/**
* Split a range into two halves by deleting a middle portion
* @param r the range to split-delete
* @param q the range to delete from r
* @return NULL if it aligned at either end else the second half
*/
range *range_split_delete( range *r, range *q )
{
if ( q->start == r->start )
{
r->len -= q->len;
r->start += q->len;
return NULL;
}
else if ( range_end(q) == range_end(r) )
{
r->len -= q->len;
return NULL;
}
else
{
range *q2 = range_create( r->name, r->html_name, r->start, r->len );
if ( q2 != NULL )
{
q2->start = range_end(q);
q2->len = range_end(r) - q->start;
r->len = q->start-r->start;
}
return q2;
}
}
static int tree_insert(struct rb_root *root, struct extent_map *em)
{
struct rb_node **p = &root->rb_node;
struct rb_node *parent = NULL;
struct extent_map *entry = NULL;
struct rb_node *orig_parent = NULL;
u64 end = range_end(em->start, em->len);
while (*p) {
parent = *p;
entry = rb_entry(parent, struct extent_map, rb_node);
WARN_ON(!entry->in_tree);
if (em->start < entry->start)
p = &(*p)->rb_left;
else if (em->start >= extent_map_end(entry))
p = &(*p)->rb_right;
else
return -EEXIST;
}
orig_parent = parent;
while (parent && em->start >= extent_map_end(entry)) {
parent = rb_next(parent);
entry = rb_entry(parent, struct extent_map, rb_node);
}
if (parent)
if (end > entry->start && em->start < extent_map_end(entry))
return -EEXIST;
parent = orig_parent;
entry = rb_entry(parent, struct extent_map, rb_node);
while (parent && em->start < entry->start) {
parent = rb_prev(parent);
entry = rb_entry(parent, struct extent_map, rb_node);
}
if (parent)
if (end > entry->start && em->start < extent_map_end(entry))
return -EEXIST;
em->in_tree = 1;
rb_link_node(&em->rb_node, orig_parent, p);
rb_insert_color(&em->rb_node, root);
return 0;
}
rint size() const
{
return range_end() - range_begin();
}
/**
* Does a range overlap this range on the right?
* @param q the range that might overlap on the right
* @param r the range to compare it to
* @return 1 if it is true
*/
int range_overlaps_right( range *q, range *r )
{
return range_end(r)>q->start && range_end(r)<range_end(q);
}
/**
* Does a range overlap this range on the left?
* @param q the range that might overlap on the left
* @param r the range to compare it to
* @return 1 if it is true
*/
int range_overlaps_left( range *q, range *r )
{
return range_end(q)>r->start && range_end(q)<range_end(r);
}
/**
* Is a range inside another. Inside can be equal
* @param r1 the first range (is it inside r2?)
* @param r2 the second range being the outside one
* @return 1 if r1 is inside r2, else 0
*/
int range_inside( range *r1, range *r2 )
{
return range_start(r1)>=range_start(r2)&&range_end(r1)<=range_end(r2);
}
