/* We use 0x1 as deleted marker. */
#define HTABLE_DELETED (0x1)
+/* perfect_bitnum 63 means there's no perfect bitnum */
+#define NO_PERFECT_BIT (sizeof(uintptr_t) * CHAR_BIT - 1)
+
+static void *htable_default_alloc(struct htable *ht, size_t len)
+{
+ return calloc(len, 1);
+}
+
+static void htable_default_free(struct htable *ht, void *p)
+{
+ free(p);
+}
+
+static void *(*htable_alloc)(struct htable *, size_t) = htable_default_alloc;
+static void (*htable_free)(struct htable *, void *) = htable_default_free;
+
+void htable_set_allocator(void *(*alloc)(struct htable *, size_t len),
+ void (*free)(struct htable *, void *p))
+{
+ if (!alloc)
+ alloc = htable_default_alloc;
+ if (!free)
+ free = htable_default_free;
+ htable_alloc = alloc;
+ htable_free = free;
+}
+
/* We clear out the bits which are always the same, and put metadata there. */
static inline uintptr_t get_extra_ptr_bits(const struct htable *ht,
uintptr_t e)
return ((uintptr_t)p & ~ht->common_mask) | bits;
}
-static inline bool entry_is_valid(uintptr_t e)
+static inline uintptr_t *actually_valid_pair(const struct htable *ht)
+{
+ return ht->table + ((size_t)1 << ht->bits);
+}
+
+/* We have have two entries which look deleted, but we remember
+ * they are not! */
+static inline bool entry_actually_valid(const struct htable *ht, size_t off)
+{
+ const uintptr_t *valid = actually_valid_pair(ht);
+ /* Empty table looks like this! */
+ if (valid == &ht->common_bits + 1)
+ return false;
+ return valid[0] == off || valid[1] == off;
+}
+
+/* Initialize the "actually valid" pair. */
+static inline void init_actually_valid(struct htable *ht)
+{
+ uintptr_t *valid = actually_valid_pair(ht);
+ valid[0] = valid[1] = ((size_t)1 << ht->bits);
+}
+
+/* Add to the "actually valid" pair: there can only ever be two! */
+static COLD void add_actually_valid(struct htable *ht, size_t off)
+{
+ uintptr_t *valid = actually_valid_pair(ht);
+ if (valid[0] == ((size_t)1 << ht->bits))
+ valid[0] = off;
+ else {
+ assert(valid[1] == ((size_t)1 << ht->bits));
+ valid[1] = off;
+ }
+}
+
+static COLD void del_actually_valid(struct htable *ht, size_t off)
+{
+ uintptr_t *validpair = actually_valid_pair(ht);
+ if (validpair[0] == off)
+ validpair[0] = ((size_t)1 << ht->bits);
+ else {
+ assert(validpair[1] == off);
+ validpair[1] = ((size_t)1 << ht->bits);
+ }
+}
+
+/* If this entry looks invalid, check entry_actually_valid! */
+static inline bool entry_looks_invalid(const struct htable *ht, size_t off)
+{
+ return ht->table[off] <= HTABLE_DELETED;
+}
+
+static inline bool entry_is_valid(const struct htable *ht, size_t off)
+{
+ if (!entry_looks_invalid(ht, off))
+ return true;
+ return entry_actually_valid(ht, off);
+}
+
+static inline bool entry_is_deleted(const struct htable *ht, size_t off)
{
- return e > HTABLE_DELETED;
+ return ht->table[off] == HTABLE_DELETED && !entry_actually_valid(ht, off);
+}
+
+static inline uintptr_t ht_perfect_mask(const struct htable *ht)
+{
+ return (uintptr_t)2 << ht->perfect_bitnum;
}
static inline uintptr_t get_hash_ptr_bits(const struct htable *ht,
* 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)
+{
+ return ((size_t)3 << ht->bits) / 4;
+}
+
+static inline size_t ht_max_with_deleted(const struct htable *ht)
+{
+ return ((size_t)9 << ht->bits) / 10;
}
-/* We've changed ht->bits, update ht->max and ht->max_with_deleted */
-static void htable_adjust_capacity(struct htable *ht)
+/* Includes the two trailing "not-deleted" entries */
+static size_t htable_alloc_size(size_t bits)
{
- ht->max = ((size_t)3 << ht->bits) / 4;
- ht->max_with_deleted = ((size_t)9 << ht->bits) / 10;
+ return (sizeof(size_t) << bits) + 2 * sizeof(size_t);
}
bool htable_init_sized(struct htable *ht,
break;
}
- ht->table = calloc(1 << ht->bits, sizeof(size_t));
+ ht->table = htable_alloc(ht, htable_alloc_size(ht->bits));
if (!ht->table) {
- ht->table = &ht->perfect_bit;
+ ht->table = &ht->common_bits;
return false;
}
- htable_adjust_capacity(ht);
+ init_actually_valid(ht);
(void)htable_debug(ht, HTABLE_LOC);
return true;
}
void htable_clear(struct htable *ht)
{
- if (ht->table != &ht->perfect_bit)
- free((void *)ht->table);
+ if (ht->table != &ht->common_bits)
+ htable_free(ht, (void *)ht->table);
htable_init(ht, ht->rehash, ht->priv);
}
bool htable_copy_(struct htable *dst, const struct htable *src)
{
- uintptr_t *htable = malloc(sizeof(size_t) << src->bits);
+ uintptr_t *htable = htable_alloc(dst, htable_alloc_size(src->bits));
if (!htable)
return false;
*dst = *src;
dst->table = htable;
- memcpy(dst->table, src->table, sizeof(size_t) << src->bits);
+ memcpy(dst->table, src->table, htable_alloc_size(src->bits));
return true;
}
{
uintptr_t h2 = get_hash_ptr_bits(ht, hash) | perfect;
- while (ht->table[i->off]) {
- if (ht->table[i->off] != HTABLE_DELETED) {
+ while (ht->table[i->off] || entry_actually_valid(ht, i->off)) {
+ if (!entry_is_deleted(ht, i->off)) {
if (get_extra_ptr_bits(ht, ht->table[i->off]) == h2)
return get_raw_ptr(ht, ht->table[i->off]);
}
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,
void *htable_first_(const struct htable *ht, struct htable_iter *i)
{
for (i->off = 0; i->off < (size_t)1 << ht->bits; i->off++) {
- if (entry_is_valid(ht->table[i->off]))
+ if (entry_is_valid(ht, i->off))
return get_raw_ptr(ht, ht->table[i->off]);
}
return NULL;
void *htable_next_(const struct htable *ht, struct htable_iter *i)
{
for (i->off++; i->off < (size_t)1 << ht->bits; i->off++) {
- if (entry_is_valid(ht->table[i->off]))
+ if (entry_is_valid(ht, i->off))
return get_raw_ptr(ht, ht->table[i->off]);
}
return NULL;
for (;;) {
if (!i->off)
return NULL;
- i->off --;
- if (entry_is_valid(ht->table[i->off]))
+ i->off--;
+ if (entry_is_valid(ht, i->off))
return get_raw_ptr(ht, ht->table[i->off]);
}
}
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);
- while (entry_is_valid(ht->table[i])) {
+ while (entry_is_valid(ht, i)) {
perfect = 0;
i = (i + 1) & ((1 << ht->bits)-1);
}
ht->table[i] = make_hval(ht, new, get_hash_ptr_bits(ht, h)|perfect);
+
+ /* If it looks invalid, add it to exceptions */
+ if (ht->table[i] <= HTABLE_DELETED)
+ add_actually_valid(ht, i);
}
static COLD bool double_table(struct htable *ht)
{
- unsigned int i;
- size_t oldnum = (size_t)1 << ht->bits;
- uintptr_t *oldtable, e;
+ size_t i;
+ struct htable oldht = *ht;
- oldtable = ht->table;
- ht->table = calloc(1 << (ht->bits+1), sizeof(size_t));
+ ht->table = htable_alloc(ht, htable_alloc_size(ht->bits+1));
if (!ht->table) {
- ht->table = oldtable;
+ ht->table = oldht.table;
return false;
}
ht->bits++;
- htable_adjust_capacity(ht);
+ init_actually_valid(ht);
/* If we lost our "perfect bit", get it back now. */
- if (!ht->perfect_bit && ht->common_mask) {
+ if (ht->perfect_bitnum == NO_PERFECT_BIT && 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;
+ if (ht->common_mask & ((size_t)2 << i)) {
+ ht->perfect_bitnum = i;
break;
}
}
}
- if (oldtable != &ht->perfect_bit) {
- for (i = 0; i < oldnum; i++) {
- if (entry_is_valid(e = oldtable[i])) {
- void *p = get_raw_ptr(ht, e);
+ if (oldht.table != &ht->common_bits) {
+ for (i = 0; i < (size_t)1 << oldht.bits; i++) {
+ if (entry_is_valid(&oldht, i)) {
+ void *p = get_raw_ptr(&oldht, oldht.table[i]);
ht_add(ht, p, ht->rehash(p, ht->priv));
}
}
- free(oldtable);
+ /* Pass ht here to callback: oldht is an internal figment */
+ htable_free(ht, oldht.table);
}
ht->deleted = 0;
static COLD void rehash_table(struct htable *ht)
{
size_t start, i;
- uintptr_t e;
+ uintptr_t e, perfect = ht_perfect_mask(ht);
+ uintptr_t *validpair = actually_valid_pair(ht);
/* Beware wrap cases: we need to start from first empty bucket. */
for (start = 0; ht->table[start]; start++);
for (i = 0; i < (size_t)1 << ht->bits; i++) {
size_t h = (i + start) & ((1 << ht->bits)-1);
+ uintptr_t *actually = NULL;
e = ht->table[h];
- if (!e)
- continue;
- if (e == HTABLE_DELETED)
- ht->table[h] = 0;
- else if (!(e & ht->perfect_bit)) {
+ if (e <= HTABLE_DELETED) {
+ /* If it's actually valid, remember in case we move it! */
+ if (validpair[0] == h) {
+ actually = &validpair[0];
+ } else if (validpair[1] == h) {
+ actually = &validpair[1];
+ } else {
+ ht->table[h] = 0;
+ continue;
+ }
+ }
+
+ if (!(e & perfect)) {
void *p = get_raw_ptr(ht, e);
ht->table[h] = 0;
+ /* Clear actuallyvalid, let ht_add refill */
+ if (actually)
+ *actually = ((size_t)1 << ht->bits);
ht_add(ht, p, ht->rehash(p, ht->priv));
}
}
uintptr_t maskdiff, bitsdiff;
if (ht->elems == 0) {
- /* Always reveal one bit of the pointer in the bucket,
- * so it's not zero or HTABLE_DELETED (1), even if
- * hash happens to be 0. Assumes (void *)1 is not a
- * valid pointer. */
- for (i = sizeof(uintptr_t)*CHAR_BIT - 1; i > 0; i--) {
- if ((uintptr_t)p & ((uintptr_t)1 << i))
- break;
- }
-
- ht->common_mask = ~((uintptr_t)1 << i);
+ ht->common_mask = -1;
ht->common_bits = ((uintptr_t)p & ht->common_mask);
- ht->perfect_bit = 1;
+ ht->perfect_bitnum = 0;
(void)htable_debug(ht, HTABLE_LOC);
return;
}
bitsdiff = ht->common_bits & maskdiff;
for (i = 0; i < (size_t)1 << ht->bits; i++) {
- if (!entry_is_valid(ht->table[i]))
+ if (!entry_is_valid(ht, i))
continue;
/* Clear the bits no longer in the mask, set them as
* expected. */
ht->table[i] &= ~maskdiff;
ht->table[i] |= bitsdiff;
+
+ /* Make sure it's not newly falsely invalid */
+ if (ht->table[i] <= HTABLE_DELETED && !entry_actually_valid(ht, i))
+ add_actually_valid(ht, i);
}
/* 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 = NO_PERFECT_BIT;
(void)htable_debug(ht, HTABLE_LOC);
}
bool htable_add_(struct htable *ht, size_t hash, const void *p)
{
- if (ht->elems+1 > ht->max && !double_table(ht))
+ if (ht->elems+1 > ht_max(ht) && !double_table(ht))
return false;
- if (ht->elems+1 + ht->deleted > ht->max_with_deleted)
+ if (ht->elems+1 + ht->deleted > ht_max_with_deleted(ht))
rehash_table(ht);
assert(p);
if (((uintptr_t)p & ht->common_mask) != ht->common_bits)
void htable_delval_(struct htable *ht, struct htable_iter *i)
{
assert(i->off < (size_t)1 << ht->bits);
- assert(entry_is_valid(ht->table[i->off]));
+
+ if (entry_looks_invalid(ht, i->off))
+ del_actually_valid(ht, i->off);
ht->elems--;
ht->table[i->off] = HTABLE_DELETED;
ht->deleted++;
}
+void *htable_pick_(const struct htable *ht, size_t seed, struct htable_iter *i)
+{
+ void *e;
+ struct htable_iter unwanted;
+
+ if (!i)
+ i = &unwanted;
+ i->off = seed % ((size_t)1 << ht->bits);
+ e = htable_next(ht, i);
+ if (!e)
+ e = htable_first(ht, i);
+ return e;
+}
+
struct htable *htable_check(const struct htable *ht, const char *abortstr)
{
void *p;
struct htable_iter i;
size_t n = 0;
+ const uintptr_t *validpair = actually_valid_pair(ht);
/* Use non-DEBUG versions here, to avoid infinite recursion with
* CCAN_HTABLE_DEBUG! */
return NULL;
}
+ /* Check validpair does actually override invalid-looking entries! */
+ if (ht->table != &ht->common_bits) {
+ size_t i;
+ for (i = 0; i < 2; i++) {
+ if (validpair[i] == ((size_t)1 << ht->bits))
+ continue;
+ if (validpair[i] > ((size_t)1 << ht->bits)) {
+ if (abortstr) {
+ fprintf(stderr,
+ "%s: validpair[%zu] points at %zu"
+ " which is out of bounds\n",
+ abortstr, i, validpair[i]);
+ abort();
+ }
+ return NULL;
+ }
+ if (entry_looks_invalid(ht, validpair[i]))
+ continue;
+
+ if (abortstr) {
+ fprintf(stderr,
+ "%s: validpair[%zu] points at %zu"
+ " which seems valid\n",
+ abortstr, i, validpair[i]);
+ abort();
+ }
+ return NULL;
+ }
+ }
+
return (struct htable *)ht;
}
projects / ccan / blobdiff