布隆过滤器.zip

#include <limits.h> #include <stdarg.h> #include "bloom.h" #define SETBIT(a,n) (a[n/CHAR_BIT] |= (1<<(n%CHAR_BIT))) #define GETBIT(a,n) (a[n/CHAR_BIT] & (1<<(n%CHAR_BIT))) BLOOM* bloom_create(size_t size,size_t nfuncs,...) { BLOOM* bloom; va_list l; int n; if (!(bloom = malloc(sizeof(BLOOM)))) return NULL; if (!(bloom->a = calloc((size+CHAR_BIT-1)/CHAR_BIT,sizeof(char)))) { free(bloom); return NULL; } if (!(bloom->funcs = (hashfunc_t*)malloc(nfuncs*sizeof(hashfunc_t)))) { free(bloom->a); free(bloom); return NULL; } va_start(l,nfuncs); for (n = 0; n < nfuncs; ++n) { bloom->funcs[n] = va_arg(l,hashfunc_t); } va_end(l); bloom->nfuncs = nfuncs; bloom->asize = size; return bloom; } int bloom_destroy(BLOOM* bloom) { free(bloom->a); free(bloom->funcs); free(bloom); return 0; } int bloom_add(BLOOM* bloom,const char* s) { size_t n; for (n = 0; n < bloom->nfuncs; ++n) { SETBIT(bloom->a,bloom->funcs[n](s)%bloom->asize); } return 0; } int bloom_check(BLOOM* bloom,const char* s) { size_t n; for (n = 0; n < bloom->nfuncs; ++n) { if (!(GETBIT(bloom->a,bloom->funcs[n](s)%bloom->asize))) return 0; } return 1; }