xref: /netbsd/lib/libc/cdb/cdbw.c (revision 6550d01e)
1 /*	$NetBSD: cdbw.c,v 1.1 2010/04/25 00:54:46 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 1.1 2010/04/25 00:54:46 joerg Exp $");
40 
41 #include "namespace.h"
42 
43 #include <sys/endian.h>
44 #include <sys/queue.h>
45 #include <cdbw.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 
50 #ifdef __weak_alias
51 __weak_alias(cdbw_close,_cdbw_close)
52 __weak_alias(cdbw_open,_cdbw_open)
53 __weak_alias(cdbw_output,_cdbw_output)
54 __weak_alias(cdbw_put,_cdbw_put)
55 __weak_alias(cdbw_put_data,_cdbw_put_data)
56 __weak_alias(cdbw_put_key,_cdbw_put_key)
57 #endif
58 
59 struct key_hash {
60 	SLIST_ENTRY(key_hash) link;
61 	uint32_t hashes[3];
62 	uint32_t idx;
63 	void *key;
64 	size_t keylen;
65 };
66 
67 SLIST_HEAD(key_hash_head, key_hash);
68 
69 struct cdbw {
70 	size_t data_counter;
71 	size_t data_allocated;
72 	size_t data_size;
73 	size_t *data_len;
74 	void **data_ptr;
75 
76 	size_t hash_size;
77 	struct key_hash_head *hash;
78 	size_t key_counter;
79 };
80 
81  /* Max. data counter that allows the index size to be 32bit. */
82 static const uint32_t max_data_counter = 0xccccccccU;
83 
84 struct cdbw *
85 cdbw_open(void)
86 {
87 	struct cdbw *cdbw;
88 	size_t i;
89 
90 	cdbw = calloc(sizeof(*cdbw), 1);
91 	if (cdbw == NULL)
92 		return NULL;
93 
94 	cdbw->hash_size = 1024;
95 	cdbw->hash = calloc(cdbw->hash_size, sizeof(*cdbw->hash));
96 	if (cdbw->hash == NULL) {
97 		free(cdbw);
98 		return NULL;
99 	}
100 
101 	for (i = 0; i < cdbw->hash_size; ++i)
102 		SLIST_INIT(cdbw->hash + i);
103 
104 	return cdbw;
105 }
106 
107 int
108 cdbw_put(struct cdbw *cdbw, const void *key, size_t keylen,
109     const void *data, size_t datalen)
110 {
111 	uint32_t idx;
112 	int rv;
113 
114 	rv = cdbw_put_data(cdbw, data, datalen, &idx);
115 	if (rv)
116 		return rv;
117 	rv = cdbw_put_key(cdbw, key, keylen, idx);
118 	if (rv) {
119 		--cdbw->data_counter;
120 		free(cdbw->data_ptr[cdbw->data_counter]);
121 		cdbw->data_size -= datalen;
122 		return rv;
123 	}
124 	return 0;
125 }
126 
127 int
128 cdbw_put_data(struct cdbw *cdbw, const void *data, size_t datalen,
129     uint32_t *idx)
130 {
131 
132 	if (cdbw->data_counter == max_data_counter)
133 		return -1;
134 
135 	if (cdbw->data_size + datalen < cdbw->data_size ||
136 	    cdbw->data_size + datalen > 0xffffffffU)
137 		return -1; /* Overflow */
138 
139 	if (cdbw->data_allocated == cdbw->data_counter) {
140 		void **new_data_ptr;
141 		size_t *new_data_len;
142 		size_t new_allocated;
143 
144 		if (cdbw->data_allocated == 0)
145 			new_allocated = 256;
146 		else
147 			new_allocated = cdbw->data_allocated * 2;
148 
149 		new_data_ptr = realloc(cdbw->data_ptr,
150 		    sizeof(*cdbw->data_ptr) * new_allocated);
151 		if (new_data_ptr == NULL)
152 			return -1;
153 		cdbw->data_ptr = new_data_ptr;
154 
155 		new_data_len = realloc(cdbw->data_len,
156 		    sizeof(*cdbw->data_len) * new_allocated);
157 		if (new_data_len == NULL)
158 			return -1;
159 		cdbw->data_len = new_data_len;
160 
161 		cdbw->data_allocated = new_allocated;
162 	}
163 
164 	cdbw->data_ptr[cdbw->data_counter] = malloc(datalen);
165 	if (cdbw->data_ptr[cdbw->data_counter] == NULL)
166 		return -1;
167 	memcpy(cdbw->data_ptr[cdbw->data_counter], data, datalen);
168 	cdbw->data_len[cdbw->data_counter] = datalen;
169 	cdbw->data_size += datalen;
170 	*idx = cdbw->data_counter++;
171 	return 0;
172 }
173 
174 int
175 cdbw_put_key(struct cdbw *cdbw, const void *key, size_t keylen, uint32_t idx)
176 {
177 	uint32_t hashes[3];
178 	struct key_hash_head *head, *head2, *new_head;
179 	struct key_hash *key_hash;
180 	size_t new_hash_size, i;
181 
182 	if (idx >= cdbw->data_counter ||
183 	    cdbw->key_counter == max_data_counter)
184 		return -1;
185 
186 	mi_vector_hash(key, keylen, 0, hashes);
187 
188 	head = cdbw->hash + (hashes[0] & (cdbw->hash_size - 1));
189 	SLIST_FOREACH(key_hash, head, link) {
190 		if (key_hash->keylen != keylen)
191 			continue;
192 		if (key_hash->hashes[0] != hashes[0])
193 			continue;
194 		if (key_hash->hashes[1] != hashes[1])
195 			continue;
196 		if (key_hash->hashes[2] != hashes[2])
197 			continue;
198 		if (memcmp(key, key_hash->key, keylen))
199 			continue;
200 		return -1;
201 	}
202 	key_hash = malloc(sizeof(*key_hash));
203 	if (key_hash == NULL)
204 		return -1;
205 	key_hash->key = malloc(keylen);
206 	if (key_hash->key == NULL) {
207 		free(key_hash);
208 		return -1;
209 	}
210 	memcpy(key_hash->key, key, keylen);
211 	key_hash->hashes[0] = hashes[0];
212 	key_hash->hashes[1] = hashes[1];
213 	key_hash->hashes[2] = hashes[2];
214 	key_hash->keylen = keylen;
215 	key_hash->idx = idx;
216 	SLIST_INSERT_HEAD(head, key_hash, link);
217 	++cdbw->key_counter;
218 
219 	if (cdbw->key_counter <= cdbw->hash_size)
220 		return 0;
221 
222 	/* Try to resize the hash table, but ignore errors. */
223 	new_hash_size = cdbw->hash_size * 2;
224 	new_head = calloc(sizeof(*new_head), new_hash_size);
225 	if (new_head == NULL)
226 		return 0;
227 
228 	head = &cdbw->hash[hashes[0] & (cdbw->hash_size - 1)];
229 	for (i = 0; i < new_hash_size; ++i)
230 		SLIST_INIT(new_head + i);
231 
232 	for (i = 0; i < cdbw->hash_size; ++i) {
233 		head = cdbw->hash + i;
234 
235 		while ((key_hash = SLIST_FIRST(head)) != NULL) {
236 			SLIST_REMOVE_HEAD(head, link);
237 			head2 = new_head +
238 			    (key_hash->hashes[0] & (new_hash_size - 1));
239 			SLIST_INSERT_HEAD(head2, key_hash, link);
240 		}
241 	}
242 	free(cdbw->hash);
243 	cdbw->hash_size = new_hash_size;
244 	cdbw->hash = new_head;
245 
246 	return 0;
247 }
248 
249 void
250 cdbw_close(struct cdbw *cdbw)
251 {
252 	struct key_hash_head *head;
253 	struct key_hash *key_hash;
254 	size_t i;
255 
256 	for (i = 0; i < cdbw->hash_size; ++i) {
257 		head = cdbw->hash + i;
258 		while ((key_hash = SLIST_FIRST(head)) != NULL) {
259 			SLIST_REMOVE_HEAD(head, link);
260 			free(key_hash->key);
261 			free(key_hash);
262 		}
263 	}
264 
265 	for (i = 0; i < cdbw->data_counter; ++i)
266 		free(cdbw->data_ptr[i]);
267 	free(cdbw->data_ptr);
268 	free(cdbw->data_len);
269 	free(cdbw->hash);
270 	free(cdbw);
271 }
272 
273 #define unused 0xffffffffU
274 
275 struct vertex {
276 	uint32_t l_edge, m_edge, r_edge;
277 };
278 
279 struct edge {
280 	uint32_t idx;
281 
282 	uint32_t left, middle, right;
283 	uint32_t l_prev, m_prev, l_next;
284 	uint32_t r_prev, m_next, r_next;
285 };
286 
287 struct state {
288 	uint32_t data_entries;
289 	uint32_t entries;
290 	uint32_t keys;
291 	uint32_t seed;
292 
293 	uint32_t *g;
294 	char *visited;
295 
296 	struct vertex *verts;
297 	struct edge *edges;
298 	uint32_t output_index;
299 	uint32_t *output_order;
300 };
301 
302 static void
303 remove_vertex(struct state *state, struct vertex *v)
304 {
305 	struct edge *e;
306 	struct vertex *vl, *vm, *vr;
307 
308 	if (v->l_edge != unused && v->m_edge != unused)
309 		return;
310 	if (v->l_edge != unused && v->r_edge != unused)
311 		return;
312 	if (v->m_edge != unused && v->r_edge != unused)
313 		return;
314 	if (v->l_edge == unused && v->m_edge == unused && v->r_edge == unused)
315 		return;
316 
317 	if (v->l_edge != unused) {
318 		e = &state->edges[v->l_edge];
319 		if (e->l_next != unused)
320 			return;
321 	} else if (v->m_edge != unused) {
322 		e = &state->edges[v->m_edge];
323 		if (e->m_next != unused)
324 			return;
325 	} else {
326 		if (v->r_edge == unused)
327 			abort();
328 		e = &state->edges[v->r_edge];
329 		if (e->r_next != unused)
330 			return;
331 	}
332 
333 	state->output_order[--state->output_index] = e - state->edges;
334 
335 	vl = &state->verts[e->left];
336 	vm = &state->verts[e->middle];
337 	vr = &state->verts[e->right];
338 
339 	if (e->l_prev == unused)
340 		vl->l_edge = e->l_next;
341 	else
342 		state->edges[e->l_prev].l_next = e->l_next;
343 	if (e->l_next != unused)
344 		state->edges[e->l_next].l_prev = e->l_prev;
345 
346 	if (e->m_prev == unused)
347 		vm->m_edge = e->m_next;
348 	else
349 		state->edges[e->m_prev].m_next = e->m_next;
350 	if (e->m_next != unused)
351 		state->edges[e->m_next].m_prev = e->m_prev;
352 
353 	if (e->r_prev == unused)
354 		vr->r_edge = e->r_next;
355 	else
356 		state->edges[e->r_prev].r_next = e->r_next;
357 	if (e->r_next != unused)
358 		state->edges[e->r_next].r_prev = e->r_prev;
359 }
360 
361 static int
362 build_graph(struct cdbw *cdbw, struct state *state)
363 {
364 	struct key_hash_head *head;
365 	struct key_hash *key_hash;
366 	struct vertex *v;
367 	struct edge *e;
368 	uint32_t hashes[3];
369 	size_t i;
370 
371 	e = state->edges;
372 	for (i = 0; i < cdbw->hash_size; ++i) {
373 		head = &cdbw->hash[i];
374 		SLIST_FOREACH(key_hash, head, link) {
375 			e->idx = key_hash->idx;
376 			mi_vector_hash(key_hash->key, key_hash->keylen,
377 			    state->seed, hashes);
378 			e->left = hashes[0] % state->entries;
379 			e->middle = hashes[1] % state->entries;
380 			e->right = hashes[2] % state->entries;
381 
382 			++e;
383 		}
384 	}
385 
386 	for (i = 0; i < state->entries; ++i) {
387 		v = state->verts + i;
388 		v->l_edge = unused;
389 		v->m_edge = unused;
390 		v->r_edge = unused;
391 	}
392 
393 	for (i = 0; i < state->keys; ++i) {
394 		e = state->edges + i;
395 		v = state->verts + e->left;
396 		if (v->l_edge != unused)
397 			state->edges[v->l_edge].l_prev = i;
398 		e->l_next = v->l_edge;
399 		e->l_prev = unused;
400 		v->l_edge = i;
401 
402 		v = &state->verts[e->middle];
403 		if (v->m_edge != unused)
404 			state->edges[v->m_edge].m_prev = i;
405 		e->m_next = v->m_edge;
406 		e->m_prev = unused;
407 		v->m_edge = i;
408 
409 		v = &state->verts[e->right];
410 		if (v->r_edge != unused)
411 			state->edges[v->r_edge].r_prev = i;
412 		e->r_next = v->r_edge;
413 		e->r_prev = unused;
414 		v->r_edge = i;
415 	}
416 
417 	state->output_index = state->keys;
418 	for (i = 0; i < state->entries; ++i)
419 		remove_vertex(state, state->verts + i);
420 
421 	i = state->keys;
422 	while (i > 0 && i > state->output_index) {
423 		--i;
424 		e = state->edges + state->output_order[i];
425 		remove_vertex(state, state->verts + e->left);
426 		remove_vertex(state, state->verts + e->middle);
427 		remove_vertex(state, state->verts + e->right);
428 	}
429 
430 	return state->output_index == 0 ? 0 : -1;
431 }
432 
433 static void
434 assign_nodes(struct state *state)
435 {
436 	struct edge *e;
437 	size_t i;
438 
439 	for (i = 0; i < state->keys; ++i) {
440 		e = state->edges + state->output_order[i];
441 
442 		if (!state->visited[e->left]) {
443 			state->g[e->left] =
444 			    (2 * state->data_entries + e->idx
445 			    - state->g[e->middle] - state->g[e->right])
446 			    % state->data_entries;
447 		} else if (!state->visited[e->middle]) {
448 			state->g[e->middle] =
449 			    (2 * state->data_entries + e->idx
450 			    - state->g[e->left] - state->g[e->right])
451 			    % state->data_entries;
452 		} else {
453 			state->g[e->right] =
454 			    (2 * state->data_entries + e->idx
455 			    - state->g[e->left] - state->g[e->middle])
456 			    % state->data_entries;
457 		}
458 		state->visited[e->left] = 1;
459 		state->visited[e->middle] = 1;
460 		state->visited[e->right] = 1;
461 	}
462 }
463 
464 static size_t
465 compute_size(uint32_t size)
466 {
467 	if (size < 0x100)
468 		return 1;
469 	else if (size < 0x10000)
470 		return 2;
471 	else
472 		return 4;
473 }
474 
475 #define COND_FLUSH_BUFFER(n) do { 				\
476 	if (__predict_false(cur_pos + (n) >= sizeof(buf))) {	\
477 		ret = write(fd, buf, cur_pos);			\
478 		if (ret == -1 || (size_t)ret != cur_pos)	\
479 			return -1;				\
480 		cur_pos = 0;					\
481 	}							\
482 } while (/* CONSTCOND */ 0)
483 
484 static int
485 print_hash(struct cdbw *cdbw, struct state *state, int fd, const char *descr)
486 {
487 	uint32_t data_size;
488 	uint8_t buf[90000];
489 	size_t i, size, size2, cur_pos;
490 	ssize_t ret;
491 
492 	memcpy(buf, "NBCDB\n\0", 7);
493 	buf[7] = 1;
494 	strncpy((char *)buf + 8, descr, 16);
495 	le32enc(buf + 24, cdbw->data_size);
496 	le32enc(buf + 28, cdbw->data_counter);
497 	le32enc(buf + 32, state->entries);
498 	le32enc(buf + 36, state->seed);
499 	cur_pos = 40;
500 
501 	size = compute_size(state->entries);
502 	for (i = 0; i < state->entries; ++i) {
503 		COND_FLUSH_BUFFER(4);
504 		le32enc(buf + cur_pos, state->g[i]);
505 		cur_pos += size;
506 	}
507 	size2 = compute_size(cdbw->data_size);
508 	size = size * state->entries % size2;
509 	if (size != 0) {
510 		size = size2 - size;
511 		COND_FLUSH_BUFFER(4);
512 		le32enc(buf + cur_pos, 0);
513 		cur_pos += size;
514 	}
515 	for (data_size = 0, i = 0; i < cdbw->data_counter; ++i) {
516 		COND_FLUSH_BUFFER(4);
517 		le32enc(buf + cur_pos, data_size);
518 		cur_pos += size2;
519 		data_size += cdbw->data_len[i];
520 	}
521 	COND_FLUSH_BUFFER(4);
522 	le32enc(buf + cur_pos, data_size);
523 	cur_pos += size2;
524 
525 	for (i = 0; i < cdbw->data_counter; ++i) {
526 		COND_FLUSH_BUFFER(cdbw->data_len[i]);
527 		if (cdbw->data_len[i] < sizeof(buf)) {
528 			memcpy(buf + cur_pos, cdbw->data_ptr[i],
529 			    cdbw->data_len[i]);
530 			cur_pos += cdbw->data_len[i];
531 		} else {
532 			ret = write(fd, cdbw->data_ptr[i], cdbw->data_len[i]);
533 			if (ret == -1 || (size_t)ret != cdbw->data_len[i])
534 				return -1;
535 		}
536 	}
537 	if (cur_pos != 0) {
538 		ret = write(fd, buf, cur_pos);
539 		if (ret == -1 || (size_t)ret != cur_pos)
540 			return -1;
541 	}
542 	return 0;
543 }
544 
545 int
546 cdbw_output(struct cdbw *cdbw, int fd, const char descr[16],
547     uint32_t (*seedgen)(void))
548 {
549 	struct state state;
550 	int rv;
551 
552 	if (cdbw->data_counter == 0 || cdbw->key_counter == 0) {
553 		state.entries = 0;
554 		state.seed = 0;
555 		print_hash(cdbw, &state, fd, descr);
556 		return 0;
557 	}
558 
559 	if (seedgen == NULL)
560 		seedgen = arc4random;
561 
562 	rv = 0;
563 
564 	state.keys = cdbw->key_counter;
565 	state.data_entries = cdbw->data_counter;
566 	state.entries = state.keys + (state.keys + 3) / 4;
567 	if (state.entries < 10)
568 		state.entries = 10;
569 
570 #define	NALLOC(var, n)	var = calloc(sizeof(*var), n)
571 	NALLOC(state.g, state.entries);
572 	NALLOC(state.visited, state.entries);
573 	NALLOC(state.verts, state.entries);
574 	NALLOC(state.edges, state.entries);
575 	NALLOC(state.output_order, state.keys);
576 #undef NALLOC
577 
578 	if (state.g == NULL || state.visited == NULL || state.verts == NULL ||
579 	    state.edges == NULL || state.output_order == NULL) {
580 		rv = -1;
581 		goto release;
582 	}
583 
584 	do {
585 		state.seed = (*seedgen)();
586 	} while (build_graph(cdbw, &state));
587 
588 	assign_nodes(&state);
589 	rv = print_hash(cdbw, &state, fd, descr);
590 
591 release:
592 	free(state.g);
593 	free(state.visited);
594 	free(state.verts);
595 	free(state.edges);
596 	free(state.output_order);
597 
598 	return rv;
599 }
600