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#include "graph.h"
#include "chm.h"
#include "cmph_structs.h"
#include "chm_structs.h"
#include "hash.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 chm_gen_edges(cmph_config_t *mph);
static void chm_traverse(chm_config_data_t *chm, cmph_uint8 *visited, cmph_uint32 v);
chm_config_data_t *chm_config_new(void)
{
chm_config_data_t *chm = NULL;
chm = (chm_config_data_t *)malloc(sizeof(chm_config_data_t));
if (!chm) return NULL;
memset(chm, 0, sizeof(chm_config_data_t));
chm->hashfuncs[0] = CMPH_HASH_JENKINS;
chm->hashfuncs[1] = CMPH_HASH_JENKINS;
chm->g = NULL;
chm->graph = NULL;
chm->hashes = NULL;
return chm;
}
void chm_config_destroy(cmph_config_t *mph)
{
chm_config_data_t *data = (chm_config_data_t *)mph->data;
DEBUGP("Destroying algorithm dependent data\n");
free(data);
}
void chm_config_set_hashfuncs(cmph_config_t *mph, CMPH_HASH *hashfuncs)
{
chm_config_data_t *chm = (chm_config_data_t *)mph->data;
CMPH_HASH *hashptr = hashfuncs;
cmph_uint32 i = 0;
while(*hashptr != CMPH_HASH_COUNT)
{
if (i >= 2) break; //chm only uses two hash functions
chm->hashfuncs[i] = *hashptr;
++i, ++hashptr;
}
}
cmph_t *chm_new(cmph_config_t *mph, double c)
{
cmph_t *mphf = NULL;
chm_data_t *chmf = NULL;
cmph_uint32 i;
cmph_uint32 iterations = 100000;
cmph_uint32 total_iterations = iterations;
cmph_uint8 *visited = NULL;
chm_config_data_t *chm = (chm_config_data_t *)mph->data;
chm->m = mph->key_source->nkeys;
if (c == 0) {
c = 2.09;
}
chm->n = (cmph_uint32)ceil(c * mph->key_source->nkeys);
DEBUGP("m (edges): %u n (vertices): %u c: %f\n", chm->m, chm->n, c);
chm->graph = graph_new(chm->n, chm->m);
DEBUGP("Created graph\n");
chm->hashes = (hash_state_t **)malloc(sizeof(hash_state_t *)*3);
for(i = 0; i < 3; ++i) chm->hashes[i] = NULL;
//Mapping step
if (mph->verbosity)
{
fprintf(stderr, "Entering mapping step for mph creation of %u keys with graph sized %u\n", chm->m, chm->n);
}
while(1)
{
int ok;
//
// N.B. The hash state constructor uses rand() to generate a
// new seed, such that new hashes will be produced each
// iteration.
//
chm->hashes[0] = hash_state_new(chm->hashfuncs[0], chm->n);
chm->hashes[1] = hash_state_new(chm->hashfuncs[1], chm->n);
//
// XXX: This results in an unnecessary graph_clear_edges() upon
// the first invocation. (Or graph_new() unnecessarily calls
// graph_clear_edges().)
//
if (mph->verbosity) {
fprintf(stderr, "Acyclic graph creation, attempt %d...\n", total_iterations - iterations);
}
ok = chm_gen_edges(mph);
if (!ok)
{
--iterations;
hash_state_destroy(chm->hashes[0]);
chm->hashes[0] = NULL;
hash_state_destroy(chm->hashes[1]);
chm->hashes[1] = NULL;
DEBUGP("%u iterations remaining\n", iterations);
if (mph->verbosity)
{
fprintf(stderr, "Acyclic graph creation failure - %u iterations remaining\n", iterations);
}
if (iterations == 0) {
break;
}
}
else {
fprintf(stderr, "Found solution after %d iterations.\n", total_iterations - iterations);
break;
}
}
if (iterations == 0)
{
graph_destroy(chm->graph);
return NULL;
}
//Assignment step
if (mph->verbosity)
{
fprintf(stderr, "Starting assignment step\n");
}
DEBUGP("Assignment step\n");
visited = (cmph_uint8 *)malloc((size_t)(chm->n/8 + 1));
memset(visited, 0, (size_t)(chm->n/8 + 1));
free(chm->g);
chm->g = (cmph_uint32 *)malloc(chm->n * sizeof(cmph_uint32));
assert(chm->g);
for (i = 0; i < chm->n; ++i)
{
if (!GETBIT(visited,i))
{
chm->g[i] = 0;
chm_traverse(chm, visited, i);
}
}
graph_destroy(chm->graph);
free(visited);
chm->graph = NULL;
mphf = (cmph_t *)malloc(sizeof(cmph_t));
mphf->algo = mph->algo;
chmf = (chm_data_t *)malloc(sizeof(chm_data_t));
chmf->g = chm->g;
chm->g = NULL; //transfer memory ownership
chmf->hashes = chm->hashes;
chm->hashes = NULL; //transfer memory ownership
chmf->n = chm->n;
chmf->m = chm->m;
mphf->data = chmf;
mphf->size = chm->m;
DEBUGP("Successfully generated minimal perfect hash\n");
if (mph->verbosity)
{
fprintf(stderr, "Successfully generated minimal perfect hash function\n");
}
return mphf;
}
static void chm_traverse(chm_config_data_t *chm, cmph_uint8 *visited, cmph_uint32 v)
{
graph_iterator_t it = graph_neighbors_it(chm->graph, v);
cmph_uint32 neighbor = 0;
SETBIT(visited,v);
DEBUGP("Visiting vertex %u\n", v);
while((neighbor = graph_next_neighbor(chm->graph, &it)) != GRAPH_NO_NEIGHBOR)
{
DEBUGP("Visiting neighbor %u\n", neighbor);
if (GETBIT(visited, neighbor)) {
continue;
}
DEBUGP("Visiting neighbor %u\n", neighbor);
DEBUGP("Visiting edge %u->%u with id %u\n", v, neighbor, graph_edge_id(chm->graph, v, neighbor));
chm->g[neighbor] = graph_edge_id(chm->graph, v, neighbor) - chm->g[v];
DEBUGP("g is %u (%u - %u mod %u)\n", chm->g[neighbor], graph_edge_id(chm->graph, v, neighbor), chm->g[v], chm->m);
chm_traverse(chm, visited, neighbor);
}
}
static int chm_gen_edges_old(cmph_config_t *mph)
{
cmph_uint32 e;
chm_config_data_t *chm = (chm_config_data_t *)mph->data;
int cycles = 0;
DEBUGP("Generating edges for %u vertices with hash functions %s and %s\n", chm->n, cmph_hash_names[chm->hashfuncs[0]], cmph_hash_names[chm->hashfuncs[1]]);
graph_clear_edges(chm->graph);
mph->key_source->rewind(mph->key_source->data);
for (e = 0; e < mph->key_source->nkeys; ++e)
{
cmph_uint32 h1, h2;
cmph_uint32 keylen;
char *key;
mph->key_source->read(mph->key_source->data, &key, &keylen);
h1 = hash(chm->hashes[0], key, keylen) % chm->n;
h2 = hash(chm->hashes[1], key, keylen) % chm->n;
if (h1 == h2) if (++h2 >= chm->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);
graph_add_edge(chm->graph, h1, h2);
}
cycles = graph_is_cyclic(chm->graph);
if (mph->verbosity && cycles) fprintf(stderr, "Cyclic graph generated\n");
DEBUGP("Looking for cycles: %u\n", cycles);
return ! cycles;
}
static int chm_gen_edges(cmph_config_t *mph)
{
cmph_uint32 e;
chm_config_data_t *chm = (chm_config_data_t *)mph->data;
cmph_uint32 *p;
cmph_uint32 h1, h2;
cmph_uint32 keylen = mph->keylen;
int cycles = 0;
DEBUGP("Generating edges for %u vertices with hash functions %s and %s\n", chm->n, cmph_hash_names[chm->hashfuncs[0]], cmph_hash_names[chm->hashfuncs[1]]);
graph_clear_edges(chm->graph);
//mph->key_source->rewind(mph->key_source->data);
p = (cmph_uint32 *)mph->base_address;
for (e = 0; e < mph->key_source->nkeys; ++e, ++p)
{
char *key;
//mph->key_source->read(mph->key_source->data, &key, &keylen);
key = (char *)p;
h1 = hash(chm->hashes[0], key, keylen) % chm->n;
h2 = hash(chm->hashes[1], key, keylen) % chm->n;
if (h1 == h2) {
if (++h2 >= chm->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 %d\n", h1, h2, *p);
//mph->key_source->dispose(mph->key_source->data, key, keylen);
graph_add_edge(chm->graph, h1, h2);
}
//graph_print(chm->graph);
cycles = graph_is_cyclic(chm->graph);
if (mph->verbosity && cycles) fprintf(stderr, "Cyclic graph generated\n");
DEBUGP("Looking for cycles: %u\n", cycles);
return ! cycles;
}
int chm_dump(cmph_t *mphf, FILE *fd)
{
char *buf = NULL;
cmph_uint32 buflen;
cmph_uint32 two = 2; //number of hash functions
chm_data_t *data = (chm_data_t *)mphf->data;
register size_t nbytes;
size_t size_in_bytes;
__cmph_dump(mphf, fd);
nbytes = fwrite(&two, (size_t)1, sizeof(cmph_uint32), fd);
hash_state_dump(data->hashes[0], &buf, &buflen);
DEBUGP("Dumping hash state with %u bytes to disk\n", buflen);
nbytes = fwrite(&buflen, (size_t)1, sizeof(cmph_uint32), fd);
nbytes = fwrite(buf, (size_t)1, (size_t)buflen, 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, (size_t)1, sizeof(cmph_uint32), fd);
nbytes = fwrite(buf, (size_t)1, (size_t)buflen, fd);
free(buf);
nbytes = fwrite(&(data->n), (size_t)1, sizeof(cmph_uint32), fd);
nbytes = fwrite(&(data->m), (size_t)1, sizeof(cmph_uint32), fd);
size_in_bytes = sizeof(cmph_uint32) * data->n;
nbytes = fwrite(data->g, (size_t)1, size_in_bytes, fd);
if (nbytes != size_in_bytes) {
int err = ferror(fd);
__debugbreak();
}
/* #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 chm_load(FILE *f, cmph_t *mphf)
{
cmph_uint32 nhashes;
char *buf = NULL;
cmph_uint32 buflen;
cmph_uint32 i;
size_t size_in_bytes;
chm_data_t *chm = (chm_data_t *)malloc(sizeof(chm_data_t));
register size_t nbytes;
DEBUGP("Loading chm mphf\n");
mphf->data = chm;
nbytes = fread(&nhashes, (size_t)1, sizeof(cmph_uint32), f);
chm->hashes = (hash_state_t **)malloc(sizeof(hash_state_t *)*(nhashes + 1));
chm->hashes[nhashes] = NULL;
DEBUGP("Reading %u hashes\n", nhashes);
for (i = 0; i < nhashes; ++i)
{
hash_state_t *state = NULL;
nbytes = fread(&buflen, (size_t)1, sizeof(cmph_uint32), f);
DEBUGP("Hash state has %u bytes\n", buflen);
buf = (char *)malloc((size_t)buflen);
nbytes = fread(buf, (size_t)1, (size_t)buflen, f);
state = hash_state_load(buf, buflen);
chm->hashes[i] = state;
free(buf);
}
DEBUGP("Reading m and n\n");
nbytes = fread(&(chm->n), (size_t)1, sizeof(cmph_uint32), f);
nbytes = fread(&(chm->m), (size_t)1, sizeof(cmph_uint32), f);
chm->g = (cmph_uint32 *)malloc(sizeof(cmph_uint32)*chm->n);
size_in_bytes = chm->n * sizeof(cmph_uint32);
nbytes = fread(chm->g, (size_t)1, size_in_bytes, f);
if (nbytes == 0) {
int err = ferror(f);
__debugbreak();
}
#ifdef DEBUG
fprintf(stderr, "G: ");
for (i = 0; i < chm->n; ++i) fprintf(stderr, "%u ", chm->g[i]);
fprintf(stderr, "\n");
#endif
return;
}
cmph_uint32 chm_search(cmph_t *mphf, const char *key, cmph_uint32 keylen)
{
chm_data_t *chm = (chm_data_t *)mphf->data;
cmph_uint32 kv = *((cmph_uint32 *)key);
cmph_uint32 h1 = hash(chm->hashes[0], key, keylen) % chm->n;
cmph_uint32 h2 = hash(chm->hashes[1], key, keylen) % chm->n;
cmph_uint32 g1, g2, g3, g4;
DEBUGP("key: %s h1: %u h2: %u\n", key, h1, h2);
if (h1 == h2 && ++h2 >= chm->n) {
h2 = 0;
}
DEBUGP("key: %s g[h1]: %u g[h2]: %u edges: %u\n", key, chm->g[h1], chm->g[h2], chm->m);
g1 = chm->g[h1];
g2 = chm->g[h2];
g3 = g1 + g2;
g4 = g3 % chm->m;
return g4;
//return (chm->g[h1] + chm->g[h2]) % chm->m;
}
void chm_destroy(cmph_t *mphf)
{
chm_data_t *data = (chm_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 chm_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 chm_pack(cmph_t *mphf, void *packed_mphf)
{
chm_data_t *data = (chm_data_t *)mphf->data;
cmph_uint8 * ptr = (cmph_uint8 *)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
*((cmph_uint32 *) ptr) = data->n;
ptr += sizeof(data->n);
// packing m
*((cmph_uint32 *) ptr) = data->m;
ptr += sizeof(data->m);
// packing g
memcpy(ptr, data->g, sizeof(cmph_uint32)*data->n);
}
/** \fn cmph_uint32 chm_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 chm_packed_size(cmph_t *mphf)
{
chm_data_t *data = (chm_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) +
4*sizeof(cmph_uint32) + sizeof(cmph_uint32)*data->n);
}
/** cmph_uint32 chm_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 chm_search_packed(void *packed_mphf, const char *key, cmph_uint32 keylen)
{
register cmph_uint8 *h1_ptr = (cmph_uint8 *)packed_mphf;
register CMPH_HASH h1_type = (CMPH_HASH)(*((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_HASH)(*((cmph_uint32 *)h2_ptr));
h2_ptr += 4;
register cmph_uint32 *g_ptr = (cmph_uint32 *)(h2_ptr + hash_state_packed_size(h2_type));
register cmph_uint32 n = *g_ptr++;
register cmph_uint32 m = *g_ptr++;
register cmph_uint32 h1 = hash_packed(h1_ptr, h1_type, key, keylen) % n;
register cmph_uint32 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]) % m;
}