1 /* $NetBSD: cdbw.c,v 1.5 2012/07/21 22:49:37 joerg Exp $ */
2 /*-
3 * Copyright (c) 2009, 2010 The NetBSD Foundation, Inc.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to The NetBSD Foundation
7 * by Joerg Sonnenberger.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
18 * distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
30 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #if HAVE_NBTOOL_CONFIG_H
35 #include "nbtool_config.h"
36 #endif
37
38 #include <sys/cdefs.h>
39 __RCSID("$NetBSD: cdbw.c,v 1.5 2012/07/21 22:49:37 joerg Exp $");
40
41 #include "namespace.h"
42
43 #if !HAVE_NBTOOL_CONFIG_H || HAVE_SYS_ENDIAN_H
44 #include <sys/endian.h>
45 #endif
46 #include <sys/queue.h>
47 #include <cdbw.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51
52 #ifdef __weak_alias
53 __weak_alias(cdbw_close,_cdbw_close)
54 __weak_alias(cdbw_open,_cdbw_open)
55 __weak_alias(cdbw_output,_cdbw_output)
56 __weak_alias(cdbw_put,_cdbw_put)
57 __weak_alias(cdbw_put_data,_cdbw_put_data)
58 __weak_alias(cdbw_put_key,_cdbw_put_key)
59 #endif
60
61 struct key_hash {
62 SLIST_ENTRY(key_hash) link;
63 uint32_t hashes[3];
64 uint32_t idx;
65 void *key;
66 size_t keylen;
67 };
68
69 SLIST_HEAD(key_hash_head, key_hash);
70
71 struct cdbw {
72 size_t data_counter;
73 size_t data_allocated;
74 size_t data_size;
75 size_t *data_len;
76 void **data_ptr;
77
78 size_t hash_size;
79 struct key_hash_head *hash;
80 size_t key_counter;
81 };
82
83 /* Max. data counter that allows the index size to be 32bit. */
84 static const uint32_t max_data_counter = 0xccccccccU;
85
86 struct cdbw *
cdbw_open(void)87 cdbw_open(void)
88 {
89 struct cdbw *cdbw;
90 size_t i;
91
92 cdbw = calloc(sizeof(*cdbw), 1);
93 if (cdbw == NULL)
94 return NULL;
95
96 cdbw->hash_size = 1024;
97 cdbw->hash = calloc(cdbw->hash_size, sizeof(*cdbw->hash));
98 if (cdbw->hash == NULL) {
99 free(cdbw);
100 return NULL;
101 }
102
103 for (i = 0; i < cdbw->hash_size; ++i)
104 SLIST_INIT(cdbw->hash + i);
105
106 return cdbw;
107 }
108
109 int
cdbw_put(struct cdbw * cdbw,const void * key,size_t keylen,const void * data,size_t datalen)110 cdbw_put(struct cdbw *cdbw, const void *key, size_t keylen,
111 const void *data, size_t datalen)
112 {
113 uint32_t idx;
114 int rv;
115
116 rv = cdbw_put_data(cdbw, data, datalen, &idx);
117 if (rv)
118 return rv;
119 rv = cdbw_put_key(cdbw, key, keylen, idx);
120 if (rv) {
121 --cdbw->data_counter;
122 free(cdbw->data_ptr[cdbw->data_counter]);
123 cdbw->data_size -= datalen;
124 return rv;
125 }
126 return 0;
127 }
128
129 int
cdbw_put_data(struct cdbw * cdbw,const void * data,size_t datalen,uint32_t * idx)130 cdbw_put_data(struct cdbw *cdbw, const void *data, size_t datalen,
131 uint32_t *idx)
132 {
133
134 if (cdbw->data_counter == max_data_counter)
135 return -1;
136
137 if (cdbw->data_size + datalen < cdbw->data_size ||
138 cdbw->data_size + datalen > 0xffffffffU)
139 return -1; /* Overflow */
140
141 if (cdbw->data_allocated == cdbw->data_counter) {
142 void **new_data_ptr;
143 size_t *new_data_len;
144 size_t new_allocated;
145
146 if (cdbw->data_allocated == 0)
147 new_allocated = 256;
148 else
149 new_allocated = cdbw->data_allocated * 2;
150
151 new_data_ptr = realloc(cdbw->data_ptr,
152 sizeof(*cdbw->data_ptr) * new_allocated);
153 if (new_data_ptr == NULL)
154 return -1;
155 cdbw->data_ptr = new_data_ptr;
156
157 new_data_len = realloc(cdbw->data_len,
158 sizeof(*cdbw->data_len) * new_allocated);
159 if (new_data_len == NULL)
160 return -1;
161 cdbw->data_len = new_data_len;
162
163 cdbw->data_allocated = new_allocated;
164 }
165
166 cdbw->data_ptr[cdbw->data_counter] = malloc(datalen);
167 if (cdbw->data_ptr[cdbw->data_counter] == NULL)
168 return -1;
169 memcpy(cdbw->data_ptr[cdbw->data_counter], data, datalen);
170 cdbw->data_len[cdbw->data_counter] = datalen;
171 cdbw->data_size += datalen;
172 *idx = cdbw->data_counter++;
173 return 0;
174 }
175
176 int
cdbw_put_key(struct cdbw * cdbw,const void * key,size_t keylen,uint32_t idx)177 cdbw_put_key(struct cdbw *cdbw, const void *key, size_t keylen, uint32_t idx)
178 {
179 uint32_t hashes[3];
180 struct key_hash_head *head, *head2, *new_head;
181 struct key_hash *key_hash;
182 size_t new_hash_size, i;
183
184 if (idx >= cdbw->data_counter ||
185 cdbw->key_counter == max_data_counter)
186 return -1;
187
188 mi_vector_hash(key, keylen, 0, hashes);
189
190 head = cdbw->hash + (hashes[0] & (cdbw->hash_size - 1));
191 SLIST_FOREACH(key_hash, head, link) {
192 if (key_hash->keylen != keylen)
193 continue;
194 if (key_hash->hashes[0] != hashes[0])
195 continue;
196 if (key_hash->hashes[1] != hashes[1])
197 continue;
198 if (key_hash->hashes[2] != hashes[2])
199 continue;
200 if (memcmp(key, key_hash->key, keylen))
201 continue;
202 return -1;
203 }
204 key_hash = malloc(sizeof(*key_hash));
205 if (key_hash == NULL)
206 return -1;
207 key_hash->key = malloc(keylen);
208 if (key_hash->key == NULL) {
209 free(key_hash);
210 return -1;
211 }
212 memcpy(key_hash->key, key, keylen);
213 key_hash->hashes[0] = hashes[0];
214 key_hash->hashes[1] = hashes[1];
215 key_hash->hashes[2] = hashes[2];
216 key_hash->keylen = keylen;
217 key_hash->idx = idx;
218 SLIST_INSERT_HEAD(head, key_hash, link);
219 ++cdbw->key_counter;
220
221 if (cdbw->key_counter <= cdbw->hash_size)
222 return 0;
223
224 /* Try to resize the hash table, but ignore errors. */
225 new_hash_size = cdbw->hash_size * 2;
226 new_head = calloc(sizeof(*new_head), new_hash_size);
227 if (new_head == NULL)
228 return 0;
229
230 head = &cdbw->hash[hashes[0] & (cdbw->hash_size - 1)];
231 for (i = 0; i < new_hash_size; ++i)
232 SLIST_INIT(new_head + i);
233
234 for (i = 0; i < cdbw->hash_size; ++i) {
235 head = cdbw->hash + i;
236
237 while ((key_hash = SLIST_FIRST(head)) != NULL) {
238 SLIST_REMOVE_HEAD(head, link);
239 head2 = new_head +
240 (key_hash->hashes[0] & (new_hash_size - 1));
241 SLIST_INSERT_HEAD(head2, key_hash, link);
242 }
243 }
244 free(cdbw->hash);
245 cdbw->hash_size = new_hash_size;
246 cdbw->hash = new_head;
247
248 return 0;
249 }
250
251 void
cdbw_close(struct cdbw * cdbw)252 cdbw_close(struct cdbw *cdbw)
253 {
254 struct key_hash_head *head;
255 struct key_hash *key_hash;
256 size_t i;
257
258 for (i = 0; i < cdbw->hash_size; ++i) {
259 head = cdbw->hash + i;
260 while ((key_hash = SLIST_FIRST(head)) != NULL) {
261 SLIST_REMOVE_HEAD(head, link);
262 free(key_hash->key);
263 free(key_hash);
264 }
265 }
266
267 for (i = 0; i < cdbw->data_counter; ++i)
268 free(cdbw->data_ptr[i]);
269 free(cdbw->data_ptr);
270 free(cdbw->data_len);
271 free(cdbw->hash);
272 free(cdbw);
273 }
274
275 uint32_t
cdbw_stable_seeder(void)276 cdbw_stable_seeder(void)
277 {
278 return 0;
279 }
280
281 #define unused 0xffffffffU
282
283 struct vertex {
284 uint32_t l_edge, m_edge, r_edge;
285 };
286
287 struct edge {
288 uint32_t idx;
289
290 uint32_t left, middle, right;
291 uint32_t l_prev, m_prev, l_next;
292 uint32_t r_prev, m_next, r_next;
293 };
294
295 struct state {
296 uint32_t data_entries;
297 uint32_t entries;
298 uint32_t keys;
299 uint32_t seed;
300
301 uint32_t *g;
302 char *visited;
303
304 struct vertex *verts;
305 struct edge *edges;
306 uint32_t output_index;
307 uint32_t *output_order;
308 };
309
310 static void
remove_vertex(struct state * state,struct vertex * v)311 remove_vertex(struct state *state, struct vertex *v)
312 {
313 struct edge *e;
314 struct vertex *vl, *vm, *vr;
315
316 if (v->l_edge != unused && v->m_edge != unused)
317 return;
318 if (v->l_edge != unused && v->r_edge != unused)
319 return;
320 if (v->m_edge != unused && v->r_edge != unused)
321 return;
322 if (v->l_edge == unused && v->m_edge == unused && v->r_edge == unused)
323 return;
324
325 if (v->l_edge != unused) {
326 e = &state->edges[v->l_edge];
327 if (e->l_next != unused)
328 return;
329 } else if (v->m_edge != unused) {
330 e = &state->edges[v->m_edge];
331 if (e->m_next != unused)
332 return;
333 } else {
334 if (v->r_edge == unused)
335 abort();
336 e = &state->edges[v->r_edge];
337 if (e->r_next != unused)
338 return;
339 }
340
341 state->output_order[--state->output_index] = e - state->edges;
342
343 vl = &state->verts[e->left];
344 vm = &state->verts[e->middle];
345 vr = &state->verts[e->right];
346
347 if (e->l_prev == unused)
348 vl->l_edge = e->l_next;
349 else
350 state->edges[e->l_prev].l_next = e->l_next;
351 if (e->l_next != unused)
352 state->edges[e->l_next].l_prev = e->l_prev;
353
354 if (e->m_prev == unused)
355 vm->m_edge = e->m_next;
356 else
357 state->edges[e->m_prev].m_next = e->m_next;
358 if (e->m_next != unused)
359 state->edges[e->m_next].m_prev = e->m_prev;
360
361 if (e->r_prev == unused)
362 vr->r_edge = e->r_next;
363 else
364 state->edges[e->r_prev].r_next = e->r_next;
365 if (e->r_next != unused)
366 state->edges[e->r_next].r_prev = e->r_prev;
367 }
368
369 static int
build_graph(struct cdbw * cdbw,struct state * state)370 build_graph(struct cdbw *cdbw, struct state *state)
371 {
372 struct key_hash_head *head;
373 struct key_hash *key_hash;
374 struct vertex *v;
375 struct edge *e;
376 uint32_t hashes[3];
377 size_t i;
378
379 e = state->edges;
380 for (i = 0; i < cdbw->hash_size; ++i) {
381 head = &cdbw->hash[i];
382 SLIST_FOREACH(key_hash, head, link) {
383 e->idx = key_hash->idx;
384 mi_vector_hash(key_hash->key, key_hash->keylen,
385 state->seed, hashes);
386 e->left = hashes[0] % state->entries;
387 e->middle = hashes[1] % state->entries;
388 e->right = hashes[2] % state->entries;
389
390 if (e->left == e->middle)
391 return -1;
392 if (e->left == e->right)
393 return -1;
394 if (e->middle == e->right)
395 return -1;
396
397 ++e;
398 }
399 }
400
401 for (i = 0; i < state->entries; ++i) {
402 v = state->verts + i;
403 v->l_edge = unused;
404 v->m_edge = unused;
405 v->r_edge = unused;
406 }
407
408 for (i = 0; i < state->keys; ++i) {
409 e = state->edges + i;
410 v = state->verts + e->left;
411 if (v->l_edge != unused)
412 state->edges[v->l_edge].l_prev = i;
413 e->l_next = v->l_edge;
414 e->l_prev = unused;
415 v->l_edge = i;
416
417 v = &state->verts[e->middle];
418 if (v->m_edge != unused)
419 state->edges[v->m_edge].m_prev = i;
420 e->m_next = v->m_edge;
421 e->m_prev = unused;
422 v->m_edge = i;
423
424 v = &state->verts[e->right];
425 if (v->r_edge != unused)
426 state->edges[v->r_edge].r_prev = i;
427 e->r_next = v->r_edge;
428 e->r_prev = unused;
429 v->r_edge = i;
430 }
431
432 state->output_index = state->keys;
433 for (i = 0; i < state->entries; ++i)
434 remove_vertex(state, state->verts + i);
435
436 i = state->keys;
437 while (i > 0 && i > state->output_index) {
438 --i;
439 e = state->edges + state->output_order[i];
440 remove_vertex(state, state->verts + e->left);
441 remove_vertex(state, state->verts + e->middle);
442 remove_vertex(state, state->verts + e->right);
443 }
444
445 return state->output_index == 0 ? 0 : -1;
446 }
447
448 static void
assign_nodes(struct state * state)449 assign_nodes(struct state *state)
450 {
451 struct edge *e;
452 size_t i;
453
454 for (i = 0; i < state->keys; ++i) {
455 e = state->edges + state->output_order[i];
456
457 if (!state->visited[e->left]) {
458 state->g[e->left] =
459 (2 * state->data_entries + e->idx
460 - state->g[e->middle] - state->g[e->right])
461 % state->data_entries;
462 } else if (!state->visited[e->middle]) {
463 state->g[e->middle] =
464 (2 * state->data_entries + e->idx
465 - state->g[e->left] - state->g[e->right])
466 % state->data_entries;
467 } else {
468 state->g[e->right] =
469 (2 * state->data_entries + e->idx
470 - state->g[e->left] - state->g[e->middle])
471 % state->data_entries;
472 }
473 state->visited[e->left] = 1;
474 state->visited[e->middle] = 1;
475 state->visited[e->right] = 1;
476 }
477 }
478
479 static size_t
compute_size(uint32_t size)480 compute_size(uint32_t size)
481 {
482 if (size < 0x100)
483 return 1;
484 else if (size < 0x10000)
485 return 2;
486 else
487 return 4;
488 }
489
490 #define COND_FLUSH_BUFFER(n) do { \
491 if (__predict_false(cur_pos + (n) >= sizeof(buf))) { \
492 ret = write(fd, buf, cur_pos); \
493 if (ret == -1 || (size_t)ret != cur_pos) \
494 return -1; \
495 cur_pos = 0; \
496 } \
497 } while (/* CONSTCOND */ 0)
498
499 static int
print_hash(struct cdbw * cdbw,struct state * state,int fd,const char * descr)500 print_hash(struct cdbw *cdbw, struct state *state, int fd, const char *descr)
501 {
502 uint32_t data_size;
503 uint8_t buf[90000];
504 size_t i, size, size2, cur_pos;
505 ssize_t ret;
506
507 memcpy(buf, "NBCDB\n\0", 7);
508 buf[7] = 1;
509 strncpy((char *)buf + 8, descr, 16);
510 le32enc(buf + 24, cdbw->data_size);
511 le32enc(buf + 28, cdbw->data_counter);
512 le32enc(buf + 32, state->entries);
513 le32enc(buf + 36, state->seed);
514 cur_pos = 40;
515
516 size = compute_size(state->entries);
517 for (i = 0; i < state->entries; ++i) {
518 COND_FLUSH_BUFFER(4);
519 le32enc(buf + cur_pos, state->g[i]);
520 cur_pos += size;
521 }
522 size2 = compute_size(cdbw->data_size);
523 size = size * state->entries % size2;
524 if (size != 0) {
525 size = size2 - size;
526 COND_FLUSH_BUFFER(4);
527 le32enc(buf + cur_pos, 0);
528 cur_pos += size;
529 }
530 for (data_size = 0, i = 0; i < cdbw->data_counter; ++i) {
531 COND_FLUSH_BUFFER(4);
532 le32enc(buf + cur_pos, data_size);
533 cur_pos += size2;
534 data_size += cdbw->data_len[i];
535 }
536 COND_FLUSH_BUFFER(4);
537 le32enc(buf + cur_pos, data_size);
538 cur_pos += size2;
539
540 for (i = 0; i < cdbw->data_counter; ++i) {
541 COND_FLUSH_BUFFER(cdbw->data_len[i]);
542 if (cdbw->data_len[i] < sizeof(buf)) {
543 memcpy(buf + cur_pos, cdbw->data_ptr[i],
544 cdbw->data_len[i]);
545 cur_pos += cdbw->data_len[i];
546 } else {
547 ret = write(fd, cdbw->data_ptr[i], cdbw->data_len[i]);
548 if (ret == -1 || (size_t)ret != cdbw->data_len[i])
549 return -1;
550 }
551 }
552 if (cur_pos != 0) {
553 ret = write(fd, buf, cur_pos);
554 if (ret == -1 || (size_t)ret != cur_pos)
555 return -1;
556 }
557 return 0;
558 }
559
560 int
cdbw_output(struct cdbw * cdbw,int fd,const char descr[16],uint32_t (* seedgen)(void))561 cdbw_output(struct cdbw *cdbw, int fd, const char descr[16],
562 uint32_t (*seedgen)(void))
563 {
564 struct state state;
565 int rv;
566
567 if (cdbw->data_counter == 0 || cdbw->key_counter == 0) {
568 state.entries = 0;
569 state.seed = 0;
570 print_hash(cdbw, &state, fd, descr);
571 return 0;
572 }
573
574 #if HAVE_NBTOOL_CONFIG_H
575 if (seedgen == NULL)
576 seedgen = cdbw_stable_seeder;
577 #else
578 if (seedgen == NULL)
579 seedgen = arc4random;
580 #endif
581
582 rv = 0;
583
584 state.keys = cdbw->key_counter;
585 state.data_entries = cdbw->data_counter;
586 state.entries = state.keys + (state.keys + 3) / 4;
587 if (state.entries < 10)
588 state.entries = 10;
589
590 #define NALLOC(var, n) var = calloc(sizeof(*var), n)
591 NALLOC(state.g, state.entries);
592 NALLOC(state.visited, state.entries);
593 NALLOC(state.verts, state.entries);
594 NALLOC(state.edges, state.entries);
595 NALLOC(state.output_order, state.keys);
596 #undef NALLOC
597
598 if (state.g == NULL || state.visited == NULL || state.verts == NULL ||
599 state.edges == NULL || state.output_order == NULL) {
600 rv = -1;
601 goto release;
602 }
603
604 state.seed = 0;
605 do {
606 if (seedgen == cdbw_stable_seeder)
607 ++state.seed;
608 else
609 state.seed = (*seedgen)();
610 } while (build_graph(cdbw, &state));
611
612 assign_nodes(&state);
613 rv = print_hash(cdbw, &state, fd, descr);
614
615 release:
616 free(state.g);
617 free(state.visited);
618 free(state.verts);
619 free(state.edges);
620 free(state.output_order);
621
622 return rv;
623 }
624