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-rw-r--r--lib/rbtree.c83
-rw-r--r--lib/rbtree_test.c58
2 files changed, 120 insertions, 21 deletions
diff --git a/lib/rbtree.c b/lib/rbtree.c
index 938061ecbe61..a37ee7954b8f 100644
--- a/lib/rbtree.c
+++ b/lib/rbtree.c
@@ -105,7 +105,9 @@ __rb_rotate_set_parents(struct rb_node *old, struct rb_node *new,
__rb_change_child(old, new, parent, root);
}
-void rb_insert_color(struct rb_node *node, struct rb_root *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;
@@ -169,6 +171,7 @@ void rb_insert_color(struct rb_node *node, struct rb_root *root)
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;
}
@@ -187,6 +190,7 @@ void rb_insert_color(struct rb_node *node, struct rb_root *root)
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;
@@ -209,6 +213,7 @@ void rb_insert_color(struct rb_node *node, struct rb_root *root)
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;
}
@@ -219,13 +224,15 @@ void rb_insert_color(struct rb_node *node, struct rb_root *root)
if (tmp)
rb_set_parent_color(tmp, gparent, RB_BLACK);
__rb_rotate_set_parents(gparent, parent, root, RB_RED);
+ augment_rotate(gparent, parent);
break;
}
}
}
-EXPORT_SYMBOL(rb_insert_color);
-static void __rb_erase_color(struct rb_node *parent, struct rb_root *root)
+static __always_inline void
+__rb_erase_color(struct rb_node *parent, struct rb_root *root,
+ const struct rb_augment_callbacks *augment)
{
struct rb_node *node = NULL, *sibling, *tmp1, *tmp2;
@@ -254,6 +261,7 @@ static void __rb_erase_color(struct rb_node *parent, struct rb_root *root)
rb_set_parent_color(tmp1, parent, RB_BLACK);
__rb_rotate_set_parents(parent, sibling, root,
RB_RED);
+ augment->rotate(parent, sibling);
sibling = tmp1;
}
tmp1 = sibling->rb_right;
@@ -305,6 +313,7 @@ static void __rb_erase_color(struct rb_node *parent, struct rb_root *root)
if (tmp1)
rb_set_parent_color(tmp1, sibling,
RB_BLACK);
+ augment->rotate(sibling, tmp2);
tmp1 = sibling;
sibling = tmp2;
}
@@ -327,6 +336,7 @@ static void __rb_erase_color(struct rb_node *parent, struct rb_root *root)
rb_set_parent(tmp2, parent);
__rb_rotate_set_parents(parent, sibling, root,
RB_BLACK);
+ augment->rotate(parent, sibling);
break;
} else {
sibling = parent->rb_left;
@@ -337,6 +347,7 @@ static void __rb_erase_color(struct rb_node *parent, struct rb_root *root)
rb_set_parent_color(tmp1, parent, RB_BLACK);
__rb_rotate_set_parents(parent, sibling, root,
RB_RED);
+ augment->rotate(parent, sibling);
sibling = tmp1;
}
tmp1 = sibling->rb_left;
@@ -363,6 +374,7 @@ static void __rb_erase_color(struct rb_node *parent, struct rb_root *root)
if (tmp1)
rb_set_parent_color(tmp1, sibling,
RB_BLACK);
+ augment->rotate(sibling, tmp2);
tmp1 = sibling;
sibling = tmp2;
}
@@ -374,12 +386,15 @@ static void __rb_erase_color(struct rb_node *parent, struct rb_root *root)
rb_set_parent(tmp2, parent);
__rb_rotate_set_parents(parent, sibling, root,
RB_BLACK);
+ augment->rotate(parent, sibling);
break;
}
}
}
-void rb_erase(struct rb_node *node, struct rb_root *root)
+static __always_inline void
+__rb_erase(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;
@@ -401,12 +416,14 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
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;
@@ -420,8 +437,9 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
* \
* (c)
*/
- parent = child;
- child2 = child->rb_right;
+ parent = successor;
+ child2 = successor->rb_right;
+ augment->copy(node, successor);
} else {
/*
* Case 3: node's successor is leftmost under
@@ -445,6 +463,8 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
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;
@@ -462,13 +482,62 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
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);
+ __rb_erase_color(rebalance, root, augment);
+}
+
+/*
+ * Non-augmented rbtree manipulation functions.
+ *
+ * We use dummy augmented callbacks here, and have the compiler optimize them
+ * out of the rb_insert_color() and rb_erase() function definitions.
+ */
+
+static inline void dummy_propagate(struct rb_node *node, struct rb_node *stop) {}
+static inline void dummy_copy(struct rb_node *old, struct rb_node *new) {}
+static inline void dummy_rotate(struct rb_node *old, struct rb_node *new) {}
+
+static const struct rb_augment_callbacks dummy_callbacks = {
+ dummy_propagate, dummy_copy, dummy_rotate
+};
+
+void rb_insert_color(struct rb_node *node, struct rb_root *root)
+{
+ __rb_insert(node, root, dummy_rotate);
+}
+EXPORT_SYMBOL(rb_insert_color);
+
+void rb_erase(struct rb_node *node, struct rb_root *root)
+{
+ __rb_erase(node, root, &dummy_callbacks);
}
EXPORT_SYMBOL(rb_erase);
+/*
+ * Augmented rbtree manipulation functions.
+ *
+ * This instantiates the same __always_inline functions as in the non-augmented
+ * case, but this time with user-defined callbacks.
+ */
+
+void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
+ void (*augment_rotate)(struct rb_node *old, struct rb_node *new))
+{
+ __rb_insert(node, root, augment_rotate);
+}
+EXPORT_SYMBOL(__rb_insert_augmented);
+
+void rb_erase_augmented(struct rb_node *node, struct rb_root *root,
+ const struct rb_augment_callbacks *augment)
+{
+ __rb_erase(node, root, augment);
+}
+EXPORT_SYMBOL(rb_erase_augmented);
+
static void rb_augment_path(struct rb_node *node, rb_augment_f func, void *data)
{
struct rb_node *parent;
diff --git a/lib/rbtree_test.c b/lib/rbtree_test.c
index 66e41d4bfc39..e28345df09bf 100644
--- a/lib/rbtree_test.c
+++ b/lib/rbtree_test.c
@@ -61,35 +61,65 @@ static inline u32 augment_recompute(struct test_node *node)
return max;
}
-static void augment_callback(struct rb_node *rb, void *unused)
+static void augment_propagate(struct rb_node *rb, struct rb_node *stop)
{
- struct test_node *node = rb_entry(rb, struct test_node, rb);
- node->augmented = augment_recompute(node);
+ while (rb != stop) {
+ struct test_node *node = rb_entry(rb, struct test_node, rb);
+ u32 augmented = augment_recompute(node);
+ if (node->augmented == augmented)
+ break;
+ node->augmented = augmented;
+ rb = rb_parent(&node->rb);
+ }
+}
+
+static void augment_copy(struct rb_node *rb_old, struct rb_node *rb_new)
+{
+ struct test_node *old = rb_entry(rb_old, struct test_node, rb);
+ struct test_node *new = rb_entry(rb_new, struct test_node, rb);
+ new->augmented = old->augmented;
}
+static void augment_rotate(struct rb_node *rb_old, struct rb_node *rb_new)
+{
+ struct test_node *old = rb_entry(rb_old, struct test_node, rb);
+ struct test_node *new = rb_entry(rb_new, struct test_node, rb);
+
+ /* Rotation doesn't change subtree's augmented value */
+ new->augmented = old->augmented;
+ old->augmented = augment_recompute(old);
+}
+
+static const struct rb_augment_callbacks augment_callbacks = {
+ augment_propagate, augment_copy, augment_rotate
+};
+
static void insert_augmented(struct test_node *node, struct rb_root *root)
{
- struct rb_node **new = &root->rb_node, *parent = NULL;
+ struct rb_node **new = &root->rb_node, *rb_parent = NULL;
u32 key = node->key;
+ u32 val = node->val;
+ struct test_node *parent;
while (*new) {
- parent = *new;
- if (key < rb_entry(parent, struct test_node, rb)->key)
- new = &parent->rb_left;
+ rb_parent = *new;
+ parent = rb_entry(rb_parent, struct test_node, rb);
+ if (parent->augmented < val)
+ parent->augmented = val;
+ if (key < parent->key)
+ new = &parent->rb.rb_left;
else
- new = &parent->rb_right;
+ new = &parent->rb.rb_right;
}
- rb_link_node(&node->rb, parent, new);
- rb_insert_color(&node->rb, root);
- rb_augment_insert(&node->rb, augment_callback, NULL);
+ node->augmented = val;
+ rb_link_node(&node->rb, rb_parent, new);
+ rb_insert_augmented(&node->rb, root, &augment_callbacks);
}
static void erase_augmented(struct test_node *node, struct rb_root *root)
{
- struct rb_node *deepest = rb_augment_erase_begin(&node->rb);
- rb_erase(&node->rb, root);
- rb_augment_erase_end(deepest, augment_callback, NULL);
+ rb_erase_augmented(&node->rb, root, &augment_callbacks);
}
static void init(void)
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-01 15:22:58 +0000