#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#define COLLISIONFACTOR 0.5

struct HashFileHeader {
    int sig;
    int reclen;
    int total_rec_num;
    int current_rec_num;
};

struct CFTag {
    char collision;
    char free;
};

int hashfile_creat(const char *filename, mode_t mode, int reclen, int recnum);
int hashfile_open(const char *filename, int flags, mode_t mode);
int hashfile_close(int fd);
int hashfile_read(int fd, int keyoffset, int keylen, void *buf);
int hashfile_write(int fd, int keyoffset, int keylen, void *buf);
int hashfile_delrec(int fd, int keyoffset, int keylen, void *buf);
int hashfile_findrec(int fd, int keyoffset, int keylen, void *buf);
int hashfile_saverec(int fd, int keyoffset, int keylen, void *buf);
int hash(int keyoffset, int keylen, void *buf, int recnum);
int checkHashFileFull(int fd);
int readHashFileHeader(int fd, struct HashFileHeader *hfh);