Bloom Filter c源码(转)

#ifndef __BLOOM_H__

#define __BLOOM_H__

#include <stdlib.h>

typedef unsigned int (*hashfunc_t)(const char *);

typedef struct {

size_t asize;

unsigned char *a;

size_t nfuncs;

hashfunc_t *funcs;

} BLOOM;

BLOOM *bloom_create(size_t size, size_t nfuncs, ...);

int bloom_destroy(BLOOM *bloom);

int bloom_add(BLOOM *bloom, const char *s);

int bloom_check(BLOOM *bloom, const char *s);

#endif

#include<stdio.h>

#include<string.h>

#include <dirent.h>

#include <time.h>

#include "bloom.h"

long n=0;

unsigned int sax_hash(const char *key)

{

unsigned int h=0;

while(*key) h^=(h<<5)+(h>>2)+(unsigned char)*key++;

return h;

}

unsigned int sdbm_hash(const char *key)

{

unsigned int h=0;

while(*key) h=(unsigned char)*key++ + (h<<6) + (h<<16) - h;

return h;

}

// JS Hash

unsigned int JS_hash(char *str)

{

unsigned int hash = 1315423911;

while (*str)

{

hash ^= ((hash << 5) + (*str++) + (hash >> 2));

}

return (hash & 0x7FFFFFFF);

}

int traverse(char *s,BLOOM *bloom1)

{

DIR *directory_pointer;

char current_path[10000];

char filepath[10000];

char now[10000];

struct dirent *entry;

strcpy(current_path,s);

if ((directory_pointer=opendir(s))==NULL)

printf("Error opening!/n");

else

{

while ((entry=readdir(directory_pointer))!=NULL)

{

if(strcmp(entry->d_name,".")!=0&&strcmp(entry->d_name,"..")!=0)

{

if(entry->d_type==4)

{

strcpy(filepath,current_path);

strcat(filepath,"/");

strcat(filepath,entry->d_name);

traverse(filepath,bloom1);

}

else if(entry->d_type==8)

{

strcpy(now,current_path);

strcat(now,"/");

strcat(now,entry->d_name);

n++;

printf("%ld/n",n);

bloom_add(bloom1,now);

}

}

}

closedir(directory_pointer);

}

}

void bloom_set(BLOOM *bloom1)

{

DIR *directory_pointer;

char temp[100]="";

struct dirent *entry;

if ((directory_pointer=opendir("/"))==NULL)

printf("Error opening!/n");

else

{

while ((entry=readdir(directory_pointer))!=NULL)

{

if(strcmp(entry->d_name,".")!=0&&strcmp(entry->d_name,"..")!=0)

{

if(entry->d_type==4)

{

strcpy(temp,"/");

strcat(temp,entry->d_name);

traverse(temp,bloom1);

}

else

{

strcpy(temp,"/");

strcat(temp,entry->d_name);

bloom_add(bloom1,temp);

n++;

printf("%ld/n",n);

}

}

}

closedir(directory_pointer);

}

}

int main()

{

BLOOM *bloom;

char s[200];

int result;

if(!(bloom=bloom_create(250000, 3, sax_hash, sdbm_hash,JS_hash)))

{

fprintf(stderr, "ERROR: Could not create bloom filter/n");

return EXIT_FAILURE;

}

bloom_set(bloom);

printf("bloom set successfully!/ninput the file u want to search:/n");

while(1)

{

scanf("%s",s);

if(strcmp(s,"quit")==0)break;

result=bloom_check(bloom,s);

if(result==1)printf("file found!/n");

else printf("no such file!/n");

}

}