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-rw-r--r--ccan/htable/htable.c325
1 files changed, 0 insertions, 325 deletions
diff --git a/ccan/htable/htable.c b/ccan/htable/htable.c
deleted file mode 100644
index e1d1369..0000000
--- a/ccan/htable/htable.c
+++ /dev/null
@@ -1,325 +0,0 @@
-/* Licensed under LGPLv2+ - see LICENSE file for details */
-#include <ccan/htable/htable.h>
-#include <ccan/compiler/compiler.h>
-#include <stdlib.h>
-#include <limits.h>
-#include <stdbool.h>
-#include <assert.h>
-#include <string.h>
-
-/* We use 0x1 as deleted marker. */
-#define HTABLE_DELETED (0x1)
-
-/* 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 & ht->common_mask;
-}
-
-static inline void *get_raw_ptr(const struct htable *ht, uintptr_t e)
-{
- return (void *)((e & ~ht->common_mask) | ht->common_bits);
-}
-
-static inline uintptr_t make_hval(const struct htable *ht,
- const void *p, uintptr_t bits)
-{
- return ((uintptr_t)p & ~ht->common_mask) | bits;
-}
-
-static inline bool entry_is_valid(uintptr_t e)
-{
- return e > HTABLE_DELETED;
-}
-
-static inline uintptr_t get_hash_ptr_bits(const struct htable *ht,
- size_t hash)
-{
- /* 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 & ~ht->perfect_bit;
-}
-
-void htable_init(struct htable *ht,
- size_t (*rehash)(const void *elem, void *priv), void *priv)
-{
- struct htable empty = HTABLE_INITIALIZER(empty, NULL, NULL);
- *ht = empty;
- ht->rehash = rehash;
- ht->priv = priv;
- ht->table = &ht->perfect_bit;
-}
-
-/* We've changed ht->bits, update ht->max and ht->max_with_deleted */
-static void htable_adjust_capacity(struct htable *ht)
-{
- ht->max = ((size_t)3 << ht->bits) / 4;
- ht->max_with_deleted = ((size_t)9 << ht->bits) / 10;
-}
-
-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; ((size_t)3 << ht->bits) / 4 < expect; ht->bits++) {
- if (ht->bits == 30)
- break;
- }
-
- ht->table = calloc(1 << ht->bits, sizeof(size_t));
- if (!ht->table) {
- ht->table = &ht->perfect_bit;
- return false;
- }
- htable_adjust_capacity(ht);
- return true;
-}
-
-void htable_clear(struct htable *ht)
-{
- if (ht->table != &ht->perfect_bit)
- free((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);
-
- 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);
-}
-
-static void *htable_val(const struct htable *ht,
- struct htable_iter *i, size_t hash, uintptr_t perfect)
-{
- uintptr_t h2 = get_hash_ptr_bits(ht, hash) | perfect;
-
- while (ht->table[i->off]) {
- if (ht->table[i->off] != HTABLE_DELETED) {
- if (get_extra_ptr_bits(ht, ht->table[i->off]) == h2)
- return get_raw_ptr(ht, ht->table[i->off]);
- }
- i->off = (i->off + 1) & ((1 << ht->bits)-1);
- h2 &= ~perfect;
- }
- return NULL;
-}
-
-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);
-}
-
-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)
-{
- for (i->off = 0; i->off < (size_t)1 << ht->bits; i->off++) {
- if (entry_is_valid(ht->table[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]))
- return get_raw_ptr(ht, 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]);
- }
-}
-
-/* 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;
-
- i = hash_bucket(ht, h);
-
- 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)|perfect);
-}
-
-static COLD bool double_table(struct htable *ht)
-{
- unsigned int i;
- size_t oldnum = (size_t)1 << ht->bits;
- uintptr_t *oldtable, e;
-
- oldtable = ht->table;
- ht->table = calloc(1 << (ht->bits+1), sizeof(size_t));
- if (!ht->table) {
- ht->table = oldtable;
- return false;
- }
- ht->bits++;
- htable_adjust_capacity(ht);
-
- /* If we lost our "perfect bit", get it back now. */
- if (!ht->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;
- 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);
- ht_add(ht, p, ht->rehash(p, ht->priv));
- }
- }
- free(oldtable);
- }
- ht->deleted = 0;
- return true;
-}
-
-static COLD void rehash_table(struct htable *ht)
-{
- size_t start, i;
- uintptr_t e;
-
- /* 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);
- e = ht->table[h];
- if (!e)
- continue;
- 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));
- }
- }
- ht->deleted = 0;
-}
-
-/* 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;
-
- 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_bits = ((uintptr_t)p & ht->common_mask);
- ht->perfect_bit = 1;
- 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;
-}
-
-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);
- assert(p);
- if (((uintptr_t)p & ht->common_mask) != ht->common_bits)
- update_common(ht, p);
-
- ht_add(ht, p, hash);
- ht->elems++;
- return true;
-}
-
-bool htable_del(struct htable *ht, size_t h, const void *p)
-{
- struct htable_iter i;
- void *c;
-
- for (c = htable_firstval(ht,&i,h); c; c = htable_nextval(ht,&i,h)) {
- if (c == p) {
- htable_delval(ht, &i);
- return true;
- }
- }
- return false;
-}
-
-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++;
-}
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