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-rw-r--r--lib/rbtree.c116
1 files changed, 72 insertions, 44 deletions
diff --git a/lib/rbtree.c b/lib/rbtree.c
index 15e10b1afdd2..4693f79195d3 100644
--- a/lib/rbtree.c
+++ b/lib/rbtree.c
@@ -44,11 +44,6 @@ static void __rb_rotate_left(struct rb_node *node, struct rb_root *root)
else
root->rb_node = right;
rb_set_parent(node, right);
-
- if (root->augment_cb) {
- root->augment_cb(node);
- root->augment_cb(right);
- }
}
static void __rb_rotate_right(struct rb_node *node, struct rb_root *root)
@@ -72,20 +67,12 @@ static void __rb_rotate_right(struct rb_node *node, struct rb_root *root)
else
root->rb_node = left;
rb_set_parent(node, left);
-
- if (root->augment_cb) {
- root->augment_cb(node);
- root->augment_cb(left);
- }
}
void rb_insert_color(struct rb_node *node, struct rb_root *root)
{
struct rb_node *parent, *gparent;
- if (root->augment_cb)
- root->augment_cb(node);
-
while ((parent = rb_parent(node)) && rb_is_red(parent))
{
gparent = rb_parent(parent);
@@ -240,15 +227,12 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
else
{
struct rb_node *old = node, *left;
- int old_parent_cb = 0;
- int successor_parent_cb = 0;
node = node->rb_right;
while ((left = node->rb_left) != NULL)
node = left;
if (rb_parent(old)) {
- old_parent_cb = 1;
if (rb_parent(old)->rb_left == old)
rb_parent(old)->rb_left = node;
else
@@ -263,10 +247,8 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
if (parent == old) {
parent = node;
} else {
- successor_parent_cb = 1;
if (child)
rb_set_parent(child, parent);
-
parent->rb_left = child;
node->rb_right = old->rb_right;
@@ -277,24 +259,6 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
node->rb_left = old->rb_left;
rb_set_parent(old->rb_left, node);
- if (root->augment_cb) {
- /*
- * Here, three different nodes can have new children.
- * The parent of the successor node that was selected
- * to replace the node to be erased.
- * The node that is getting erased and is now replaced
- * by its successor.
- * The parent of the node getting erased-replaced.
- */
- if (successor_parent_cb)
- root->augment_cb(parent);
-
- root->augment_cb(node);
-
- if (old_parent_cb)
- root->augment_cb(rb_parent(old));
- }
-
goto color;
}
@@ -303,19 +267,15 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
if (child)
rb_set_parent(child, parent);
-
- if (parent) {
+ if (parent)
+ {
if (parent->rb_left == node)
parent->rb_left = child;
else
parent->rb_right = child;
-
- if (root->augment_cb)
- root->augment_cb(parent);
-
- } else {
- root->rb_node = child;
}
+ else
+ root->rb_node = child;
color:
if (color == RB_BLACK)
@@ -323,6 +283,74 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
}
EXPORT_SYMBOL(rb_erase);
+static void rb_augment_path(struct rb_node *node, rb_augment_f func, void *data)
+{
+ struct rb_node *parent;
+
+up:
+ func(node, data);
+ parent = rb_parent(node);
+ if (!parent)
+ return;
+
+ if (node == parent->rb_left && parent->rb_right)
+ func(parent->rb_right, data);
+ else if (parent->rb_left)
+ func(parent->rb_left, data);
+
+ node = parent;
+ goto up;
+}
+
+/*
+ * after inserting @node into the tree, update the tree to account for
+ * both the new entry and any damage done by rebalance
+ */
+void rb_augment_insert(struct rb_node *node, rb_augment_f func, void *data)
+{
+ if (node->rb_left)
+ node = node->rb_left;
+ else if (node->rb_right)
+ node = node->rb_right;
+
+ rb_augment_path(node, func, data);
+}
+
+/*
+ * before removing the node, find the deepest node on the rebalance path
+ * that will still be there after @node gets removed
+ */
+struct rb_node *rb_augment_erase_begin(struct rb_node *node)
+{
+ struct rb_node *deepest;
+
+ if (!node->rb_right && !node->rb_left)
+ deepest = rb_parent(node);
+ else if (!node->rb_right)
+ deepest = node->rb_left;
+ else if (!node->rb_left)
+ deepest = node->rb_right;
+ else {
+ deepest = rb_next(node);
+ if (deepest->rb_right)
+ deepest = deepest->rb_right;
+ else if (rb_parent(deepest) != node)
+ deepest = rb_parent(deepest);
+ }
+
+ return deepest;
+}
+
+/*
+ * after removal, update the tree to account for the removed entry
+ * and any rebalance damage.
+ */
+void rb_augment_erase_end(struct rb_node *node, rb_augment_f func, void *data)
+{
+ if (node)
+ rb_augment_path(node, func, data);
+}
+
/*
* This function returns the first node (in sort order) of the tree.
*/
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