/* search in a node's child */
int _search_child(struct cursor *cur,
struct search *so,
struct node *n,
int childnum)
{
int ret;
NID child_nid;
int child_to_search;
struct node *child;
nassert(n->height > 0);
ancestors_append(cur, n->parts[childnum].msgbuf);
child_nid = n->parts[childnum].child_nid;
if (!cache_get_and_pin(cur->tree->cf, child_nid, (void**)&child, L_READ)) {
__ERROR("cache get node error, nid [%" PRIu64 "]", child_nid);
return NESS_ERR;
}
child_to_search = _search_in_which_child(so, child);
ret = _search_node(cur, so, child, child_to_search);
/* unpin */
cache_unpin(cur->tree->cf, child->cpair);
return ret;
}
GsTreeNode *GsTreeBase::insert ( GsTreeNode *key )
{
int cmp = _search_node ( key );
if ( _cur!=NIL )
{ if ( cmp>0 ) // key>_cur
{ // if (_cur->right) REPORT_ERROR;
_cur->right = key;
key->parent = _cur;
_rebalance ( key );
_root->color = GsTreeNode::Black;
_elements++;
return key;
}
else if ( cmp<0 ) // key<_cur
{ // if (_cur->left) REPORT_ERROR
_cur->left = key;
key->parent = _cur;
_rebalance ( key );
_root->color = GsTreeNode::Black;
_elements++;
return key;
}
else return 0; // not inserted, already in the tree
}
else // tree empty
{ _root = key;
_root->init ();
_root->color = GsTreeNode::Black;
_elements++;
return key;
}
}
/*
* |key44, key88|
* / \
* |key10, key20| |key90|
* / | \ \
* |basement0| |basement1| |basement2| |basement3|
*
* (a tree with height 2)
*
* cursor search is very similar to depth-first-search algorithm.
* for cursor_seektofirst operation, the root-to-leaf path is:
* key44 -> key10 -> basement0
* and do the inner sliding along with the basement.
* if we get the end of one leaf, CURSOR_EOF will be returned to upper on,
* and we also set search->pivot_bound = key10, for the next time,
* the root-to-leaf path(restart with a jump) will be:
* key44 -> key10 -> basement1
*/
void _tree_search(struct cursor *cur, struct search *so)
{
int r;
NID root_nid;
int child_to_search;
struct tree *t;
struct node *root;
struct cache_operations *c_op = cur->tree->cache->c_op;
t = cur->tree;
try_again:
root_nid = t->hdr->root_nid;
if (c_op->cache_get_and_pin(t->cache,
root_nid,
&root,
L_READ) < 0) {
__ERROR("cache get root node error, nid [%" PRIu64 "]",
root_nid);
return;
}
child_to_search = _search_in_which_child(so, root);
r = _search_node(cur,
so,
root,
child_to_search);
/* unpin */
c_op->cache_unpin_readonly(t->cache, root);
switch (r) {
case CURSOR_CONTINUE:
break;
case CURSOR_TRY_AGAIN:
goto try_again;
break;
case CURSOR_EOF:
break;
default: break;
}
}
/* search in a node's child */
int _search_child(struct cursor *cur,
struct search *so,
struct node *n,
int childnum)
{
int ret;
int child_to_search;
NID child_nid;
struct node *child;
struct cache_operations *c_op = cur->tree->cache->c_op;
nassert(n->height > 0);
/* add basement to ances */
ancestors_append(cur, n->u.n.parts[childnum].buffer);
child_nid = n->u.n.parts[childnum].child_nid;
if (c_op->cache_get_and_pin(cur->tree->cache,
child_nid,
&child,
L_READ) < 0) {
__ERROR("cache get node error, nid [%" PRIu64 "]",
child_nid);
return NESS_ERR;
}
child_to_search = _search_in_which_child(so, child);
ret = _search_node(cur,
so,
child,
child_to_search);
/* unpin */
c_op->cache_unpin_readonly(cur->tree->cache, child);
return ret;
}
/*
* |key44, key88|
* / \
* |key10, key20| |key90|
* / | \ \
* |msgbuf0| |msgbuf1| |msgbuf2| |msgbuf3|
*
* (a tree with height 2)
*
* cursor search is very similar to depth-first-search algorithm.
* for cursor_seektofirst operation, the root-to-leaf path is:
* key44 -> key10 -> msgbuf0
* and do the inner sliding along with the msgbuf.
* if we get the end of one leaf, CURSOR_EOF will be returned to upper on,
* and we also set search->pivot_bound = key10, for the next time,
* the root-to-leaf path(restart with a jump) will be:
* key44 -> key10 -> msgbuf1
*/
void _tree_search(struct cursor * cur, struct search * so)
{
int r;
NID root_nid;
int child_to_search;
struct buftree *t;
struct node *root;
t = cur->tree;
TRY_AGAIN:
root_nid = t->hdr->root_nid;
if (!cache_get_and_pin(t->cf, root_nid, (void**)&root, L_READ)) {
__ERROR("cache get root node error, nid [%" PRIu64 "]", root_nid);
return;
}
child_to_search = _search_in_which_child(so, root);
r = _search_node(cur, so, root, child_to_search);
/* unpin */
cache_unpin(t->cf, root->cpair);
switch (r) {
case CURSOR_CONTINUE: /* got the end of leaf */
goto TRY_AGAIN;
break;
case CURSOR_TRY_AGAIN: /* got the end of node */
goto TRY_AGAIN;
break;
case CURSOR_EOF:
break;
default:
break;
}
}
bool GsTreeBase::search_and_remove ( const GsTreeNode* key )
{
int cmp = _search_node ( key );
if ( cmp==0 ) { remove ( _cur ); return true; }
return false;
}
GsTreeNode* GsTreeBase::search_and_extract ( const GsTreeNode* key )
{
int cmp = _search_node ( key );
if ( cmp!=0 ) return 0; // not found
return extract ( _cur );
}
GsTreeNode *GsTreeBase::search ( const GsTreeNode *key )
{
if ( _root==NIL ) return 0;
return _search_node(key)==0? _cur:0;
}
