return NULL;
}
-static tdb_off_t hash_off(struct tdb_context *tdb, uint64_t list)
+tdb_off_t hash_off(struct tdb_context *tdb, uint64_t list)
{
return tdb->header.v.hash_off
+ ((list & ((1ULL << tdb->header.v.hash_bits) - 1))
if (unlikely(num == len)) {
/* We wrapped. Look through start of hash table. */
+ i = 0;
hoff = hash_off(tdb, 0);
len = (1ULL << tdb->header.v.hash_bits);
num = tdb_find_zero_off(tdb, hoff, len);
- if (i == len) {
+ if (num == len) {
tdb->ecode = TDB_ERR_CORRUPT;
tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
"hash_add: full hash table!\n");
return -1;
}
}
+ if (tdb_read_off(tdb, hash_off(tdb, i + num)) != 0) {
+ tdb->ecode = TDB_ERR_CORRUPT;
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
+ "hash_add: overwriting hash table?\n");
+ return -1;
+ }
+
/* FIXME: Encode extra hash bits! */
return tdb_write_off(tdb, hash_off(tdb, i + num), off);
}
tdb_len_t hlen;
uint64_t num = 1ULL << tdb->header.v.hash_bits;
struct tdb_used_record pad, *r;
+ unsigned int records = 0;
/* FIXME: We should do this without holding locks throughout. */
if (tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_WAIT, false) == -1)
goto oldheader;
if (off && hash_add(tdb, hash_record(tdb, off), off) == -1)
goto oldheader;
+ if (off)
+ records++;
}
+ tdb->log(tdb, TDB_DEBUG_TRACE, tdb->log_priv,
+ "enlarge_hash: moved %u records from %llu buckets.\n",
+ records, (long long)num);
+
/* Free up old hash. */
r = tdb_get(tdb, oldoff - sizeof(*r), &pad, sizeof(*r));
if (!r)
goto unlock;
}
+
+/* This is the slow version of the routine which searches the
+ * hashtable for an entry.
+ * We lock every hash bucket up to and including the next zero one.
+ */
+static tdb_off_t find_and_lock_slow(struct tdb_context *tdb,
+ struct tdb_data key,
+ uint64_t h,
+ int ltype,
+ tdb_off_t *start_lock,
+ tdb_len_t *num_locks,
+ tdb_off_t *bucket,
+ struct tdb_used_record *rec)
+{
+ /* Warning: this may drop the lock on *bucket! */
+ *num_locks = relock_hash_to_zero(tdb, *start_lock, ltype);
+ if (*num_locks == TDB_OFF_ERR)
+ return TDB_OFF_ERR;
+
+ for (*bucket = *start_lock;
+ *bucket < *start_lock + *num_locks;
+ (*bucket)++) {
+ tdb_off_t off = entry_matches(tdb, *bucket, h, &key, rec);
+ /* Empty entry or we found it? */
+ if (off == 0 || off != TDB_OFF_ERR)
+ return off;
+ }
+
+ /* We didn't find a zero entry? Something went badly wrong... */
+ unlock_lists(tdb, *start_lock, *start_lock + *num_locks, ltype);
+ tdb->ecode = TDB_ERR_CORRUPT;
+ tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
+ "find_and_lock: expected to find an empty hash bucket!\n");
+ return TDB_OFF_ERR;
+}
+
/* 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, *num_locks locks of type ltype from *start_lock are held.
}
/* Slow path, need to grab more locks and search. */
-
- /* Warning: this may drop the lock on *bucket! */
- *num_locks = relock_hash_to_zero(tdb, *start_lock, ltype);
- if (*num_locks == TDB_OFF_ERR)
- return TDB_OFF_ERR;
-
- for (*bucket = *start_lock;
- *bucket < *start_lock + *num_locks;
- (*bucket)++) {
- off = entry_matches(tdb, *bucket, h, &key, rec);
- /* Empty entry or we found it? */
- if (off == 0 || off != TDB_OFF_ERR)
- return off;
- }
-
- /* We didn't find a zero entry? Something went badly wrong... */
- unlock_lists(tdb, *start_lock, *start_lock + *num_locks, ltype);
- tdb->ecode = TDB_ERR_CORRUPT;
- tdb->log(tdb, TDB_DEBUG_FATAL, tdb->log_priv,
- "find_and_lock: expected to find an empty hash bucket!\n");
- return TDB_OFF_ERR;
+ return find_and_lock_slow(tdb, key, h, ltype, start_lock, num_locks,
+ bucket, rec);
}
/* Returns -1 on error, 0 on OK, 1 on "expand and retry." */
/* Allocate a new record. */
new_off = alloc(tdb, key.dsize, dbuf.dsize, h, growing);
- if (new_off == 0)
+ if (unlikely(new_off == TDB_OFF_ERR))
+ return -1;
+
+ if (unlikely(new_off == 0))
return 1;
/* We didn't like the existing one: remove it. */
if (unlikely(num > 4 * tdb->header.v.hash_bits - 30))
enlarge_hash(tdb);
- return 0;
+ return ret;
fail:
unlock_lists(tdb, start, num, F_WRLCK);
uint64_t h;
h = tdb_hash(tdb, key.dptr, key.dsize);
- off = find_and_lock(tdb, key, h, F_WRLCK, &start, &num, &bucket, &rec);
+ start = tdb_lock_list(tdb, h, F_WRLCK, TDB_LOCK_WAIT);
+ if (unlikely(start == TDB_OFF_ERR))
+ return -1;
+
+ /* FIXME: Fastpath: if next is zero, we can delete without lock,
+ * since this lock protects us. */
+ off = find_and_lock_slow(tdb, key, h, F_WRLCK,
+ &start, &num, &bucket, &rec);
if (unlikely(off == TDB_OFF_ERR))
return -1;
if (!off) {
+ /* FIXME: We could optimize not found case if it mattered, by
+ * reading offset after first lock: if it's zero, goto here. */
unlock_lists(tdb, start, num, F_WRLCK);
tdb->ecode = TDB_ERR_NOEXIST;
return -1;
}
+ /* Since we found the entry, we must have locked it and a zero. */
+ assert(num >= 2);
/* This actually unlinks it. */
if (tdb_write_off(tdb, hash_off(tdb, bucket), 0) == -1)
goto unlock_err;
/* Rehash anything following. */
- for (i = hash_off(tdb, bucket+1);
- i != hash_off(tdb, h + num - 1);
- i += sizeof(tdb_off_t)) {
- tdb_off_t off2;
+ for (i = bucket+1; i != bucket + num - 1; i++) {
+ tdb_off_t hoff, off2;
uint64_t h2;
- off2 = tdb_read_off(tdb, i);
+ hoff = hash_off(tdb, i);
+ off2 = tdb_read_off(tdb, hoff);
if (unlikely(off2 == TDB_OFF_ERR))
goto unlock_err;
/* Maybe use a bit to indicate it is in ideal place? */
h2 = hash_record(tdb, off2);
/* Is it happy where it is? */
- if (hash_off(tdb, h2) == i)
+ if (hash_off(tdb, h2) == hoff)
continue;
/* Remove it. */
- if (tdb_write_off(tdb, i, 0) == -1)
+ if (tdb_write_off(tdb, hoff, 0) == -1)
goto unlock_err;
/* Rehash it. */
projects / ccan / blobdiff