From eb34f70aa8288124da89838c7a71f2a49fb8def5 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Tue, 18 Dec 2012 11:58:36 -0600 Subject: [PATCH] rbtree code: Reorganize and delete some unneeded stuff --- src/rbtree.c | 397 ++++++++++++++++++++++++++++------------- src/rbtree.h | 27 +-- src/rbtree_augmented.h | 224 ----------------------- 3 files changed, 271 insertions(+), 377 deletions(-) delete mode 100644 src/rbtree_augmented.h diff --git a/src/rbtree.c b/src/rbtree.c index 90e467d7..71a2c533 100644 --- a/src/rbtree.c +++ b/src/rbtree.c @@ -21,8 +21,7 @@ linux/lib/rbtree.c */ -#include "rbtree_augmented.h" -#include "util.h" +#include "rbtree.h" /* * red-black trees properties: http://en.wikipedia.org/wiki/Rbtree @@ -44,6 +43,35 @@ * parentheses and have some accompanying text comment. */ +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); +}; + +#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_set_black(struct rb_node *rb) { rb->__rb_parent_color |= RB_BLACK; @@ -54,6 +82,19 @@ static inline struct rb_node *rb_red_parent(struct rb_node *red) return (struct rb_node *)red->__rb_parent_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) + parent->rb_left = new; + else + parent->rb_right = new; + } else + root->rb_node = new; +} + /* * Helper function for rotations: * - old's parent and color get assigned to new @@ -69,132 +110,7 @@ __rb_rotate_set_parents(struct rb_node *old, struct rb_node *new, __rb_change_child(old, new, parent, root); } -static ALWAYS_INLINE void -__rb_insert(struct rb_node *node, struct rb_root *root, - void (*augment_rotate)(struct rb_node *old, struct rb_node *new)) -{ - struct rb_node *parent = rb_red_parent(node), *gparent, *tmp; - - while (true) { - /* - * Loop invariant: node is red - * - * If there is a black parent, we are done. - * Otherwise, take some corrective action as we don't - * want a red root or two consecutive red nodes. - */ - if (!parent) { - rb_set_parent_color(node, NULL, RB_BLACK); - break; - } else if (rb_is_black(parent)) - break; - - gparent = rb_red_parent(parent); - - tmp = gparent->rb_right; - if (parent != tmp) { /* parent == gparent->rb_left */ - if (tmp && rb_is_red(tmp)) { - /* - * Case 1 - color flips - * - * G g - * / \ / \ - * p u --> P U - * / / - * n N - * - * However, since g's parent might be red, and - * 4) does not allow this, we need to recurse - * at g. - */ - rb_set_parent_color(tmp, gparent, RB_BLACK); - rb_set_parent_color(parent, gparent, RB_BLACK); - node = gparent; - parent = rb_parent(node); - rb_set_parent_color(node, parent, RB_RED); - continue; - } - - tmp = parent->rb_right; - if (node == tmp) { - /* - * Case 2 - left rotate at parent - * - * G G - * / \ / \ - * p U --> n U - * \ / - * n p - * - * This still leaves us in violation of 4), the - * continuation into Case 3 will fix that. - */ - parent->rb_right = tmp = node->rb_left; - node->rb_left = parent; - if (tmp) - rb_set_parent_color(tmp, parent, - RB_BLACK); - rb_set_parent_color(parent, node, RB_RED); - augment_rotate(parent, node); - parent = node; - tmp = node->rb_right; - } - - /* - * Case 3 - right rotate at gparent - * - * G P - * / \ / \ - * p U --> n g - * / \ - * n U - */ - gparent->rb_left = tmp; /* == parent->rb_right */ - parent->rb_right = gparent; - if (tmp) - rb_set_parent_color(tmp, gparent, RB_BLACK); - __rb_rotate_set_parents(gparent, parent, root, RB_RED); - augment_rotate(gparent, parent); - break; - } else { - tmp = gparent->rb_left; - if (tmp && rb_is_red(tmp)) { - /* Case 1 - color flips */ - rb_set_parent_color(tmp, gparent, RB_BLACK); - rb_set_parent_color(parent, gparent, RB_BLACK); - node = gparent; - parent = rb_parent(node); - rb_set_parent_color(node, parent, RB_RED); - continue; - } - - tmp = parent->rb_left; - if (node == tmp) { - /* Case 2 - right rotate at parent */ - parent->rb_left = tmp = node->rb_right; - node->rb_right = parent; - if (tmp) - rb_set_parent_color(tmp, parent, - RB_BLACK); - rb_set_parent_color(parent, node, RB_RED); - augment_rotate(parent, node); - parent = node; - tmp = node->rb_left; - } - - /* Case 3 - left rotate at gparent */ - gparent->rb_right = tmp; /* == parent->rb_left */ - parent->rb_left = gparent; - if (tmp) - rb_set_parent_color(tmp, gparent, RB_BLACK); - __rb_rotate_set_parents(gparent, parent, root, RB_RED); - augment_rotate(gparent, parent); - break; - } - } -} - -ALWAYS_INLINE void +static inline void __rb_erase_color(struct rb_node *parent, struct rb_root *root, void (*augment_rotate)(struct rb_node *old, struct rb_node *new)) { @@ -356,6 +272,231 @@ __rb_erase_color(struct rb_node *parent, struct rb_root *root, } } +static inline void +rb_erase_augmented(struct rb_node *node, struct rb_root *root, + const struct rb_augment_callbacks *augment) +{ + struct rb_node *child = node->rb_right, *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); + parent->rb_left = child2 = successor->rb_right; + successor->rb_right = child; + rb_set_parent(child, successor); + augment->copy(node, successor); + augment->propagate(parent, successor); + } + + successor->rb_left = tmp = node->rb_left; + 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); + if (rebalance) + __rb_erase_color(rebalance, root, augment->rotate); +} + + +static inline void +__rb_insert(struct rb_node *node, struct rb_root *root, + void (*augment_rotate)(struct rb_node *old, struct rb_node *new)) +{ + struct rb_node *parent = rb_red_parent(node), *gparent, *tmp; + + while (true) { + /* + * Loop invariant: node is red + * + * If there is a black parent, we are done. + * Otherwise, take some corrective action as we don't + * want a red root or two consecutive red nodes. + */ + if (!parent) { + rb_set_parent_color(node, NULL, RB_BLACK); + break; + } else if (rb_is_black(parent)) + break; + + gparent = rb_red_parent(parent); + + tmp = gparent->rb_right; + if (parent != tmp) { /* parent == gparent->rb_left */ + if (tmp && rb_is_red(tmp)) { + /* + * Case 1 - color flips + * + * G g + * / \ / \ + * p u --> P U + * / / + * n N + * + * However, since g's parent might be red, and + * 4) does not allow this, we need to recurse + * at g. + */ + rb_set_parent_color(tmp, gparent, RB_BLACK); + rb_set_parent_color(parent, gparent, RB_BLACK); + node = gparent; + parent = rb_parent(node); + rb_set_parent_color(node, parent, RB_RED); + continue; + } + + tmp = parent->rb_right; + if (node == tmp) { + /* + * Case 2 - left rotate at parent + * + * G G + * / \ / \ + * p U --> n U + * \ / + * n p + * + * This still leaves us in violation of 4), the + * continuation into Case 3 will fix that. + */ + parent->rb_right = tmp = node->rb_left; + node->rb_left = parent; + if (tmp) + rb_set_parent_color(tmp, parent, + RB_BLACK); + rb_set_parent_color(parent, node, RB_RED); + augment_rotate(parent, node); + parent = node; + tmp = node->rb_right; + } + + /* + * Case 3 - right rotate at gparent + * + * G P + * / \ / \ + * p U --> n g + * / \ + * n U + */ + gparent->rb_left = tmp; /* == parent->rb_right */ + parent->rb_right = gparent; + if (tmp) + rb_set_parent_color(tmp, gparent, RB_BLACK); + __rb_rotate_set_parents(gparent, parent, root, RB_RED); + augment_rotate(gparent, parent); + break; + } else { + tmp = gparent->rb_left; + if (tmp && rb_is_red(tmp)) { + /* Case 1 - color flips */ + rb_set_parent_color(tmp, gparent, RB_BLACK); + rb_set_parent_color(parent, gparent, RB_BLACK); + node = gparent; + parent = rb_parent(node); + rb_set_parent_color(node, parent, RB_RED); + continue; + } + + tmp = parent->rb_left; + if (node == tmp) { + /* Case 2 - right rotate at parent */ + parent->rb_left = tmp = node->rb_right; + node->rb_right = parent; + if (tmp) + rb_set_parent_color(tmp, parent, + RB_BLACK); + rb_set_parent_color(parent, node, RB_RED); + augment_rotate(parent, node); + parent = node; + tmp = node->rb_left; + } + + /* Case 3 - left rotate at gparent */ + gparent->rb_right = tmp; /* == parent->rb_left */ + parent->rb_left = gparent; + if (tmp) + rb_set_parent_color(tmp, gparent, RB_BLACK); + __rb_rotate_set_parents(gparent, parent, root, RB_RED); + augment_rotate(gparent, parent); + break; + } + } +} + + /* * Non-augmented rbtree manipulation functions. * diff --git a/src/rbtree.h b/src/rbtree.h index 3fa0f16c..583230e0 100644 --- a/src/rbtree.h +++ b/src/rbtree.h @@ -29,14 +29,13 @@ #ifndef _LINUX_RBTREE_H #define _LINUX_RBTREE_H -#include +#include "util.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; @@ -44,33 +43,11 @@ struct rb_root { #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) ((root)->rb_node == NULL) - -/* 'empty' nodes are nodes that are known not to be inserted in an rbree */ -#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 *); - -/* 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) { diff --git a/src/rbtree_augmented.h b/src/rbtree_augmented.h deleted file mode 100644 index 9bca3bbc..00000000 --- a/src/rbtree_augmented.h +++ /dev/null @@ -1,224 +0,0 @@ -/* - Red Black Trees - (C) 1999 Andrea Arcangeli - (C) 2002 David Woodhouse - (C) 2012 Michel Lespinasse - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or - (at your option) any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - - linux/include/linux/rbtree_augmented.h -*/ - -#ifndef _LINUX_RBTREE_AUGMENTED_H -#define _LINUX_RBTREE_AUGMENTED_H - -#include "rbtree.h" -#include "util.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/rbtree.txt 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)); -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); -} - -#define RB_DECLARE_CALLBACKS(rbstatic, rbname, rbstruct, rbfield, \ - rbtype, 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); \ - rbtype augmented = rbcompute(node); \ - if (node->rbaugmented == augmented) \ - break; \ - node->rbaugmented = augmented; \ - 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; \ - old->rbaugmented = rbcompute(old); \ -} \ -rbstatic const struct rb_augment_callbacks rbname = { \ - rbname ## _propagate, rbname ## _copy, rbname ## _rotate \ -}; - - -#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) - parent->rb_left = new; - else - parent->rb_right = new; - } else - 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 void -rb_erase_augmented(struct rb_node *node, struct rb_root *root, - const struct rb_augment_callbacks *augment) -{ - struct rb_node *child = node->rb_right, *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); - parent->rb_left = child2 = successor->rb_right; - successor->rb_right = child; - rb_set_parent(child, successor); - augment->copy(node, successor); - augment->propagate(parent, successor); - } - - successor->rb_left = tmp = node->rb_left; - 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); - if (rebalance) - __rb_erase_color(rebalance, root, augment->rotate); -} - -#endif /* _LINUX_RBTREE_AUGMENTED_H */ -- 2.43.0