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authorPau Espin Pedrol <pespin@sysmocom.de>2023-01-18 17:04:04 +0100
committerPau Espin Pedrol <pespin@sysmocom.de>2023-01-18 17:14:06 +0100
commitd4c3dc8d59a809cff277bba5e5fe19dd6604deec (patch)
treea50d6f7a3147c99ae9d9020afa421febb21f6d65 /src/core/rbtree.c
parentcc296c9293dc9d0e1f198485f5f744b0086b5826 (diff)
Move src/*.{c,h} to src/core/
This way we have all libosmocore.so in an own subdir instead of having lots of files in the parent dir, which also contains subdirs to other libraries. This also matches the schema under include/osmocom/. Change-Id: I6c76fafebdd5e961aed88bbecd2c16bc69d580e2
Diffstat (limited to 'src/core/rbtree.c')
-rw-r--r--src/core/rbtree.c381
1 files changed, 381 insertions, 0 deletions
diff --git a/src/core/rbtree.c b/src/core/rbtree.c
new file mode 100644
index 00000000..f4dc219b
--- /dev/null
+++ b/src/core/rbtree.c
@@ -0,0 +1,381 @@
+/*
+ Red Black Trees
+ (C) 1999 Andrea Arcangeli <andrea@suse.de>
+ (C) 2002 David Woodhouse <dwmw2@infradead.org>
+
+ SPDX-License-Identifier: GPL-2.0+
+
+ 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.
+
+ linux/lib/rbtree.c
+*/
+
+#include <osmocom/core/linuxrbtree.h>
+
+static void __rb_rotate_left(struct rb_node *node, struct rb_root *root)
+{
+ struct rb_node *right = node->rb_right;
+ struct rb_node *parent = rb_parent(node);
+
+ if ((node->rb_right = right->rb_left))
+ rb_set_parent(right->rb_left, node);
+ right->rb_left = node;
+
+ rb_set_parent(right, parent);
+
+ if (parent)
+ {
+ if (node == parent->rb_left)
+ parent->rb_left = right;
+ else
+ parent->rb_right = right;
+ }
+ else
+ root->rb_node = right;
+ rb_set_parent(node, right);
+}
+
+static void __rb_rotate_right(struct rb_node *node, struct rb_root *root)
+{
+ struct rb_node *left = node->rb_left;
+ struct rb_node *parent = rb_parent(node);
+
+ if ((node->rb_left = left->rb_right))
+ rb_set_parent(left->rb_right, node);
+ left->rb_right = node;
+
+ rb_set_parent(left, parent);
+
+ if (parent)
+ {
+ if (node == parent->rb_right)
+ parent->rb_right = left;
+ else
+ parent->rb_left = left;
+ }
+ else
+ root->rb_node = left;
+ rb_set_parent(node, left);
+}
+
+void rb_insert_color(struct rb_node *node, struct rb_root *root)
+{
+ struct rb_node *parent, *gparent;
+
+ while ((parent = rb_parent(node)) && rb_is_red(parent))
+ {
+ gparent = rb_parent(parent);
+
+ if (parent == gparent->rb_left)
+ {
+ {
+ register struct rb_node *uncle = gparent->rb_right;
+ if (uncle && rb_is_red(uncle))
+ {
+ rb_set_black(uncle);
+ rb_set_black(parent);
+ rb_set_red(gparent);
+ node = gparent;
+ continue;
+ }
+ }
+
+ if (parent->rb_right == node)
+ {
+ register struct rb_node *tmp;
+ __rb_rotate_left(parent, root);
+ tmp = parent;
+ parent = node;
+ node = tmp;
+ }
+
+ rb_set_black(parent);
+ rb_set_red(gparent);
+ __rb_rotate_right(gparent, root);
+ } else {
+ {
+ register struct rb_node *uncle = gparent->rb_left;
+ if (uncle && rb_is_red(uncle))
+ {
+ rb_set_black(uncle);
+ rb_set_black(parent);
+ rb_set_red(gparent);
+ node = gparent;
+ continue;
+ }
+ }
+
+ if (parent->rb_left == node)
+ {
+ register struct rb_node *tmp;
+ __rb_rotate_right(parent, root);
+ tmp = parent;
+ parent = node;
+ node = tmp;
+ }
+
+ rb_set_black(parent);
+ rb_set_red(gparent);
+ __rb_rotate_left(gparent, root);
+ }
+ }
+
+ rb_set_black(root->rb_node);
+}
+
+static void __rb_erase_color(struct rb_node *node, struct rb_node *parent,
+ struct rb_root *root)
+{
+ struct rb_node *other;
+
+ while ((!node || rb_is_black(node)) && node != root->rb_node)
+ {
+ if (parent->rb_left == node)
+ {
+ other = parent->rb_right;
+ if (rb_is_red(other))
+ {
+ rb_set_black(other);
+ rb_set_red(parent);
+ __rb_rotate_left(parent, root);
+ other = parent->rb_right;
+ }
+ if ((!other->rb_left || rb_is_black(other->rb_left)) &&
+ (!other->rb_right || rb_is_black(other->rb_right)))
+ {
+ rb_set_red(other);
+ node = parent;
+ parent = rb_parent(node);
+ }
+ else
+ {
+ if (!other->rb_right || rb_is_black(other->rb_right))
+ {
+ rb_set_black(other->rb_left);
+ rb_set_red(other);
+ __rb_rotate_right(other, root);
+ other = parent->rb_right;
+ }
+ rb_set_color(other, rb_color(parent));
+ rb_set_black(parent);
+ rb_set_black(other->rb_right);
+ __rb_rotate_left(parent, root);
+ node = root->rb_node;
+ break;
+ }
+ }
+ else
+ {
+ other = parent->rb_left;
+ if (rb_is_red(other))
+ {
+ rb_set_black(other);
+ rb_set_red(parent);
+ __rb_rotate_right(parent, root);
+ other = parent->rb_left;
+ }
+ if ((!other->rb_left || rb_is_black(other->rb_left)) &&
+ (!other->rb_right || rb_is_black(other->rb_right)))
+ {
+ rb_set_red(other);
+ node = parent;
+ parent = rb_parent(node);
+ }
+ else
+ {
+ if (!other->rb_left || rb_is_black(other->rb_left))
+ {
+ rb_set_black(other->rb_right);
+ rb_set_red(other);
+ __rb_rotate_left(other, root);
+ other = parent->rb_left;
+ }
+ rb_set_color(other, rb_color(parent));
+ rb_set_black(parent);
+ rb_set_black(other->rb_left);
+ __rb_rotate_right(parent, root);
+ node = root->rb_node;
+ break;
+ }
+ }
+ }
+ if (node)
+ rb_set_black(node);
+}
+
+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) != NULL)
+ node = left;
+
+ if (rb_parent(old)) {
+ if (rb_parent(old)->rb_left == old)
+ rb_parent(old)->rb_left = node;
+ else
+ rb_parent(old)->rb_right = node;
+ } else
+ root->rb_node = node;
+
+ child = node->rb_right;
+ parent = rb_parent(node);
+ color = rb_color(node);
+
+ if (parent == old) {
+ parent = node;
+ } else {
+ if (child)
+ rb_set_parent(child, parent);
+ parent->rb_left = child;
+
+ node->rb_right = old->rb_right;
+ rb_set_parent(old->rb_right, node);
+ }
+
+ node->rb_parent_color = old->rb_parent_color;
+ node->rb_left = old->rb_left;
+ rb_set_parent(old->rb_left, node);
+
+ goto color;
+ }
+
+ parent = rb_parent(node);
+ color = rb_color(node);
+
+ if (child)
+ rb_set_parent(child, 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);
+}
+
+/*
+ * This function returns the first node (in sort order) of the tree.
+ */
+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;
+}
+
+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;
+}
+
+struct rb_node *rb_next(const struct rb_node *node)
+{
+ struct rb_node *parent;
+
+ if (rb_parent(node) == node)
+ return NULL;
+
+ /* 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 (struct rb_node *)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 ((parent = rb_parent(node)) && node == parent->rb_right)
+ node = parent;
+
+ return parent;
+}
+
+struct rb_node *rb_prev(const struct rb_node *node)
+{
+ struct rb_node *parent;
+
+ if (rb_parent(node) == node)
+ return NULL;
+
+ /* If we have a left-hand child, go down and then right as far
+ as we can. */
+ if (node->rb_left) {
+ node = node->rb_left;
+ while (node->rb_right)
+ node=node->rb_right;
+ return (struct rb_node *)node;
+ }
+
+ /* No left-hand children. Go up till we find an ancestor which
+ is a right-hand child of its parent */
+ while ((parent = rb_parent(node)) && node == parent->rb_left)
+ node = parent;
+
+ return parent;
+}
+
+void rb_replace_node(struct rb_node *victim, struct rb_node *new,
+ struct rb_root *root)
+{
+ struct rb_node *parent = rb_parent(victim);
+
+ /* 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)
+ rb_set_parent(victim->rb_left, new);
+ if (victim->rb_right)
+ rb_set_parent(victim->rb_right, new);
+
+ /* Copy the pointers/colour from the victim to the replacement */
+ *new = *victim;
+}