diff options
Diffstat (limited to 'girepository/cmph/bmz8.c')
-rw-r--r-- | girepository/cmph/bmz8.c | 632 |
1 files changed, 632 insertions, 0 deletions
diff --git a/girepository/cmph/bmz8.c b/girepository/cmph/bmz8.c new file mode 100644 index 00000000..203f4fc1 --- /dev/null +++ b/girepository/cmph/bmz8.c @@ -0,0 +1,632 @@ +#include "graph.h" +#include "bmz8.h" +#include "cmph_structs.h" +#include "bmz8_structs.h" +#include "hash.h" +#include "vqueue.h" +#include "bitbool.h" +#include <math.h> +#include <stdlib.h> +#include <stdio.h> +#include <assert.h> +#include <string.h> + +//#define DEBUG +#include "debug.h" + +static int bmz8_gen_edges(cmph_config_t *mph); +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); +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); +static void bmz8_traverse_non_critical_nodes(bmz8_config_data_t *bmz8, cmph_uint8 * used_edges, cmph_uint8 * visited); + +bmz8_config_data_t *bmz8_config_new() +{ + bmz8_config_data_t *bmz8; + bmz8 = (bmz8_config_data_t *)malloc(sizeof(bmz8_config_data_t)); + assert(bmz8); + memset(bmz8, 0, sizeof(bmz8_config_data_t)); + bmz8->hashfuncs[0] = CMPH_HASH_JENKINS; + bmz8->hashfuncs[1] = CMPH_HASH_JENKINS; + bmz8->g = NULL; + bmz8->graph = NULL; + bmz8->hashes = NULL; + return bmz8; +} + +void bmz8_config_destroy(cmph_config_t *mph) +{ + bmz8_config_data_t *data = (bmz8_config_data_t *)mph->data; + DEBUGP("Destroying algorithm dependent data\n"); + free(data); +} + +void bmz8_config_set_hashfuncs(cmph_config_t *mph, CMPH_HASH *hashfuncs) +{ + bmz8_config_data_t *bmz8 = (bmz8_config_data_t *)mph->data; + CMPH_HASH *hashptr = hashfuncs; + cmph_uint8 i = 0; + while(*hashptr != CMPH_HASH_COUNT) + { + if (i >= 2) break; //bmz8 only uses two hash functions + bmz8->hashfuncs[i] = *hashptr; + ++i, ++hashptr; + } +} + +cmph_t *bmz8_new(cmph_config_t *mph, double c) +{ + cmph_t *mphf = NULL; + bmz8_data_t *bmz8f = NULL; + cmph_uint8 i; + cmph_uint8 iterations; + cmph_uint8 iterations_map = 20; + cmph_uint8 *used_edges = NULL; + cmph_uint8 restart_mapping = 0; + cmph_uint8 * visited = NULL; + bmz8_config_data_t *bmz8 = (bmz8_config_data_t *)mph->data; + + if (mph->key_source->nkeys >= 256) + { + if (mph->verbosity) fprintf(stderr, "The number of keys in BMZ8 must be lower than 256.\n"); + return NULL; + } + if (c == 0) c = 1.15; // validating restrictions over parameter c. + DEBUGP("c: %f\n", c); + bmz8->m = (cmph_uint8) mph->key_source->nkeys; + bmz8->n = (cmph_uint8) ceil(c * mph->key_source->nkeys); + DEBUGP("m (edges): %u n (vertices): %u c: %f\n", bmz8->m, bmz8->n, c); + bmz8->graph = graph_new(bmz8->n, bmz8->m); + DEBUGP("Created graph\n"); + + bmz8->hashes = (hash_state_t **)malloc(sizeof(hash_state_t *)*3); + for(i = 0; i < 3; ++i) bmz8->hashes[i] = NULL; + + do + { + // Mapping step + cmph_uint8 biggest_g_value = 0; + cmph_uint8 biggest_edge_value = 1; + iterations = 100; + if (mph->verbosity) + { + fprintf(stderr, "Entering mapping step for mph creation of %u keys with graph sized %u\n", bmz8->m, bmz8->n); + } + while(1) + { + int ok; + DEBUGP("hash function 1\n"); + bmz8->hashes[0] = hash_state_new(bmz8->hashfuncs[0], bmz8->n); + DEBUGP("hash function 2\n"); + bmz8->hashes[1] = hash_state_new(bmz8->hashfuncs[1], bmz8->n); + DEBUGP("Generating edges\n"); + ok = bmz8_gen_edges(mph); + if (!ok) + { + --iterations; + hash_state_destroy(bmz8->hashes[0]); + bmz8->hashes[0] = NULL; + hash_state_destroy(bmz8->hashes[1]); + bmz8->hashes[1] = NULL; + DEBUGP("%u iterations remaining\n", iterations); + if (mph->verbosity) + { + fprintf(stderr, "simple graph creation failure - %u iterations remaining\n", iterations); + } + if (iterations == 0) break; + } + else break; + } + if (iterations == 0) + { + graph_destroy(bmz8->graph); + return NULL; + } + + // Ordering step + if (mph->verbosity) + { + fprintf(stderr, "Starting ordering step\n"); + } + + graph_obtain_critical_nodes(bmz8->graph); + + // Searching step + if (mph->verbosity) + { + fprintf(stderr, "Starting Searching step.\n"); + fprintf(stderr, "\tTraversing critical vertices.\n"); + } + DEBUGP("Searching step\n"); + visited = (cmph_uint8 *)malloc((size_t)bmz8->n/8 + 1); + memset(visited, 0, (size_t)bmz8->n/8 + 1); + used_edges = (cmph_uint8 *)malloc((size_t)bmz8->m/8 + 1); + memset(used_edges, 0, (size_t)bmz8->m/8 + 1); + free(bmz8->g); + bmz8->g = (cmph_uint8 *)calloc((size_t)bmz8->n, sizeof(cmph_uint8)); + assert(bmz8->g); + for (i = 0; i < bmz8->n; ++i) // critical nodes + { + if (graph_node_is_critical(bmz8->graph, i) && (!GETBIT(visited,i))) + { + if(c > 1.14) restart_mapping = bmz8_traverse_critical_nodes(bmz8, i, &biggest_g_value, &biggest_edge_value, used_edges, visited); + else restart_mapping = bmz8_traverse_critical_nodes_heuristic(bmz8, i, &biggest_g_value, &biggest_edge_value, used_edges, visited); + if(restart_mapping) break; + } + } + if(!restart_mapping) + { + if (mph->verbosity) + { + fprintf(stderr, "\tTraversing non critical vertices.\n"); + } + bmz8_traverse_non_critical_nodes(bmz8, used_edges, visited); // non_critical_nodes + } + else + { + iterations_map--; + if (mph->verbosity) fprintf(stderr, "Restarting mapping step. %u iterations remaining.\n", iterations_map); + } + + free(used_edges); + free(visited); + + }while(restart_mapping && iterations_map > 0); + graph_destroy(bmz8->graph); + bmz8->graph = NULL; + if (iterations_map == 0) + { + return NULL; + } + mphf = (cmph_t *)malloc(sizeof(cmph_t)); + mphf->algo = mph->algo; + bmz8f = (bmz8_data_t *)malloc(sizeof(bmz8_data_t)); + bmz8f->g = bmz8->g; + bmz8->g = NULL; //transfer memory ownership + bmz8f->hashes = bmz8->hashes; + bmz8->hashes = NULL; //transfer memory ownership + bmz8f->n = bmz8->n; + bmz8f->m = bmz8->m; + mphf->data = bmz8f; + mphf->size = bmz8->m; + DEBUGP("Successfully generated minimal perfect hash\n"); + if (mph->verbosity) + { + fprintf(stderr, "Successfully generated minimal perfect hash function\n"); + } + return mphf; +} + +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) +{ + cmph_uint8 next_g; + cmph_uint32 u; /* Auxiliary vertex */ + cmph_uint32 lav; /* lookahead vertex */ + cmph_uint8 collision; + vqueue_t * q = vqueue_new((cmph_uint32)(graph_ncritical_nodes(bmz8->graph))); + graph_iterator_t it, it1; + + DEBUGP("Labelling critical vertices\n"); + bmz8->g[v] = (cmph_uint8)(ceil ((double)(*biggest_edge_value)/2) - 1); + SETBIT(visited, v); + next_g = (cmph_uint8)floor((double)(*biggest_edge_value/2)); /* next_g is incremented in the do..while statement*/ + vqueue_insert(q, v); + while(!vqueue_is_empty(q)) + { + v = vqueue_remove(q); + it = graph_neighbors_it(bmz8->graph, v); + while ((u = graph_next_neighbor(bmz8->graph, &it)) != GRAPH_NO_NEIGHBOR) + { + if (graph_node_is_critical(bmz8->graph, u) && (!GETBIT(visited,u))) + { + collision = 1; + while(collision) // lookahead to resolve collisions + { + next_g = (cmph_uint8)(*biggest_g_value + 1); + it1 = graph_neighbors_it(bmz8->graph, u); + collision = 0; + while((lav = graph_next_neighbor(bmz8->graph, &it1)) != GRAPH_NO_NEIGHBOR) + { + if (graph_node_is_critical(bmz8->graph, lav) && GETBIT(visited,lav)) + { + if(next_g + bmz8->g[lav] >= bmz8->m) + { + vqueue_destroy(q); + return 1; // restart mapping step. + } + if (GETBIT(used_edges, (next_g + bmz8->g[lav]))) + { + collision = 1; + break; + } + } + } + if (next_g > *biggest_g_value) *biggest_g_value = next_g; + } + // Marking used edges... + it1 = graph_neighbors_it(bmz8->graph, u); + while((lav = graph_next_neighbor(bmz8->graph, &it1)) != GRAPH_NO_NEIGHBOR) + { + if (graph_node_is_critical(bmz8->graph, lav) && GETBIT(visited, lav)) + { + SETBIT(used_edges,(next_g + bmz8->g[lav])); + + if(next_g + bmz8->g[lav] > *biggest_edge_value) + *biggest_edge_value = (cmph_uint8)(next_g + bmz8->g[lav]); + } + } + bmz8->g[u] = next_g; // Labelling vertex u. + SETBIT(visited,u); + vqueue_insert(q, u); + } + } + + } + vqueue_destroy(q); + return 0; +} + +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) +{ + cmph_uint8 next_g; + cmph_uint32 u; + cmph_uint32 lav; + cmph_uint8 collision; + cmph_uint8 * unused_g_values = NULL; + cmph_uint8 unused_g_values_capacity = 0; + cmph_uint8 nunused_g_values = 0; + vqueue_t * q = vqueue_new((cmph_uint32)(graph_ncritical_nodes(bmz8->graph))); + graph_iterator_t it, it1; + + DEBUGP("Labelling critical vertices\n"); + bmz8->g[v] = (cmph_uint8)(ceil ((double)(*biggest_edge_value)/2) - 1); + SETBIT(visited, v); + next_g = (cmph_uint8)floor((double)(*biggest_edge_value/2)); + vqueue_insert(q, v); + while(!vqueue_is_empty(q)) + { + v = vqueue_remove(q); + it = graph_neighbors_it(bmz8->graph, v); + while ((u = graph_next_neighbor(bmz8->graph, &it)) != GRAPH_NO_NEIGHBOR) + { + if (graph_node_is_critical(bmz8->graph, u) && (!GETBIT(visited,u))) + { + cmph_uint8 next_g_index = 0; + collision = 1; + while(collision) // lookahead to resolve collisions + { + if (next_g_index < nunused_g_values) + { + next_g = unused_g_values[next_g_index++]; + } + else + { + next_g = (cmph_uint8)(*biggest_g_value + 1); + next_g_index = 255;//UINT_MAX; + } + it1 = graph_neighbors_it(bmz8->graph, u); + collision = 0; + while((lav = graph_next_neighbor(bmz8->graph, &it1)) != GRAPH_NO_NEIGHBOR) + { + if (graph_node_is_critical(bmz8->graph, lav) && GETBIT(visited,lav)) + { + if(next_g + bmz8->g[lav] >= bmz8->m) + { + vqueue_destroy(q); + free(unused_g_values); + return 1; // restart mapping step. + } + if (GETBIT(used_edges, (next_g + bmz8->g[lav]))) + { + collision = 1; + break; + } + } + } + if(collision && (next_g > *biggest_g_value)) // saving the current g value stored in next_g. + { + if(nunused_g_values == unused_g_values_capacity) + { + unused_g_values = (cmph_uint8*)realloc(unused_g_values, ((size_t)(unused_g_values_capacity + BUFSIZ))*sizeof(cmph_uint8)); + unused_g_values_capacity += (cmph_uint8)BUFSIZ; + } + unused_g_values[nunused_g_values++] = next_g; + + } + if (next_g > *biggest_g_value) *biggest_g_value = next_g; + } + + next_g_index--; + if (next_g_index < nunused_g_values) unused_g_values[next_g_index] = unused_g_values[--nunused_g_values]; + + // Marking used edges... + it1 = graph_neighbors_it(bmz8->graph, u); + while((lav = graph_next_neighbor(bmz8->graph, &it1)) != GRAPH_NO_NEIGHBOR) + { + if (graph_node_is_critical(bmz8->graph, lav) && GETBIT(visited, lav)) + { + SETBIT(used_edges,(next_g + bmz8->g[lav])); + if(next_g + bmz8->g[lav] > *biggest_edge_value) + *biggest_edge_value = (cmph_uint8)(next_g + bmz8->g[lav]); + } + } + + bmz8->g[u] = next_g; // Labelling vertex u. + SETBIT(visited, u); + vqueue_insert(q, u); + + } + } + + } + vqueue_destroy(q); + free(unused_g_values); + return 0; +} + +static cmph_uint8 next_unused_edge(bmz8_config_data_t *bmz8, cmph_uint8 * used_edges, cmph_uint32 unused_edge_index) +{ + while(1) + { + assert(unused_edge_index < bmz8->m); + if(GETBIT(used_edges, unused_edge_index)) unused_edge_index ++; + else break; + } + return (cmph_uint8)unused_edge_index; +} + +static void bmz8_traverse(bmz8_config_data_t *bmz8, cmph_uint8 * used_edges, cmph_uint32 v, cmph_uint8 * unused_edge_index, cmph_uint8 * visited) +{ + graph_iterator_t it = graph_neighbors_it(bmz8->graph, v); + cmph_uint32 neighbor = 0; + while((neighbor = graph_next_neighbor(bmz8->graph, &it)) != GRAPH_NO_NEIGHBOR) + { + if(GETBIT(visited,neighbor)) continue; + //DEBUGP("Visiting neighbor %u\n", neighbor); + *unused_edge_index = next_unused_edge(bmz8, used_edges, *unused_edge_index); + bmz8->g[neighbor] = (cmph_uint8)(*unused_edge_index - bmz8->g[v]); + //if (bmz8->g[neighbor] >= bmz8->m) bmz8->g[neighbor] += bmz8->m; + SETBIT(visited, neighbor); + (*unused_edge_index)++; + bmz8_traverse(bmz8, used_edges, neighbor, unused_edge_index, visited); + + } +} + +static void bmz8_traverse_non_critical_nodes(bmz8_config_data_t *bmz8, cmph_uint8 * used_edges, cmph_uint8 * visited) +{ + + cmph_uint8 i, v1, v2, unused_edge_index = 0; + DEBUGP("Labelling non critical vertices\n"); + for(i = 0; i < bmz8->m; i++) + { + v1 = (cmph_uint8)graph_vertex_id(bmz8->graph, i, 0); + v2 = (cmph_uint8)graph_vertex_id(bmz8->graph, i, 1); + if((GETBIT(visited,v1) && GETBIT(visited,v2)) || (!GETBIT(visited,v1) && !GETBIT(visited,v2))) continue; + if(GETBIT(visited,v1)) bmz8_traverse(bmz8, used_edges, v1, &unused_edge_index, visited); + else bmz8_traverse(bmz8, used_edges, v2, &unused_edge_index, visited); + + } + + for(i = 0; i < bmz8->n; i++) + { + if(!GETBIT(visited,i)) + { + bmz8->g[i] = 0; + SETBIT(visited, i); + bmz8_traverse(bmz8, used_edges, i, &unused_edge_index, visited); + } + } + +} + +static int bmz8_gen_edges(cmph_config_t *mph) +{ + cmph_uint8 e; + bmz8_config_data_t *bmz8 = (bmz8_config_data_t *)mph->data; + cmph_uint8 multiple_edges = 0; + DEBUGP("Generating edges for %u vertices\n", bmz8->n); + graph_clear_edges(bmz8->graph); + mph->key_source->rewind(mph->key_source->data); + for (e = 0; e < mph->key_source->nkeys; ++e) + { + cmph_uint8 h1, h2; + cmph_uint32 keylen; + char *key = NULL; + mph->key_source->read(mph->key_source->data, &key, &keylen); + +// if (key == NULL)fprintf(stderr, "key = %s -- read BMZ\n", key); + h1 = (cmph_uint8)(hash(bmz8->hashes[0], key, keylen) % bmz8->n); + h2 = (cmph_uint8)(hash(bmz8->hashes[1], key, keylen) % bmz8->n); + if (h1 == h2) if (++h2 >= bmz8->n) h2 = 0; + if (h1 == h2) + { + if (mph->verbosity) fprintf(stderr, "Self loop for key %u\n", e); + mph->key_source->dispose(mph->key_source->data, key, keylen); + return 0; + } + //DEBUGP("Adding edge: %u -> %u for key %s\n", h1, h2, key); + mph->key_source->dispose(mph->key_source->data, key, keylen); +// fprintf(stderr, "key = %s -- dispose BMZ\n", key); + multiple_edges = graph_contains_edge(bmz8->graph, h1, h2); + if (mph->verbosity && multiple_edges) fprintf(stderr, "A non simple graph was generated\n"); + if (multiple_edges) return 0; // checking multiple edge restriction. + graph_add_edge(bmz8->graph, h1, h2); + } + return !multiple_edges; +} + +int bmz8_dump(cmph_t *mphf, FILE *fd) +{ + char *buf = NULL; + cmph_uint32 buflen; + cmph_uint8 two = 2; //number of hash functions + bmz8_data_t *data = (bmz8_data_t *)mphf->data; + register size_t nbytes; + __cmph_dump(mphf, fd); + + nbytes = fwrite(&two, sizeof(cmph_uint8), (size_t)1, fd); + + hash_state_dump(data->hashes[0], &buf, &buflen); + DEBUGP("Dumping hash state with %u bytes to disk\n", buflen); + nbytes = fwrite(&buflen, sizeof(cmph_uint32), (size_t)1, fd); + nbytes = fwrite(buf, (size_t)buflen, (size_t)1, fd); + free(buf); + + hash_state_dump(data->hashes[1], &buf, &buflen); + DEBUGP("Dumping hash state with %u bytes to disk\n", buflen); + nbytes = fwrite(&buflen, sizeof(cmph_uint32), (size_t)1, fd); + nbytes = fwrite(buf, (size_t)buflen, (size_t)1, fd); + free(buf); + + nbytes = fwrite(&(data->n), sizeof(cmph_uint8), (size_t)1, fd); + nbytes = fwrite(&(data->m), sizeof(cmph_uint8), (size_t)1, fd); + + nbytes = fwrite(data->g, sizeof(cmph_uint8)*(data->n), (size_t)1, fd); +/* #ifdef DEBUG + fprintf(stderr, "G: "); + for (i = 0; i < data->n; ++i) fprintf(stderr, "%u ", data->g[i]); + fprintf(stderr, "\n"); + #endif*/ + return 1; +} + +void bmz8_load(FILE *f, cmph_t *mphf) +{ + cmph_uint8 nhashes; + char *buf = NULL; + cmph_uint32 buflen; + cmph_uint8 i; + register size_t nbytes; + bmz8_data_t *bmz8 = (bmz8_data_t *)malloc(sizeof(bmz8_data_t)); + + DEBUGP("Loading bmz8 mphf\n"); + mphf->data = bmz8; + nbytes = fread(&nhashes, sizeof(cmph_uint8), (size_t)1, f); + bmz8->hashes = (hash_state_t **)malloc(sizeof(hash_state_t *)*(size_t)(nhashes + 1)); + bmz8->hashes[nhashes] = NULL; + DEBUGP("Reading %u hashes\n", nhashes); + for (i = 0; i < nhashes; ++i) + { + hash_state_t *state = NULL; + nbytes = fread(&buflen, sizeof(cmph_uint32), (size_t)1, f); + DEBUGP("Hash state has %u bytes\n", buflen); + buf = (char *)malloc((size_t)buflen); + nbytes = fread(buf, (size_t)buflen, (size_t)1, f); + state = hash_state_load(buf, buflen); + bmz8->hashes[i] = state; + free(buf); + } + + DEBUGP("Reading m and n\n"); + nbytes = fread(&(bmz8->n), sizeof(cmph_uint8), (size_t)1, f); + nbytes = fread(&(bmz8->m), sizeof(cmph_uint8), (size_t)1, f); + + bmz8->g = (cmph_uint8 *)malloc(sizeof(cmph_uint8)*bmz8->n); + nbytes = fread(bmz8->g, bmz8->n*sizeof(cmph_uint8), (size_t)1, f); + #ifdef DEBUG + fprintf(stderr, "G: "); + for (i = 0; i < bmz8->n; ++i) fprintf(stderr, "%u ", bmz8->g[i]); + fprintf(stderr, "\n"); + #endif + return; +} + + +cmph_uint8 bmz8_search(cmph_t *mphf, const char *key, cmph_uint32 keylen) +{ + bmz8_data_t *bmz8 = mphf->data; + cmph_uint8 h1 = (cmph_uint8)(hash(bmz8->hashes[0], key, keylen) % bmz8->n); + cmph_uint8 h2 = (cmph_uint8)(hash(bmz8->hashes[1], key, keylen) % bmz8->n); + DEBUGP("key: %s h1: %u h2: %u\n", key, h1, h2); + if (h1 == h2 && ++h2 > bmz8->n) h2 = 0; + DEBUGP("key: %s g[h1]: %u g[h2]: %u edges: %u\n", key, bmz8->g[h1], bmz8->g[h2], bmz8->m); + return (cmph_uint8)(bmz8->g[h1] + bmz8->g[h2]); +} +void bmz8_destroy(cmph_t *mphf) +{ + bmz8_data_t *data = (bmz8_data_t *)mphf->data; + free(data->g); + hash_state_destroy(data->hashes[0]); + hash_state_destroy(data->hashes[1]); + free(data->hashes); + free(data); + free(mphf); +} + +/** \fn void bmz8_pack(cmph_t *mphf, void *packed_mphf); + * \brief Support the ability to pack a perfect hash function into a preallocated contiguous memory space pointed by packed_mphf. + * \param mphf pointer to the resulting mphf + * \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() + */ +void bmz8_pack(cmph_t *mphf, void *packed_mphf) +{ + bmz8_data_t *data = (bmz8_data_t *)mphf->data; + cmph_uint8 * ptr = packed_mphf; + + // packing h1 type + CMPH_HASH h1_type = hash_get_type(data->hashes[0]); + *((cmph_uint32 *) ptr) = h1_type; + ptr += sizeof(cmph_uint32); + + // packing h1 + hash_state_pack(data->hashes[0], ptr); + ptr += hash_state_packed_size(h1_type); + + // packing h2 type + CMPH_HASH h2_type = hash_get_type(data->hashes[1]); + *((cmph_uint32 *) ptr) = h2_type; + ptr += sizeof(cmph_uint32); + + // packing h2 + hash_state_pack(data->hashes[1], ptr); + ptr += hash_state_packed_size(h2_type); + + // packing n + *ptr++ = data->n; + + // packing g + memcpy(ptr, data->g, sizeof(cmph_uint8)*data->n); +} + +/** \fn cmph_uint32 bmz8_packed_size(cmph_t *mphf); + * \brief Return the amount of space needed to pack mphf. + * \param mphf pointer to a mphf + * \return the size of the packed function or zero for failures + */ +cmph_uint32 bmz8_packed_size(cmph_t *mphf) +{ + bmz8_data_t *data = (bmz8_data_t *)mphf->data; + CMPH_HASH h1_type = hash_get_type(data->hashes[0]); + CMPH_HASH h2_type = hash_get_type(data->hashes[1]); + + return (cmph_uint32)(sizeof(CMPH_ALGO) + hash_state_packed_size(h1_type) + hash_state_packed_size(h2_type) + + 2*sizeof(cmph_uint32) + sizeof(cmph_uint8) + sizeof(cmph_uint8)*data->n); +} + +/** cmph_uint8 bmz8_search(void *packed_mphf, const char *key, cmph_uint32 keylen); + * \brief Use the packed mphf to do a search. + * \param packed_mphf pointer to the packed mphf + * \param key key to be hashed + * \param keylen key legth in bytes + * \return The mphf value + */ +cmph_uint8 bmz8_search_packed(void *packed_mphf, const char *key, cmph_uint32 keylen) +{ + register cmph_uint8 *h1_ptr = packed_mphf; + register CMPH_HASH h1_type = *((cmph_uint32 *)h1_ptr); + h1_ptr += 4; + + register cmph_uint8 *h2_ptr = h1_ptr + hash_state_packed_size(h1_type); + register CMPH_HASH h2_type = *((cmph_uint32 *)h2_ptr); + h2_ptr += 4; + + register cmph_uint8 *g_ptr = h2_ptr + hash_state_packed_size(h2_type); + + register cmph_uint8 n = *g_ptr++; + + register cmph_uint8 h1 = (cmph_uint8)(hash_packed(h1_ptr, h1_type, key, keylen) % n); + register cmph_uint8 h2 = (cmph_uint8)(hash_packed(h2_ptr, h2_type, key, keylen) % n); + DEBUGP("key: %s h1: %u h2: %u\n", key, h1, h2); + if (h1 == h2 && ++h2 > n) h2 = 0; + return (cmph_uint8)(g_ptr[h1] + g_ptr[h2]); +} |