Programming

#include "khash.h"

// Declares a hash map with integer keys and character values.
// "32" seems to be a name, not a size.  It'd actually become kh_struct_something_something_32 or such.
KHASH_MAP_INIT_INT(32, char)

int main() {
        int ret, is_missing;
        khiter_t k;
        // Declares a pointer to a hash table, and allocates it
        khash_t(32) *h = kh_init(32);
        // Insert key 5 into the table, get index in k
        k = kh_put(32, h, 5, &ret);
        // Set index k to value 10
        kh_value(h, k) = 10;
        // Look up key 10 in the hash table
        // We inserted key 5, so it ought to be missing.
        k = kh_get(32, h, 10);
        // If it's missing, it will equal kh_end.         
        is_missing = (k == kh_end(h));
        // Loopk up key 5, which we inserted earlier.       
        k = kh_get(32, h, 5);
        // Delete it.
        kh_del(32, h, k);
        // Loop from beginning to end.
        for (k = kh_begin(h); k != kh_end(h); ++k)
                // Set all existing values to 1.
                if (kh_exist(h, k)) kh_value(h, k) = 1;

        // Free the hash table.
        kh_destroy(32, h);
        return 0;
}

#define __KHASH_TYPE(name, khkey_t, khval_t) \
typedef struct { \
khint_t n_buckets, size, n_occupied, upper_bound; \
khint32_t *flags; \
khkey_t *keys; \
khval_t *vals; \
} kh_##name##_t;

typedef struct {
khint_t n_buckets, size, n_occupied, upper_bound;
khint32_t *flags;
int *keys;
char *vals;
} kh_32_t;

SCOPE khint_t kh_put_32(kh_32_t *h, khkey_t key, int *ret) \
{ \
khint_t x; \
if (h->n_occupied >= h->upper_bound) { /* update the hash table */ \
if (h->n_buckets > (h->size<<1)) kh_resize_32(h, h->n_buckets - 1);
else kh_resize_##name(h, h->n_buckets + 1); /* expand the hash table */ \
} /* TODO: to implement automatically shrinking; resize() already support shrin$
{ \
khint_t inc, k, i, site, last, mask = h->n_buckets - 1; \
x = site = h->n_buckets; k = __hash_func(key); i = k & mask; \
if (__ac_isempty(h->flags, i)) x = i; /* for speed up */        \
else { \
inc = __ac_inc(k, mask); last = i; \
while (!__ac_isempty(h->flags, i) && (__ac_isdel(h->flags, i) || !__hash_equal($
if (__ac_isdel(h->flags, i)) site = i; \
i = (i + inc) & mask; \
if (i == last) { x = site; break; } \
} \
if (x == h->n_buckets) { \
if (__ac_isempty(h->flags, i) && site != h->n_buckets) x = site; \
else x = i; \
} \
} \
} \
if (__ac_isempty(h->flags, x)) { /* not present at all */       \
h->keys[x] = key; \
__ac_set_isboth_false(h->flags, x); \
++h->size; ++h->n_occupied; \
__ac_set_isboth_false(h->flags, x); \
++h->size; ++h->n_occupied; \
*ret = 1; \
} else if (__ac_isdel(h->flags, x)) { /* deleted */     \
h->keys[x] = key; \
__ac_set_isboth_false(h->flags, x); \
++h->size; \
*ret = 2; \
} else *ret = 0; /* Don't touch h->keys[x] if present and not deleted */ \
return x; \
} \

#ifndef __AC_KHASH_H
#define __AC_KHASH_H
#define AC_VERSION_KHASH_H "0.2.6"