summaryrefslogtreecommitdiff
path: root/src/lib/libc/stdlib/icdb.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/lib/libc/stdlib/icdb.c')
-rw-r--r--src/lib/libc/stdlib/icdb.c391
1 files changed, 0 insertions, 391 deletions
diff --git a/src/lib/libc/stdlib/icdb.c b/src/lib/libc/stdlib/icdb.c
deleted file mode 100644
index 2ddd9db48c..0000000000
--- a/src/lib/libc/stdlib/icdb.c
+++ /dev/null
@@ -1,391 +0,0 @@
1/* $OpenBSD: icdb.c,v 1.8 2016/09/04 16:56:02 nicm Exp $ */
2/*
3 * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18#include <errno.h>
19#include <fcntl.h>
20#include <icdb.h>
21#include <stddef.h>
22#include <stdint.h>
23#include <stdio.h>
24#include <stdlib.h>
25#include <string.h>
26#include <unistd.h>
27
28#include <sys/mman.h>
29#include <sys/stat.h>
30
31#include <siphash.h>
32
33/*
34 * Creating a new icdb: icdb_new
35 * Opening existing icdb: icdb_open
36 *
37 * Adding new entries: icdb_add
38 * Adding entries does not update the disk or indices.
39 *
40 * Save to disk: icdb_save
41 * Update indices: icdb_rehash
42 * icdb_save will call rehash.
43 *
44 * Change an existing entry: icdb_update
45 * Changing entries does write to disk.
46 *
47 * Find an entry: icdb_lookup
48 * Looking up an entry is only defined when the indices are synced.
49 *
50 * Close and free resources: icdb_close
51 */
52
53/*
54 * There are two major modes of operation.
55 *
56 * Existing databases use the mmap codepath. The entire database is mapped
57 * into the address space for quick access. Individual entries may be updated,
58 * but no new entries added.
59 *
60 * New databases use malloc backed memory instead. The database may be saved
61 * with icdb_save. It should be saved to a new file to avoid corrupting any
62 * open databases in other processes.
63 */
64
65/*
66 * An icdb has the following format:
67 * struct icbinfo header
68 * indexes [ uint32_t * indexsize * nkeys ]
69 * entries [ entrysize * nentries ]
70 *
71 * To find an entry in the file, the user specifies which key to use.
72 * The key is hashed and looked up in the index. The index contains the
73 * position of the entry in the entries array. -1 identifies not found.
74 * Chaining is done by rehashing the hash. All keys are fixed size byte arrays.
75 */
76
77/*
78 * Header info for icdb. This struct is stored on disk.
79 */
80struct icdbinfo {
81 uint32_t magic; /* magic */
82 uint32_t version; /* user specified version */
83 uint32_t nentries; /* number of entries stored */
84 uint32_t entrysize; /* size of each entry */
85 uint32_t indexsize; /* number of entries in hash index */
86 uint32_t nkeys; /* number of keys defined */
87 uint32_t keysize[8]; /* size of each key */
88 uint32_t keyoffset[8]; /* offset of each key in entry */
89 SIPHASH_KEY siphashkey; /* random hash key */
90};
91
92/*
93 * In memory representation with auxiliary data.
94 * idxdata and entries will be written to disk after info.
95 */
96struct icdb {
97 struct icdbinfo *info;
98 void *idxdata[8];
99 void *entries;
100 size_t maplen;
101 uint32_t allocated;
102 int fd;
103};
104
105static const uint32_t magic = 0x1ca9d0b7;
106
107static uint32_t
108roundup(uint32_t num)
109{
110 uint32_t r = 2;
111
112 while (r < num * 3 / 2)
113 r *= 2;
114 return r;
115}
116
117struct icdb *
118icdb_new(uint32_t version, uint32_t nentries, uint32_t entrysize,
119 uint32_t nkeys, const uint32_t *keysizes, const uint32_t *keyoffsets)
120{
121 struct icdb *db;
122 struct icdbinfo *info;
123 int i;
124
125 if (entrysize == 0 || entrysize > 1048576 || nkeys > 8) {
126 errno = EINVAL;
127 return NULL;
128 }
129
130 if (!(db = calloc(1, sizeof(*db))))
131 return NULL;
132 if (!(info = calloc(1, sizeof(*info)))) {
133 free(db);
134 return NULL;
135 }
136 db->info = info;
137 db->fd = -1;
138 info->magic = magic;
139 info->version = version;
140 if (nentries)
141 if ((db->entries = reallocarray(NULL, nentries, entrysize)))
142 db->allocated = nentries;
143 info->entrysize = entrysize;
144 info->nkeys = nkeys;
145 for (i = 0; i < nkeys; i++) {
146 info->keysize[i] = keysizes[i];
147 info->keyoffset[i] = keyoffsets[i];
148 }
149 return db;
150}
151DEF_WEAK(icdb_new);
152
153struct icdb *
154icdb_open(const char *name, int flags, uint32_t version)
155{
156 struct icdb *db = NULL;
157 struct icdbinfo *info;
158 struct stat sb;
159 uint8_t *ptr = MAP_FAILED;
160 uint32_t baseoff, indexsize, idxmask, idxlen;
161 int fd, i, saved_errno;
162
163 if ((fd = open(name, flags | O_CLOEXEC)) == -1)
164 return NULL;
165 if (fstat(fd, &sb) != 0)
166 goto fail;
167 if (sb.st_size < sizeof(struct icdbinfo))
168 goto fail;
169 ptr = mmap(NULL, sb.st_size, PROT_READ |
170 ((flags & O_RDWR) ? PROT_WRITE : 0), MAP_SHARED, fd, 0);
171 if (ptr == MAP_FAILED)
172 goto fail;
173 info = (struct icdbinfo *)ptr;
174 if (info->magic != magic || info->version != version) {
175 errno = ENOENT;
176 goto fail;
177 }
178
179 if (!(db = calloc(1, sizeof(*db))))
180 goto fail;
181 db->info = info;
182
183 indexsize = info->indexsize;
184 idxmask = indexsize - 1;
185 idxlen = indexsize * sizeof(uint32_t);
186 baseoff = sizeof(*info) + idxlen * info->nkeys;
187
188 for (i = 0; i < info->nkeys; i++)
189 db->idxdata[i] = ptr + sizeof(*info) + i * idxlen;
190 db->entries = ptr + baseoff;
191 db->maplen = sb.st_size;
192 db->fd = fd;
193 return db;
194
195fail:
196 saved_errno = errno;
197 if (ptr != MAP_FAILED)
198 munmap(ptr, sb.st_size);
199 if (fd != -1)
200 close(fd);
201 free(db);
202 errno = saved_errno;
203 return NULL;
204}
205DEF_WEAK(icdb_open);
206
207int
208icdb_get(struct icdb *db, void *entry, uint32_t idx)
209{
210 uint32_t entrysize = db->info->entrysize;
211
212 memcpy(entry, (uint8_t *)db->entries + idx * entrysize, entrysize);
213 return 0;
214}
215DEF_WEAK(icdb_get);
216
217int
218icdb_lookup(struct icdb *db, int keynum, const void *key, void *entry,
219 uint32_t *idxp)
220{
221 struct icdbinfo *info = db->info;
222 uint32_t offset;
223 uint64_t hash;
224 uint32_t indexsize, idxmask, idxlen;
225 uint32_t *idxdata;
226
227 indexsize = info->indexsize;
228 idxmask = indexsize - 1;
229 idxlen = indexsize * sizeof(uint32_t);
230
231 idxdata = db->idxdata[keynum];
232
233 hash = SipHash24(&info->siphashkey, key, info->keysize[keynum]);
234 while ((offset = idxdata[hash & idxmask]) != -1) {
235 if (icdb_get(db, entry, offset) != 0) {
236 errno = ENOENT;
237 return -1;
238 }
239 if (memcmp((uint8_t *)entry + info->keyoffset[keynum], key,
240 info->keysize[keynum]) == 0) {
241 if (idxp)
242 *idxp = offset;
243 return 0;
244 }
245 hash = SipHash24(&info->siphashkey, &hash, sizeof(hash));
246 }
247 return 1;
248}
249DEF_WEAK(icdb_lookup);
250
251int
252icdb_nentries(struct icdb *db)
253{
254 return db->info->nentries;
255}
256DEF_WEAK(icdb_nentries);
257
258const void *
259icdb_entries(struct icdb *db)
260{
261 return db->entries;
262}
263DEF_WEAK(icdb_entries);
264
265int
266icdb_update(struct icdb *db, const void *entry, int offset)
267{
268 struct icdbinfo *info = db->info;
269 uint32_t entrysize = info->entrysize;
270 uint32_t baseoff;
271 uint32_t indexsize, idxmask, idxlen;
272
273 indexsize = info->indexsize;
274 idxmask = indexsize - 1;
275 idxlen = indexsize * sizeof(uint32_t);
276 baseoff = sizeof(*info) + idxlen * info->nkeys;
277
278 memcpy((uint8_t *)db->entries + offset * entrysize, entry, entrysize);
279 if (db->fd != -1) {
280 msync((uint8_t *)db->entries + offset * entrysize, entrysize,
281 MS_SYNC);
282 }
283 return 0;
284}
285DEF_WEAK(icdb_update);
286
287int
288icdb_add(struct icdb *db, const void *entry)
289{
290 struct icdbinfo *info = db->info;
291 size_t entrysize = info->entrysize;
292
293 if (db->allocated == info->nentries) {
294 void *p;
295 size_t amt = db->allocated ? db->allocated * 2 : 63;
296 if (!(p = reallocarray(db->entries, amt, entrysize)))
297 return -1;
298 db->allocated = amt;
299 db->entries = p;
300 }
301 memcpy((uint8_t *)db->entries + info->nentries * entrysize,
302 entry, entrysize);
303 info->nentries++;
304 return 0;
305}
306DEF_WEAK(icdb_add);
307
308int
309icdb_rehash(struct icdb *db)
310{
311 struct icdbinfo *info = db->info;
312 uint32_t entrysize = info->entrysize;
313 uint32_t indexsize, idxmask, idxlen;
314 int i, j;
315
316 indexsize = info->indexsize = roundup(info->nentries);
317 idxmask = indexsize - 1;
318 idxlen = sizeof(uint32_t) * indexsize;
319
320 arc4random_buf(&info->siphashkey, sizeof(info->siphashkey));
321
322 for (i = 0; i < info->nkeys; i++) {
323 uint32_t *idxdata = reallocarray(db->idxdata[i],
324 indexsize, sizeof(uint32_t));
325 if (!idxdata)
326 return -1;
327 memset(idxdata, 0xff, idxlen);
328 db->idxdata[i] = idxdata;
329 }
330 for (j = 0; j < info->nentries; j++) {
331 for (i = 0; i < info->nkeys; i++) {
332 uint32_t *idxdata = db->idxdata[i];
333 uint64_t hash = SipHash24(&info->siphashkey,
334 (uint8_t *)db->entries + j * entrysize +
335 info->keyoffset[i], info->keysize[i]);
336 while (idxdata[hash & idxmask] != -1)
337 hash = SipHash24(&info->siphashkey, &hash, sizeof(hash));
338 idxdata[hash & idxmask] = j;
339 }
340 }
341 return 0;
342}
343DEF_WEAK(icdb_rehash);
344
345int
346icdb_save(struct icdb *db, int fd)
347{
348 struct icdbinfo *info = db->info;
349 uint32_t entrysize = info->entrysize;
350 uint32_t indexsize, idxlen;
351 int i;
352
353 if (icdb_rehash(db) != 0)
354 return -1;
355
356 indexsize = info->indexsize;
357 idxlen = sizeof(uint32_t) * indexsize;
358
359 if (ftruncate(fd, 0) != 0)
360 return -1;
361 if (write(fd, info, sizeof(*info)) != sizeof(*info))
362 return -1;
363 for (i = 0; i < info->nkeys; i++) {
364 if (write(fd, db->idxdata[i], idxlen) != idxlen)
365 return -1;
366 }
367 if (write(fd, db->entries, info->nentries * entrysize) !=
368 info->nentries * entrysize)
369 return -1;
370 return 0;
371}
372DEF_WEAK(icdb_save);
373
374int
375icdb_close(struct icdb *db)
376{
377 int i;
378
379 if (db->fd == -1) {
380 for (i = 0; i < db->info->nkeys; i++)
381 free(db->idxdata[i]);
382 free(db->entries);
383 free(db->info);
384 } else {
385 munmap(db->info, db->maplen);
386 close(db->fd);
387 }
388 free(db);
389 return 0;
390}
391DEF_WEAK(icdb_close);
generated by cgit v1.2.3-55-g6feb (git 2.39.1) at 2025-04-26 17:53:33 +0000