mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
308 lines
9.3 KiB
308 lines
9.3 KiB
/* SPDX-License-Identifier: GPL-2.0-or-later */ |
|
/* |
|
Red Black Trees |
|
(C) 1999 Andrea Arcangeli <[email protected]> |
|
(C) 2002 David Woodhouse <[email protected]> |
|
(C) 2012 Michel Lespinasse <[email protected]> |
|
|
|
|
|
tools/linux/include/linux/rbtree_augmented.h |
|
|
|
Copied from: |
|
linux/include/linux/rbtree_augmented.h |
|
*/ |
|
|
|
#ifndef _TOOLS_LINUX_RBTREE_AUGMENTED_H |
|
#define _TOOLS_LINUX_RBTREE_AUGMENTED_H |
|
|
|
#include <linux/compiler.h> |
|
#include <linux/rbtree.h> |
|
|
|
/* |
|
* Please note - only struct rb_augment_callbacks and the prototypes for |
|
* rb_insert_augmented() and rb_erase_augmented() are intended to be public. |
|
* The rest are implementation details you are not expected to depend on. |
|
* |
|
* See Documentation/core-api/rbtree.rst for documentation and samples. |
|
*/ |
|
|
|
struct rb_augment_callbacks { |
|
void (*propagate)(struct rb_node *node, struct rb_node *stop); |
|
void (*copy)(struct rb_node *old, struct rb_node *new); |
|
void (*rotate)(struct rb_node *old, struct rb_node *new); |
|
}; |
|
|
|
extern void __rb_insert_augmented(struct rb_node *node, struct rb_root *root, |
|
void (*augment_rotate)(struct rb_node *old, struct rb_node *new)); |
|
|
|
/* |
|
* Fixup the rbtree and update the augmented information when rebalancing. |
|
* |
|
* On insertion, the user must update the augmented information on the path |
|
* leading to the inserted node, then call rb_link_node() as usual and |
|
* rb_insert_augmented() instead of the usual rb_insert_color() call. |
|
* If rb_insert_augmented() rebalances the rbtree, it will callback into |
|
* a user provided function to update the augmented information on the |
|
* affected subtrees. |
|
*/ |
|
static inline void |
|
rb_insert_augmented(struct rb_node *node, struct rb_root *root, |
|
const struct rb_augment_callbacks *augment) |
|
{ |
|
__rb_insert_augmented(node, root, augment->rotate); |
|
} |
|
|
|
static inline void |
|
rb_insert_augmented_cached(struct rb_node *node, |
|
struct rb_root_cached *root, bool newleft, |
|
const struct rb_augment_callbacks *augment) |
|
{ |
|
if (newleft) |
|
root->rb_leftmost = node; |
|
rb_insert_augmented(node, &root->rb_root, augment); |
|
} |
|
|
|
/* |
|
* Template for declaring augmented rbtree callbacks (generic case) |
|
* |
|
* RBSTATIC: 'static' or empty |
|
* RBNAME: name of the rb_augment_callbacks structure |
|
* RBSTRUCT: struct type of the tree nodes |
|
* RBFIELD: name of struct rb_node field within RBSTRUCT |
|
* RBAUGMENTED: name of field within RBSTRUCT holding data for subtree |
|
* RBCOMPUTE: name of function that recomputes the RBAUGMENTED data |
|
*/ |
|
|
|
#define RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \ |
|
RBSTRUCT, RBFIELD, RBAUGMENTED, RBCOMPUTE) \ |
|
static inline void \ |
|
RBNAME ## _propagate(struct rb_node *rb, struct rb_node *stop) \ |
|
{ \ |
|
while (rb != stop) { \ |
|
RBSTRUCT *node = rb_entry(rb, RBSTRUCT, RBFIELD); \ |
|
if (RBCOMPUTE(node, true)) \ |
|
break; \ |
|
rb = rb_parent(&node->RBFIELD); \ |
|
} \ |
|
} \ |
|
static inline void \ |
|
RBNAME ## _copy(struct rb_node *rb_old, struct rb_node *rb_new) \ |
|
{ \ |
|
RBSTRUCT *old = rb_entry(rb_old, RBSTRUCT, RBFIELD); \ |
|
RBSTRUCT *new = rb_entry(rb_new, RBSTRUCT, RBFIELD); \ |
|
new->RBAUGMENTED = old->RBAUGMENTED; \ |
|
} \ |
|
static void \ |
|
RBNAME ## _rotate(struct rb_node *rb_old, struct rb_node *rb_new) \ |
|
{ \ |
|
RBSTRUCT *old = rb_entry(rb_old, RBSTRUCT, RBFIELD); \ |
|
RBSTRUCT *new = rb_entry(rb_new, RBSTRUCT, RBFIELD); \ |
|
new->RBAUGMENTED = old->RBAUGMENTED; \ |
|
RBCOMPUTE(old, false); \ |
|
} \ |
|
RBSTATIC const struct rb_augment_callbacks RBNAME = { \ |
|
.propagate = RBNAME ## _propagate, \ |
|
.copy = RBNAME ## _copy, \ |
|
.rotate = RBNAME ## _rotate \ |
|
}; |
|
|
|
/* |
|
* Template for declaring augmented rbtree callbacks, |
|
* computing RBAUGMENTED scalar as max(RBCOMPUTE(node)) for all subtree nodes. |
|
* |
|
* RBSTATIC: 'static' or empty |
|
* RBNAME: name of the rb_augment_callbacks structure |
|
* RBSTRUCT: struct type of the tree nodes |
|
* RBFIELD: name of struct rb_node field within RBSTRUCT |
|
* RBTYPE: type of the RBAUGMENTED field |
|
* RBAUGMENTED: name of RBTYPE field within RBSTRUCT holding data for subtree |
|
* RBCOMPUTE: name of function that returns the per-node RBTYPE scalar |
|
*/ |
|
|
|
#define RB_DECLARE_CALLBACKS_MAX(RBSTATIC, RBNAME, RBSTRUCT, RBFIELD, \ |
|
RBTYPE, RBAUGMENTED, RBCOMPUTE) \ |
|
static inline bool RBNAME ## _compute_max(RBSTRUCT *node, bool exit) \ |
|
{ \ |
|
RBSTRUCT *child; \ |
|
RBTYPE max = RBCOMPUTE(node); \ |
|
if (node->RBFIELD.rb_left) { \ |
|
child = rb_entry(node->RBFIELD.rb_left, RBSTRUCT, RBFIELD); \ |
|
if (child->RBAUGMENTED > max) \ |
|
max = child->RBAUGMENTED; \ |
|
} \ |
|
if (node->RBFIELD.rb_right) { \ |
|
child = rb_entry(node->RBFIELD.rb_right, RBSTRUCT, RBFIELD); \ |
|
if (child->RBAUGMENTED > max) \ |
|
max = child->RBAUGMENTED; \ |
|
} \ |
|
if (exit && node->RBAUGMENTED == max) \ |
|
return true; \ |
|
node->RBAUGMENTED = max; \ |
|
return false; \ |
|
} \ |
|
RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \ |
|
RBSTRUCT, RBFIELD, RBAUGMENTED, RBNAME ## _compute_max) |
|
|
|
|
|
#define RB_RED 0 |
|
#define RB_BLACK 1 |
|
|
|
#define __rb_parent(pc) ((struct rb_node *)(pc & ~3)) |
|
|
|
#define __rb_color(pc) ((pc) & 1) |
|
#define __rb_is_black(pc) __rb_color(pc) |
|
#define __rb_is_red(pc) (!__rb_color(pc)) |
|
#define rb_color(rb) __rb_color((rb)->__rb_parent_color) |
|
#define rb_is_red(rb) __rb_is_red((rb)->__rb_parent_color) |
|
#define rb_is_black(rb) __rb_is_black((rb)->__rb_parent_color) |
|
|
|
static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p) |
|
{ |
|
rb->__rb_parent_color = rb_color(rb) | (unsigned long)p; |
|
} |
|
|
|
static inline void rb_set_parent_color(struct rb_node *rb, |
|
struct rb_node *p, int color) |
|
{ |
|
rb->__rb_parent_color = (unsigned long)p | color; |
|
} |
|
|
|
static inline void |
|
__rb_change_child(struct rb_node *old, struct rb_node *new, |
|
struct rb_node *parent, struct rb_root *root) |
|
{ |
|
if (parent) { |
|
if (parent->rb_left == old) |
|
WRITE_ONCE(parent->rb_left, new); |
|
else |
|
WRITE_ONCE(parent->rb_right, new); |
|
} else |
|
WRITE_ONCE(root->rb_node, new); |
|
} |
|
|
|
extern void __rb_erase_color(struct rb_node *parent, struct rb_root *root, |
|
void (*augment_rotate)(struct rb_node *old, struct rb_node *new)); |
|
|
|
static __always_inline struct rb_node * |
|
__rb_erase_augmented(struct rb_node *node, struct rb_root *root, |
|
const struct rb_augment_callbacks *augment) |
|
{ |
|
struct rb_node *child = node->rb_right; |
|
struct rb_node *tmp = node->rb_left; |
|
struct rb_node *parent, *rebalance; |
|
unsigned long pc; |
|
|
|
if (!tmp) { |
|
/* |
|
* Case 1: node to erase has no more than 1 child (easy!) |
|
* |
|
* Note that if there is one child it must be red due to 5) |
|
* and node must be black due to 4). We adjust colors locally |
|
* so as to bypass __rb_erase_color() later on. |
|
*/ |
|
pc = node->__rb_parent_color; |
|
parent = __rb_parent(pc); |
|
__rb_change_child(node, child, parent, root); |
|
if (child) { |
|
child->__rb_parent_color = pc; |
|
rebalance = NULL; |
|
} else |
|
rebalance = __rb_is_black(pc) ? parent : NULL; |
|
tmp = parent; |
|
} else if (!child) { |
|
/* Still case 1, but this time the child is node->rb_left */ |
|
tmp->__rb_parent_color = pc = node->__rb_parent_color; |
|
parent = __rb_parent(pc); |
|
__rb_change_child(node, tmp, parent, root); |
|
rebalance = NULL; |
|
tmp = parent; |
|
} else { |
|
struct rb_node *successor = child, *child2; |
|
|
|
tmp = child->rb_left; |
|
if (!tmp) { |
|
/* |
|
* Case 2: node's successor is its right child |
|
* |
|
* (n) (s) |
|
* / \ / \ |
|
* (x) (s) -> (x) (c) |
|
* \ |
|
* (c) |
|
*/ |
|
parent = successor; |
|
child2 = successor->rb_right; |
|
|
|
augment->copy(node, successor); |
|
} else { |
|
/* |
|
* Case 3: node's successor is leftmost under |
|
* node's right child subtree |
|
* |
|
* (n) (s) |
|
* / \ / \ |
|
* (x) (y) -> (x) (y) |
|
* / / |
|
* (p) (p) |
|
* / / |
|
* (s) (c) |
|
* \ |
|
* (c) |
|
*/ |
|
do { |
|
parent = successor; |
|
successor = tmp; |
|
tmp = tmp->rb_left; |
|
} while (tmp); |
|
child2 = successor->rb_right; |
|
WRITE_ONCE(parent->rb_left, child2); |
|
WRITE_ONCE(successor->rb_right, child); |
|
rb_set_parent(child, successor); |
|
|
|
augment->copy(node, successor); |
|
augment->propagate(parent, successor); |
|
} |
|
|
|
tmp = node->rb_left; |
|
WRITE_ONCE(successor->rb_left, tmp); |
|
rb_set_parent(tmp, successor); |
|
|
|
pc = node->__rb_parent_color; |
|
tmp = __rb_parent(pc); |
|
__rb_change_child(node, successor, tmp, root); |
|
|
|
if (child2) { |
|
successor->__rb_parent_color = pc; |
|
rb_set_parent_color(child2, parent, RB_BLACK); |
|
rebalance = NULL; |
|
} else { |
|
unsigned long pc2 = successor->__rb_parent_color; |
|
successor->__rb_parent_color = pc; |
|
rebalance = __rb_is_black(pc2) ? parent : NULL; |
|
} |
|
tmp = successor; |
|
} |
|
|
|
augment->propagate(tmp, NULL); |
|
return rebalance; |
|
} |
|
|
|
static __always_inline void |
|
rb_erase_augmented(struct rb_node *node, struct rb_root *root, |
|
const struct rb_augment_callbacks *augment) |
|
{ |
|
struct rb_node *rebalance = __rb_erase_augmented(node, root, augment); |
|
if (rebalance) |
|
__rb_erase_color(rebalance, root, augment->rotate); |
|
} |
|
|
|
static __always_inline void |
|
rb_erase_augmented_cached(struct rb_node *node, struct rb_root_cached *root, |
|
const struct rb_augment_callbacks *augment) |
|
{ |
|
if (root->rb_leftmost == node) |
|
root->rb_leftmost = rb_next(node); |
|
rb_erase_augmented(node, &root->rb_root, augment); |
|
} |
|
|
|
#endif /* _TOOLS_LINUX_RBTREE_AUGMENTED_H */
|
|
|