size_t elems, deleted, max, max_with_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;
};
/* Shuffling the extra bits (as specified in mask) down the
* end is quite expensive. But the lower bits are redundant, so
* we fold the value first. */
- return (hash ^ (hash >> ht->bits)) & ht->common_mask;
+ return (hash ^ (hash >> ht->bits))
+ & ht->common_mask & ~ht->perfect_bit;
}
struct htable *htable_new(size_t (*rehash)(const void *elem, void *priv),
/* This guarantees we enter update_common first add. */
ht->common_mask = -1;
ht->common_bits = 0;
+ ht->perfect_bit = 0;
ht->table = calloc(1 << ht->bits, sizeof(uintptr_t));
if (!ht->table) {
free(ht);
}
static void *htable_val(const struct htable *ht,
- struct htable_iter *i, size_t hash)
+ struct htable_iter *i, size_t hash, uintptr_t perfect)
{
- uintptr_t h2 = get_hash_ptr_bits(ht, hash);
+ uintptr_t h2 = get_hash_ptr_bits(ht, hash) | perfect;
while (ht->table[i->off]) {
if (ht->table[i->off] != HTABLE_DELETED) {
return get_raw_ptr(ht, ht->table[i->off]);
}
i->off = (i->off + 1) & ((1 << ht->bits)-1);
+ h2 &= ~perfect;
}
return NULL;
}
struct htable_iter *i, size_t hash)
{
i->off = hash_bucket(ht, hash);
- return htable_val(ht, i, hash);
+ return htable_val(ht, i, hash, ht->perfect_bit);
}
void *htable_nextval(const struct htable *ht,
struct htable_iter *i, size_t hash)
{
i->off = (i->off + 1) & ((1 << ht->bits)-1);
- return htable_val(ht, i, hash);
+ return htable_val(ht, i, hash, 0);
}
void *htable_first(const struct htable *ht, struct htable_iter *i)
static void ht_add(struct htable *ht, const void *new, size_t h)
{
size_t i;
+ uintptr_t perfect = ht->perfect_bit;
i = hash_bucket(ht, h);
- while (entry_is_valid(ht->table[i]))
+ while (entry_is_valid(ht->table[i])) {
+ perfect = 0;
i = (i + 1) & ((1 << ht->bits)-1);
-
- ht->table[i] = make_hval(ht, new, get_hash_ptr_bits(ht, h));
+ }
+ ht->table[i] = make_hval(ht, new, get_hash_ptr_bits(ht, h)|perfect);
}
static COLD_ATTRIBUTE bool double_table(struct htable *ht)
ht->max *= 2;
ht->max_with_deleted *= 2;
+ /* FIXME: If we lost our perfect bit, we could reclaim it here! */
for (i = 0; i < oldnum; i++) {
if (entry_is_valid(e = oldtable[i])) {
void *p = get_raw_ptr(ht, e);
e = ht->table[h];
if (!e)
continue;
- ht->table[h] = 0;
- if (e != HTABLE_DELETED) {
+ if (e == HTABLE_DELETED)
+ ht->table[h] = 0;
+ else if (!(e & ht->perfect_bit)) {
void *p = get_raw_ptr(ht, e);
+ ht->table[h] = 0;
ht_add(ht, p, ht->rehash(p, ht->priv));
}
}
if (ht->elems == 0) {
ht->common_mask = -1;
ht->common_bits = (uintptr_t)p;
+ ht->perfect_bit = 1;
return;
}
ht->table[i] |= bitsdiff;
}
- /* Take away those bits from our mask and set. */
+ /* Take away those bits from our mask, bits and perfect bit. */
ht->common_mask &= ~maskdiff;
ht->common_bits &= ~maskdiff;
+ ht->perfect_bit &= ~maskdiff;
}
bool htable_add(struct htable *ht, size_t hash, const void *p)