return e > HTABLE_DELETED;
}
+/* We use 0 to mean we don't have a perfect bit, otherwise it's
+ * bit n - 1 */
+static inline uintptr_t ht_perfect_mask(const struct htable *ht)
+{
+ if (ht->perfect_bitnum > 0)
+ return (uintptr_t)1 << (ht->perfect_bitnum - 1);
+ return 0;
+}
+
static inline uintptr_t get_hash_ptr_bits(const struct htable *ht,
size_t hash)
{
* end is quite expensive. But the lower bits are redundant, so
* we fold the value first. */
return (hash ^ (hash >> ht->bits))
- & ht->common_mask & ~ht->perfect_bit;
+ & ht->common_mask & ~ht_perfect_mask(ht);
}
void htable_init(struct htable *ht,
*ht = empty;
ht->rehash = rehash;
ht->priv = priv;
- ht->table = &ht->perfect_bit;
+ ht->table = &ht->common_bits;
}
static inline size_t ht_max(const struct htable *ht)
ht->table = htable_alloc(ht, sizeof(size_t) << ht->bits);
if (!ht->table) {
- ht->table = &ht->perfect_bit;
+ ht->table = &ht->common_bits;
return false;
}
(void)htable_debug(ht, HTABLE_LOC);
void htable_clear(struct htable *ht)
{
- if (ht->table != &ht->perfect_bit)
+ if (ht->table != &ht->common_bits)
htable_free(ht, (void *)ht->table);
htable_init(ht, ht->rehash, ht->priv);
}
struct htable_iter *i, size_t hash)
{
i->off = hash_bucket(ht, hash);
- return htable_val(ht, i, hash, ht->perfect_bit);
+ return htable_val(ht, i, hash, ht_perfect_mask(ht));
}
void *htable_nextval_(const struct htable *ht,
static void ht_add(struct htable *ht, const void *new, size_t h)
{
size_t i;
- uintptr_t perfect = ht->perfect_bit;
+ uintptr_t perfect = ht_perfect_mask(ht);
i = hash_bucket(ht, h);
ht->bits++;
/* If we lost our "perfect bit", get it back now. */
- if (!ht->perfect_bit && ht->common_mask) {
+ if (ht->perfect_bitnum == 0 && ht->common_mask) {
for (i = 0; i < sizeof(ht->common_mask) * CHAR_BIT; i++) {
if (ht->common_mask & ((size_t)1 << i)) {
- ht->perfect_bit = (size_t)1 << i;
+ ht->perfect_bitnum = i + 1;
break;
}
}
}
- if (oldtable != &ht->perfect_bit) {
+ if (oldtable != &ht->common_bits) {
for (i = 0; i < oldnum; i++) {
if (entry_is_valid(e = oldtable[i])) {
void *p = get_raw_ptr(ht, e);
continue;
if (e == HTABLE_DELETED)
ht->table[h] = 0;
- else if (!(e & ht->perfect_bit)) {
+ else if (!(e & ht_perfect_mask(ht))) {
void *p = get_raw_ptr(ht, e);
ht->table[h] = 0;
ht_add(ht, p, ht->rehash(p, ht->priv));
ht->common_mask = ~((uintptr_t)1 << i);
ht->common_bits = ((uintptr_t)p & ht->common_mask);
- ht->perfect_bit = 1;
+ ht->perfect_bitnum = 1;
(void)htable_debug(ht, HTABLE_LOC);
return;
}
/* Take away those bits from our mask, bits and perfect bit. */
ht->common_mask &= ~maskdiff;
ht->common_bits &= ~maskdiff;
- ht->perfect_bit &= ~maskdiff;
+ if (ht_perfect_mask(ht) & maskdiff)
+ ht->perfect_bitnum = 0;
(void)htable_debug(ht, HTABLE_LOC);
}
struct htable {
size_t (*rehash)(const void *elem, void *priv);
void *priv;
- unsigned int bits;
+ unsigned int bits, perfect_bitnum;
size_t elems, deleted;
/* These are the bits which are the same in all pointers. */
uintptr_t common_mask, common_bits;
- uintptr_t perfect_bit;
uintptr_t *table;
};
* static struct htable ht = HTABLE_INITIALIZER(ht, rehash, NULL);
*/
#define HTABLE_INITIALIZER(name, rehash, priv) \
- { rehash, priv, 0, 0, 0, -1, 0, 0, &name.perfect_bit }
+ { rehash, priv, 0, 0, 0, 0, -1, 0, &name.common_bits }
/**
* htable_init - initialize an empty hash table.
/* Corner cases: wipe out the perfect bit using bogus pointer. */
htable_clear(&ht);
htable_add(&ht, hash(&val[NUM_VALS-1], NULL), &val[NUM_VALS-1]);
- ok1(ht.perfect_bit);
- perfect_bit = ht.perfect_bit;
+ ok1(ht_perfect_mask(&ht));
+ perfect_bit = ht_perfect_mask(&ht);
bad_pointer = (void *)((uintptr_t)&val[NUM_VALS-1] | perfect_bit);
htable_add(&ht, 0, bad_pointer);
- ok1(ht.perfect_bit == 0);
+ ok1(ht_perfect_mask(&ht) == 0);
htable_del(&ht, 0, bad_pointer);
/* Enlarging should restore it... */
add_vals(&ht, val, 0, NUM_VALS-1);
- ok1(ht.perfect_bit != 0);
+ ok1(ht_perfect_mask(&ht) != 0);
htable_clear(&ht);
ok1(htable_init_sized(&ht, hash, NULL, 1024));
/* Corner cases: wipe out the perfect bit using bogus pointer. */
htable_clear(&ht);
htable_add(&ht, 0, (void *)((uintptr_t)&val[NUM_VALS-1]));
- ok1(ht.perfect_bit);
- perfect_bit = ht.perfect_bit;
+ ok1(ht_perfect_mask(&ht));
+ perfect_bit = ht_perfect_mask(&ht);
htable_add(&ht, 0, (void *)((uintptr_t)&val[NUM_VALS-1]
| perfect_bit));
- ok1(ht.perfect_bit == 0);
+ ok1(ht_perfect_mask(&ht) == 0);
htable_del(&ht, 0, (void *)((uintptr_t)&val[NUM_VALS-1] | perfect_bit));
/* Enlarging should restore it... */
add_vals(&ht, val, 0, NUM_VALS-1);
- ok1(ht.perfect_bit != 0);
+ ok1(ht_perfect_mask(&ht) != 0);
htable_clear(&ht);
ok1(htable_init_sized(&ht, hash, NULL, 1024));