xref: /freebsd/contrib/unbound/util/storage/slabhash.c (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
1 /*
2  * util/storage/slabhash.c - hashtable consisting of several smaller tables.
3  *
4  * Copyright (c) 2007, NLnet Labs. All rights reserved.
5  *
6  * This software is open source.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * Redistributions of source code must retain the above copyright notice,
13  * this list of conditions and the following disclaimer.
14  *
15  * Redistributions in binary form must reproduce the above copyright notice,
16  * this list of conditions and the following disclaimer in the documentation
17  * and/or other materials provided with the distribution.
18  *
19  * Neither the name of the NLNET LABS nor the names of its contributors may
20  * be used to endorse or promote products derived from this software without
21  * specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 /**
37  * \file
38  *
39  * Implementation of hash table that consists of smaller hash tables.
40  * This results in a partitioned lruhash table.
41  * It cannot grow, but that gives it the ability to have multiple
42  * locks. Also this means there are multiple LRU lists.
43  */
44 
45 #include "config.h"
46 #include "util/storage/slabhash.h"
47 
48 struct slabhash* slabhash_create(size_t numtables, size_t start_size,
49 	size_t maxmem, lruhash_sizefunc_type sizefunc,
50 	lruhash_compfunc_type compfunc, lruhash_delkeyfunc_type delkeyfunc,
51 	lruhash_deldatafunc_type deldatafunc, void* arg)
52 {
53 	size_t i;
54 	struct slabhash* sl = (struct slabhash*)calloc(1,
55 		sizeof(struct slabhash));
56 	if(!sl) return NULL;
57 	sl->size = numtables;
58 	log_assert(sl->size > 0);
59 	sl->array = (struct lruhash**)calloc(sl->size, sizeof(struct lruhash*));
60 	if(!sl->array) {
61 		free(sl);
62 		return NULL;
63 	}
64 	sl->mask = (uint32_t)(sl->size - 1);
65 	if(sl->mask == 0) {
66 		sl->shift = 0;
67 	} else {
68 		log_assert( (sl->size & sl->mask) == 0
69 			/* size must be power of 2 */ );
70 		sl->shift = 0;
71 		while(!(sl->mask & 0x80000000)) {
72 			sl->mask <<= 1;
73 			sl->shift ++;
74 		}
75 	}
76 	for(i=0; i<sl->size; i++) {
77 		sl->array[i] = lruhash_create(start_size, maxmem / sl->size,
78 			sizefunc, compfunc, delkeyfunc, deldatafunc, arg);
79 		if(!sl->array[i]) {
80 			slabhash_delete(sl);
81 			return NULL;
82 		}
83 	}
84 	return sl;
85 }
86 
87 void slabhash_delete(struct slabhash* sl)
88 {
89 	if(!sl)
90 		return;
91 	if(sl->array) {
92 		size_t i;
93 		for(i=0; i<sl->size; i++)
94 			lruhash_delete(sl->array[i]);
95 		free(sl->array);
96 	}
97 	free(sl);
98 }
99 
100 void slabhash_clear(struct slabhash* sl)
101 {
102 	size_t i;
103 	if(!sl)
104 		return;
105 	for(i=0; i<sl->size; i++)
106 		lruhash_clear(sl->array[i]);
107 }
108 
109 /** helper routine to calculate the slabhash index */
110 static unsigned int
111 slab_idx(struct slabhash* sl, hashvalue_type hash)
112 {
113 	return ((hash & sl->mask) >> sl->shift);
114 }
115 
116 void slabhash_insert(struct slabhash* sl, hashvalue_type hash,
117 	struct lruhash_entry* entry, void* data, void* arg)
118 {
119 	lruhash_insert(sl->array[slab_idx(sl, hash)], hash, entry, data, arg);
120 }
121 
122 struct lruhash_entry* slabhash_lookup(struct slabhash* sl,
123 	hashvalue_type hash, void* key, int wr)
124 {
125 	return lruhash_lookup(sl->array[slab_idx(sl, hash)], hash, key, wr);
126 }
127 
128 void slabhash_remove(struct slabhash* sl, hashvalue_type hash, void* key)
129 {
130 	lruhash_remove(sl->array[slab_idx(sl, hash)], hash, key);
131 }
132 
133 void slabhash_status(struct slabhash* sl, const char* id, int extended)
134 {
135 	size_t i;
136 	char num[17];
137 	log_info("Slabhash %s: %u tables mask=%x shift=%d",
138 		id, (unsigned)sl->size, (unsigned)sl->mask, sl->shift);
139 	for(i=0; i<sl->size; i++) {
140 		snprintf(num, sizeof(num), "table %u", (unsigned)i);
141 		lruhash_status(sl->array[i], num, extended);
142 	}
143 }
144 
145 size_t slabhash_get_size(struct slabhash* sl)
146 {
147 	size_t i, total = 0;
148 	for(i=0; i<sl->size; i++) {
149 		lock_quick_lock(&sl->array[i]->lock);
150 		total += sl->array[i]->space_max;
151 		lock_quick_unlock(&sl->array[i]->lock);
152 	}
153 	return total;
154 }
155 
156 int slabhash_is_size(struct slabhash* sl, size_t size, size_t slabs)
157 {
158 	/* divide by slabs and then multiply by the number of slabs,
159 	 * because if the size is not an even multiple of slabs, the
160 	 * uneven amount needs to be removed for comparison */
161 	if(!sl) return 0;
162 	if(sl->size != slabs) return 0;
163 	if(slabs == 0) return 0;
164 	if( (size/slabs)*slabs == slabhash_get_size(sl))
165 		return 1;
166 	return 0;
167 }
168 
169 size_t slabhash_get_mem(struct slabhash* sl)
170 {
171 	size_t i, total = sizeof(*sl);
172 	total += sizeof(struct lruhash*)*sl->size;
173 	for(i=0; i<sl->size; i++) {
174 		total += lruhash_get_mem(sl->array[i]);
175 	}
176 	return total;
177 }
178 
179 struct lruhash* slabhash_gettable(struct slabhash* sl, hashvalue_type hash)
180 {
181 	return sl->array[slab_idx(sl, hash)];
182 }
183 
184 /* test code, here to avoid linking problems with fptr_wlist */
185 /** delete key */
186 static void delkey(struct slabhash_testkey* k) {
187 	lock_rw_destroy(&k->entry.lock); free(k);}
188 /** delete data */
189 static void deldata(struct slabhash_testdata* d) {free(d);}
190 
191 size_t test_slabhash_sizefunc(void* ATTR_UNUSED(key), void* ATTR_UNUSED(data))
192 {
193 	return sizeof(struct slabhash_testkey) +
194 		sizeof(struct slabhash_testdata);
195 }
196 
197 int test_slabhash_compfunc(void* key1, void* key2)
198 {
199 	struct slabhash_testkey* k1 = (struct slabhash_testkey*)key1;
200 	struct slabhash_testkey* k2 = (struct slabhash_testkey*)key2;
201 	if(k1->id == k2->id)
202 		return 0;
203 	if(k1->id > k2->id)
204 		return 1;
205 	return -1;
206 }
207 
208 void test_slabhash_delkey(void* key, void* ATTR_UNUSED(arg))
209 {
210 	delkey((struct slabhash_testkey*)key);
211 }
212 
213 void test_slabhash_deldata(void* data, void* ATTR_UNUSED(arg))
214 {
215 	deldata((struct slabhash_testdata*)data);
216 }
217 
218 void slabhash_setmarkdel(struct slabhash* sl, lruhash_markdelfunc_type md)
219 {
220 	size_t i;
221 	for(i=0; i<sl->size; i++) {
222 		lruhash_setmarkdel(sl->array[i], md);
223 	}
224 }
225 
226 void slabhash_traverse(struct slabhash* sh, int wr,
227 	void (*func)(struct lruhash_entry*, void*), void* arg)
228 {
229 	size_t i;
230 	for(i=0; i<sh->size; i++)
231 		lruhash_traverse(sh->array[i], wr, func, arg);
232 }
233 
234 size_t count_slabhash_entries(struct slabhash* sh)
235 {
236 	size_t slab, cnt = 0;
237 
238 	for(slab=0; slab<sh->size; slab++) {
239 		lock_quick_lock(&sh->array[slab]->lock);
240 		cnt += sh->array[slab]->num;
241 		lock_quick_unlock(&sh->array[slab]->lock);
242 	}
243 	return cnt;
244 }
245 
246 void get_slabhash_stats(struct slabhash* sh, long long* num, long long* collisions)
247 {
248 	size_t slab, cnt = 0, max_collisions = 0;
249 
250 	for(slab=0; slab<sh->size; slab++) {
251 		lock_quick_lock(&sh->array[slab]->lock);
252 		cnt += sh->array[slab]->num;
253 		if (max_collisions < sh->array[slab]->max_collisions) {
254 			max_collisions = sh->array[slab]->max_collisions;
255 		}
256 		lock_quick_unlock(&sh->array[slab]->lock);
257 	}
258 	if (num != NULL)
259 		*num = cnt;
260 	if (collisions != NULL)
261 		*collisions = max_collisions;
262 }
263