/* SPDX-License-Identifier: GPL-2.0-or-later *//*  Red Black Trees  (C) 1999  Andrea Arcangeli <andrea@suse.de>    linux/include/linux/rbtree.h   To use rbtrees you'll have to implement your own insert and search cores.  This will avoid us to use callbacks and to drop drammatically performances.  I know it's not the cleaner way,  but in C (not in C++) to get  performances and genericity...   See Documentation/core-api/rbtree.rst for documentation and samples.*/ #ifndef __TOOLS_LINUX_PERF_RBTREE_H#define __TOOLS_LINUX_PERF_RBTREE_H #include <linux/kernel.h>#include <linux/stddef.h> struct rb_node {	unsigned long  __rb_parent_color;	struct rb_node *rb_right;	struct rb_node *rb_left;} __attribute__((aligned(sizeof(long))));    /* The alignment might seem pointless, but allegedly CRIS needs it */ struct rb_root {	struct rb_node *rb_node;}; #define rb_parent(r)   ((struct rb_node *)((r)->__rb_parent_color & ~3)) #define RB_ROOT	(struct rb_root) { NULL, }#define	rb_entry(ptr, type, member) container_of(ptr, type, member) #define RB_EMPTY_ROOT(root)  (READ_ONCE((root)->rb_node) == NULL) /* 'empty' nodes are nodes that are known not to be inserted in an rbtree */#define RB_EMPTY_NODE(node)  \	((node)->__rb_parent_color == (unsigned long)(node))#define RB_CLEAR_NODE(node)  \	((node)->__rb_parent_color = (unsigned long)(node))  extern void rb_insert_color(struct rb_node *, struct rb_root *);extern void rb_erase(struct rb_node *, struct rb_root *);  /* Find logical next and previous nodes in a tree */extern struct rb_node *rb_next(const struct rb_node *);extern struct rb_node *rb_prev(const struct rb_node *);extern struct rb_node *rb_first(const struct rb_root *);extern struct rb_node *rb_last(const struct rb_root *); /* Postorder iteration - always visit the parent after its children */extern struct rb_node *rb_first_postorder(const struct rb_root *);extern struct rb_node *rb_next_postorder(const struct rb_node *); /* Fast replacement of a single node without remove/rebalance/add/rebalance */extern void rb_replace_node(struct rb_node *victim, struct rb_node *new,			    struct rb_root *root); static inline void rb_link_node(struct rb_node *node, struct rb_node *parent,				struct rb_node **rb_link){	node->__rb_parent_color = (unsigned long)parent;	node->rb_left = node->rb_right = NULL; 	*rb_link = node;} #define rb_entry_safe(ptr, type, member) \	({ typeof(ptr) ____ptr = (ptr); \	   ____ptr ? rb_entry(____ptr, type, member) : NULL; \	}) /** * rbtree_postorder_for_each_entry_safe - iterate in post-order over rb_root of * given type allowing the backing memory of @pos to be invalidated * * @pos:	the 'type *' to use as a loop cursor. * @n:		another 'type *' to use as temporary storage * @root:	'rb_root *' of the rbtree. * @field:	the name of the rb_node field within 'type'. * * rbtree_postorder_for_each_entry_safe() provides a similar guarantee as * list_for_each_entry_safe() and allows the iteration to continue independent * of changes to @pos by the body of the loop. * * Note, however, that it cannot handle other modifications that re-order the * rbtree it is iterating over. This includes calling rb_erase() on @pos, as * rb_erase() may rebalance the tree, causing us to miss some nodes. */#define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \	for (pos = rb_entry_safe(rb_first_postorder(root), typeof(*pos), field); \	     pos && ({ n = rb_entry_safe(rb_next_postorder(&pos->field), \			typeof(*pos), field); 1; }); \	     pos = n) static inline void rb_erase_init(struct rb_node *n, struct rb_root *root){	rb_erase(n, root);	RB_CLEAR_NODE(n);} /* * Leftmost-cached rbtrees. * * We do not cache the rightmost node based on footprint * size vs number of potential users that could benefit * from O(1) rb_last(). Just not worth it, users that want * this feature can always implement the logic explicitly. * Furthermore, users that want to cache both pointers may * find it a bit asymmetric, but that's ok. */struct rb_root_cached {	struct rb_root rb_root;	struct rb_node *rb_leftmost;}; #define RB_ROOT_CACHED (struct rb_root_cached) { {NULL, }, NULL } /* Same as rb_first(), but O(1) */#define rb_first_cached(root) (root)->rb_leftmost static inline void rb_insert_color_cached(struct rb_node *node,					  struct rb_root_cached *root,					  bool leftmost){	if (leftmost)		root->rb_leftmost = node;	rb_insert_color(node, &root->rb_root);} static inline void rb_erase_cached(struct rb_node *node,				   struct rb_root_cached *root){	if (root->rb_leftmost == node)		root->rb_leftmost = rb_next(node);	rb_erase(node, &root->rb_root);} static inline void rb_replace_node_cached(struct rb_node *victim,					  struct rb_node *new,					  struct rb_root_cached *root){	if (root->rb_leftmost == victim)		root->rb_leftmost = new;	rb_replace_node(victim, new, &root->rb_root);} /* * The below helper functions use 2 operators with 3 different * calling conventions. The operators are related like: * *	comp(a->key,b) < 0  := less(a,b) *	comp(a->key,b) > 0  := less(b,a) *	comp(a->key,b) == 0 := !less(a,b) && !less(b,a) * * If these operators define a partial order on the elements we make no * guarantee on which of the elements matching the key is found. See * rb_find(). * * The reason for this is to allow the find() interface without requiring an * on-stack dummy object, which might not be feasible due to object size. */ /** * rb_add_cached() - insert @node into the leftmost cached tree @tree * @node: node to insert * @tree: leftmost cached tree to insert @node into * @less: operator defining the (partial) node order */static __always_inline voidrb_add_cached(struct rb_node *node, struct rb_root_cached *tree,	      bool (*less)(struct rb_node *, const struct rb_node *)){	struct rb_node **link = &tree->rb_root.rb_node;	struct rb_node *parent = NULL;	bool leftmost = true; 	while (*link) {		parent = *link;		if (less(node, parent)) {			link = &parent->rb_left;		} else {			link = &parent->rb_right;			leftmost = false;		}	} 	rb_link_node(node, parent, link);	rb_insert_color_cached(node, tree, leftmost);} /** * rb_add() - insert @node into @tree * @node: node to insert * @tree: tree to insert @node into * @less: operator defining the (partial) node order */static __always_inline voidrb_add(struct rb_node *node, struct rb_root *tree,       bool (*less)(struct rb_node *, const struct rb_node *)){	struct rb_node **link = &tree->rb_node;	struct rb_node *parent = NULL; 	while (*link) {		parent = *link;		if (less(node, parent))			link = &parent->rb_left;		else			link = &parent->rb_right;	} 	rb_link_node(node, parent, link);	rb_insert_color(node, tree);} /** * rb_find_add() - find equivalent @node in @tree, or add @node * @node: node to look-for / insert * @tree: tree to search / modify * @cmp: operator defining the node order * * Returns the rb_node matching @node, or NULL when no match is found and @node * is inserted. */static __always_inline struct rb_node *rb_find_add(struct rb_node *node, struct rb_root *tree,	    int (*cmp)(struct rb_node *, const struct rb_node *)){	struct rb_node **link = &tree->rb_node;	struct rb_node *parent = NULL;	int c; 	while (*link) {		parent = *link;		c = cmp(node, parent); 		if (c < 0)			link = &parent->rb_left;		else if (c > 0)			link = &parent->rb_right;		else			return parent;	} 	rb_link_node(node, parent, link);	rb_insert_color(node, tree);	return NULL;} /** * rb_find() - find @key in tree @tree * @key: key to match * @tree: tree to search * @cmp: operator defining the node order * * Returns the rb_node matching @key or NULL. */static __always_inline struct rb_node *rb_find(const void *key, const struct rb_root *tree,	int (*cmp)(const void *key, const struct rb_node *)){	struct rb_node *node = tree->rb_node; 	while (node) {		int c = cmp(key, node); 		if (c < 0)			node = node->rb_left;		else if (c > 0)			node = node->rb_right;		else			return node;	} 	return NULL;} /** * rb_find_first() - find the first @key in @tree * @key: key to match * @tree: tree to search * @cmp: operator defining node order * * Returns the leftmost node matching @key, or NULL. */static __always_inline struct rb_node *rb_find_first(const void *key, const struct rb_root *tree,	      int (*cmp)(const void *key, const struct rb_node *)){	struct rb_node *node = tree->rb_node;	struct rb_node *match = NULL; 	while (node) {		int c = cmp(key, node); 		if (c <= 0) {			if (!c)				match = node;			node = node->rb_left;		} else if (c > 0) {			node = node->rb_right;		}	} 	return match;} /** * rb_next_match() - find the next @key in @tree * @key: key to match * @tree: tree to search * @cmp: operator defining node order * * Returns the next node matching @key, or NULL. */static __always_inline struct rb_node *rb_next_match(const void *key, struct rb_node *node,	      int (*cmp)(const void *key, const struct rb_node *)){	node = rb_next(node);	if (node && cmp(key, node))		node = NULL;	return node;} /** * rb_for_each() - iterates a subtree matching @key * @node: iterator * @key: key to match * @tree: tree to search * @cmp: operator defining node order */#define rb_for_each(node, key, tree, cmp) \	for ((node) = rb_find_first((key), (tree), (cmp)); \	     (node); (node) = rb_next_match((key), (node), (cmp))) #endif	/* __TOOLS_LINUX_PERF_RBTREE_H */