89 lines
2.9 KiB
C
89 lines
2.9 KiB
C
|
/* SPDX-License-Identifier: GPL-2.0 */
|
||
|
|
#ifndef _LINUX_INTERVAL_TREE_H
|
||
|
|
#define _LINUX_INTERVAL_TREE_H
|
||
|
|
|
||
|
|
#include <linux/rbtree.h>
|
||
|
|
|
||
|
|
struct interval_tree_node {
|
||
|
|
struct rb_node rb;
|
||
|
|
unsigned long start; /* Start of interval */
|
||
|
|
unsigned long last; /* Last location _in_ interval */
|
||
|
|
unsigned long __subtree_last;
|
||
|
|
};
|
||
|
|
|
||
|
|
extern void
|
||
|
|
interval_tree_insert(struct interval_tree_node *node,
|
||
|
|
struct rb_root_cached *root);
|
||
|
|
|
||
|
|
extern void
|
||
|
|
interval_tree_remove(struct interval_tree_node *node,
|
||
|
|
struct rb_root_cached *root);
|
||
|
|
|
||
|
|
extern struct interval_tree_node *
|
||
|
|
interval_tree_iter_first(struct rb_root_cached *root,
|
||
|
|
unsigned long start, unsigned long last);
|
||
|
|
|
||
|
|
extern struct interval_tree_node *
|
||
|
|
interval_tree_iter_next(struct interval_tree_node *node,
|
||
|
|
unsigned long start, unsigned long last);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* struct interval_tree_span_iter - Find used and unused spans.
|
||
|
|
* @start_hole: Start of an interval for a hole when is_hole == 1
|
||
|
|
* @last_hole: Inclusive end of an interval for a hole when is_hole == 1
|
||
|
|
* @start_used: Start of a used interval when is_hole == 0
|
||
|
|
* @last_used: Inclusive end of a used interval when is_hole == 0
|
||
|
|
* @is_hole: 0 == used, 1 == is_hole, -1 == done iteration
|
||
|
|
*
|
||
|
|
* This iterator travels over spans in an interval tree. It does not return
|
||
|
|
* nodes but classifies each span as either a hole, where no nodes intersect, or
|
||
|
|
* a used, which is fully covered by nodes. Each iteration step toggles between
|
||
|
|
* hole and used until the entire range is covered. The returned spans always
|
||
|
|
* fully cover the requested range.
|
||
|
|
*
|
||
|
|
* The iterator is greedy, it always returns the largest hole or used possible,
|
||
|
|
* consolidating all consecutive nodes.
|
||
|
|
*
|
||
|
|
* Use interval_tree_span_iter_done() to detect end of iteration.
|
||
|
|
*/
|
||
|
|
struct interval_tree_span_iter {
|
||
|
|
/* private: not for use by the caller */
|
||
|
|
struct interval_tree_node *nodes[2];
|
||
|
|
unsigned long first_index;
|
||
|
|
unsigned long last_index;
|
||
|
|
|
||
|
|
/* public: */
|
||
|
|
union {
|
||
|
|
unsigned long start_hole;
|
||
|
|
unsigned long start_used;
|
||
|
|
};
|
||
|
|
union {
|
||
|
|
unsigned long last_hole;
|
||
|
|
unsigned long last_used;
|
||
|
|
};
|
||
|
|
int is_hole;
|
||
|
|
};
|
||
|
|
|
||
|
|
void interval_tree_span_iter_first(struct interval_tree_span_iter *state,
|
||
|
|
struct rb_root_cached *itree,
|
||
|
|
unsigned long first_index,
|
||
|
|
unsigned long last_index);
|
||
|
|
void interval_tree_span_iter_advance(struct interval_tree_span_iter *iter,
|
||
|
|
struct rb_root_cached *itree,
|
||
|
|
unsigned long new_index);
|
||
|
|
void interval_tree_span_iter_next(struct interval_tree_span_iter *state);
|
||
|
|
|
||
|
|
static inline bool
|
||
|
|
interval_tree_span_iter_done(struct interval_tree_span_iter *state)
|
||
|
|
{
|
||
|
|
return state->is_hole == -1;
|
||
|
|
}
|
||
|
|
|
||
|
|
#define interval_tree_for_each_span(span, itree, first_index, last_index) \
|
||
|
|
for (interval_tree_span_iter_first(span, itree, \
|
||
|
|
first_index, last_index); \
|
||
|
|
!interval_tree_span_iter_done(span); \
|
||
|
|
interval_tree_span_iter_next(span))
|
||
|
|
|
||
|
|
#endif /* _LINUX_INTERVAL_TREE_H */
|