diff options
Diffstat (limited to 'linux-2.4.x/fs/jffs2/rbtree.c')
-rw-r--r-- | linux-2.4.x/fs/jffs2/rbtree.c | 363 |
1 files changed, 363 insertions, 0 deletions
diff --git a/linux-2.4.x/fs/jffs2/rbtree.c b/linux-2.4.x/fs/jffs2/rbtree.c new file mode 100644 index 0000000..de0bb6a --- /dev/null +++ b/linux-2.4.x/fs/jffs2/rbtree.c @@ -0,0 +1,363 @@ +/* + Red Black Trees + (C) 1999 Andrea Arcangeli <andrea@suse.de> + (C) 2002 David Woodhouse <dwmw2@infradead.org> + + 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 + + $Id: rbtree.c,v 1.4 2005/11/07 11:14:41 gleixner Exp $ +*/ + +#ifdef __ECOS /* This file is _not_ under the eCos licence; it is pure GPL. */ +#error "Licence problem. eCos has its own rbtree code." +#endif + +#include <linux/version.h> +#include <linux/rbtree.h> + +/* This wasn't present till 2.4.11, wasn't exported till 2.4.19 */ +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,11) || \ + (LINUX_VERSION_CODE < KERNEL_VERSION(2,4,19) && defined(MODULE)) +static void __rb_rotate_left(struct rb_node * node, struct rb_root * root) +{ + struct rb_node * right = node->rb_right; + + if ((node->rb_right = right->rb_left)) + right->rb_left->rb_parent = node; + right->rb_left = node; + + if ((right->rb_parent = node->rb_parent)) + { + if (node == node->rb_parent->rb_left) + node->rb_parent->rb_left = right; + else + node->rb_parent->rb_right = right; + } + else + root->rb_node = right; + node->rb_parent = right; +} + +static void __rb_rotate_right(struct rb_node * node, struct rb_root * root) +{ + struct rb_node * left = node->rb_left; + + if ((node->rb_left = left->rb_right)) + left->rb_right->rb_parent = node; + left->rb_right = node; + + if ((left->rb_parent = node->rb_parent)) + { + if (node == node->rb_parent->rb_right) + node->rb_parent->rb_right = left; + else + node->rb_parent->rb_left = left; + } + else + root->rb_node = left; + node->rb_parent = left; +} + +void rb_insert_color(struct rb_node * node, struct rb_root * root) +{ + struct rb_node * parent, * gparent; + + while ((parent = node->rb_parent) && parent->rb_color == RB_RED) + { + gparent = parent->rb_parent; + + if (parent == gparent->rb_left) + { + { + register struct rb_node * uncle = gparent->rb_right; + if (uncle && uncle->rb_color == RB_RED) + { + uncle->rb_color = RB_BLACK; + parent->rb_color = RB_BLACK; + gparent->rb_color = RB_RED; + node = gparent; + continue; + } + } + + if (parent->rb_right == node) + { + register struct rb_node * tmp; + __rb_rotate_left(parent, root); + tmp = parent; + parent = node; + node = tmp; + } + + parent->rb_color = RB_BLACK; + gparent->rb_color = RB_RED; + __rb_rotate_right(gparent, root); + } else { + { + register struct rb_node * uncle = gparent->rb_left; + if (uncle && uncle->rb_color == RB_RED) + { + uncle->rb_color = RB_BLACK; + parent->rb_color = RB_BLACK; + gparent->rb_color = RB_RED; + node = gparent; + continue; + } + } + + if (parent->rb_left == node) + { + register struct rb_node * tmp; + __rb_rotate_right(parent, root); + tmp = parent; + parent = node; + node = tmp; + } + + parent->rb_color = RB_BLACK; + gparent->rb_color = RB_RED; + __rb_rotate_left(gparent, root); + } + } + + root->rb_node->rb_color = RB_BLACK; +} + +static void __rb_erase_color(struct rb_node * node, struct rb_node * parent, + struct rb_root * root) +{ + struct rb_node * other; + + while ((!node || node->rb_color == RB_BLACK) && node != root->rb_node) + { + if (parent->rb_left == node) + { + other = parent->rb_right; + if (other->rb_color == RB_RED) + { + other->rb_color = RB_BLACK; + parent->rb_color = RB_RED; + __rb_rotate_left(parent, root); + other = parent->rb_right; + } + if ((!other->rb_left || + other->rb_left->rb_color == RB_BLACK) + && (!other->rb_right || + other->rb_right->rb_color == RB_BLACK)) + { + other->rb_color = RB_RED; + node = parent; + parent = node->rb_parent; + } + else + { + if (!other->rb_right || + other->rb_right->rb_color == RB_BLACK) + { + register struct rb_node * o_left; + if ((o_left = other->rb_left)) + o_left->rb_color = RB_BLACK; + other->rb_color = RB_RED; + __rb_rotate_right(other, root); + other = parent->rb_right; + } + other->rb_color = parent->rb_color; + parent->rb_color = RB_BLACK; + if (other->rb_right) + other->rb_right->rb_color = RB_BLACK; + __rb_rotate_left(parent, root); + node = root->rb_node; + break; + } + } + else + { + other = parent->rb_left; + if (other->rb_color == RB_RED) + { + other->rb_color = RB_BLACK; + parent->rb_color = RB_RED; + __rb_rotate_right(parent, root); + other = parent->rb_left; + } + if ((!other->rb_left || + other->rb_left->rb_color == RB_BLACK) + && (!other->rb_right || + other->rb_right->rb_color == RB_BLACK)) + { + other->rb_color = RB_RED; + node = parent; + parent = node->rb_parent; + } + else + { + if (!other->rb_left || + other->rb_left->rb_color == RB_BLACK) + { + register struct rb_node * o_right; + if ((o_right = other->rb_right)) + o_right->rb_color = RB_BLACK; + other->rb_color = RB_RED; + __rb_rotate_left(other, root); + other = parent->rb_left; + } + other->rb_color = parent->rb_color; + parent->rb_color = RB_BLACK; + if (other->rb_left) + other->rb_left->rb_color = RB_BLACK; + __rb_rotate_right(parent, root); + node = root->rb_node; + break; + } + } + } + if (node) + node->rb_color = RB_BLACK; +} + +void rb_erase(struct rb_node * node, struct rb_root * root) +{ + struct rb_node * child, * parent; + int color; + + if (!node->rb_left) + child = node->rb_right; + else if (!node->rb_right) + child = node->rb_left; + else + { + struct rb_node * old = node, * left; + + node = node->rb_right; + while ((left = node->rb_left)) + node = left; + child = node->rb_right; + parent = node->rb_parent; + color = node->rb_color; + + if (child) + child->rb_parent = parent; + if (parent) + { + if (parent->rb_left == node) + parent->rb_left = child; + else + parent->rb_right = child; + } + else + root->rb_node = child; + + if (node->rb_parent == old) + parent = node; + node->rb_parent = old->rb_parent; + node->rb_color = old->rb_color; + node->rb_right = old->rb_right; + node->rb_left = old->rb_left; + + if (old->rb_parent) + { + if (old->rb_parent->rb_left == old) + old->rb_parent->rb_left = node; + else + old->rb_parent->rb_right = node; + } else + root->rb_node = node; + + old->rb_left->rb_parent = node; + if (old->rb_right) + old->rb_right->rb_parent = node; + goto color; + } + + parent = node->rb_parent; + color = node->rb_color; + + if (child) + child->rb_parent = parent; + if (parent) + { + if (parent->rb_left == node) + parent->rb_left = child; + else + parent->rb_right = child; + } + else + root->rb_node = child; + + color: + if (color == RB_BLACK) + __rb_erase_color(child, parent, root); +} +#endif /* Before 2.4.11 */ + + /* These routines haven't made it into 2.4 (yet) */ +struct rb_node *rb_next(struct rb_node *node) +{ + /* If we have a right-hand child, go down and then left as far + as we can. */ + if (node->rb_right) { + node = node->rb_right; + while (node->rb_left) + node=node->rb_left; + return node; + } + + /* No right-hand children. Everything down and left is + smaller than us, so any 'next' node must be in the general + direction of our parent. Go up the tree; any time the + ancestor is a right-hand child of its parent, keep going + up. First time it's a left-hand child of its parent, said + parent is our 'next' node. */ + while (node->rb_parent && node == node->rb_parent->rb_right) + node = node->rb_parent; + + return node->rb_parent; +} + +struct rb_node *rb_prev(struct rb_node *node) +{ + if (node->rb_left) { + node = node->rb_left; + while (node->rb_right) + node=node->rb_right; + return node; + } + while (node->rb_parent && node == node->rb_parent->rb_left) + node = node->rb_parent; + + return node->rb_parent; +} + +void rb_replace_node(struct rb_node *victim, struct rb_node *new, struct rb_root *root) +{ + struct rb_node *parent = victim->rb_parent; + + /* Set the surrounding nodes to point to the replacement */ + if (parent) { + if (victim == parent->rb_left) + parent->rb_left = new; + else + parent->rb_right = new; + } else { + root->rb_node = new; + } + if (victim->rb_left) + victim->rb_left->rb_parent = new; + if (victim->rb_right) + victim->rb_right->rb_parent = new; + + /* Copy the pointers/colour from the victim to the replacement */ + *new = *victim; +} |