rbtree: faster augmented rbtree manipulation

[karo-tx-linux.git] / lib / rbtree_test.c

diff --git a/lib/rbtree_test.c b/lib/rbtree_test.c
index 66e41d4bfc39885adc4550373a0091b6e7ab3c5c..e28345df09bff66a87fa79d8de4648b06af6f213 100644 (file)
--- 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)