[CRIU] [PATCH 05/10] Add rbtree helpers
Cyrill Gorcunov
gorcunov at openvz.org
Fri Feb 24 18:24:26 EST 2012
Signed-off-by: Cyrill Gorcunov <gorcunov at openvz.org>
---
Makefile | 1 +
include/rbtree.h | 85 +++++++++++++
rbtree.c | 356 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 442 insertions(+), 0 deletions(-)
create mode 100644 include/rbtree.h
create mode 100644 rbtree.c
diff --git a/Makefile b/Makefile
index 748a649..00d731f 100644
--- a/Makefile
+++ b/Makefile
@@ -36,6 +36,7 @@ OBJS += util.o
OBJS += util-net.o
OBJS += sysctl.o
OBJS += ptrace.o
+OBJS += rbtree.o
OBJS += log.o
OBJS += libnetlink.o
OBJS += sockets.o
diff --git a/include/rbtree.h b/include/rbtree.h
new file mode 100644
index 0000000..1d56bb0
--- /dev/null
+++ b/include/rbtree.h
@@ -0,0 +1,85 @@
+/*
+ * RBtree implementation adopted from the Linux kernel sources.
+ */
+
+#ifndef RBTREE_H__
+#define RBTREE_H__
+
+#include <stddef.h>
+
+#include "compiler.h"
+#include "types.h"
+
+#define RB_RED 0
+#define RB_BLACK 1
+#define RB_MASK 3
+
+struct rb_node {
+ unsigned long rb_parent_color; /* Keeps both parent anc color */
+ struct rb_node *rb_right;
+ struct rb_node *rb_left;
+} __aligned(sizeof(long));
+
+struct rb_root {
+ struct rb_node *rb_node;
+};
+
+#define rb_parent(r) ((struct rb_node *)((r)->rb_parent_color & ~RB_MASK))
+#define rb_color(r) ((r)->rb_parent_color & RB_BLACK)
+#define rb_is_red(r) (!rb_color(r))
+#define rb_is_black(r) (rb_color(r))
+#define rb_set_red(r) do { (r)->rb_parent_color &= ~RB_BLACK; } while (0)
+#define rb_set_black(r) do { (r)->rb_parent_color |= RB_BLACK; } while (0)
+
+static void rb_set_parent(struct rb_node *rb, struct rb_node *p)
+{
+ rb->rb_parent_color = (rb->rb_parent_color & RB_MASK) | (unsigned long)p;
+}
+
+static void rb_set_color(struct rb_node *rb, int color)
+{
+ rb->rb_parent_color = (rb->rb_parent_color & ~RB_BLACK) | color;
+}
+
+#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)
+#define RB_EMPTY_NODE(node) (rb_parent(node) == node)
+#define RB_CLEAR_NODE(node) (rb_set_parent(node, node))
+
+static void rb_init_node(struct rb_node *node)
+{
+ *node = (struct rb_node){ };
+
+ RB_CLEAR_NODE(node);
+}
+
+static void rb_attach_node(struct rb_root *root, struct rb_node *node)
+{
+ root->rb_node = node;
+}
+
+extern void rb_insert_color(struct rb_node *node, struct rb_root *root);
+extern void rb_erase(struct rb_node *node, struct rb_root *root);
+
+/* Find logical next and previous nodes in a tree */
+extern struct rb_node *rb_first(const struct rb_root *root);
+extern struct rb_node *rb_last(const struct rb_root *root);
+extern struct rb_node *rb_next(const struct rb_node *node);
+extern struct rb_node *rb_prev(const struct rb_node *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);
+
+static 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;
+}
+
+#endif /* RBTREE_H__ */
diff --git a/rbtree.c b/rbtree.c
new file mode 100644
index 0000000..5a60757
--- /dev/null
+++ b/rbtree.c
@@ -0,0 +1,356 @@
+/*
+ * RBtree implementation adopted from the Linux kernel sources.
+ */
+
+#include "rbtree.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);
+
+ node->rb_right = right->rb_left;
+ if (node->rb_right)
+ 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);
+
+ node->rb_left = left->rb_right;
+ if (node->rb_left)
+ 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))
+ 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;
+}
--
1.7.7.6
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