->ptr;
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|       lnext = le->next;
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|       /* ask the callback function if we shall remove this entry or not */
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|       if(comp(user, he->ptr)) {
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|         Curl_llist_remove(list, le, (void *) h);
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|         --h->size; /* one less entry in the hash now */
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|       }
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|       le = lnext;
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|     }
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|   }
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| }
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| 
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| void
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| Curl_hash_destroy(struct curl_hash *h)
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| {
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|   if(!h)
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|     return;
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| 
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|   Curl_hash_clean(h);
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| 
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|   free(h);
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| }
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| 
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| size_t Curl_hash_str(void* key, size_t key_length, size_t slots_num)
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| {
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|   const char* key_str = (const char *) key;
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|   const char *end = key_str + key_length;
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|   unsigned long h = 5381;
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| 
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|   while(key_str < end) {
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|     h += h << 5;
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|     h ^= (unsigned long) *key_str++;
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|   }
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| 
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|   return (h % slots_num);
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| }
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| 
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| size_t Curl_str_key_compare(void*k1, size_t key1_len, void*k2, size_t key2_len)
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| {
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|   char *key1 = (char *)k1;
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|   char *key2 = (char *)k2;
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| 
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|   if(key1_len == key2_len &&
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|       *key1 == *key2 &&
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|       memcmp(key1, key2, key1_len) == 0) {
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|     return 1;
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|   }
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| 
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|   return 0;
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| }
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| 
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| #if 0 /* useful function for debugging hashes and their contents */
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| void Curl_hash_print(struct curl_hash *h,
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|                      void (*func)(void *))
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| {
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|   int i;
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|   struct curl_llist_element *le;
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|   struct curl_llist *list;
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|   struct curl_hash_element  *he;
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|   if(!h)
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|     return;
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| 
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|   fprintf(stderr, "=Hash dump=\n");
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| 
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|   for (i = 0; i < h->slots; i++) {
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|     list = h->table[i];
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|     le = list->head; /* get first list entry */
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|     if(le) {
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|       fprintf(stderr, "index %d:", i);
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|       while(le) {
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|         he = le->ptr;
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|         if(func)
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|           func(he->ptr);
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|         else
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|           fprintf(stderr, " [%p]", he->ptr);
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|         le = le->next;
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|       }
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|       fprintf(stderr, "\n");
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|     }
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|   }
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| }
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| #endif
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