motiejus
/
turbonss
1
Fork 0
Code Releases Activity
turbonss/src/bmz8.c

658 lines
21 KiB
C
Raw Blame History

#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_uint8 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_uint8 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, float 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 = mph->key_source->nkeys;
bmz8->n = 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(bmz8->n/8 + 1);
memset(visited, 0, bmz8->n/8 + 1);
used_edges = (cmph_uint8 *)malloc(bmz8->m/8 + 1);
memset(used_edges, 0, bmz8->m/8 + 1);
free(bmz8->g);
bmz8->g = (cmph_uint8 *)calloc(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_uint8 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 = *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 = 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_uint8 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 = *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, (unused_g_values_capacity + BUFSIZ)*sizeof(cmph_uint8));
unused_g_values_capacity += 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 = 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_uint8 unused_edge_index)
{
while(1)
{
assert(unused_edge_index < bmz8->m);
if(GETBIT(used_edges, unused_edge_index)) unused_edge_index ++;
else break;
}
return unused_edge_index;
}
static void bmz8_traverse(bmz8_config_data_t *bmz8, cmph_uint8 * used_edges, cmph_uint8 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] = *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 = graph_vertex_id(bmz8->graph, i, 0);
v2 = 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 = hash(bmz8->hashes[0], key, keylen) % bmz8->n;
h2 = 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;
__cmph_dump(mphf, fd);
fwrite(&two, sizeof(cmph_uint8), 1, fd);
hash_state_dump(data->hashes[0], &buf, &buflen);
DEBUGP("Dumping hash state with %u bytes to disk\n", buflen);
fwrite(&buflen, sizeof(cmph_uint32), 1, fd);
fwrite(buf, buflen, 1, fd);
free(buf);
hash_state_dump(data->hashes[1], &buf, &buflen);
DEBUGP("Dumping hash state with %u bytes to disk\n", buflen);
fwrite(&buflen, sizeof(cmph_uint32), 1, fd);
fwrite(buf, buflen, 1, fd);
free(buf);
fwrite(&(data->n), sizeof(cmph_uint8), 1, fd);
fwrite(&(data->m), sizeof(cmph_uint8), 1, fd);
fwrite(data->g, sizeof(cmph_uint8)*(data->n), 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;
bmz8_data_t *bmz8 = (bmz8_data_t *)malloc(sizeof(bmz8_data_t));
DEBUGP("Loading bmz8 mphf\n");
mphf->data = bmz8;
fread(&nhashes, sizeof(cmph_uint8), 1, f);
bmz8->hashes = (hash_state_t **)malloc(sizeof(hash_state_t *)*(nhashes + 1));
bmz8->hashes[nhashes] = NULL;
DEBUGP("Reading %u hashes\n", nhashes);
for (i = 0; i < nhashes; ++i)
{
hash_state_t *state = NULL;
fread(&buflen, sizeof(cmph_uint32), 1, f);
DEBUGP("Hash state has %u bytes\n", buflen);
buf = (char *)malloc(buflen);
fread(buf, buflen, 1, f);
state = hash_state_load(buf, buflen);
bmz8->hashes[i] = state;
free(buf);
}
DEBUGP("Reading m and n\n");
fread(&(bmz8->n), sizeof(cmph_uint8), 1, f);
fread(&(bmz8->m), sizeof(cmph_uint8), 1, f);
bmz8->g = (cmph_uint8 *)malloc(sizeof(cmph_uint8)*bmz8->n);
fread(bmz8->g, bmz8->n*sizeof(cmph_uint8), 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 = hash(bmz8->hashes[0], key, keylen) % bmz8->n;
cmph_uint8 h2 = 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 (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);
}
/** cmph_uint8 bmz8_search_fingerprint(cmph_t *mphf, const char *key, cmph_uint32 keylen, cmph_uint32 * fingerprint);
* \brief Computes the mphf value and a fingerprint of 12 bytes (i.e., figerprint should be a prealocated area to fit three 4-byte integers).
* \param mphf pointer to the resulting function
* \param key is the key to be hashed
* \param keylen is the key legth in bytes
* \return The mphf value
*
* Computes the mphf value and a fingerprint of 12 bytes. The figerprint pointer should be
* a prealocated area to fit three 4-byte integers. You don't need to use all the 12 bytes
* as fingerprint. According to the application, just few bits can be enough, once mphf does
* not allow collisions for the keys previously known.
*/
cmph_uint8 bmz8_search_fingerprint(cmph_t *mphf, const char *key, cmph_uint32 keylen, cmph_uint32 * fingerprint)
{
bmz8_data_t *bmz8 = mphf->data;
cmph_uint8 h1, h2;
hash_vector(bmz8->hashes[0], key, keylen, fingerprint);
h1 = fingerprint[2] % bmz8->n;
hash_vector(bmz8->hashes[1], key, keylen, fingerprint);
h2 = fingerprint[2] % 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 bmz8->g[h1] + bmz8->g[h2];
}
/** \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 (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 = hash_packed(h1_ptr, h1_type, key, keylen) % n;
register cmph_uint8 h2 = 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;
DEBUGP("key: %s g[h1]: %u g[h2]: %u edges: %u\n", key, g_ptr[h1], g_ptr[h2], m);
return (g_ptr[h1] + g_ptr[h2]);
}
View Git Blame Copy Permalink