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BRZ algorithm is almost stable

This commit is contained in:
fc_botelho 2005-07-29 18:29:30 +00:00
parent be73e6b2a4
commit f54cbcdfdc
4 changed files with 179 additions and 67 deletions

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@ -368,12 +368,15 @@ static void bmz_traverse(bmz_config_data_t *bmz, cmph_uint8 * used_edges, cmph_u
{
graph_iterator_t it = graph_neighbors_it(bmz->graph, v);
cmph_uint32 neighbor = 0;
cmph_uint32 gvalue;
while((neighbor = graph_next_neighbor(bmz->graph, &it)) != GRAPH_NO_NEIGHBOR)
{
if(GETBIT(visited,neighbor)) continue;
DEBUGP("Visiting neighbor %u\n", neighbor);
*unused_edge_index = next_unused_edge(bmz, used_edges, *unused_edge_index);
bmz->g[neighbor] = *unused_edge_index - bmz->g[v];
if(*unused_edge_index < bmz->g[v]) gvalue = *unused_edge_index + bmz->m;
else gvalue = *unused_edge_index;
bmz->g[neighbor] = gvalue - bmz->g[v];
SETBIT(visited, neighbor);
(*unused_edge_index)++;
bmz_traverse(bmz, used_edges, neighbor, unused_edge_index, visited);
@ -530,7 +533,7 @@ cmph_uint32 bmz_search(cmph_t *mphf, const char *key, cmph_uint32 keylen)
DEBUGP("key: %s h1: %u h2: %u\n", key, h1, h2);
if (h1 == h2 && ++h2 > bmz->n) h2 = 0;
DEBUGP("key: %s g[h1]: %u g[h2]: %u edges: %u\n", key, bmz->g[h1], bmz->g[h2], bmz->m);
return bmz->g[h1] + bmz->g[h2];
return ((bmz->g[h1] + bmz->g[h2]) % bmz->m);
}
void bmz_destroy(cmph_t *mphf)
{

236
src/brz.c
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@ -14,14 +14,14 @@
#include <assert.h>
#include <string.h>
#define DEBUG
//#define DEBUG
#include "debug.h"
static int brz_before_gen_graphs(cmph_config_t *mph, cmph_uint32 * disksize, cmph_uint32 * diskoffset);
static void brz_gen_graphs(cmph_config_t *mph, cmph_uint32 * disksize, cmph_uint32 * diskoffset, FILE * graphs_fd);
static char ** brz_read_keys_vd(FILE * graphs_fd, cmph_uint8 nkeys);
static void brz_destroy_keys_vd(char ** keys_vd, cmph_uint8 nkeys);
static void brz_copy_partial_mphf(brz_config_data_t *brz, bmz_data_t * bmzf, cmph_uint32 index);
static void brz_copy_partial_mphf(brz_config_data_t *brz, bmz_data_t * bmzf, cmph_uint32 index, cmph_io_adapter_t *source);
brz_config_data_t *brz_config_new()
{
@ -59,6 +59,72 @@ void brz_config_set_hashfuncs(cmph_config_t *mph, CMPH_HASH *hashfuncs)
++i, ++hashptr;
}
}
static cmph_uint8 brz_verify_mphf(cmph_t * mphf, cmph_io_adapter_t *source)
{
cmph_uint8 * hashtable = NULL;
cmph_uint32 i;
hashtable = (cmph_uint8*)malloc(source->nkeys*sizeof(cmph_uint8));
source->rewind(source->data);
memset(hashtable, 0, source->nkeys);
//check all keys
for (i = 0; i < source->nkeys; ++i)
{
cmph_uint32 h;
char *buf;
cmph_uint32 buflen = 0;
source->read(source->data, &buf, &buflen);
h = cmph_search(mphf, buf, buflen);
if(hashtable[h])
{
fprintf(stderr, "collision: %u\n",h);
return 0;
}
//assert(hashtable[h]==0);
hashtable[h] = 1;
source->dispose(source->data, buf, buflen);
}
free(hashtable);
return 1;
}
static cmph_uint8 brz_verify_mphf1(hash_state_t *h1, hash_state_t *h2, cmph_uint8 * g, cmph_uint32 n, cmph_io_adapter_t *source)
{
cmph_uint8 * hashtable = NULL;
cmph_uint32 i;
hashtable = (cmph_uint8*)calloc(source->nkeys, sizeof(cmph_uint8));
source->rewind(source->data);
//memset(hashtable, 0, source->nkeys);
//check all keys
for (i = 0; i < source->nkeys; ++i)
{
cmph_uint32 h1_v;
cmph_uint32 h2_v;
cmph_uint32 h;
char *buf;
cmph_uint32 buflen = 0;
source->read(source->data, &buf, &buflen);
h1_v = hash(h1, buf, buflen) % n;
h2_v = hash(h2, buf, buflen) % n;
if (h1_v == h2_v && ++h2_v >= n) h2_v = 0;
h = ((cmph_uint32)g[h1_v] + (cmph_uint32)g[h2_v]) % source->nkeys;
if(hashtable[h])
{
fprintf(stderr, "collision: %u\n",h);
return 0;
}
//assert(hashtable[h]==0);
hashtable[h] = 1;
source->dispose(source->data, buf, buflen);
}
free(hashtable);
return 1;
}
cmph_t *brz_new(cmph_config_t *mph, float c)
{
@ -77,6 +143,7 @@ cmph_t *brz_new(cmph_config_t *mph, float c)
FILE * graphs_fd = NULL;
DEBUGP("c: %f\n", c);
brz_config_data_t *brz = (brz_config_data_t *)mph->data;
brz->c = c;
brz->m = mph->key_source->nkeys;
DEBUGP("m: %u\n", brz->m);
brz->k = ceil(brz->m/128);
@ -151,23 +218,25 @@ cmph_t *brz_new(cmph_config_t *mph, float c)
brz->h1 = (hash_state_t **)malloc(sizeof(hash_state_t *)*brz->k);
brz->h2 = (hash_state_t **)malloc(sizeof(hash_state_t *)*brz->k);
brz->g = (cmph_uint8 **) malloc(sizeof(cmph_uint8 *) *brz->k);
DEBUGP("Generating mphf\n");
for(i = 0; i < brz->k; i++)
{
cmph_uint32 j;
bmz_data_t * bmzf = NULL;
if (brz->size[i] == 0) continue;
keys_vd = brz_read_keys_vd(graphs_fd, brz->size[i]);
cmph_uint8 nkeys = brz->size[i];
if (nkeys == 0) continue;
keys_vd = brz_read_keys_vd(graphs_fd, nkeys);
// Source of keys
source = cmph_io_vector_adapter(keys_vd, (cmph_uint32)brz->size[i]);
source = cmph_io_vector_adapter(keys_vd, (cmph_uint32)nkeys);
config = cmph_config_new(source);
cmph_config_set_algo(config, CMPH_BMZ);
cmph_config_set_graphsize(config, c);
mphf_tmp = cmph_new(config);
bmzf = (bmz_data_t *)mphf_tmp->data;
brz_copy_partial_mphf(brz, bmzf, i); // implementar
bmzf = (bmz_data_t *)mphf_tmp->data;
//assert(brz_verify_mphf(mphf_tmp, source));
brz_copy_partial_mphf(brz, bmzf, i, source); // implementar
cmph_config_destroy(config);
brz_destroy_keys_vd(keys_vd, brz->size[i]);
brz_destroy_keys_vd(keys_vd, nkeys);
free(keys_vd);
cmph_destroy(mphf_tmp);
free(source);
@ -192,7 +261,8 @@ cmph_t *brz_new(cmph_config_t *mph, float c)
brzf->offset = brz->offset;
brz->offset = NULL; //transfer memory ownership
brzf->k = brz->k;
brzf->m = brz->m;
brzf->c = brz->c;
brzf->m = brz->m;
mphf->data = brzf;
mphf->size = brz->m;
DEBUGP("Successfully generated minimal perfect hash\n");
@ -304,59 +374,75 @@ static void brz_destroy_keys_vd(char ** keys_vd, cmph_uint8 nkeys)
for(i = 0; i < nkeys; i++) free(keys_vd[i]);
}
static void brz_copy_partial_mphf(brz_config_data_t *brz, bmz_data_t * bmzf, cmph_uint32 index)
static void brz_copy_partial_mphf(brz_config_data_t *brz, bmz_data_t * bmzf, cmph_uint32 index, cmph_io_adapter_t *source)
{
cmph_uint32 i;
brz->g[index] = (cmph_uint8 *)malloc(sizeof(cmph_uint8)*bmzf->m);
for(i = 0; i < bmzf->m; i++)
cmph_uint32 n = ceil(brz->c * brz->size[index]);
brz->g[index] = (cmph_uint8 *)calloc(n, sizeof(cmph_uint8));
for(i = 0; i < n; i++)
{
brz->g[index][i] = (cmph_uint8) bmzf->g[i];
//fprintf(stderr, "gsrc[%u]: %u gdest: %u\n", i, (cmph_uint8) bmzf->g[i], brz->g[index][i]);
}
brz->h1[index] = hash_state_copy(bmzf->hashes[0]);
brz->h2[index] = hash_state_copy(bmzf->hashes[1]);
//brz->size[index] = bmzf->n;
//assert(brz_verify_mphf1(brz->h1[index], brz->h2[index], brz->g[index], n, source));
}
int brz_dump(cmph_t *mphf, FILE *fd)
{
/*char *buf = NULL;
char *buf = NULL;
cmph_uint32 buflen;
cmph_uint32 nbuflen;
cmph_uint32 i;
cmph_uint32 two = 2; //number of hash functions
brz_data_t *data = (brz_data_t *)mphf->data;
cmph_uint32 nn, nm;
DEBUGP("Dumping brzf\n");
__cmph_dump(mphf, fd);
fwrite(&two, sizeof(cmph_uint32), 1, fd);
hash_state_dump(data->hashes[0], &buf, &buflen);
fwrite(&(data->k), sizeof(cmph_uint32), 1, fd);
//dumping h1 and h2.
for(i = 0; i < data->k; i++)
{
// h1
hash_state_dump(data->h1[i], &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);
// h2
hash_state_dump(data->h2[i], &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);
}
// Dumping h3.
hash_state_dump(data->h3, &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_uint32), 1, fd);
fwrite(&(data->m), sizeof(cmph_uint32), 1, fd);
fwrite(data->g, sizeof(cmph_uint32)*(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
*/
// Dumping c, m, size vector and offset vector.
fwrite(&(data->c), sizeof(cmph_float32), 1, fd);
fwrite(&(data->m), sizeof(cmph_uint32), 1, fd);
fwrite(data->size, sizeof(cmph_uint8)*(data->k), 1, fd);
fwrite(data->offset, sizeof(cmph_uint32)*(data->k), 1, fd);
// Dumping g function.
for(i = 0; i < data->k; i++)
{
cmph_uint32 n = ceil(data->c * data->size[i]);
fwrite(data->g[i], sizeof(cmph_uint8)*n, 1, fd);
}
return 1;
}
void brz_load(FILE *f, cmph_t *mphf)
{
/* cmph_uint32 nhashes;
cmph_uint32 nhashes;
char *buf = NULL;
cmph_uint32 buflen;
cmph_uint32 i;
@ -364,49 +450,69 @@ void brz_load(FILE *f, cmph_t *mphf)
DEBUGP("Loading brz mphf\n");
mphf->data = brz;
fread(&nhashes, sizeof(cmph_uint32), 1, f);
brz->hashes = (hash_state_t **)malloc(sizeof(hash_state_t *)*(nhashes + 1));
brz->hashes[nhashes] = NULL;
DEBUGP("Reading %u hashes\n", nhashes);
for (i = 0; i < nhashes; ++i)
fread(&(brz->k), sizeof(cmph_uint32), 1, f);
brz->h1 = (hash_state_t **)malloc(sizeof(hash_state_t *)*brz->k);
brz->h2 = (hash_state_t **)malloc(sizeof(hash_state_t *)*brz->k);
DEBUGP("Reading %u h1 and %u h2\n", brz->k, brz->k);
//loading h1 and h2.
for(i = 0; i < brz->k; i++)
{
hash_state_t *state = NULL;
// h1
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);
brz->hashes[i] = state;
brz->h1[i] = hash_state_load(buf, buflen);
free(buf);
//h2
fread(&buflen, sizeof(cmph_uint32), 1, f);
DEBUGP("Hash state has %u bytes\n", buflen);
buf = (char *)malloc(buflen);
fread(buf, buflen, 1, f);
brz->h2[i] = hash_state_load(buf, buflen);
free(buf);
}
//loading h3
fread(&buflen, sizeof(cmph_uint32), 1, f);
DEBUGP("Hash state has %u bytes\n", buflen);
buf = (char *)malloc(buflen);
fread(buf, buflen, 1, f);
brz->h3 = hash_state_load(buf, buflen);
free(buf);
DEBUGP("Reading m and n\n");
fread(&(brz->n), sizeof(cmph_uint32), 1, f);
fread(&(brz->m), sizeof(cmph_uint32), 1, f);
brz->g = (cmph_uint32 *)malloc(sizeof(cmph_uint32)*brz->n);
fread(brz->g, brz->n*sizeof(cmph_uint32), 1, f);
#ifdef DEBUG
fprintf(stderr, "G: ");
for (i = 0; i < brz->n; ++i) fprintf(stderr, "%u ", brz->g[i]);
fprintf(stderr, "\n");
#endif
//loading c, m, size vector and offset vector.
fread(&(brz->c), sizeof(cmph_float32), 1, f);
fread(&(brz->m), sizeof(cmph_uint32), 1, f);
brz->size = (cmph_uint8 *) malloc(sizeof(cmph_uint8)*brz->k);
brz->offset = (cmph_uint32 *)malloc(sizeof(cmph_uint32)*brz->k);
fread(brz->size, sizeof(cmph_uint8)*(brz->k), 1, f);
fread(brz->offset, sizeof(cmph_uint32)*(brz->k), 1, f);
//loading g function.
brz->g = (cmph_uint8 **) malloc(sizeof(cmph_uint8 *)*brz->k);
for(i = 0; i < brz->k; i++)
{
cmph_uint32 n = ceil(brz->c * brz->size[i]);
brz->g[i] = (cmph_uint8 *)malloc(sizeof(cmph_uint8)*n);
fread(brz->g[i], sizeof(cmph_uint8)*n, 1, f);
}
return;
*/
}
cmph_uint32 brz_search(cmph_t *mphf, const char *key, cmph_uint32 keylen)
{
/* brz_data_t *brz = mphf->data;
cmph_uint32 h1 = hash(brz->hashes[0], key, keylen) % brz->n;
cmph_uint32 h2 = hash(brz->hashes[1], key, keylen) % brz->n;
DEBUGP("key: %s h1: %u h2: %u\n", key, h1, h2);
if (h1 == h2 && ++h2 > brz->n) h2 = 0;
DEBUGP("key: %s g[h1]: %u g[h2]: %u edges: %u\n", key, brz->g[h1], brz->g[h2], brz->m);
return brz->g[h1] + brz->g[h2];
*/
return 0;
brz_data_t *brz = mphf->data;
cmph_uint32 h3 = hash(brz->h3, key, keylen) % brz->k;
cmph_uint32 m = brz->size[h3];
cmph_uint32 n = ceil(brz->c * m);
cmph_uint32 h1 = hash(brz->h1[h3], key, keylen) % n;
cmph_uint32 h2 = hash(brz->h2[h3], key, keylen) % n;
if (h1 == h2 && ++h2 >= n) h2 = 0;
DEBUGP("key: %s h1: %u h2: %u h3: %u\n", key, h1, h2, h3);
DEBUGP("key: %s g[h1]: %u g[h2]: %u offset[h3]: %u edges: %u\n", key, brz->g[h3][h1], brz->g[h3][h2], brz->offset[h3], brz->m);
DEBUGP("Address: %u\n", (((cmph_uint32)brz->g[h3][h1] + (cmph_uint32)brz->g[h3][h2])% m + brz->offset[h3]));
return (((cmph_uint32)brz->g[h3][h1] + (cmph_uint32)brz->g[h3][h2])% m + brz->offset[h3]);
}
void brz_destroy(cmph_t *mphf)
{

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@ -6,6 +6,7 @@
struct __brz_data_t
{
cmph_uint32 m; // edges (words) count
cmph_float32 c; // constant c
cmph_uint8 *size; // size[i] stores the number of edges represented by g[i][...].
cmph_uint32 *offset; // offset[i] stores the sum: size[0] + size[1] + ... size[i-1].
cmph_uint8 **g; // g function.
@ -18,6 +19,7 @@ struct __brz_data_t
struct __brz_config_data_t
{
CMPH_HASH hashfuncs[3];
cmph_float32 c; // constant c
cmph_uint32 m; // edges (words) count
cmph_uint8 *size; // size[i] stores the number of edges represented by g[i][...].
cmph_uint32 *offset; // offset[i] stores the sum: size[0] + size[1] + ... size[i-1].

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@ -4,6 +4,7 @@
typedef unsigned char cmph_uint8;
typedef unsigned short cmph_uint16;
typedef unsigned int cmph_uint32;
typedef float cmph_float32;
typedef enum { CMPH_HASH_DJB2, CMPH_HASH_FNV, CMPH_HASH_JENKINS,
CMPH_HASH_SDBM, CMPH_HASH_COUNT } CMPH_HASH;