[PATCH 12/13] lib min_heap: Add min_heap_sift_up()

Kuan-Wei Chiu
2024-03-19T18:01:11Z

Add min_heap_sift_up() to sift up the element at index 'idx' in the
heap.

Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
---
include/linux/min_heap.h | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)

diff --git a/include/linux/min_heap.h b/include/linux/min_heap.h
index ce085137fce7..586965977104 100644
--- a/include/linux/min_heap.h
+++ b/include/linux/min_heap.h
@@ -199,6 +199,26 @@ bool __min_heap_push(struct __min_heap *heap, const void *element, size_t elem_s
#define min_heap_push(_heap, _element, _func, _args) \
__min_heap_push(&(_heap)->heap, _element, __minheap_obj_size(_heap), _func, _args)

+/* Sift up ith element from the heap, O(log2(nr)). */
+static __always_inline
+void __min_heap_sift_up(struct __min_heap *heap, size_t elem_size, size_t idx,
+ const struct min_heap_callbacks *func, void *args)
+{
+ void *data = heap->data;
+ size_t parent;
+
+ while (idx) {
+ parent = (idx - 1) / 2;
+ if (func->less(data + parent * elem_size, data + idx * elem_size, args))
+ break;
+ func->swp(data + parent * elem_size, data + idx * elem_size, args);
+ idx = parent;
+ }
+}
+
+#define min_heap_sift_up(_heap, _idx, _func, _args) \
+ __min_heap_sift_up(&(_heap)->heap, __minheap_obj_size(_heap), _idx, _func, _args)
+
/* Remove ith element from the heap, O(log2(nr)). */
static __always_inline
bool __min_heap_del(struct __min_heap *heap, size_t elem_size, size_t idx,
--
2.34.1