1 #include "graph.h"
2 #include "bmz8.h"
3 #include "cmph_structs.h"
4 #include "bmz8_structs.h"
5 #include "hash.h"
6 #include "vqueue.h"
7 #include "bitbool.h"
8 #include <math.h>
9 #include <stdlib.h>
10 #include <stdio.h>
11 #include <assert.h>
12 #include <string.h>
13 #include <errno.h>
14
15 //#define DEBUG
16 #include "debug.h"
17
18 static int bmz8_gen_edges(cmph_config_t *mph);
19 static cmph_uint8 bmz8_traverse_critical_nodes(bmz8_config_data_t *bmz8, cmph_uint32 v, cmph_uint8 * biggest_g_value, cmph_uint8 * biggest_edge_value, cmph_uint8 * used_edges, cmph_uint8 * visited);
20 static cmph_uint8 bmz8_traverse_critical_nodes_heuristic(bmz8_config_data_t *bmz8, cmph_uint32 v, cmph_uint8 * biggest_g_value, cmph_uint8 * biggest_edge_value, cmph_uint8 * used_edges, cmph_uint8 * visited);
21 static void bmz8_traverse_non_critical_nodes(bmz8_config_data_t *bmz8, cmph_uint8 * used_edges, cmph_uint8 * visited);
22
23 bmz8_config_data_t *bmz8_config_new(void)
24 {
25 bmz8_config_data_t *bmz8;
26 bmz8 = (bmz8_config_data_t *)malloc(sizeof(bmz8_config_data_t));
27 assert(bmz8);
28 memset(bmz8, 0, sizeof(bmz8_config_data_t));
29 bmz8->hashfuncs[0] = CMPH_HASH_JENKINS;
30 bmz8->hashfuncs[1] = CMPH_HASH_JENKINS;
31 bmz8->g = NULL;
32 bmz8->graph = NULL;
33 bmz8->hashes = NULL;
34 return bmz8;
35 }
36
37 void bmz8_config_destroy(cmph_config_t *mph)
38 {
39 bmz8_config_data_t *data = (bmz8_config_data_t *)mph->data;
40 DEBUGP("Destroying algorithm dependent data\n");
41 free(data);
42 }
43
44 void bmz8_config_set_hashfuncs(cmph_config_t *mph, CMPH_HASH *hashfuncs)
45 {
46 bmz8_config_data_t *bmz8 = (bmz8_config_data_t *)mph->data;
47 CMPH_HASH *hashptr = hashfuncs;
48 cmph_uint8 i = 0;
49 while(*hashptr != CMPH_HASH_COUNT)
50 {
51 if (i >= 2) break; //bmz8 only uses two hash functions
52 bmz8->hashfuncs[i] = *hashptr;
53 ++i, ++hashptr;
54 }
55 }
56
57 cmph_t *bmz8_new(cmph_config_t *mph, double c)
58 {
59 cmph_t *mphf = NULL;
60 bmz8_data_t *bmz8f = NULL;
61 cmph_uint8 i;
62 cmph_uint8 iterations;
63 cmph_uint8 iterations_map = 20;
64 cmph_uint8 *used_edges = NULL;
65 cmph_uint8 restart_mapping = 0;
66 cmph_uint8 * visited = NULL;
67 bmz8_config_data_t *bmz8 = (bmz8_config_data_t *)mph->data;
68
69 if (mph->key_source->nkeys >= 256)
70 {
71 if (mph->verbosity) fprintf(stderr, "The number of keys in BMZ8 must be lower than 256.\n");
72 return NULL;
73 }
74 if (c == 0) c = 1.15; // validating restrictions over parameter c.
75 DEBUGP("c: %f\n", c);
76 bmz8->m = (cmph_uint8) mph->key_source->nkeys;
77 bmz8->n = (cmph_uint8) ceil(c * mph->key_source->nkeys);
78 DEBUGP("m (edges): %u n (vertices): %u c: %f\n", bmz8->m, bmz8->n, c);
79 bmz8->graph = graph_new(bmz8->n, bmz8->m);
80 DEBUGP("Created graph\n");
81
82 bmz8->hashes = (hash_state_t **)malloc(sizeof(hash_state_t *)*3);
83 for(i = 0; i < 3; ++i) bmz8->hashes[i] = NULL;
84
85 do
86 {
87 // Mapping step
88 cmph_uint8 biggest_g_value = 0;
89 cmph_uint8 biggest_edge_value = 1;
90 iterations = 100;
91 if (mph->verbosity)
92 {
93 fprintf(stderr, "Entering mapping step for mph creation of %u keys with graph sized %u\n", bmz8->m, bmz8->n);
94 }
95 while(1)
96 {
97 int ok;
98 DEBUGP("hash function 1\n");
99 bmz8->hashes[0] = hash_state_new(bmz8->hashfuncs[0], bmz8->n);
100 DEBUGP("hash function 2\n");
101 bmz8->hashes[1] = hash_state_new(bmz8->hashfuncs[1], bmz8->n);
102 DEBUGP("Generating edges\n");
103 ok = bmz8_gen_edges(mph);
104 if (!ok)
105 {
106 --iterations;
107 hash_state_destroy(bmz8->hashes[0]);
108 bmz8->hashes[0] = NULL;
109 hash_state_destroy(bmz8->hashes[1]);
110 bmz8->hashes[1] = NULL;
111 DEBUGP("%u iterations remaining\n", iterations);
112 if (mph->verbosity)
113 {
114 fprintf(stderr, "simple graph creation failure - %u iterations remaining\n", iterations);
115 }
116 if (iterations == 0) break;
117 }
118 else break;
119 }
120 if (iterations == 0)
121 {
122 graph_destroy(bmz8->graph);
123 return NULL;
124 }
125
126 // Ordering step
127 if (mph->verbosity)
128 {
129 fprintf(stderr, "Starting ordering step\n");
130 }
131
132 graph_obtain_critical_nodes(bmz8->graph);
133
134 // Searching step
135 if (mph->verbosity)
136 {
137 fprintf(stderr, "Starting Searching step.\n");
138 fprintf(stderr, "\tTraversing critical vertices.\n");
139 }
140 DEBUGP("Searching step\n");
141 visited = (cmph_uint8 *)malloc((size_t)bmz8->n/8 + 1);
142 memset(visited, 0, (size_t)bmz8->n/8 + 1);
143 used_edges = (cmph_uint8 *)malloc((size_t)bmz8->m/8 + 1);
144 memset(used_edges, 0, (size_t)bmz8->m/8 + 1);
145 free(bmz8->g);
146 bmz8->g = (cmph_uint8 *)calloc((size_t)bmz8->n, sizeof(cmph_uint8));
147 assert(bmz8->g);
148 for (i = 0; i < bmz8->n; ++i) // critical nodes
149 {
150 if (graph_node_is_critical(bmz8->graph, i) && (!GETBIT(visited,i)))
151 {
152 if(c > 1.14) restart_mapping = bmz8_traverse_critical_nodes(bmz8, i, &biggest_g_value, &biggest_edge_value, used_edges, visited);
153 else restart_mapping = bmz8_traverse_critical_nodes_heuristic(bmz8, i, &biggest_g_value, &biggest_edge_value, used_edges, visited);
154 if(restart_mapping) break;
155 }
156 }
157 if(!restart_mapping)
158 {
159 if (mph->verbosity)
160 {
161 fprintf(stderr, "\tTraversing non critical vertices.\n");
162 }
163 bmz8_traverse_non_critical_nodes(bmz8, used_edges, visited); // non_critical_nodes
164 }
165 else
166 {
167 iterations_map--;
168 if (mph->verbosity) fprintf(stderr, "Restarting mapping step. %u iterations remaining.\n", iterations_map);
169 }
170
171 free(used_edges);
172 free(visited);
173
174 }while(restart_mapping && iterations_map > 0);
175 graph_destroy(bmz8->graph);
176 bmz8->graph = NULL;
177 if (iterations_map == 0)
178 {
179 return NULL;
180 }
181 mphf = (cmph_t *)malloc(sizeof(cmph_t));
182 mphf->algo = mph->algo;
183 bmz8f = (bmz8_data_t *)malloc(sizeof(bmz8_data_t));
184 bmz8f->g = bmz8->g;
185 bmz8->g = NULL; //transfer memory ownership
186 bmz8f->hashes = bmz8->hashes;
187 bmz8->hashes = NULL; //transfer memory ownership
188 bmz8f->n = bmz8->n;
189 bmz8f->m = bmz8->m;
190 mphf->data = bmz8f;
191 mphf->size = bmz8->m;
192 DEBUGP("Successfully generated minimal perfect hash\n");
193 if (mph->verbosity)
194 {
195 fprintf(stderr, "Successfully generated minimal perfect hash function\n");
196 }
197 return mphf;
198 }
199
200 static cmph_uint8 bmz8_traverse_critical_nodes(bmz8_config_data_t *bmz8, cmph_uint32 v, cmph_uint8 * biggest_g_value, cmph_uint8 * biggest_edge_value, cmph_uint8 * used_edges, cmph_uint8 * visited)
201 {
202 cmph_uint8 next_g;
203 cmph_uint32 u; /* Auxiliary vertex */
204 cmph_uint32 lav; /* lookahead vertex */
205 cmph_uint8 collision;
206 vqueue_t * q = vqueue_new((cmph_uint32)(graph_ncritical_nodes(bmz8->graph)));
207 graph_iterator_t it, it1;
208
209 DEBUGP("Labelling critical vertices\n");
210 bmz8->g[v] = (cmph_uint8)(ceil ((double)(*biggest_edge_value)/2) - 1);
211 SETBIT(visited, v);
212 next_g = (cmph_uint8)floor((double)(*biggest_edge_value/2)); /* next_g is incremented in the do..while statement*/
213 vqueue_insert(q, v);
214 while(!vqueue_is_empty(q))
215 {
216 v = vqueue_remove(q);
217 it = graph_neighbors_it(bmz8->graph, v);
218 while ((u = graph_next_neighbor(bmz8->graph, &it)) != GRAPH_NO_NEIGHBOR)
219 {
220 if (graph_node_is_critical(bmz8->graph, u) && (!GETBIT(visited,u)))
221 {
222 collision = 1;
223 while(collision) // lookahead to resolve collisions
224 {
225 next_g = (cmph_uint8)(*biggest_g_value + 1);
226 it1 = graph_neighbors_it(bmz8->graph, u);
227 collision = 0;
228 while((lav = graph_next_neighbor(bmz8->graph, &it1)) != GRAPH_NO_NEIGHBOR)
229 {
230 if (graph_node_is_critical(bmz8->graph, lav) && GETBIT(visited,lav))
231 {
232 if(next_g + bmz8->g[lav] >= bmz8->m)
233 {
234 vqueue_destroy(q);
235 return 1; // restart mapping step.
236 }
237 if (GETBIT(used_edges, (next_g + bmz8->g[lav])))
238 {
239 collision = 1;
240 break;
241 }
242 }
243 }
244 if (next_g > *biggest_g_value) *biggest_g_value = next_g;
245 }
246 // Marking used edges...
247 it1 = graph_neighbors_it(bmz8->graph, u);
248 while((lav = graph_next_neighbor(bmz8->graph, &it1)) != GRAPH_NO_NEIGHBOR)
249 {
250 if (graph_node_is_critical(bmz8->graph, lav) && GETBIT(visited, lav))
251 {
252 SETBIT(used_edges,(next_g + bmz8->g[lav]));
253
254 if(next_g + bmz8->g[lav] > *biggest_edge_value)
255 *biggest_edge_value = (cmph_uint8)(next_g + bmz8->g[lav]);
256 }
257 }
258 bmz8->g[u] = next_g; // Labelling vertex u.
259 SETBIT(visited,u);
260 vqueue_insert(q, u);
261 }
262 }
263
264 }
265 vqueue_destroy(q);
266 return 0;
267 }
268
269 static cmph_uint8 bmz8_traverse_critical_nodes_heuristic(bmz8_config_data_t *bmz8, cmph_uint32 v, cmph_uint8 * biggest_g_value, cmph_uint8 * biggest_edge_value, cmph_uint8 * used_edges, cmph_uint8 * visited)
270 {
271 cmph_uint8 next_g;
272 cmph_uint32 u;
273 cmph_uint32 lav;
274 cmph_uint8 collision;
275 cmph_uint8 * unused_g_values = NULL;
276 cmph_uint8 unused_g_values_capacity = 0;
277 cmph_uint8 nunused_g_values = 0;
278 vqueue_t * q = vqueue_new((cmph_uint32)(graph_ncritical_nodes(bmz8->graph)));
279 graph_iterator_t it, it1;
280
281 DEBUGP("Labelling critical vertices\n");
282 bmz8->g[v] = (cmph_uint8)(ceil ((double)(*biggest_edge_value)/2) - 1);
283 SETBIT(visited, v);
284 next_g = (cmph_uint8)floor((double)(*biggest_edge_value/2));
285 vqueue_insert(q, v);
286 while(!vqueue_is_empty(q))
287 {
288 v = vqueue_remove(q);
289 it = graph_neighbors_it(bmz8->graph, v);
290 while ((u = graph_next_neighbor(bmz8->graph, &it)) != GRAPH_NO_NEIGHBOR)
291 {
292 if (graph_node_is_critical(bmz8->graph, u) && (!GETBIT(visited,u)))
293 {
294 cmph_uint8 next_g_index = 0;
295 collision = 1;
296 while(collision) // lookahead to resolve collisions
297 {
298 if (next_g_index < nunused_g_values)
299 {
300 next_g = unused_g_values[next_g_index++];
301 }
302 else
303 {
304 next_g = (cmph_uint8)(*biggest_g_value + 1);
305 next_g_index = 255;//UINT_MAX;
306 }
307 it1 = graph_neighbors_it(bmz8->graph, u);
308 collision = 0;
309 while((lav = graph_next_neighbor(bmz8->graph, &it1)) != GRAPH_NO_NEIGHBOR)
310 {
311 if (graph_node_is_critical(bmz8->graph, lav) && GETBIT(visited,lav))
312 {
313 if(next_g + bmz8->g[lav] >= bmz8->m)
314 {
315 vqueue_destroy(q);
316 free(unused_g_values);
317 return 1; // restart mapping step.
318 }
319 if (GETBIT(used_edges, (next_g + bmz8->g[lav])))
320 {
321 collision = 1;
322 break;
323 }
324 }
325 }
326 if(collision && (next_g > *biggest_g_value)) // saving the current g value stored in next_g.
327 {
328 if(nunused_g_values == unused_g_values_capacity)
329 {
330 unused_g_values = (cmph_uint8*)realloc(unused_g_values, ((size_t)(unused_g_values_capacity + BUFSIZ))*sizeof(cmph_uint8));
331 unused_g_values_capacity += (cmph_uint8)BUFSIZ;
332 }
333 unused_g_values[nunused_g_values++] = next_g;
334
335 }
336 if (next_g > *biggest_g_value) *biggest_g_value = next_g;
337 }
338
339 next_g_index--;
340 if (next_g_index < nunused_g_values) unused_g_values[next_g_index] = unused_g_values[--nunused_g_values];
341
342 // Marking used edges...
343 it1 = graph_neighbors_it(bmz8->graph, u);
344 while((lav = graph_next_neighbor(bmz8->graph, &it1)) != GRAPH_NO_NEIGHBOR)
345 {
346 if (graph_node_is_critical(bmz8->graph, lav) && GETBIT(visited, lav))
347 {
348 SETBIT(used_edges,(next_g + bmz8->g[lav]));
349 if(next_g + bmz8->g[lav] > *biggest_edge_value)
350 *biggest_edge_value = (cmph_uint8)(next_g + bmz8->g[lav]);
351 }
352 }
353
354 bmz8->g[u] = next_g; // Labelling vertex u.
355 SETBIT(visited, u);
356 vqueue_insert(q, u);
357
358 }
359 }
360
361 }
362 vqueue_destroy(q);
363 free(unused_g_values);
364 return 0;
365 }
366
367 static cmph_uint8 next_unused_edge(bmz8_config_data_t *bmz8, cmph_uint8 * used_edges, cmph_uint32 unused_edge_index)
368 {
369 while(1)
370 {
371 assert(unused_edge_index < bmz8->m);
372 if(GETBIT(used_edges, unused_edge_index)) unused_edge_index ++;
373 else break;
374 }
375 return (cmph_uint8)unused_edge_index;
376 }
377
378 static void bmz8_traverse(bmz8_config_data_t *bmz8, cmph_uint8 * used_edges, cmph_uint32 v, cmph_uint8 * unused_edge_index, cmph_uint8 * visited)
379 {
380 graph_iterator_t it = graph_neighbors_it(bmz8->graph, v);
381 cmph_uint32 neighbor = 0;
382 while((neighbor = graph_next_neighbor(bmz8->graph, &it)) != GRAPH_NO_NEIGHBOR)
383 {
384 if(GETBIT(visited,neighbor)) continue;
385 //DEBUGP("Visiting neighbor %u\n", neighbor);
386 *unused_edge_index = next_unused_edge(bmz8, used_edges, *unused_edge_index);
387 bmz8->g[neighbor] = (cmph_uint8)(*unused_edge_index - bmz8->g[v]);
388 //if (bmz8->g[neighbor] >= bmz8->m) bmz8->g[neighbor] += bmz8->m;
389 SETBIT(visited, neighbor);
390 (*unused_edge_index)++;
391 bmz8_traverse(bmz8, used_edges, neighbor, unused_edge_index, visited);
392
393 }
394 }
395
396 static void bmz8_traverse_non_critical_nodes(bmz8_config_data_t *bmz8, cmph_uint8 * used_edges, cmph_uint8 * visited)
397 {
398
399 cmph_uint8 i, v1, v2, unused_edge_index = 0;
400 DEBUGP("Labelling non critical vertices\n");
401 for(i = 0; i < bmz8->m; i++)
402 {
403 v1 = (cmph_uint8)graph_vertex_id(bmz8->graph, i, 0);
404 v2 = (cmph_uint8)graph_vertex_id(bmz8->graph, i, 1);
405 if((GETBIT(visited,v1) && GETBIT(visited,v2)) || (!GETBIT(visited,v1) && !GETBIT(visited,v2))) continue;
406 if(GETBIT(visited,v1)) bmz8_traverse(bmz8, used_edges, v1, &unused_edge_index, visited);
407 else bmz8_traverse(bmz8, used_edges, v2, &unused_edge_index, visited);
408
409 }
410
411 for(i = 0; i < bmz8->n; i++)
412 {
413 if(!GETBIT(visited,i))
414 {
415 bmz8->g[i] = 0;
416 SETBIT(visited, i);
417 bmz8_traverse(bmz8, used_edges, i, &unused_edge_index, visited);
418 }
419 }
420
421 }
422
423 static int bmz8_gen_edges(cmph_config_t *mph)
424 {
425 cmph_uint8 e;
426 bmz8_config_data_t *bmz8 = (bmz8_config_data_t *)mph->data;
427 cmph_uint8 multiple_edges = 0;
428 DEBUGP("Generating edges for %u vertices\n", bmz8->n);
429 graph_clear_edges(bmz8->graph);
430 mph->key_source->rewind(mph->key_source->data);
431 for (e = 0; e < mph->key_source->nkeys; ++e)
432 {
433 cmph_uint8 h1, h2;
434 cmph_uint32 keylen;
435 char *key = NULL;
436 mph->key_source->read(mph->key_source->data, &key, &keylen);
437
438 // if (key == NULL)fprintf(stderr, "key = %s -- read BMZ\n", key);
439 h1 = (cmph_uint8)(hash(bmz8->hashes[0], key, keylen) % bmz8->n);
440 h2 = (cmph_uint8)(hash(bmz8->hashes[1], key, keylen) % bmz8->n);
441 if (h1 == h2) if (++h2 >= bmz8->n) h2 = 0;
442 if (h1 == h2)
443 {
444 if (mph->verbosity) fprintf(stderr, "Self loop for key %u\n", e);
445 mph->key_source->dispose(mph->key_source->data, key, keylen);
446 return 0;
447 }
448 //DEBUGP("Adding edge: %u -> %u for key %s\n", h1, h2, key);
449 mph->key_source->dispose(mph->key_source->data, key, keylen);
450 // fprintf(stderr, "key = %s -- dispose BMZ\n", key);
451 multiple_edges = graph_contains_edge(bmz8->graph, h1, h2);
452 if (mph->verbosity && multiple_edges) fprintf(stderr, "A non simple graph was generated\n");
453 if (multiple_edges) return 0; // checking multiple edge restriction.
454 graph_add_edge(bmz8->graph, h1, h2);
455 }
456 return !multiple_edges;
457 }
458
459 int bmz8_dump(cmph_t *mphf, FILE *fd)
460 {
461 char *buf = NULL;
462 cmph_uint32 buflen;
463 cmph_uint8 two = 2; //number of hash functions
464 bmz8_data_t *data = (bmz8_data_t *)mphf->data;
465 register size_t nbytes;
466 __cmph_dump(mphf, fd);
467
468 nbytes = fwrite(&two, sizeof(cmph_uint8), (size_t)1, fd);
469
470 hash_state_dump(data->hashes[0], &buf, &buflen);
471 DEBUGP("Dumping hash state with %u bytes to disk\n", buflen);
472 nbytes = fwrite(&buflen, sizeof(cmph_uint32), (size_t)1, fd);
473 nbytes = fwrite(buf, (size_t)buflen, (size_t)1, fd);
474 free(buf);
475
476 hash_state_dump(data->hashes[1], &buf, &buflen);
477 DEBUGP("Dumping hash state with %u bytes to disk\n", buflen);
478 nbytes = fwrite(&buflen, sizeof(cmph_uint32), (size_t)1, fd);
479 nbytes = fwrite(buf, (size_t)buflen, (size_t)1, fd);
480 free(buf);
481
482 nbytes = fwrite(&(data->n), sizeof(cmph_uint8), (size_t)1, fd);
483 nbytes = fwrite(&(data->m), sizeof(cmph_uint8), (size_t)1, fd);
484
485 nbytes = fwrite(data->g, sizeof(cmph_uint8)*(data->n), (size_t)1, fd);
486 if (nbytes == 0 && ferror(fd)) {
487 fprintf(stderr, "ERROR: %s\n", strerror(errno));
488 return 0;
489 }
490 /* #ifdef DEBUG
491 fprintf(stderr, "G: ");
492 for (i = 0; i < data->n; ++i) fprintf(stderr, "%u ", data->g[i]);
493 fprintf(stderr, "\n");
494 #endif*/
495 return 1;
496 }
497
498 void bmz8_load(FILE *f, cmph_t *mphf)
499 {
500 cmph_uint8 nhashes;
501 char *buf = NULL;
502 cmph_uint32 buflen;
503 cmph_uint8 i;
504 register size_t nbytes;
505 bmz8_data_t *bmz8 = (bmz8_data_t *)malloc(sizeof(bmz8_data_t));
506
507 DEBUGP("Loading bmz8 mphf\n");
508 mphf->data = bmz8;
509 nbytes = fread(&nhashes, sizeof(cmph_uint8), (size_t)1, f);
510 bmz8->hashes = (hash_state_t **)malloc(sizeof(hash_state_t *)*(size_t)(nhashes + 1));
511 bmz8->hashes[nhashes] = NULL;
512 DEBUGP("Reading %u hashes\n", nhashes);
513 for (i = 0; i < nhashes; ++i)
514 {
515 hash_state_t *state = NULL;
516 nbytes = fread(&buflen, sizeof(cmph_uint32), (size_t)1, f);
517 DEBUGP("Hash state has %u bytes\n", buflen);
518 buf = (char *)malloc((size_t)buflen);
519 nbytes = fread(buf, (size_t)buflen, (size_t)1, f);
520 state = hash_state_load(buf, buflen);
521 bmz8->hashes[i] = state;
522 free(buf);
523 }
524
525 DEBUGP("Reading m and n\n");
526 nbytes = fread(&(bmz8->n), sizeof(cmph_uint8), (size_t)1, f);
527 nbytes = fread(&(bmz8->m), sizeof(cmph_uint8), (size_t)1, f);
528
529 bmz8->g = (cmph_uint8 *)malloc(sizeof(cmph_uint8)*bmz8->n);
530 nbytes = fread(bmz8->g, bmz8->n*sizeof(cmph_uint8), (size_t)1, f);
531 if (nbytes == 0 && ferror(f)) {
532 fprintf(stderr, "ERROR: %s\n", strerror(errno));
533 return;
534 }
535
536 #ifdef DEBUG
537 fprintf(stderr, "G: ");
538 for (i = 0; i < bmz8->n; ++i) fprintf(stderr, "%u ", bmz8->g[i]);
539 fprintf(stderr, "\n");
540 #endif
541 return;
542 }
543
544
545 cmph_uint8 bmz8_search(cmph_t *mphf, const char *key, cmph_uint32 keylen)
546 {
547 bmz8_data_t *bmz8 = mphf->data;
548 cmph_uint8 h1 = (cmph_uint8)(hash(bmz8->hashes[0], key, keylen) % bmz8->n);
549 cmph_uint8 h2 = (cmph_uint8)(hash(bmz8->hashes[1], key, keylen) % bmz8->n);
550 DEBUGP("key: %s h1: %u h2: %u\n", key, h1, h2);
551 if (h1 == h2 && ++h2 > bmz8->n) h2 = 0;
552 DEBUGP("key: %s g[h1]: %u g[h2]: %u edges: %u\n", key, bmz8->g[h1], bmz8->g[h2], bmz8->m);
553 return (cmph_uint8)(bmz8->g[h1] + bmz8->g[h2]);
554 }
555 void bmz8_destroy(cmph_t *mphf)
556 {
557 bmz8_data_t *data = (bmz8_data_t *)mphf->data;
558 free(data->g);
559 hash_state_destroy(data->hashes[0]);
560 hash_state_destroy(data->hashes[1]);
561 free(data->hashes);
562 free(data);
563 free(mphf);
564 }
565
566 /** \fn void bmz8_pack(cmph_t *mphf, void *packed_mphf);
567 * \brief Support the ability to pack a perfect hash function into a preallocated contiguous memory space pointed by packed_mphf.
568 * \param mphf pointer to the resulting mphf
569 * \param packed_mphf pointer to the contiguous memory area used to store the resulting mphf. The size of packed_mphf must be at least cmph_packed_size()
570 */
571 void bmz8_pack(cmph_t *mphf, void *packed_mphf)
572 {
573 bmz8_data_t *data = (bmz8_data_t *)mphf->data;
574 cmph_uint8 * ptr = packed_mphf;
575 CMPH_HASH h2_type;
576
577 // packing h1 type
578 CMPH_HASH h1_type = hash_get_type(data->hashes[0]);
579 *((cmph_uint32 *) ptr) = h1_type;
580 ptr += sizeof(cmph_uint32);
581
582 // packing h1
583 hash_state_pack(data->hashes[0], ptr);
584 ptr += hash_state_packed_size(h1_type);
585
586 // packing h2 type
587 h2_type = hash_get_type(data->hashes[1]);
588 *((cmph_uint32 *) ptr) = h2_type;
589 ptr += sizeof(cmph_uint32);
590
591 // packing h2
592 hash_state_pack(data->hashes[1], ptr);
593 ptr += hash_state_packed_size(h2_type);
594
595 // packing n
596 *ptr++ = data->n;
597
598 // packing g
599 memcpy(ptr, data->g, sizeof(cmph_uint8)*data->n);
600 }
601
602 /** \fn cmph_uint32 bmz8_packed_size(cmph_t *mphf);
603 * \brief Return the amount of space needed to pack mphf.
604 * \param mphf pointer to a mphf
605 * \return the size of the packed function or zero for failures
606 */
607 cmph_uint32 bmz8_packed_size(cmph_t *mphf)
608 {
609 bmz8_data_t *data = (bmz8_data_t *)mphf->data;
610 CMPH_HASH h1_type = hash_get_type(data->hashes[0]);
611 CMPH_HASH h2_type = hash_get_type(data->hashes[1]);
612
613 return (cmph_uint32)(sizeof(CMPH_ALGO) + hash_state_packed_size(h1_type) + hash_state_packed_size(h2_type) +
614 2*sizeof(cmph_uint32) + sizeof(cmph_uint8) + sizeof(cmph_uint8)*data->n);
615 }
616
617 /** cmph_uint8 bmz8_search(void *packed_mphf, const char *key, cmph_uint32 keylen);
618 * \brief Use the packed mphf to do a search.
619 * \param packed_mphf pointer to the packed mphf
620 * \param key key to be hashed
621 * \param keylen key legth in bytes
622 * \return The mphf value
623 */
624 cmph_uint8 bmz8_search_packed(void *packed_mphf, const char *key, cmph_uint32 keylen)
625 {
626 register cmph_uint8 *h1_ptr = packed_mphf;
627 register CMPH_HASH h1_type = *((cmph_uint32 *)h1_ptr);
628 register cmph_uint8 *h2_ptr;
629 register CMPH_HASH h2_type;
630 register cmph_uint8 *g_ptr, n, h1, h2;
631
632 h1_ptr += 4;
633
634 h2_ptr = h1_ptr + hash_state_packed_size(h1_type);
635 h2_type = *((cmph_uint32 *)h2_ptr);
636 h2_ptr += 4;
637
638 g_ptr = h2_ptr + hash_state_packed_size(h2_type);
639
640 n = *g_ptr++;
641
642 h1 = (cmph_uint8)(hash_packed(h1_ptr, h1_type, key, keylen) % n);
643 h2 = (cmph_uint8)(hash_packed(h2_ptr, h2_type, key, keylen) % n);
644 DEBUGP("key: %s h1: %u h2: %u\n", key, h1, h2);
645 if (h1 == h2 && ++h2 > n) h2 = 0;
646 return (cmph_uint8)(g_ptr[h1] + g_ptr[h2]);
647 }