From a8c4aa7a458897a24231e515cec247206faf6433 Mon Sep 17 00:00:00 2001 From: davi Date: Fri, 23 Sep 2005 21:43:33 +0000 Subject: [PATCH] Started to implement new algorithm hashtree. --- src/hashtree.c | 293 +++++++++++++++++++++++++++++++++++++++++ src/hashtree.h | 18 +++ src/hashtree_structs.h | 31 +++++ 3 files changed, 342 insertions(+) create mode 100644 src/hashtree.c create mode 100644 src/hashtree.h create mode 100644 src/hashtree_structs.h diff --git a/src/hashtree.c b/src/hashtree.c new file mode 100644 index 0000000..7feec29 --- /dev/null +++ b/src/hashtree.c @@ -0,0 +1,293 @@ +#include "graph.h" +#include "chm.h" +#include "cmph_structs.h" +#include "chm_structs.h" +#include "hash.h" +#include "bitbool.h" + +#include +#include +#include +#include +#include + +//#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() +{ + chm_config_data_t *chm; + chm = (chm_config_data_t *)malloc(sizeof(chm_config_data_t)); + assert(chm); + 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, float c) +{ + cmph_t *mphf = NULL; + chm_data_t *chmf = NULL; + + cmph_uint32 i; + cmph_uint32 iterations = 20; + cmph_uint8 *visited = NULL; + chm_config_data_t *chm = (chm_config_data_t *)mph->data; + chm->m = mph->key_source->nkeys; + chm->n = 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; + chm->hashes[0] = hash_state_new(chm->hashfuncs[0], chm->n); + chm->hashes[1] = hash_state_new(chm->hashfuncs[1], chm->n); + 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 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 = (char *)malloc(chm->n/8 + 1); + memset(visited, 0, chm->n/8 + 1); + free(chm->g); + chm->g = 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(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; +} + +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; + __cmph_dump(mphf, fd); + + fwrite(&two, sizeof(cmph_uint32), 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_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 + return 1; +} + +void chm_load(FILE *f, cmph_t *mphf) +{ + cmph_uint32 nhashes; + char *buf = NULL; + cmph_uint32 buflen; + cmph_uint32 i; + chm_data_t *chm = (chm_data_t *)malloc(sizeof(chm_data_t)); + + DEBUGP("Loading chm mphf\n"); + mphf->data = chm; + fread(&nhashes, sizeof(cmph_uint32), 1, 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; + 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); + chm->hashes[i] = state; + free(buf); + } + + DEBUGP("Reading m and n\n"); + fread(&(chm->n), sizeof(cmph_uint32), 1, f); + fread(&(chm->m), sizeof(cmph_uint32), 1, f); + + chm->g = (cmph_uint32 *)malloc(sizeof(cmph_uint32)*chm->n); + fread(chm->g, chm->n*sizeof(cmph_uint32), 1, f); + #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 = mphf->data; + cmph_uint32 h1 = hash(chm->hashes[0], key, keylen) % chm->n; + cmph_uint32 h2 = hash(chm->hashes[1], key, keylen) % chm->n; + 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); + 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); +} diff --git a/src/hashtree.h b/src/hashtree.h new file mode 100644 index 0000000..7c736e7 --- /dev/null +++ b/src/hashtree.h @@ -0,0 +1,18 @@ +#ifndef __CMPH_HASHTREE_H__ +#define __CMPH_HASHTREE_H__ + +#include "cmph.h" + +typedef struct __hashtree_data_t hashtree_data_t; +typedef struct __hashtree_config_data_t hashtree_config_data_t; + +hashtree_config_data_t *hashtree_config_new(); +void hashtree_config_set_hashfuncs(cmph_config_t *mph, CMPH_HASH *hashfuncs); +void hashtree_config_destroy(cmph_config_t *mph); +cmph_t *hashtree_new(cmph_config_t *mph, float c); + +void hashtree_load(FILE *f, cmph_t *mphf); +int hashtree_dump(cmph_t *mphf, FILE *f); +void hashtree_destroy(cmph_t *mphf); +cmph_uint32 hashtree_search(cmph_t *mphf, const char *key, cmph_uint32 keylen); +#endif diff --git a/src/hashtree_structs.h b/src/hashtree_structs.h new file mode 100644 index 0000000..f45a343 --- /dev/null +++ b/src/hashtree_structs.h @@ -0,0 +1,31 @@ +#ifndef __CMPH_HASHTREE_STRUCTS_H__ +#define __CMPH_HASHTREE_STRUCTS_H__ + +#include "hash_state.h" + +struct __hashtree_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 **g; + cmph_uint32 k; //number of components + hash_state_t **h1; + hash_state_t **h2; + hash_state_t *h3; +}; + +struct __hashtree_config_data_t +{ + CMPH_HASH hashfuncs[3]; + 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[i - 1] + cmph_uint32 k; //number of components + cmph_uint32 memory; + hash_state_t **h1; + hash_state_t **h2; + hash_state_t *h3; +}; + +#endif