#include <ccan/htable/htable.h>
#include <ccan/compiler/compiler.h>
#include <stdlib.h>
+#include <stdio.h>
#include <limits.h>
#include <stdbool.h>
#include <assert.h>
+#include <string.h>
/* 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 e > HTABLE_DELETED;
}
+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,
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;
}
+/* Fill to 87.5% */
+static inline size_t ht_max(const struct htable *ht)
+{
+ return ((size_t)7 << ht->bits) / 8;
+}
+
+/* Clean deleted if we're full, and more than 12.5% deleted */
+static inline size_t ht_max_deleted(const struct htable *ht)
+{
+ return ((size_t)1 << ht->bits) / 8;
+}
+
+bool htable_init_sized(struct htable *ht,
+ size_t (*rehash)(const void *, void *),
+ void *priv, size_t expect)
+{
+ htable_init(ht, rehash, priv);
+
+ /* Don't go insane with sizing. */
+ for (ht->bits = 1; ht_max(ht) < expect; ht->bits++) {
+ if (ht->bits == 30)
+ break;
+ }
+
+ ht->table = htable_alloc(ht, sizeof(size_t) << ht->bits);
+ if (!ht->table) {
+ ht->table = &ht->common_bits;
+ return false;
+ }
+ (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 = htable_alloc(dst, sizeof(size_t) << src->bits);
+
+ if (!htable)
+ return false;
+
+ *dst = *src;
+ dst->table = htable;
+ memcpy(dst->table, src->table, sizeof(size_t) << src->bits);
+ return true;
+}
+
static size_t hash_bucket(const struct htable *ht, size_t h)
{
return h & ((1 << ht->bits)-1);
return NULL;
}
-void *htable_firstval(const struct htable *ht,
- struct htable_iter *i, size_t hash)
+void *htable_firstval_(const struct htable *ht,
+ 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,
- struct htable_iter *i, size_t hash)
+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, 0);
}
-void *htable_first(const struct htable *ht, struct htable_iter *i)
+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]))
return NULL;
}
-void *htable_next(const struct htable *ht, struct htable_iter *i)
+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]))
return NULL;
}
+void *htable_prev_(const struct htable *ht, struct htable_iter *i)
+{
+ for (;;) {
+ if (!i->off)
+ return NULL;
+ i->off--;
+ if (entry_is_valid(ht->table[i->off]))
+ return get_raw_ptr(ht, ht->table[i->off]);
+ }
+}
+
+/* Another bit currently in mask needs to be exposed, so that a bucket with p in
+ * it won't appear invalid */
+static COLD void unset_another_common_bit(struct htable *ht,
+ uintptr_t *maskdiff,
+ const void *p)
+{
+ size_t i;
+
+ for (i = sizeof(uintptr_t) * CHAR_BIT - 1; i > 0; i--) {
+ if (((uintptr_t)p & ((uintptr_t)1 << i))
+ && ht->common_mask & ~*maskdiff & ((uintptr_t)1 << i))
+ break;
+ }
+ /* There must have been one, right? */
+ assert(i > 0);
+
+ *maskdiff |= ((uintptr_t)1 << i);
+}
+
+/* We want to change the common mask: this fixes up the table */
+static COLD void fixup_table_common(struct htable *ht, uintptr_t maskdiff)
+{
+ size_t i;
+ uintptr_t bitsdiff;
+
+again:
+ bitsdiff = ht->common_bits & maskdiff;
+
+ for (i = 0; i < (size_t)1 << ht->bits; i++) {
+ uintptr_t e;
+ if (!entry_is_valid(e = ht->table[i]))
+ continue;
+
+ /* Clear the bits no longer in the mask, set them as
+ * expected. */
+ e &= ~maskdiff;
+ e |= bitsdiff;
+ /* If this made it invalid, restart with more exposed */
+ if (!entry_is_valid(e)) {
+ unset_another_common_bit(ht, &maskdiff, get_raw_ptr(ht, e));
+ goto again;
+ }
+ ht->table[i] = e;
+ }
+
+ /* Take away those bits from our mask, bits and perfect bit. */
+ ht->common_mask &= ~maskdiff;
+ ht->common_bits &= ~maskdiff;
+ if (ht_perfect_mask(ht) & maskdiff)
+ ht->perfect_bitnum = NO_PERFECT_BIT;
+}
+
+/* Limited recursion */
+static void ht_add(struct htable *ht, const void *new, size_t h);
+
+/* We tried to add this entry, but it looked invalid! We need to
+ * let another pointer bit through mask */
+static COLD void update_common_fix_invalid(struct htable *ht, const void *p, size_t h)
+{
+ uintptr_t maskdiff;
+
+ assert(ht->elems != 0);
+
+ maskdiff = 0;
+ unset_another_common_bit(ht, &maskdiff, p);
+ fixup_table_common(ht, maskdiff);
+
+ /* Now won't recurse */
+ ht_add(ht, p, h);
+}
+
/* This does not expand the hash table, that's up to caller. */
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);
i = (i + 1) & ((1 << ht->bits)-1);
}
ht->table[i] = make_hval(ht, new, get_hash_ptr_bits(ht, h)|perfect);
+ if (!entry_is_valid(ht->table[i]))
+ update_common_fix_invalid(ht, new, h);
}
static COLD bool double_table(struct htable *ht)
uintptr_t *oldtable, e;
oldtable = ht->table;
- ht->table = calloc(1 << (ht->bits+1), sizeof(size_t));
+ ht->table = htable_alloc(ht, sizeof(size_t) << (ht->bits+1));
if (!ht->table) {
ht->table = oldtable;
return false;
}
ht->bits++;
- ht->max = ((size_t)3 << ht->bits) / 4;
- ht->max_with_deleted = ((size_t)9 << ht->bits) / 10;
/* 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) {
+ 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);
ht_add(ht, p, ht->rehash(p, ht->priv));
}
}
- free(oldtable);
+ htable_free(ht, oldtable);
}
ht->deleted = 0;
+
+ (void)htable_debug(ht, HTABLE_LOC);
return true;
}
static COLD void rehash_table(struct htable *ht)
{
size_t start, i;
- uintptr_t e;
+ uintptr_t e, perfect = ht_perfect_mask(ht);
/* Beware wrap cases: we need to start from first empty bucket. */
for (start = 0; ht->table[start]; start++);
continue;
if (e == HTABLE_DELETED)
ht->table[h] = 0;
- else if (!(e & ht->perfect_bit)) {
+ else if (!(e & perfect)) {
void *p = get_raw_ptr(ht, e);
ht->table[h] = 0;
ht_add(ht, p, ht->rehash(p, ht->priv));
}
}
ht->deleted = 0;
+ (void)htable_debug(ht, HTABLE_LOC);
}
/* We stole some bits, now we need to put them back... */
static COLD void update_common(struct htable *ht, const void *p)
{
- unsigned int i;
- uintptr_t maskdiff, bitsdiff;
+ uintptr_t maskdiff;
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;
}
/* Find bits which are unequal to old common set. */
maskdiff = ht->common_bits ^ ((uintptr_t)p & ht->common_mask);
- /* These are the bits which go there in existing entries. */
- bitsdiff = ht->common_bits & maskdiff;
-
- for (i = 0; i < (size_t)1 << ht->bits; i++) {
- if (!entry_is_valid(ht->table[i]))
- continue;
- /* Clear the bits no longer in the mask, set them as
- * expected. */
- ht->table[i] &= ~maskdiff;
- ht->table[i] |= bitsdiff;
- }
-
- /* Take away those bits from our mask, bits and perfect bit. */
- ht->common_mask &= ~maskdiff;
- ht->common_bits &= ~maskdiff;
- ht->perfect_bit &= ~maskdiff;
+ fixup_table_common(ht, maskdiff);
+ (void)htable_debug(ht, HTABLE_LOC);
}
-bool htable_add(struct htable *ht, size_t hash, const void *p)
+bool htable_add_(struct htable *ht, size_t hash, const void *p)
{
- if (ht->elems+1 > ht->max && !double_table(ht))
- return false;
- if (ht->elems+1 + ht->deleted > ht->max_with_deleted)
- rehash_table(ht);
+ /* Cannot insert NULL, or (void *)1. */
assert(p);
+ assert(entry_is_valid((uintptr_t)p));
+
+ /* Getting too full? */
+ if (ht->elems+1 + ht->deleted > ht_max(ht)) {
+ /* If we're more than 1/8 deleted, clean those,
+ * otherwise double table size. */
+ if (ht->deleted > ht_max_deleted(ht))
+ rehash_table(ht);
+ else if (!double_table(ht))
+ return false;
+ }
if (((uintptr_t)p & ht->common_mask) != ht->common_bits)
update_common(ht, p);
return true;
}
-bool htable_del(struct htable *ht, size_t h, const void *p)
+bool htable_del_(struct htable *ht, size_t h, const void *p)
{
struct htable_iter i;
void *c;
return false;
}
-void htable_delval(struct htable *ht, struct htable_iter *i)
+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]));
ht->elems--;
- ht->table[i->off] = HTABLE_DELETED;
- ht->deleted++;
+ /* Cheap test: if the next bucket is empty, don't need delete marker */
+ if (ht->table[hash_bucket(ht, i->off+1)] != 0) {
+ ht->table[i->off] = HTABLE_DELETED;
+ ht->deleted++;
+ } else
+ ht->table[i->off] = 0;
+}
+
+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;
+
+ /* Use non-DEBUG versions here, to avoid infinite recursion with
+ * CCAN_HTABLE_DEBUG! */
+ for (p = htable_first_(ht, &i); p; p = htable_next_(ht, &i)) {
+ struct htable_iter i2;
+ void *c;
+ size_t h = ht->rehash(p, ht->priv);
+ bool found = false;
+
+ n++;
+
+ /* Open-code htable_get to avoid CCAN_HTABLE_DEBUG */
+ for (c = htable_firstval_(ht, &i2, h);
+ c;
+ c = htable_nextval_(ht, &i2, h)) {
+ if (c == p) {
+ found = true;
+ break;
+ }
+ }
+
+ if (!found) {
+ if (abortstr) {
+ fprintf(stderr,
+ "%s: element %p in position %zu"
+ " cannot find itself\n",
+ abortstr, p, i.off);
+ abort();
+ }
+ return NULL;
+ }
+ }
+ if (n != ht->elems) {
+ if (abortstr) {
+ fprintf(stderr,
+ "%s: found %zu elems, expected %zu\n",
+ abortstr, n, ht->elems);
+ abort();
+ }
+ return NULL;
+ }
+
+ return (struct htable *)ht;
}
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