一个开源的哈希表源码实现

First let's see what data struction he used.
struct entry
{
void *k, *v;
unsigned int h;
struct entry *next;
};
struct hashtable {
unsigned int tablelength;
struct entry **table;
unsigned int entrycount;
unsigned int loadlimit;
unsigned int primeindex;
unsigned int (*hashfn) (void *k);
int (*eqfn) (void *k1, void *k2);
};

static const unsigned int primes[] = {
53, 97, 193, 389,
769, 1543, 3079, 6151,
12289, 24593, 49157, 98317,
196613, 393241, 786433, 1572869,
3145739, 6291469, 12582917, 25165843,
50331653, 100663319, 201326611, 402653189,
805306457, 1610612741
};
const unsigned int prime_table_length = sizeof(primes)/sizeof(primes[0]);
const float max_load_factor = 0.65;

The import function is creat_hashtable here.
struct hashtable *create_hashtable(unsigned int minsize,
unsigned int (*hashf) (void*),
int (*eqf) (void*,void*))
{
struct hashtable *h;
unsigned int pindex, size = primes[0];
/* Check requested hashtable isn't too large */
if (minsize > (1u << 30)) return NULL;
/* Enforce size as prime */
for (pindex=0; pindex < prime_table_length; pindex++) {
if (primes[pindex] > minsize) { size = primes[pindex]; break; }
}
h = (struct hashtable *)malloc(sizeof(struct hashtable));
if (NULL == h) return NULL; /*oom*/
h->table = (struct entry **)malloc(sizeof(struct entry*) * size);
if (NULL == h->table) { free(h); return NULL; } /*oom*/
memset(h->table, 0, size * sizeof(struct entry *));
h->tablelength = size;
h->primeindex = pindex;
h->entrycount = 0;
h->hashfn = hashf;
h->eqfn = eqf;
h->loadlimit = (unsigned int) ceil(size * max_load_factor);
return h;
}
We can find that "creat_hashtable" is initialing some data.
unsigned int hash(struct hashtable *h, void *k)
{
/* Aim to protect against poor hash functions by adding logic here
* - logic taken from java 1.4 hashtable source */
unsigned int i = h->hashfn(k);
i += ~(i << 9);
i ^= ((i >> 14) | (i <<>>> */
i += (i << 4);
i ^= ((i >> 10) | (i <<>>> */
return i;
}
I have not understood hash(struct hashtable,void *);