322 lines
		
	
	
		
			8.2 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			322 lines
		
	
	
		
			8.2 KiB
		
	
	
	
		
			C
		
	
	
	
| /* x-hash.c - basic hash tables
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|  *
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|  * Copyright (c) 2002-2012 Apple Inc. All rights reserved.
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|  *
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|  * Permission is hereby granted, free of charge, to any person
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|  * obtaining a copy of this software and associated documentation files
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|  * (the "Software"), to deal in the Software without restriction,
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|  * including without limitation the rights to use, copy, modify, merge,
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|  * publish, distribute, sublicense, and/or sell copies of the Software,
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|  * and to permit persons to whom the Software is furnished to do so,
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|  * subject to the following conditions:
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|  *
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|  * The above copyright notice and this permission notice shall be
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|  * included in all copies or substantial portions of the Software.
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|  *
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|  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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|  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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|  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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|  * NONINFRINGEMENT.  IN NO EVENT SHALL THE ABOVE LISTED COPYRIGHT
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|  * HOLDER(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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|  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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|  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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|  * DEALINGS IN THE SOFTWARE.
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|  *
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|  * Except as contained in this notice, the name(s) of the above
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|  * copyright holders shall not be used in advertising or otherwise to
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|  * promote the sale, use or other dealings in this Software without
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|  * prior written authorization.
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|  */
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| 
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| #ifdef HAVE_DIX_CONFIG_H
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| #include <dix-config.h>
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| #endif
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| 
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| #include "x-hash.h"
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| #include "x-list.h"
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| #include <stdlib.h>
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| #include <assert.h>
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| 
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| struct x_hash_table_struct {
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|     unsigned int bucket_index;
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|     unsigned int total_keys;
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|     x_list **buckets;
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| 
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|     x_hash_fun *hash_key;
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|     x_compare_fun *compare_keys;
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|     x_destroy_fun *destroy_key;
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|     x_destroy_fun *destroy_value;
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| };
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| 
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| #define ITEM_NEW(k, v) X_PFX(list_prepend) ((x_list *)(k), v)
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| #define ITEM_FREE(i)   X_PFX(list_free_1) (i)
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| #define ITEM_KEY(i)    ((void *)(i)->next)
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| #define ITEM_VALUE(i)  ((i)->data)
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| 
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| #define SPLIT_THRESHOLD_FACTOR 2
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| 
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| /* http://planetmath.org/?op=getobj&from=objects&name=GoodHashTablePrimes */
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| static const unsigned int bucket_sizes[] = {
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|     29,       53,        97,        193,        389,        769,       1543,
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|     3079,     6151, 12289, 24593, 49157,
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|     98317,    196613,   393241,    786433,    1572869,   3145739,   6291469,
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|     12582917,
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|     25165843, 50331653, 100663319, 201326611, 402653189, 805306457,
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|     1610612741
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| };
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| 
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| #define N_BUCKET_SIZES (sizeof(bucket_sizes) / sizeof(bucket_sizes[0]))
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| 
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| static inline unsigned int
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| hash_table_total_buckets(x_hash_table *h)
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| {
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|     return bucket_sizes[h->bucket_index];
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| }
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| 
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| static inline void
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| hash_table_destroy_item(x_hash_table *h, void *k, void *v)
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| {
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|     if (h->destroy_key != 0)
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|         (*h->destroy_key)(k);
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| 
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|     if (h->destroy_value != 0)
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|         (*h->destroy_value)(v);
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| }
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| 
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| static inline size_t
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| hash_table_hash_key(x_hash_table *h, void *k)
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| {
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|     if (h->hash_key != 0)
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|         return (*h->hash_key)(k);
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|     else
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|         return (size_t)k;
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| }
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| 
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| static inline int
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| hash_table_compare_keys(x_hash_table *h, void *k1, void *k2)
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| {
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|     if (h->compare_keys == 0)
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|         return k1 == k2;
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|     else
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|         return (*h->compare_keys)(k1, k2) == 0;
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| }
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| 
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| static void
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| hash_table_split(x_hash_table *h)
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| {
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|     x_list **new, **old;
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|     x_list *node, *item, *next;
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|     int new_size, old_size;
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|     size_t b;
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|     int i;
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| 
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|     if (h->bucket_index == N_BUCKET_SIZES - 1)
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|         return;
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| 
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|     old_size = hash_table_total_buckets(h);
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|     old = h->buckets;
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| 
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|     h->bucket_index++;
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| 
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|     new_size = hash_table_total_buckets(h);
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|     new = calloc(new_size, sizeof(x_list *));
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| 
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|     if (new == 0) {
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|         h->bucket_index--;
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|         return;
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|     }
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| 
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|     for (i = 0; i < old_size; i++) {
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|         for (node = old[i]; node != 0; node = next) {
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|             next = node->next;
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|             item = node->data;
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| 
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|             b = hash_table_hash_key(h, ITEM_KEY(item)) % new_size;
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| 
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|             node->next = new[b];
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|             new[b] = node;
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|         }
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|     }
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| 
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|     h->buckets = new;
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|     free(old);
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| }
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| 
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| X_EXTERN x_hash_table *
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| X_PFX(hash_table_new) (x_hash_fun * hash,
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|                        x_compare_fun * compare,
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|                        x_destroy_fun * key_destroy,
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|                        x_destroy_fun * value_destroy) {
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|     x_hash_table *h;
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| 
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|     h = calloc(1, sizeof(x_hash_table));
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|     if (h == 0)
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|         return 0;
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| 
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|     h->bucket_index = 0;
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|     h->buckets = calloc(hash_table_total_buckets(h), sizeof(x_list *));
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| 
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|     if (h->buckets == 0) {
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|         free(h);
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|         return 0;
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|     }
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| 
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|     h->hash_key = hash;
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|     h->compare_keys = compare;
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|     h->destroy_key = key_destroy;
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|     h->destroy_value = value_destroy;
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| 
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|     return h;
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| }
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| 
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| X_EXTERN void
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| X_PFX(hash_table_free) (x_hash_table * h) {
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|     int n, i;
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|     x_list *node, *item;
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| 
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|     assert(h != NULL);
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| 
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|     n = hash_table_total_buckets(h);
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| 
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|     for (i = 0; i < n; i++) {
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|         for (node = h->buckets[i]; node != 0; node = node->next) {
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|             item = node->data;
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|             hash_table_destroy_item(h, ITEM_KEY(item), ITEM_VALUE(item));
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|             ITEM_FREE(item);
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|         }
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|         X_PFX(list_free) (h->buckets[i]);
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|     }
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| 
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|     free(h->buckets);
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|     free(h);
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| }
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| 
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| X_EXTERN unsigned int
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| X_PFX(hash_table_size) (x_hash_table * h) {
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|     assert(h != NULL);
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| 
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|     return h->total_keys;
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| }
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| 
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| static void
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| hash_table_modify(x_hash_table *h, void *k, void *v, int replace)
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| {
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|     size_t hash_value;
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|     x_list *node, *item;
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| 
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|     assert(h != NULL);
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| 
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|     hash_value = hash_table_hash_key(h, k);
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| 
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|     for (node = h->buckets[hash_value % hash_table_total_buckets(h)];
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|          node != 0; node = node->next) {
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|         item = node->data;
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| 
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|         if (hash_table_compare_keys(h, ITEM_KEY(item), k)) {
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|             if (replace) {
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|                 hash_table_destroy_item(h, ITEM_KEY(item),
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|                                         ITEM_VALUE(item));
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|                 item->next = k;
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|                 ITEM_VALUE(item) = v;
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|             }
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|             else {
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|                 hash_table_destroy_item(h, k, ITEM_VALUE(item));
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|                 ITEM_VALUE(item) = v;
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|             }
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|             return;
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|         }
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|     }
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| 
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|     /* Key isn't already in the table. Insert it. */
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| 
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|     if (h->total_keys + 1
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|         > hash_table_total_buckets(h) * SPLIT_THRESHOLD_FACTOR) {
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|         hash_table_split(h);
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|     }
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| 
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|     hash_value = hash_value % hash_table_total_buckets(h);
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|     h->buckets[hash_value] = X_PFX(list_prepend) (h->buckets[hash_value],
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|                                                   ITEM_NEW(k, v));
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|     h->total_keys++;
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| }
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| 
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| X_EXTERN void
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| X_PFX(hash_table_insert) (x_hash_table * h, void *k, void *v) {
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|     hash_table_modify(h, k, v, 0);
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| }
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| 
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| X_EXTERN void
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| X_PFX(hash_table_replace) (x_hash_table * h, void *k, void *v) {
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|     hash_table_modify(h, k, v, 1);
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| }
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| 
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| X_EXTERN void
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| X_PFX(hash_table_remove) (x_hash_table * h, void *k) {
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|     size_t hash_value;
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|     x_list **ptr, *item;
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| 
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|     assert(h != NULL);
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| 
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|     hash_value = hash_table_hash_key(h, k);
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| 
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|     for (ptr = &h->buckets[hash_value % hash_table_total_buckets(h)];
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|          *ptr != 0; ptr = &((*ptr)->next)) {
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|         item = (*ptr)->data;
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| 
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|         if (hash_table_compare_keys(h, ITEM_KEY(item), k)) {
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|             hash_table_destroy_item(h, ITEM_KEY(item), ITEM_VALUE(item));
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|             ITEM_FREE(item);
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|             item = *ptr;
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|             *ptr = item->next;
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|             X_PFX(list_free_1) (item);
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|             h->total_keys--;
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|             return;
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|         }
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|     }
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| }
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| 
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| X_EXTERN void *
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| X_PFX(hash_table_lookup) (x_hash_table * h, void *k, void **k_ret) {
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|     size_t hash_value;
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|     x_list *node, *item;
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| 
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|     assert(h != NULL);
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| 
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|     hash_value = hash_table_hash_key(h, k);
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| 
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|     for (node = h->buckets[hash_value % hash_table_total_buckets(h)];
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|          node != 0; node = node->next) {
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|         item = node->data;
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| 
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|         if (hash_table_compare_keys(h, ITEM_KEY(item), k)) {
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|             if (k_ret != 0)
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|                 *k_ret = ITEM_KEY(item);
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| 
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|             return ITEM_VALUE(item);
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|         }
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|     }
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| 
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|     if (k_ret != 0)
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|         *k_ret = 0;
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| 
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|     return 0;
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| }
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| 
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| X_EXTERN void
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| X_PFX(hash_table_foreach) (x_hash_table * h,
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|                            x_hash_foreach_fun * fun, void *data) {
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|     int i, n;
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|     x_list *node, *item;
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| 
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|     assert(h != NULL);
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| 
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|     n = hash_table_total_buckets(h);
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| 
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|     for (i = 0; i < n; i++) {
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|         for (node = h->buckets[i]; node != 0; node = node->next) {
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|             item = node->data;
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|             (*fun)(ITEM_KEY(item), ITEM_VALUE(item), data);
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|         }
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|     }
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| }
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