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Diffstat (limited to 'ospf6d/ospf6_bintree.c')
-rw-r--r--ospf6d/ospf6_bintree.c436
1 files changed, 436 insertions, 0 deletions
diff --git a/ospf6d/ospf6_bintree.c b/ospf6d/ospf6_bintree.c
new file mode 100644
index 00000000..c1e9e558
--- /dev/null
+++ b/ospf6d/ospf6_bintree.c
@@ -0,0 +1,436 @@
+
+#include <zebra.h>
+#include "ospf6_bintree.h"
+
+static struct bintree_node *
+bintree_lookup_node_min (struct bintree_node *subroot)
+{
+ struct bintree_node *node;
+
+ if (subroot == NULL)
+ return NULL;
+
+ node = subroot;
+ while (node->bl_left)
+ node = node->bl_left;
+ return node;
+}
+
+static struct bintree_node *
+bintree_lookup_node_max (struct bintree_node *subroot)
+{
+ struct bintree_node *node;
+
+ assert (subroot != NULL);
+ node = subroot;
+ while (node->bl_right)
+ node = node->bl_right;
+ return node;
+}
+
+void *
+bintree_lookup (void *data, struct bintree *tree)
+{
+ int cmp;
+ struct bintree_node *node;
+
+ node = tree->root;
+
+ while (node)
+ {
+ if (tree->cmp)
+ cmp = (*tree->cmp) (node->data, data);
+ else
+ cmp = (node->data - data);
+
+ if (cmp == 0)
+ break;
+
+ if (cmp > 0)
+ node = node->bl_left;
+ else /* if (cmp < 0) */
+ node = node->bl_right;
+ }
+
+ if (node)
+ return node->data;
+
+ return NULL;
+}
+
+void *
+bintree_lookup_min (struct bintree *tree)
+{
+ struct bintree_node *node;
+ node = bintree_lookup_node_min (tree->root);
+ if (node == NULL)
+ return NULL;
+ return node->data;
+}
+
+void *
+bintree_lookup_max (struct bintree *tree)
+{
+ struct bintree_node *node;
+ node = bintree_lookup_node_max (tree->root);
+ if (node == NULL)
+ return NULL;
+ return node->data;
+}
+
+int
+bintree_add (void *data, struct bintree *tree)
+{
+ int cmp = 0;
+ struct bintree_node *node, *parent;
+
+ node = tree->root;
+ parent = NULL;
+
+ while (node)
+ {
+ if (tree->cmp)
+ cmp = (*tree->cmp) (node->data, data);
+ else
+ cmp = (node->data - data);
+
+ if (cmp == 0)
+ break;
+
+ parent = node;
+ if (cmp > 0)
+ node = node->bl_left;
+ else /* if (cmp < 0) */
+ node = node->bl_right;
+ }
+
+ if (node)
+ return -1;
+
+ node = malloc (sizeof (struct bintree_node));
+ memset (node, 0, sizeof (struct bintree_node));
+ node->tree = tree;
+ node->data = data;
+
+ if (parent)
+ {
+ node->parent = parent;
+
+ assert (cmp != 0);
+ if (cmp > 0)
+ {
+ node->parent_link = BL_LEFT;
+ parent->bl_left = node;
+ }
+ else /* if (cmp < 0) */
+ {
+ node->parent_link = BL_RIGHT;
+ parent->bl_right = node;
+ }
+ }
+ else
+ tree->root = node;
+
+ tree->count++;
+ return 0;
+}
+
+static void
+bintree_remove_nochild (struct bintree_node *node)
+{
+ assert (node->bl_left == NULL && node->bl_right == NULL);
+
+ if (node->parent == NULL)
+ node->tree->root = NULL;
+ else
+ node->parent->link[node->parent_link] = NULL;
+}
+
+static void
+bintree_remove_onechild (struct bintree_node *node)
+{
+ assert ((node->bl_left == NULL && node->bl_right != NULL) ||
+ (node->bl_left != NULL && node->bl_right == NULL));
+
+ if (node->bl_left)
+ {
+ if (node->parent == NULL)
+ {
+ node->tree->root = node->bl_left;
+ node->bl_left->parent = NULL;
+ }
+ else
+ {
+ node->parent->link[node->parent_link] = node->bl_left;
+ node->bl_left->parent = node->parent;
+ node->bl_left->parent_link = node->parent_link;
+ }
+ }
+ else if (node->bl_right)
+ {
+ if (node->parent == NULL)
+ {
+ node->tree->root = node->bl_right;
+ node->bl_right->parent = NULL;
+ }
+ else
+ {
+ node->parent->link[node->parent_link] = node->bl_right;
+ node->bl_right->parent = node->parent;
+ node->bl_right->parent_link = node->parent_link;
+ }
+ }
+ else
+ assert (0);
+}
+
+int
+bintree_remove (void *data, struct bintree *tree)
+{
+ int cmp;
+ struct bintree_node *node;
+
+ node = tree->root;
+
+ while (node)
+ {
+ if (tree->cmp)
+ cmp = (*tree->cmp) (node->data, data);
+ else
+ cmp = (node->data - data);
+
+ if (cmp == 0)
+ break;
+
+ if (cmp > 0)
+ node = node->bl_left;
+ else /* if (cmp < 0) */
+ node = node->bl_right;
+ }
+
+ if (node == NULL)
+ return -1;
+
+ if (node->bl_left == NULL && node->bl_right == NULL)
+ {
+ bintree_remove_nochild (node);
+ free (node);
+ tree->count--;
+ return 0;
+ }
+
+ if ((node->bl_left == NULL && node->bl_right != NULL) ||
+ (node->bl_left != NULL && node->bl_right == NULL))
+ {
+ bintree_remove_onechild (node);
+ free (node);
+ tree->count--;
+ return 0;
+ }
+
+ if (node->bl_left != NULL && node->bl_right != NULL)
+ {
+ struct bintree_node *successor;
+
+ /* find successor of the removing node */
+ successor = bintree_lookup_node_min (node->bl_right);
+
+ /* remove successor from tree */
+ if (successor->bl_right)
+ bintree_remove_onechild (successor);
+ else
+ bintree_remove_nochild (successor);
+
+ /* swap removing node with successor */
+ successor->parent = node->parent;
+ successor->parent_link = node->parent_link;
+ successor->bl_left = node->bl_left;
+ successor->bl_right = node->bl_right;
+
+ /* if the successor was the node->bl_right itself,
+ bintree_remove_**child may touch node->bl_right,
+ so only the successor->bl_right may be NULL
+ by above assignment */
+ successor->bl_left->parent = successor;
+ if (successor->bl_right)
+ successor->bl_right->parent = successor;
+
+ if (successor->parent == NULL)
+ tree->root = successor;
+ else
+ successor->parent->link[successor->parent_link] = successor;
+
+ free (node);
+ tree->count--;
+ return 0;
+ }
+
+ /* not reached */
+ return -1;
+}
+
+/* in-order traversal */
+
+void
+bintree_head (struct bintree *tree, struct bintree_node *node)
+{
+ struct bintree_node *head;
+
+ head = bintree_lookup_node_min (tree->root);
+ if (head == NULL)
+ {
+ node->parent = NULL;
+ node->bl_left = NULL;
+ node->bl_right = NULL;
+ node->data = NULL;
+ return;
+ }
+
+ node->tree = head->tree;
+ node->parent = head->parent;
+ node->parent_link = head->parent_link;
+ node->bl_left = head->bl_left;
+ node->bl_right = head->bl_right;
+ node->data = head->data;
+}
+
+int
+bintree_end (struct bintree_node *node)
+{
+ if (node->parent || node->bl_left || node->bl_right || node->data)
+ return 0;
+ return 1;
+}
+
+#define GOTO_PROCED_SUBTREE_TOP(node) \
+ while (node->parent && node->parent->bl_right && \
+ node->parent->bl_right->data == node->data) \
+ { \
+ node->data = node->parent->data; \
+ node->bl_left = node->parent->bl_left; \
+ node->bl_right = node->parent->bl_right; \
+ node->parent_link = node->parent->parent_link; \
+ node->parent = node->parent->parent; \
+ }
+
+void
+bintree_next (struct bintree_node *node)
+{
+ struct bintree_node *next = NULL;
+
+ /* if node have just been removed, current point should have just been
+ replaced with its successor. that certainly will not be processed
+ yet, so process it */
+ if (node->parent == NULL)
+ {
+ if (node->tree->root == NULL)
+ {
+ assert (node->tree->count == 0);
+ node->parent = NULL;
+ node->bl_left = NULL;
+ node->bl_right = NULL;
+ node->data = NULL;
+ return;
+ }
+ else if (node->tree->root->data != node->data)
+ next = node->tree->root;
+ }
+ else if (node->parent->link[node->parent_link] == NULL)
+ {
+ if (node->parent_link == BL_LEFT)
+ next = node->parent;
+ else
+ {
+ GOTO_PROCED_SUBTREE_TOP (node);
+ next = node->parent;
+ }
+ }
+ else if (node->parent->link[node->parent_link]->data != node->data)
+ next = node->parent->link[node->parent_link];
+
+ if (next == NULL)
+ {
+ if (node->bl_right)
+ next = bintree_lookup_node_min (node->bl_right);
+ else
+ {
+ GOTO_PROCED_SUBTREE_TOP (node);
+ next = node->parent;
+ }
+ }
+
+ if (next)
+ {
+ node->tree = next->tree;
+ node->parent = next->parent;
+ node->parent_link = next->parent_link;
+ node->bl_left = next->bl_left;
+ node->bl_right = next->bl_right;
+ node->data = next->data;
+ }
+ else
+ {
+ node->parent = NULL;
+ node->bl_left = NULL;
+ node->bl_right = NULL;
+ node->data = NULL;
+ }
+}
+
+struct bintree *
+bintree_create ()
+{
+ struct bintree *tree;
+
+ tree = malloc (sizeof (struct bintree));
+ memset (tree, 0, sizeof (struct bintree));
+
+ return tree;
+}
+
+void
+bintree_delete (struct bintree *tree)
+{
+ struct bintree_node node;
+
+ for (bintree_head (tree, &node); ! bintree_end (&node);
+ bintree_next (&node))
+ bintree_remove (node.data, tree);
+
+ assert (tree->count == 0);
+ free (tree);
+}
+
+int indent_num = 0;
+
+void
+bintree_print_sub (void (*print) (int, void *), struct bintree_node *subroot)
+{
+ if (subroot == NULL)
+ return;
+
+ if (subroot->bl_right)
+ {
+ indent_num++;
+ bintree_print_sub (print, subroot->bl_right);
+ indent_num--;
+ }
+
+ (*print) (indent_num, subroot->data);
+
+ if (subroot->bl_left)
+ {
+ indent_num++;
+ bintree_print_sub (print, subroot->bl_left);
+ indent_num--;
+ }
+}
+
+void
+bintree_print (void (*print) (int, void *), struct bintree *tree)
+{
+ indent_num = 0;
+ bintree_print_sub (print, tree->root);
+}
+
+
generated by cgit v1.2.1 (git 2.18.0) at 2024-06-30 19:32:42 +0000