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fc_botelho
2008-03-26 20:26:48 +00:00
parent 2665414b4e
commit c8a1c4fef9
25 changed files with 1875 additions and 88 deletions
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121
src/bdz_ph.c
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@@ -478,21 +478,23 @@ void bdz_ph_load(FILE *f, cmph_t *mphf)
bdz_ph->g = (cmph_uint8 *)calloc((bdz_ph->n/5)+1, sizeof(cmph_uint8));
fread(bdz_ph->g, ((bdz_ph->n/5)+1)*sizeof(cmph_uint8), 1, f);
#ifdef DEBUG
/* #ifdef DEBUG
cmph_uint32 i;
fprintf(stderr, "G: ");
for (i = 0; i < bdz_ph->n; ++i) fprintf(stderr, "%u ", GETVALUE(bdz_ph->g,i));
fprintf(stderr, "\n");
#endif
*/
return;
}
cmph_uint32 bdz_ph_search(cmph_t *mphf, const char *key, cmph_uint32 keylen)
{
bdz_ph_data_t *bdz_ph = mphf->data;
register bdz_ph_data_t *bdz_ph = mphf->data;
cmph_uint32 hl[3];
cmph_uint8 byte0, byte1, byte2;
cmph_uint32 vertex;
register cmph_uint8 byte0, byte1, byte2;
register cmph_uint32 vertex;
hash_vector(bdz_ph->hl, key, keylen,hl);
hl[0] = hl[0] % bdz_ph->r;
@@ -520,3 +522,114 @@ void bdz_ph_destroy(cmph_t *mphf)
free(data);
free(mphf);
}
/** cmph_uint32 bdz_ph_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_uint32 bdz_ph_search_fingerprint(cmph_t *mphf, const char *key, cmph_uint32 keylen, cmph_uint32 * fingerprint)
{
register bdz_ph_data_t *bdz_ph = mphf->data;
cmph_uint32 hl[3];
register cmph_uint8 byte0, byte1, byte2;
register cmph_uint32 vertex;
hash_vector(bdz_ph->hl, key, keylen,hl);
memcpy(fingerprint, hl, sizeof(hl));
hl[0] = hl[0] % bdz_ph->r;
hl[1] = hl[1] % bdz_ph->r + bdz_ph->r;
hl[2] = hl[2] % bdz_ph->r + (bdz_ph->r << 1);
byte0 = bdz_ph->g[hl[0]/5];
byte1 = bdz_ph->g[hl[1]/5];
byte2 = bdz_ph->g[hl[2]/5];
byte0 = lookup_table[hl[0]%5][byte0];
byte1 = lookup_table[hl[1]%5][byte1];
byte2 = lookup_table[hl[2]%5][byte2];
vertex = hl[(byte0 + byte1 + byte2)%3];
return vertex;
}
/** \fn void bdz_ph_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 bdz_ph_pack(cmph_t *mphf, void *packed_mphf)
{
bdz_ph_data_t *data = (bdz_ph_data_t *)mphf->data;
cmph_uint32 * ptr = packed_mphf;
// packing hl
hash_state_pack(data->hl, ptr);
ptr += (hash_state_packed_size(data->hl) >> 2); // (hash_state_packed_size(data->hl) / 4);
// packing r
*ptr++ = data->r;
// packing g
memcpy(ptr, data->g, sizeof(cmph_uint8)*((data->n/5)+1));
}
/** \fn cmph_uint32 bdz_ph_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 bdz_ph_packed_size(cmph_t *mphf)
{
bdz_ph_data_t *data = (bdz_ph_data_t *)mphf->data;
return (sizeof(CMPH_ALGO) + hash_state_packed_size(data->hl) + sizeof(cmph_uint32) + sizeof(cmph_uint8)*((data->n/5)+1));
}
/** cmph_uint32 bdz_ph_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_uint32 bdz_ph_search_packed(void *packed_mphf, const char *key, cmph_uint32 keylen)
{
register cmph_uint32 *hl_ptr = (cmph_uint32 *)packed_mphf;
register cmph_uint32 hl_size = *hl_ptr;
register cmph_uint32 *ptr = hl_ptr + (hl_size >> 2); // h2_ptr + h2_size/4
register cmph_uint32 r = *ptr++;
register cmph_uint8 * g = (cmph_uint8 *)ptr;
cmph_uint32 hl[3];
register cmph_uint8 byte0, byte1, byte2;
register cmph_uint32 vertex;
hash_vector_packed(hl_ptr, key, keylen, hl);
hl[0] = hl[0] % r;
hl[1] = hl[1] % r + r;
hl[2] = hl[2] % r + (r << 1);
byte0 = g[hl[0]/5];
byte1 = g[hl[1]/5];
byte2 = g[hl[2]/5];
byte0 = lookup_table[hl[0]%5][byte0];
byte1 = lookup_table[hl[1]%5][byte1];
byte2 = lookup_table[hl[2]%5][byte2];
vertex = hl[(byte0 + byte1 + byte2)%3];
return vertex;
}