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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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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 _LINUX_RBTREE_H#define _LINUX_RBTREE_H
#include <linux/container_of.h>#include <linux/rbtree_types.h>
#include <linux/stddef.h>#include <linux/rcupdate.h>
#define rb_parent(r) ((struct rb_node *)((r)->__rb_parent_color & ~3))
#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))
#define RB_EMPTY_LINKED_NODE(lnode) RB_EMPTY_NODE(&(lnode)->node)#define RB_CLEAR_LINKED_NODE(lnode) ({ \ RB_CLEAR_NODE(&(lnode)->node); \ (lnode)->prev = (lnode)->next = NULL; \})
extern void rb_insert_color(struct rb_node *, struct rb_root *);extern void rb_erase(struct rb_node *, struct rb_root *);extern bool rb_erase_linked(struct rb_node_linked *, struct rb_root_linked *);
/* 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 *);
/* * This function returns the first node (in sort order) of the tree. */static inline struct rb_node *rb_first(const struct rb_root *root){ struct rb_node *n;
n = root->rb_node; if (!n) return NULL; while (n->rb_left) n = n->rb_left; return n;}
/* * This function returns the last node (in sort order) of the tree. */static inline struct rb_node *rb_last(const struct rb_root *root){ struct rb_node *n;
n = root->rb_node; if (!n) return NULL; while (n->rb_right) n = n->rb_right; return n;}
/* 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);extern void rb_replace_node_rcu(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;}
static inline void rb_link_node_rcu(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;
rcu_assign_pointer(*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)
/* 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 struct rb_node *rb_erase_cached(struct rb_node *node, struct rb_root_cached *root){ struct rb_node *leftmost = NULL;
if (root->rb_leftmost == node) leftmost = root->rb_leftmost = rb_next(node);
rb_erase(node, &root->rb_root);
return leftmost;}
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 * * Returns @node when it is the new leftmost, or NULL. */static __always_inline struct rb_node *rb_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);
return leftmost ? node : NULL;}
static __always_inline void__rb_add(struct rb_node *node, struct rb_root *tree, bool (*less)(struct rb_node *, const struct rb_node *), void (*linkop)(struct rb_node *, struct rb_node *, 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; }
linkop(node, parent, link); rb_link_node(node, parent, link); rb_insert_color(node, tree);}
#define __node_2_linked_node(_n) \ rb_entry((_n), struct rb_node_linked, node)
static inline voidrb_link_linked_node(struct rb_node *node, struct rb_node *parent, struct rb_node **link){ if (!parent) return;
struct rb_node_linked *nnew = __node_2_linked_node(node); struct rb_node_linked *npar = __node_2_linked_node(parent);
if (link == &parent->rb_left) { nnew->prev = npar->prev; nnew->next = npar; npar->prev = nnew; if (nnew->prev) nnew->prev->next = nnew; } else { nnew->next = npar->next; nnew->prev = npar; npar->next = nnew; if (nnew->next) nnew->next->prev = nnew; }}
/** * rb_add_linked() - insert @node into the leftmost linked tree @tree * @node: node to insert * @tree: linked tree to insert @node into * @less: operator defining the (partial) node order * * Returns @true when @node is the new leftmost, @false otherwise. */static __always_inline boolrb_add_linked(struct rb_node_linked *node, struct rb_root_linked *tree, bool (*less)(struct rb_node *, const struct rb_node *)){ __rb_add(&node->node, &tree->rb_root, less, rb_link_linked_node); if (!node->prev) tree->rb_leftmost = node; return !node->prev;}
/* Empty linkop function which is optimized away by the compiler */static __always_inline voidrb_link_noop(struct rb_node *n, struct rb_node *p, struct rb_node **l) { }
/** * 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 *)){ __rb_add(node, tree, less, rb_link_noop);}
/** * rb_find_add_cached() - 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_cached(struct rb_node *node, struct rb_root_cached *tree, int (*cmp)(const struct rb_node *new, const struct rb_node *exist)){ bool leftmost = true; struct rb_node **link = &tree->rb_root.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; leftmost = false; } else { return parent; } }
rb_link_node(node, parent, link); rb_insert_color_cached(node, tree, leftmost); return NULL;}
/** * 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_add_rcu() - 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 * * Adds a Store-Release for link_node. * * 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_rcu(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_rcu(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_rcu() - find @key in tree @tree * @key: key to match * @tree: tree to search * @cmp: operator defining the node order * * Notably, tree descent vs concurrent tree rotations is unsound and can result * in false-negatives. * * Returns the rb_node matching @key or NULL. */static __always_inline struct rb_node *rb_find_rcu(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 = rcu_dereference_raw(node->rb_left); else if (c > 0) node = rcu_dereference_raw(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 /* _LINUX_RBTREE_H */