rbtree: add rb_search_exact()

Sometimes we want to search for an exact key only, and reject the case
when tree->key < key. Add rb_search_exact() for this purpose, rather
than forcing the caller to perform the comparison in open code.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
This commit is contained in:
H. Peter Anvin (Intel) 2020-07-08 09:48:43 -07:00
parent c341ad7300
commit 68e3802b23
2 changed files with 13 additions and 0 deletions

View File

@ -72,6 +72,11 @@ struct rbtree *rb_insert(struct rbtree *, struct rbtree *);
*/
struct rbtree *rb_search(const struct rbtree *, uint64_t);
/*
* Find a node in the tree exactly matching the key value.
*/
struct rbtree *rb_search_exact(const struct rbtree *, uint64_t);
/*
* Return the immediately previous or next node in key order.
* Returns NULL if this node is the end of the tree.

View File

@ -87,6 +87,14 @@ struct rbtree *rb_search(const struct rbtree *tree, uint64_t key)
return (struct rbtree *)best;
}
struct rbtree *rb_search_exact(const struct rbtree *tree, uint64_t key)
{
struct rbtree *rv;
rv = rb_search(tree, key);
return (rv && rv->key == key) ? rv : NULL;
}
/* Reds two left in a row? */
static inline bool is_red_left_left(struct rbtree *h)
{