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#ifndef SHASH_H
#define SHASH_H
#include <stdlib.h>
#include <stdint.h>
#include <ctype.h>
#include "stdwrm.h"
#include "dynarr.h"
#include "str.h"
#define SHASH_SLOTS 8192
typedef uint64_t hash_t;
typedef struct {
string key;
void *value;
hash_t hash;
} StrHashEntry;
typedef struct {
DYNARR(StrHashEntry) entries;
} StrHashSlot;
typedef struct {
StrHashSlot slots[SHASH_SLOTS];
} StrHashTable;
hash_t shash(strv_t s);
void shash_init(StrHashTable *h);
void shash_free(StrHashTable *h);
void *shash_get(StrHashTable *h, strv_t key);
void shash_put(StrHashTable *h, strv_t key, void *value);
StrHashEntry *shash_find(StrHashTable *h, strv_t key);
#ifdef STDWRM_IMPL_SHASH
/* hacky FNV-1a hash */
#define FNV_64_PRIME (hash_t)1099511628211LU
#define FNV_OFFSET_BASIS (hash_t)14695981039346656037LU
hash_t shash(strv_t s) {
hash_t h = FNV_OFFSET_BASIS;
for (size_t i = 0; i < s.n; i++) h = (h ^ s.s[i]) * FNV_64_PRIME;
return h;
}
/* hash table */
void shash_init(StrHashTable *h) {
*h = (StrHashTable) { 0 };
}
void shash_free(StrHashTable *h) {
for (unsigned i = 0; i < SHASH_SLOTS; i++) {
StrHashSlot *s = &h->slots[i];
if (!s->entries) continue;
DA_FOR(s->entries, e) sfree(e->key);
DA_FREE(s->entries);
}
}
static inline int shash_entry_match(StrHashEntry *h, strv_t s, hash_t shash) {
return h->hash == shash && slen(h->key) == s.n && !strncmp(h->key, s.s, s.n);
}
static inline StrHashEntry *shash_find_hashed(StrHashTable *h, strv_t key, hash_t k) {
size_t i = k & (SHASH_SLOTS - 1);
if (h->slots[i].entries) {
DA_FOR(h->slots[i].entries, e) {
if (shash_entry_match(e, key, k)) {
return e;
}
}
}
return NULL;
}
StrHashEntry *shash_find(StrHashTable *h, strv_t key) {
return shash_find_hashed(h, key, shash(key));
}
void *shash_get(StrHashTable *h, strv_t key) {
StrHashEntry *e = shash_find(h, key);
return e ? e->value : NULL;
}
void shash_put(StrHashTable *h, strv_t key, void *value) {
hash_t keyh = shash(key);
StrHashEntry *e = shash_find_hashed(h, key, keyh);
if (e) {
e->value = value;
} else {
hash_t keyi = keyh & (SHASH_SLOTS - 1);
if (!h->slots[keyi].entries) {
DA_INIT(h->slots[keyi].entries);
}
string s = snew();
scats(&s, key);
DA_PUSH(h->slots[keyi].entries, (StrHashEntry) {
.key = s,
.value = value,
.hash = keyh
});
}
}
#endif
#endif
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