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FCH algorithm is working...

This commit is contained in:
fc_botelho 2006-08-04 17:55:13 +00:00
parent 3825c0a511
commit 99f0705fed
3 changed files with 39 additions and 29 deletions
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2
src/cmph.c
View File

@ -374,7 +374,7 @@ cmph_t *cmph_new(cmph_config_t *mph)
break;
case CMPH_FCH: /* included -- Fabiano */
DEBUGP("Creating fch hash\n");
if (c <= 2) c = 2.1;
if (c <= 2) c = 2.6;
mphf = fch_new(mph, c);
break;
default:

60
src/fch.c
View File

@ -4,22 +4,20 @@
#include "hash.h"
#include "bitbool.h"
#include "fch_buckets.h"
//#include <sys/time.h>
#include <time.h>
#include <math.h>
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include <string.h>
#define INDEX 0 /* alignment index within a bucket */
#define DEBUG
//#define DEBUG
#include "debug.h"
static cmph_uint32 mixh10h11h12(cmph_uint32 b, cmph_float32 p1, cmph_float32 p2, cmph_uint32 initial_index);
static void calc_parameters(fch_config_data_t *fch);
static fch_buckets_t * mapping(cmph_config_t *mph);
static cmph_uint32 * ordering(fch_buckets_t * buckets);
static cmph_uint8 check_for_collisions_h2(fch_config_data_t *fch, fch_buckets_t * buckets);
static cmph_uint8 check_for_collisions_h2(fch_config_data_t *fch, fch_buckets_t * buckets, cmph_uint32 *sorted_indexes);
static void permut(cmph_uint32 * vector, cmph_uint32 n);
static cmph_uint8 searching(fch_config_data_t *fch, fch_buckets_t *buckets, cmph_uint32 *sorted_indexes);
@ -72,22 +70,19 @@ static cmph_uint32 mixh10h11h12(cmph_uint32 b, cmph_float32 p1, cmph_float32 p2,
static void calc_parameters(fch_config_data_t *fch)
{
fch->b = (cmph_uint32)ceil((fch->c*fch->m)/(log(fch->m)/log(2) + 1));
fch->p1 = ceil(0.6*fch->m);
fch->p1 = ceil(0.55*fch->m);
fch->p2 = ceil(0.3*fch->b);
}
static fch_buckets_t * mapping(cmph_config_t *mph)
{
// struct timeval seed;
cmph_uint32 i = 0;
fch_buckets_t *buckets = NULL;
fch_config_data_t *fch = (fch_config_data_t *)mph->data;
// gettimeofday(&seed,NULL);
// srand((cmph_uint32)((seed.tv_sec + 1001*seed.tv_usec)));
srand((cmph_uint32)time(NULL));
if (fch->h1) hash_state_destroy(fch->h1);
fch->h1 = hash_state_new(fch->hashfuncs[0], fch->m);
calc_parameters (fch);
//DEBUGP("b:%u p1:%f p2:%f\n", fch->b, fch->p1, fch->p2);
buckets = fch_buckets_new(fch->b);
mph->key_source->rewind(mph->key_source->data);
@ -113,7 +108,7 @@ static cmph_uint32 * ordering(fch_buckets_t * buckets)
}
/* Check whether function h2 causes collisions among the keys of each bucket */
static cmph_uint8 check_for_collisions_h2(fch_config_data_t *fch, fch_buckets_t * buckets)
static cmph_uint8 check_for_collisions_h2(fch_config_data_t *fch, fch_buckets_t * buckets, cmph_uint32 *sorted_indexes)
{
//cmph_uint32 max_size = fch_buckets_get_max_size(buckets);
cmph_uint8 * hashtable = (cmph_uint8 *)calloc(fch->m, sizeof(cmph_uint8));
@ -121,12 +116,13 @@ static cmph_uint8 check_for_collisions_h2(fch_config_data_t *fch, fch_buckets_t
cmph_uint32 i = 0, index = 0, j =0;
for (i = 0; i < nbuckets; i++)
{
cmph_uint32 nkeys = fch_buckets_get_size(buckets, i);
cmph_uint32 nkeys = fch_buckets_get_size(buckets, sorted_indexes[i]);
memset(hashtable, 0, fch->m);
//DEBUGP("bucket %u -- nkeys: %u\n", i, nkeys);
for (j = 0; j < nkeys; j++)
{
char * key = fch_buckets_get_key(buckets, i, j);
cmph_uint32 keylen = fch_buckets_get_keylength(buckets, i, j);
char * key = fch_buckets_get_key(buckets, sorted_indexes[i], j);
cmph_uint32 keylen = fch_buckets_get_keylength(buckets, sorted_indexes[i], j);
index = hash(fch->h2, key, keylen) % fch->m;
if(hashtable[index]) { // collision detected
free(hashtable);
@ -142,7 +138,6 @@ static cmph_uint8 check_for_collisions_h2(fch_config_data_t *fch, fch_buckets_t
static void permut(cmph_uint32 * vector, cmph_uint32 n)
{
cmph_uint32 i, j, b;
srand((cmph_uint32)time(NULL));
for (i = 0; i < n; i++) {
j = rand() % n;
b = vector[i];
@ -163,6 +158,8 @@ static cmph_uint8 searching(fch_config_data_t *fch, fch_buckets_t *buckets, cmph
if (fch->g) free (fch->g);
fch->g = (cmph_uint32 *) calloc(fch->b, sizeof(cmph_uint32));
//DEBUGP("max bucket size: %u\n", fch_buckets_get_max_size(buckets));
for(i = 0; i < fch->m; i++)
{
random_table[i] = i;
@ -172,27 +169,36 @@ static cmph_uint8 searching(fch_config_data_t *fch, fch_buckets_t *buckets, cmph
{
map_table[random_table[i]] = i;
}
//DEBUGP("max bucket size: %u\n", fch_buckets_get_max_size(buckets));
do {
srand((cmph_uint32)time(NULL));
if (fch->h2) hash_state_destroy(fch->h2);
fch->h2 = hash_state_new(fch->hashfuncs[1], fch->m);
restart = check_for_collisions_h2(fch, buckets);
restart = check_for_collisions_h2(fch, buckets, sorted_indexes);
filled_count = 0;
if (!restart) searching_iterations++;
else iteration_to_generate_h2++;
if (!restart)
{
searching_iterations++; iteration_to_generate_h2 = 0;
//DEBUGP("searching_iterations: %u\n", searching_iterations);
}
else {
iteration_to_generate_h2++;
//DEBUGP("iteration_to_generate_h2: %u\n", iteration_to_generate_h2);
}
for(i = 0; (i < nbuckets) && !restart; i++) {
restart = 1; // true
cmph_uint32 bucketsize = fch_buckets_get_size(buckets, sorted_indexes[i]);
if (bucketsize == 0)
{
restart = 0; // false
break;
}
else restart = 1; // true
for(z = 0; (z < (fch->m - filled_count)) && restart; z++) {
char * key = fch_buckets_get_key(buckets, sorted_indexes[i], INDEX);
cmph_uint32 keylen = fch_buckets_get_keylength(buckets, sorted_indexes[i], INDEX);
cmph_uint32 h2 = hash(fch->h2, key, keylen) % fch->m;
cmph_uint32 bucketsize = fch_buckets_get_size(buckets, sorted_indexes[i]);
counter = 0;
restart = 0; // false
fch->g[sorted_indexes[i]] = (fch->m + random_table[filled_count + z] - h2) % fch->m;
//DEBUGP("g[%u]: %u\n", sorted_indexes[i], fch->g[sorted_indexes[i]]);
j = INDEX;
do {
cmph_uint32 index = 0;
@ -200,6 +206,7 @@ static cmph_uint8 searching(fch_config_data_t *fch, fch_buckets_t *buckets, cmph
keylen = fch_buckets_get_keylength(buckets, sorted_indexes[i], j);
h2 = hash(fch->h2, key, keylen) % fch->m;
index = (h2 + fch->g[sorted_indexes[i]]) % fch->m;
//DEBUGP("key:%s keylen:%u index: %u h2:%u bucketsize:%u\n", key, keylen, index, h2, bucketsize);
if (map_table[index] >= filled_count) {
cmph_uint32 y = map_table[index];
cmph_uint32 ry = random_table[y];
@ -219,8 +226,9 @@ static cmph_uint8 searching(fch_config_data_t *fch, fch_buckets_t *buckets, cmph
j = (j + 1) % bucketsize;
} while(j % bucketsize != INDEX);
}
//getchar();
}
} while(restart && (searching_iterations < 100000));
} while(restart && (searching_iterations < 10));
free(map_table);
free(random_table);
return restart;
@ -258,11 +266,14 @@ cmph_t *fch_new(cmph_config_t *mph, float c)
}
if (sorted_indexes) free (sorted_indexes);
sorted_indexes = ordering(buckets);
cmph_uint32 nbuckets = fch_buckets_get_nbuckets(buckets);
cmph_uint32 i = 0;
if (mph->verbosity)
{
fprintf(stderr, "Starting searching step.\n");
}
restart_mapping = searching(fch, buckets, sorted_indexes);
iterations--;
} while(restart_mapping && iterations > 0);
if (buckets) fch_buckets_destroy(buckets);
@ -316,7 +327,6 @@ int fch_dump(cmph_t *mphf, FILE *fd)
fwrite(&(data->b), sizeof(cmph_uint32), 1, fd);
fwrite(&(data->p1), sizeof(cmph_float32), 1, fd);
fwrite(&(data->p2), sizeof(cmph_float32), 1, fd);
fwrite(data->g, sizeof(cmph_uint32)*(data->b), 1, fd);
#ifdef DEBUG
cmph_uint32 i;

4
src/fch_buckets.c
View File

@ -162,12 +162,12 @@ cmph_uint32 fch_buckets_get_keylength(fch_buckets_t * buckets, cmph_uint32 index
cmph_uint32 fch_buckets_get_max_size(fch_buckets_t * buckets)
{
return buckets->nbuckets;
return buckets->max_size;
}
cmph_uint32 fch_buckets_get_nbuckets(fch_buckets_t * buckets)
{
return buckets->max_size;
return buckets->nbuckets;
}
cmph_uint32 * fch_buckets_get_indexes_sorted_by_size(fch_buckets_t * buckets)