/**
* eblob_l2hash_compare_index() - goes to index and compares @key with data in disk
* control.
* Index has higher probability to be in memory so use if instead of data file.
*
* Returns:
* 0: @key belongs to @rctl
* 1: @key does not belong to @rctl
* Other: Error
*/
static int eblob_l2hash_compare_index(struct eblob_key *key, struct eblob_ram_control *rctl)
{
struct eblob_disk_control dc;
ssize_t err;
assert(key != NULL);
assert(rctl != NULL);
assert(rctl->index_fd >= 0);
/* Got to disk for index header */
if ((err = __eblob_l2hash_index_hdr(rctl, &dc)) != 0)
return err;
/* Compare given @key with index */
return !!(eblob_id_cmp(dc.key.id, key->id));
}
/**
* __eblob_l2hash_insert() - inserts @rctl entry into l2hash.
* @type: changes behaviour depending on existence of @key in cache.
*
* This is very complicated routine - should be modified with care.
*
* Returns:
* 0: Success
* Other: Error
*/
static int __eblob_l2hash_insert(struct eblob_l2hash *l2h, struct eblob_key *key,
struct eblob_ram_control *rctl, unsigned int type)
{
struct eblob_l2hash_collision *collision;
struct eblob_l2hash_entry *e;
struct rb_node *n, *parent, **node;
int err = 0;
assert(l2h != NULL);
assert(key != NULL);
assert(rctl != NULL);
assert(pthread_mutex_trylock(&l2h->root_lock) == EBUSY);
if (type <= EBLOB_L2HASH_TYPE_FIRST)
return -EINVAL;
if (type >= EBLOB_L2HASH_TYPE_LAST)
return -EINVAL;
/* Search tree for matching entry */
e = __eblob_l2hash_lookup(l2h, key);
if (e == NULL) {
/* No entry with matching l2hash - inserting */
if (type == EBLOB_L2HASH_TYPE_UPDATE)
return -ENOENT;
return __eblob_l2hash_noncollision_insert(&l2h->root, key, rctl);
}
/* There is already entry with matching l2hash */
if (e->collision == 0) {
struct eblob_disk_control dc;
/* No collisions - only one entry to check */
if ((err = __eblob_l2hash_index_hdr(&e->rctl, &dc)) != 0)
return err;
if (eblob_id_cmp(key->id, dc.key.id) == 0) {
/* Not a collision - updating in-place */
if (type == EBLOB_L2HASH_TYPE_INSERT)
return -EEXIST;
e->rctl = *rctl;
return 0;
}
/* This is a collision */
if (type == EBLOB_L2HASH_TYPE_UPDATE)
return -ENOENT;
/* Move old entry to collision tree */
err = __eblob_l2hash_collision_insert(&l2h->collisions, &dc.key, &e->rctl);
if (err != 0)
return err;
e->collision = 1;
memset(&e->rctl, 0, sizeof(struct eblob_ram_control));
return __eblob_l2hash_collision_insert(&l2h->collisions, key, rctl);
}
/* Search tree of collisions for matching entry */
n = __eblob_l2hash_collision_walk(&l2h->collisions, key, &parent, &node);
if (n == NULL) {
/* No entry found - inserting one */
if (type == EBLOB_L2HASH_TYPE_UPDATE)
return -ENOENT;
return __eblob_l2hash_collision_insert(&l2h->collisions, key, rctl);
}
/* Entry found - modifying in-place */
if (type == EBLOB_L2HASH_TYPE_INSERT)
return -EEXIST;
collision = rb_entry(n, struct eblob_l2hash_collision, node);
collision->rctl = *rctl;
return 0;
}
/**
* _eblob_l2hash_insert() - inserts @rctl entry into l2hash.
* @flavor: changes behaviour depending on existence of @key in cache.
* @replaced: set to 1 if entry was replaced, to 0 otherwise.
*
* This is very complicated routine - should be modified with care.
*
* Returns:
* 0: Success
* Other: Error
*/
static int _eblob_l2hash_insert(struct eblob_l2hash *l2h,
const struct eblob_key *key,
const struct eblob_ram_control *rctl,
const unsigned int flavor,
int *replaced)
{
struct eblob_l2hash_collision *collision;
struct eblob_l2hash_entry *e;
struct rb_node *n, *parent, **node;
int err = 0;
if (l2h == NULL || key == NULL || rctl == NULL)
return -EINVAL;
if (flavor <= EBLOB_L2HASH_FLAVOR_FIRST)
return -EINVAL;
if (flavor >= EBLOB_L2HASH_FLAVOR_LAST)
return -EINVAL;
if (replaced != NULL)
*replaced = 0;
/* Search tree for matching entry */
e = __eblob_l2hash_lookup(l2h, key);
if (e == NULL) {
/* No entry with matching l2hash - inserting */
if (flavor == EBLOB_L2HASH_FLAVOR_UPDATE)
return -ENOENT;
return __eblob_l2hash_noncollision_insert(&l2h->root, key, rctl);
}
/* There is already entry with matching l2hash */
if (e->collision == 0) {
struct eblob_disk_control dc;
/* No collisions - only one entry to check */
if ((err = __eblob_l2hash_index_hdr(&e->rctl, &dc)) != 0)
return err;
if (eblob_id_cmp(key->id, dc.key.id) == 0) {
/* Not a collision - updating in-place */
if (flavor == EBLOB_L2HASH_FLAVOR_INSERT)
return -EEXIST;
/* If entry was replaced - notify caller */
if (replaced != NULL)
*replaced = 1;
e->rctl = *rctl;
return 0;
}
/* This is a collision */
if (flavor == EBLOB_L2HASH_FLAVOR_UPDATE)
return -ENOENT;
/* Move old entry to collision tree */
err = __eblob_l2hash_collision_insert(&l2h->collisions, &dc.key, &e->rctl);
if (err != 0)
return err;
e->collision = 1;
memset(&e->rctl, 0, sizeof(struct eblob_ram_control));
return __eblob_l2hash_collision_insert(&l2h->collisions, key, rctl);
}
/* Search tree of collisions for matching entry */
n = __eblob_l2hash_collision_walk(&l2h->collisions, key, &parent, &node);
if (n == NULL) {
/* No entry found - inserting one */
if (flavor == EBLOB_L2HASH_FLAVOR_UPDATE)
return -ENOENT;
return __eblob_l2hash_collision_insert(&l2h->collisions, key, rctl);
}
/* Entry found - modifying in-place */
if (flavor == EBLOB_L2HASH_FLAVOR_INSERT)
return -EEXIST;
collision = rb_entry(n, struct eblob_l2hash_collision, node);
collision->rctl = *rctl;
/* If entry was replaced - notify caller */
if (replaced != NULL)
*replaced = 1;
return 0;
}