/* Delete a sub-tree rooted at [addr].
*
* Recursive decent through the tree. Remove the leaves and perform
* the user-defined "data_release" function for all data. Deallocate all
* internal nodes.
*/
void oc_bpt_utl_delete_subtree_b(
struct Oc_wu *wu_p,
struct Oc_bpt_state *s_p,
Oc_bpt_node *node_p)
{
int fs_refcnt = s_p->cfg_p->fs_get_refcount(wu_p, node_p->disk_addr);
oc_utl_debugassert(fs_refcnt > 0);
if (1 == fs_refcnt) {
/* If this node is referenced from a single snapshot only,
* Then recurse down and then delete it on the way back up.
*/
if (!oc_bpt_nd_is_leaf(s_p, node_p)) {
// An index node, recurse through its children
int i;
int num_entries = oc_bpt_nd_num_entries(s_p, node_p);
Oc_bpt_node *child_node_p;
struct Oc_bpt_key *dummy_key_p;
uint64 child_addr;
for (i=0; i< num_entries; i++) {
oc_bpt_nd_index_get_kth(s_p, node_p, i,
&dummy_key_p,
&child_addr);
child_node_p = oc_bpt_nd_get_for_read(wu_p, s_p, child_addr);
oc_bpt_utl_delete_subtree_b(wu_p, s_p, child_node_p);
}
}
}
// reduce the ref-count on this node
oc_bpt_nd_delete(wu_p, s_p, node_p);
}
/* Delete all the key-value pairs in the tree.
* Leave the root node empty but do not delete it.
*/
void oc_bpt_utl_delete_all_b(
struct Oc_wu *wu_p,
struct Oc_bpt_state *s_p)
{
int num_entries = oc_bpt_nd_num_entries(s_p, s_p->root_node_p);
if (!oc_bpt_nd_is_leaf(s_p, s_p->root_node_p)) {
// This is a full fledged tree. Remove all the sub-trees.
int i;
Oc_bpt_node *child_node_p;
struct Oc_bpt_key *dummy_key_p;
uint64 child_addr;
for (i=0; i< num_entries; i++) {
oc_bpt_nd_index_get_kth(s_p, s_p->root_node_p, i,
&dummy_key_p,
&child_addr);
child_node_p = oc_bpt_nd_get_for_read(wu_p, s_p, child_addr);
oc_bpt_utl_delete_subtree_b(wu_p, s_p, child_node_p);
}
}
// Remove all the entries from the root node
oc_bpt_nd_remove_range(wu_p, s_p,
s_p->root_node_p,
0, num_entries - 1);
}
void oc_bpt_delete_b(
struct Oc_wu *wu_p,
struct Oc_bpt_state *s_p)
{
oc_bpt_trace_wu_lvl(2, OC_EV_BPT_DELETE, wu_p, "tid=%Lu", s_p->tid);
oc_utl_debugassert(s_p->cfg_p->initialized);
oc_utl_trk_crt_lock_write(wu_p, &s_p->lock);
/* We need to upgrade the root-lock to a shared-lock
* because the delete-code unlocks all the pages after
* deleting them. This means that the root cannot remain
* unlocked, as usual.
*/
oc_utl_trk_crt_lock_read(wu_p, &s_p->root_node_p->lock);
oc_bpt_utl_delete_subtree_b(wu_p, s_p, s_p->root_node_p);
s_p->root_node_p = NULL;
oc_utl_trk_crt_unlock(wu_p, &s_p->lock);
}
