xenocara/xserver/hw/xquartz/xpr/x-hash.c
2019-07-27 07:57:06 +00:00

322 lines
8.2 KiB
C

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