struct event_entry* find_entry_in_table(struct mevent *evt, const unsigned char *key, size_t ksize)
{
uint32_t h;
struct event_chain *c;
h = hash(key, ksize) % evt->hashlen;
c = evt->table + h;
return find_in_chain(c, key, ksize);
}
/* This is the core routine which searches the hashtable for an entry.
* On error, no locks are held and -ve is returned.
* Otherwise, hinfo is filled in (and the optional tinfo).
* If not found, the return value is 0.
* If found, the return value is the offset, and *rec is the record. */
tdb_off_t find_and_lock(struct tdb_context *tdb,
struct tdb_data key,
int ltype,
struct hash_info *h,
struct tdb_used_record *rec,
struct traverse_info *tinfo)
{
uint32_t i, group;
tdb_off_t hashtable;
enum TDB_ERROR ecode;
h->h = tdb_hash(tdb, key.dptr, key.dsize);
h->hash_used = 0;
group = use_bits(h, TDB_TOPLEVEL_HASH_BITS - TDB_HASH_GROUP_BITS);
h->home_bucket = use_bits(h, TDB_HASH_GROUP_BITS);
h->hlock_start = hlock_range(group, &h->hlock_range);
ecode = tdb_lock_hashes(tdb, h->hlock_start, h->hlock_range, ltype,
TDB_LOCK_WAIT);
if (ecode != TDB_SUCCESS) {
return ecode;
}
hashtable = offsetof(struct tdb_header, hashtable);
if (tinfo) {
tinfo->toplevel_group = group;
tinfo->num_levels = 1;
tinfo->levels[0].entry = 0;
tinfo->levels[0].hashtable = hashtable
+ (group << TDB_HASH_GROUP_BITS) * sizeof(tdb_off_t);
tinfo->levels[0].total_buckets = 1 << TDB_HASH_GROUP_BITS;
}
while (h->hash_used <= 64) {
/* Read in the hash group. */
h->group_start = hashtable
+ group * (sizeof(tdb_off_t) << TDB_HASH_GROUP_BITS);
ecode = tdb_read_convert(tdb, h->group_start, &h->group,
sizeof(h->group));
if (ecode != TDB_SUCCESS) {
goto fail;
}
/* Pointer to another hash table? Go down... */
if (is_subhash(h->group[h->home_bucket])) {
hashtable = (h->group[h->home_bucket] & TDB_OFF_MASK)
+ sizeof(struct tdb_used_record);
if (tinfo) {
/* When we come back, use *next* bucket */
tinfo->levels[tinfo->num_levels-1].entry
+= h->home_bucket + 1;
}
group = use_bits(h, TDB_SUBLEVEL_HASH_BITS
- TDB_HASH_GROUP_BITS);
h->home_bucket = use_bits(h, TDB_HASH_GROUP_BITS);
if (tinfo) {
tinfo->levels[tinfo->num_levels].hashtable
= hashtable;
tinfo->levels[tinfo->num_levels].total_buckets
= 1 << TDB_SUBLEVEL_HASH_BITS;
tinfo->levels[tinfo->num_levels].entry
= group << TDB_HASH_GROUP_BITS;
tinfo->num_levels++;
}
continue;
}
/* It's in this group: search (until 0 or all searched) */
for (i = 0, h->found_bucket = h->home_bucket;
i < (1 << TDB_HASH_GROUP_BITS);
i++, h->found_bucket = ((h->found_bucket+1)
% (1 << TDB_HASH_GROUP_BITS))) {
tdb_bool_err berr;
if (is_subhash(h->group[h->found_bucket]))
continue;
if (!h->group[h->found_bucket])
break;
berr = match(tdb, h, &key, h->group[h->found_bucket],
rec);
if (berr < 0) {
ecode = berr;
goto fail;
}
if (berr) {
if (tinfo) {
tinfo->levels[tinfo->num_levels-1].entry
+= h->found_bucket;
}
return h->group[h->found_bucket] & TDB_OFF_MASK;
}
}
/* Didn't find it: h indicates where it would go. */
return 0;
}
return find_in_chain(tdb, key, hashtable, h, rec, tinfo);
fail:
tdb_unlock_hashes(tdb, h->hlock_start, h->hlock_range, ltype);
return ecode;
}
