/* This is the core routine which searches the hashtable for an entry.
* On error, no locks are held and TDB_OFF_ERR is returned.
- * Otherwise, hinfo is filled in.
+ * 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 tdb_used_record *rec,
+ struct traverse_info *tinfo)
{
uint32_t i, group;
tdb_off_t hashtable;
return TDB_OFF_ERR;
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 (likely(h->hash_used < 64)) {
/* Read in the hash group. */
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;
}
if (!h->group[h->found_bucket])
break;
- if (match(tdb, h, &key, h->group[h->found_bucket], rec))
+ if (match(tdb, h, &key, h->group[h->found_bucket],
+ rec)) {
+ 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 add_to_hash(tdb, h, new_off);
}
-/* No point holding references/copies of db once we drop lock. */
-static void release_entries(struct tdb_context *tdb,
- struct traverse_info *tinfo)
-{
- unsigned int i;
-
- for (i = 0; i < tinfo->num_levels; i++) {
- if (tinfo->levels[i].entries) {
- tdb_access_release(tdb, tinfo->levels[i].entries);
- tinfo->levels[i].entries = NULL;
- }
- }
-}
-
/* Traverse support: returns offset of record, or 0 or TDB_OFF_ERR. */
static tdb_off_t iterate_hash(struct tdb_context *tdb,
struct traverse_info *tinfo)
{
- tdb_off_t off;
+ tdb_off_t off, val;
unsigned int i;
struct traverse_level *tlevel;
tlevel = &tinfo->levels[tinfo->num_levels-1];
again:
- if (!tlevel->entries) {
- tlevel->entries = tdb_access_read(tdb, tlevel->hashtable,
- sizeof(tdb_off_t)
- * tlevel->total_buckets,
- true);
- if (!tlevel->entries)
+ for (i = tdb_find_nonzero_off(tdb, tlevel->hashtable,
+ tlevel->entry, tlevel->total_buckets);
+ i != tlevel->total_buckets;
+ i = tdb_find_nonzero_off(tdb, tlevel->hashtable,
+ i+1, tlevel->total_buckets)) {
+ val = tdb_read_off(tdb, tlevel->hashtable+sizeof(tdb_off_t)*i);
+ if (unlikely(val == TDB_OFF_ERR))
return TDB_OFF_ERR;
- }
- /* FIXME: Use tdb_find_nonzero_off? */
- for (i = tlevel->entry; i < tlevel->total_buckets; i++) {
- if (!tlevel->entries[i] || tlevel->entries[i] == tinfo->prev)
+ off = val & TDB_OFF_MASK;
+
+ /* This makes the delete-all-in-traverse case work
+ * (and simplifies our logic a little). */
+ if (off == tinfo->prev)
continue;
tlevel->entry = i;
- off = tlevel->entries[i] & TDB_OFF_MASK;
- if (!is_subhash(tlevel->entries[i])) {
+ if (!is_subhash(val)) {
/* Found one. */
- tinfo->prev = tlevel->entries[i];
- release_entries(tdb, tinfo);
+ tinfo->prev = off;
return off;
}
- /* When we come back, we want tne next one */
+ /* When we come back, we want the next one */
tlevel->entry++;
tinfo->num_levels++;
tlevel++;
tlevel->hashtable = off + sizeof(struct tdb_used_record);
tlevel->entry = 0;
- tlevel->entries = NULL;
tlevel->total_buckets = (1 << TDB_SUBLEVEL_HASH_BITS);
goto again;
}
/* Nothing there? */
- if (tinfo->num_levels == 1) {
- release_entries(tdb, tinfo);
+ if (tinfo->num_levels == 1)
return 0;
- }
/* Go back up and keep searching. */
- tdb_access_release(tdb, tlevel->entries);
tinfo->num_levels--;
tlevel--;
goto again;
/* Return 1 if we find something, 0 if not, -1 on error. */
int next_in_hash(struct tdb_context *tdb, int ltype,
struct traverse_info *tinfo,
- TDB_DATA *kbuf, unsigned int *dlen)
+ TDB_DATA *kbuf, size_t *dlen)
{
const unsigned group_bits = TDB_TOPLEVEL_HASH_BITS-TDB_HASH_GROUP_BITS;
tdb_off_t hlock_start, hlock_range, off;
/* Return 1 if we find something, 0 if not, -1 on error. */
int first_in_hash(struct tdb_context *tdb, int ltype,
struct traverse_info *tinfo,
- TDB_DATA *kbuf, unsigned int *dlen)
+ TDB_DATA *kbuf, size_t *dlen)
{
tinfo->prev = 0;
tinfo->toplevel_group = 0;
tinfo->num_levels = 1;
tinfo->levels[0].hashtable = offsetof(struct tdb_header, hashtable);
- tinfo->levels[0].entries = NULL;
tinfo->levels[0].entry = 0;
tinfo->levels[0].total_buckets = (1 << TDB_HASH_GROUP_BITS);
projects / ccan / blobdiff