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 e > HTABLE_DELETED;
+ 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 ht->table[off] == HTABLE_DELETED && !entry_actually_valid(ht, off);
}
static inline uintptr_t ht_perfect_mask(const struct htable *ht)
return ((size_t)9 << ht->bits) / 10;
}
+/* Includes the two trailing "not-deleted" entries */
+static size_t htable_alloc_size(size_t bits)
+{
+ return (sizeof(size_t) << bits) + 2 * sizeof(size_t);
+}
+
bool htable_init_sized(struct htable *ht,
size_t (*rehash)(const void *, void *),
void *priv, size_t expect)
break;
}
- ht->table = htable_alloc(ht, sizeof(size_t) << ht->bits);
+ ht->table = htable_alloc(ht, htable_alloc_size(ht->bits));
if (!ht->table) {
ht->table = &ht->common_bits;
return false;
}
+ init_actually_valid(ht);
(void)htable_debug(ht, HTABLE_LOC);
return true;
}
bool htable_copy_(struct htable *dst, const struct htable *src)
{
- uintptr_t *htable = htable_alloc(dst, 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]);
}
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]);
}
}
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 = htable_alloc(ht, sizeof(size_t) << (ht->bits+1));
+ 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++;
+ init_actually_valid(ht);
/* If we lost our "perfect bit", get it back now. */
if (ht->perfect_bitnum == NO_PERFECT_BIT && ht->common_mask) {
}
}
- 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);
+ 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));
}
}
- htable_free(ht, oldtable);
+ /* Pass ht here to callback: oldht is an internal figment */
+ htable_free(ht, oldht.table);
}
ht->deleted = 0;
{
size_t start, i;
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 & perfect)) {
+ 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_bitnum = 0;
(void)htable_debug(ht, HTABLE_LOC);
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. */
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;
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