/* find the next entry in the database, returning its key */
TDB_DATA tdb_nextkey(struct tdb_context *tdb, TDB_DATA oldkey)
{
u32 oldhash;
TDB_DATA key = tdb_null;
struct list_struct rec;
char *k = NULL;
/* Is locked key the old key? If so, traverse will be reliable. */
if (tdb->travlocks.off) {
if (tdb_lock(tdb,tdb->travlocks.hash,tdb->travlocks.lock_rw))
return tdb_null;
if (tdb_rec_read(tdb, tdb->travlocks.off, &rec) == -1
|| !(k = tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec),
rec.key_len))
|| memcmp(k, oldkey.dptr, oldkey.dsize) != 0) {
/* No, it wasn't: unlock it and start from scratch */
if (tdb_unlock_record(tdb, tdb->travlocks.off) != 0) {
SAFE_FREE(k);
return tdb_null;
}
if (tdb_unlock(tdb, tdb->travlocks.hash, tdb->travlocks.lock_rw) != 0) {
SAFE_FREE(k);
return tdb_null;
}
tdb->travlocks.off = 0;
}
SAFE_FREE(k);
}
if (!tdb->travlocks.off) {
/* No previous element: do normal find, and lock record */
tdb->travlocks.off = tdb_find_lock_hash(tdb, oldkey, tdb->hash_fn(&oldkey), tdb->travlocks.lock_rw, &rec);
if (!tdb->travlocks.off)
return tdb_null;
tdb->travlocks.hash = BUCKET(rec.full_hash);
if (tdb_lock_record(tdb, tdb->travlocks.off) != 0) {
TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_nextkey: lock_record failed (%s)!\n", strerror(errno)));
return tdb_null;
}
}
oldhash = tdb->travlocks.hash;
/* Grab next record: locks chain and returned record,
unlocks old record */
if (tdb_next_lock(tdb, &tdb->travlocks, &rec) > 0) {
key.dsize = rec.key_len;
key.dptr = tdb_alloc_read(tdb, tdb->travlocks.off+sizeof(rec),
key.dsize);
/* Unlock the chain of this new record */
if (tdb_unlock(tdb, tdb->travlocks.hash, tdb->travlocks.lock_rw) != 0)
TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_nextkey: WARNING tdb_unlock failed!\n"));
}
/* Unlock the chain of old record */
if (tdb_unlock(tdb, BUCKET(oldhash), tdb->travlocks.lock_rw) != 0)
TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_nextkey: WARNING tdb_unlock failed!\n"));
return key;
}
/* find the first entry in the database and return its key */
_PUBLIC_ TDB_DATA tdb_firstkey(struct tdb_context *tdb)
{
TDB_DATA key;
struct tdb_record rec;
tdb_off_t off;
/* release any old lock */
if (tdb_unlock_record(tdb, tdb->travlocks.off) != 0)
return tdb_null;
tdb->travlocks.off = tdb->travlocks.list = 0;
tdb->travlocks.lock_rw = F_RDLCK;
/* Grab first record: locks chain and returned record. */
off = tdb_next_lock(tdb, &tdb->travlocks, &rec);
if (off == 0 || off == TDB_NEXT_LOCK_ERR) {
tdb_trace_retrec(tdb, "tdb_firstkey", tdb_null);
return tdb_null;
}
/* now read the key */
key.dsize = rec.key_len;
key.dptr =tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec),key.dsize);
tdb_trace_retrec(tdb, "tdb_firstkey", key);
/* Unlock the hash chain of the record we just read. */
if (tdb_unlock(tdb, tdb->travlocks.list, tdb->travlocks.lock_rw) != 0)
TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_firstkey: error occurred while tdb_unlocking!\n"));
return key;
}
enum TDB_ERROR tdb_fetch(struct tdb_context *tdb, struct tdb_data key,
struct tdb_data *data)
{
tdb_off_t off;
struct tdb_used_record rec;
struct hash_info h;
enum TDB_ERROR ecode;
off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
if (TDB_OFF_IS_ERR(off)) {
return tdb->last_error = off;
}
if (!off) {
ecode = TDB_ERR_NOEXIST;
} else {
data->dsize = rec_data_length(&rec);
data->dptr = tdb_alloc_read(tdb, off + sizeof(rec) + key.dsize,
data->dsize);
if (TDB_PTR_IS_ERR(data->dptr)) {
ecode = TDB_PTR_ERR(data->dptr);
} else
ecode = TDB_SUCCESS;
}
tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
return tdb->last_error = ecode;
}
int tdb_parse_data(struct tdb_context *tdb, TDB_DATA key,
tdb_off_t offset, tdb_len_t len,
int (*parser)(TDB_DATA key, TDB_DATA data,
void *private_data),
void *private_data)
{
TDB_DATA data;
int result;
data.dsize = len;
if ((tdb->transaction == NULL) && (tdb->map_ptr != NULL)) {
/*
* Optimize by avoiding the malloc/memcpy/free, point the
* parser directly at the mmap area.
*/
if (tdb->methods->tdb_oob(tdb, offset+len, 0) != 0) {
return -1;
}
data.dptr = offset + (unsigned char *)tdb->map_ptr;
return parser(key, data, private_data);
}
if (!(data.dptr = tdb_alloc_read(tdb, offset, len))) {
return -1;
}
result = parser(key, data, private_data);
free(data.dptr);
return result;
}
/* traverse the entire database - calling fn(tdb, key, data) on each element.
return -1 on error or the record count traversed
if fn is NULL then it is not called
a non-zero return value from fn() indicates that the traversal should stop
*/
static int tdb_traverse_internal(struct tdb_context *tdb,
tdb_traverse_func fn, void *private_data,
struct tdb_traverse_lock *tl)
{
TDB_DATA key, dbuf;
struct list_struct rec;
int ret, count = 0;
/* This was in the initializaton, above, but the IRIX compiler
* did not like it. crh
*/
tl->next = tdb->travlocks.next;
/* fcntl locks don't stack: beware traverse inside traverse */
tdb->travlocks.next = tl;
/* tdb_next_lock places locks on the record returned, and its chain */
while ((ret = tdb_next_lock(tdb, tl, &rec)) > 0) {
count++;
/* now read the full record */
key.dptr = tdb_alloc_read(tdb, tl->off + sizeof(rec),
rec.key_len + rec.data_len);
if (!key.dptr) {
ret = -1;
if (tdb_unlock(tdb, tl->hash, tl->lock_rw) != 0)
goto out;
if (tdb_unlock_record(tdb, tl->off) != 0)
TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_traverse: key.dptr == NULL and unlock_record failed!\n"));
goto out;
}
key.dsize = rec.key_len;
dbuf.dptr = key.dptr + rec.key_len;
dbuf.dsize = rec.data_len;
/* Drop chain lock, call out */
if (tdb_unlock(tdb, tl->hash, tl->lock_rw) != 0) {
ret = -1;
SAFE_FREE(key.dptr);
goto out;
}
if (fn && fn(tdb, key, dbuf, private_data)) {
/* They want us to terminate traversal */
ret = count;
if (tdb_unlock_record(tdb, tl->off) != 0) {
TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_traverse: unlock_record failed!\n"));;
ret = -1;
}
SAFE_FREE(key.dptr);
goto out;
}
SAFE_FREE(key.dptr);
}
out:
tdb->travlocks.next = tl->next;
if (ret < 0)
return -1;
else
return count;
}
/* Grab some bytes: may copy if can't use mmap.
Caller has already done bounds check. */
static TDB_DATA get_bytes(struct tdb_context *tdb,
tdb_off_t off, tdb_len_t len)
{
TDB_DATA d;
d.dsize = len;
if (tdb->transaction == NULL && tdb->map_ptr != NULL)
d.dptr = (unsigned char *)tdb->map_ptr + off;
else
d.dptr = tdb_alloc_read(tdb, off, d.dsize);
return d;
}
/* If an entry doesn't exist tdb_err will be set to
* TDB_ERR_NOEXIST. If a key has no data attached
* then the TDB_DATA will have zero length but
* a non-zero pointer
*/
TDB_DATA tdb_fetch(struct tdb_context *tdb, TDB_DATA key)
{
tdb_off_t rec_ptr;
struct list_struct rec;
TDB_DATA ret;
u32 hash;
/* find which hash bucket it is in */
hash = tdb->hash_fn(&key);
if (!(rec_ptr = tdb_find_lock_hash(tdb,key,hash,F_RDLCK,&rec)))
return tdb_null;
ret.dptr = tdb_alloc_read(tdb, rec_ptr + sizeof(rec) + rec.key_len,
rec.data_len);
ret.dsize = rec.data_len;
tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK);
return ret;
}
/* find the first entry in the database and return its key */
TDB_DATA tdb_firstkey(struct tdb_context *tdb)
{
TDB_DATA key;
struct list_struct rec;
/* release any old lock */
if (tdb_unlock_record(tdb, tdb->travlocks.off) != 0)
return tdb_null;
tdb->travlocks.off = tdb->travlocks.hash = 0;
tdb->travlocks.lock_rw = F_RDLCK;
/* Grab first record: locks chain and returned record. */
if (tdb_next_lock(tdb, &tdb->travlocks, &rec) <= 0)
return tdb_null;
/* now read the key */
key.dsize = rec.key_len;
key.dptr =tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec),key.dsize);
/* Unlock the hash chain of the record we just read. */
if (tdb_unlock(tdb, tdb->travlocks.hash, tdb->travlocks.lock_rw) != 0)
TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_firstkey: error occurred while tdb_unlocking!\n"));
return key;
}
