- {
- /* node->balance is outside the range [-1,1]. Must rotate. */
- gl_list_node_t *nodep;
-
- if (node->parent == NULL)
- /* node == list->root */
- nodep = &list->root;
- else if (node->parent->left == node)
- nodep = &node->parent->left;
- else if (node->parent->right == node)
- nodep = &node->parent->right;
- else
- abort ();
-
- nodeleft = node->left;
- noderight = node->right;
-
- if (balance_diff < 0)
- {
- /* node->balance = -2. The subtree is heavier on the left side.
- Rotate from left to right:
-
- *
- / \
- h+2 h
- */
- gl_list_node_t nodeleftleft = nodeleft->left;
- gl_list_node_t nodeleftright = nodeleft->right;
- if (nodeleft->balance <= 0)
- {
- /*
- * h+2|h+3
- / \ / \
- h+2 h --> / h+1|h+2
- / \ | / \
- h+1 h|h+1 h+1 h|h+1 h
- */
- node->left = nodeleftright;
- nodeleft->right = node;
-
- nodeleft->parent = node->parent;
- node->parent = nodeleft;
- if (nodeleftright != NULL)
- nodeleftright->parent = node;
-
- nodeleft->balance += 1;
- node->balance = - nodeleft->balance;
-
- node->branch_size =
- (nodeleftright != NULL ? nodeleftright->branch_size : 0)
- + 1 + (noderight != NULL ? noderight->branch_size : 0);
- nodeleft->branch_size =
- nodeleftleft->branch_size + 1 + node->branch_size;
-
- *nodep = nodeleft;
- height_diff = (height_diff < 0
- ? /* noderight's height had been decremented from
- h+1 to h. The subtree's height changes from
- h+3 to h+2|h+3. */
- nodeleft->balance - 1
- : /* nodeleft's height had been incremented from
- h+1 to h+2. The subtree's height changes from
- h+2 to h+2|h+3. */
- nodeleft->balance);
- }
- else
- {
- /*
- * h+2
- / \ / \
- h+2 h --> h+1 h+1
- / \ / \ / \
- h h+1 h L R h
- / \
- L R
-
- */
- gl_list_node_t L = nodeleft->right = nodeleftright->left;
- gl_list_node_t R = node->left = nodeleftright->right;
- nodeleftright->left = nodeleft;
- nodeleftright->right = node;
-
- nodeleftright->parent = node->parent;
- if (L != NULL)
- L->parent = nodeleft;
- if (R != NULL)
- R->parent = node;
- nodeleft->parent = nodeleftright;
- node->parent = nodeleftright;
-
- nodeleft->balance = (nodeleftright->balance > 0 ? -1 : 0);
- node->balance = (nodeleftright->balance < 0 ? 1 : 0);
- nodeleftright->balance = 0;
-
- nodeleft->branch_size =
- (nodeleft->left != NULL ? nodeleft->left->branch_size : 0)
- + 1 + (nodeleft->right != NULL ? nodeleft->right->branch_size : 0);
- node->branch_size =
- (node->left != NULL ? node->left->branch_size : 0)
- + 1 + (node->right != NULL ? node->right->branch_size : 0);
- nodeleftright->branch_size =
- nodeleft->branch_size + 1 + node->branch_size;
-
- *nodep = nodeleftright;
- height_diff = (height_diff < 0
- ? /* noderight's height had been decremented from
- h+1 to h. The subtree's height changes from
- h+3 to h+2. */
- -1
- : /* nodeleft's height had been incremented from
- h+1 to h+2. The subtree's height changes from
- h+2 to h+2. */
- 0);
- }
- }
- else
- {
- /* node->balance = 2. The subtree is heavier on the right side.
- Rotate from right to left:
-
- *
- / \
- h h+2
- */
- gl_list_node_t noderightleft = noderight->left;
- gl_list_node_t noderightright = noderight->right;
- if (noderight->balance >= 0)
- {
- /*
- * h+2|h+3
- / \ / \
- h h+2 --> h+1|h+2 \
- / \ / \ |
- h|h+1 h+1 h h|h+1 h+1
- */
- node->right = noderightleft;
- noderight->left = node;
-
- noderight->parent = node->parent;
- node->parent = noderight;
- if (noderightleft != NULL)
- noderightleft->parent = node;
-
- noderight->balance -= 1;
- node->balance = - noderight->balance;
-
- node->branch_size =
- (nodeleft != NULL ? nodeleft->branch_size : 0)
- + 1 + (noderightleft != NULL ? noderightleft->branch_size : 0);
- noderight->branch_size =
- node->branch_size + 1 + noderightright->branch_size;
-
- *nodep = noderight;
- height_diff = (height_diff < 0
- ? /* nodeleft's height had been decremented from
- h+1 to h. The subtree's height changes from
- h+3 to h+2|h+3. */
- - noderight->balance - 1
- : /* noderight's height had been incremented from
- h+1 to h+2. The subtree's height changes from
- h+2 to h+2|h+3. */
- - noderight->balance);
- }
- else
- {
- /*
- * h+2
- / \ / \
- h h+2 --> h+1 h+1
- / \ / \ / \
- h+1 h h L R h
- / \
- L R
-
- */
- gl_list_node_t L = node->right = noderightleft->left;
- gl_list_node_t R = noderight->left = noderightleft->right;
- noderightleft->left = node;
- noderightleft->right = noderight;
-
- noderightleft->parent = node->parent;
- if (L != NULL)
- L->parent = node;
- if (R != NULL)
- R->parent = noderight;
- node->parent = noderightleft;
- noderight->parent = noderightleft;
-
- node->balance = (noderightleft->balance > 0 ? -1 : 0);
- noderight->balance = (noderightleft->balance < 0 ? 1 : 0);
- noderightleft->balance = 0;
-
- node->branch_size =
- (node->left != NULL ? node->left->branch_size : 0)
- + 1 + (node->right != NULL ? node->right->branch_size : 0);
- noderight->branch_size =
- (noderight->left != NULL ? noderight->left->branch_size : 0)
- + 1 + (noderight->right != NULL ? noderight->right->branch_size : 0);
- noderightleft->branch_size =
- node->branch_size + 1 + noderight->branch_size;
-
- *nodep = noderightleft;
- height_diff = (height_diff < 0
- ? /* nodeleft's height had been decremented from
- h+1 to h. The subtree's height changes from
- h+3 to h+2. */
- -1
- : /* noderight's height had been incremented from
- h+1 to h+2. The subtree's height changes from
- h+2 to h+2. */
- 0);
- }
- }
- node = *nodep;
- }
+ {
+ /* node->balance is outside the range [-1,1]. Must rotate. */
+ gl_list_node_t *nodep;
+
+ if (node->parent == NULL)
+ /* node == list->root */
+ nodep = &list->root;
+ else if (node->parent->left == node)
+ nodep = &node->parent->left;
+ else if (node->parent->right == node)
+ nodep = &node->parent->right;
+ else
+ abort ();
+
+ nodeleft = node->left;
+ noderight = node->right;
+
+ if (balance_diff < 0)
+ {
+ /* node->balance = -2. The subtree is heavier on the left side.
+ Rotate from left to right:
+
+ *
+ / \
+ h+2 h
+ */
+ gl_list_node_t nodeleftleft = nodeleft->left;
+ gl_list_node_t nodeleftright = nodeleft->right;
+ if (nodeleft->balance <= 0)
+ {
+ /*
+ * h+2|h+3
+ / \ / \
+ h+2 h --> / h+1|h+2
+ / \ | / \
+ h+1 h|h+1 h+1 h|h+1 h
+ */
+ node->left = nodeleftright;
+ nodeleft->right = node;
+
+ nodeleft->parent = node->parent;
+ node->parent = nodeleft;
+ if (nodeleftright != NULL)
+ nodeleftright->parent = node;
+
+ nodeleft->balance += 1;
+ node->balance = - nodeleft->balance;
+
+ node->branch_size =
+ (nodeleftright != NULL ? nodeleftright->branch_size : 0)
+ + 1 + (noderight != NULL ? noderight->branch_size : 0);
+ nodeleft->branch_size =
+ nodeleftleft->branch_size + 1 + node->branch_size;
+
+ *nodep = nodeleft;
+ height_diff = (height_diff < 0
+ ? /* noderight's height had been decremented from
+ h+1 to h. The subtree's height changes from
+ h+3 to h+2|h+3. */
+ nodeleft->balance - 1
+ : /* nodeleft's height had been incremented from
+ h+1 to h+2. The subtree's height changes from
+ h+2 to h+2|h+3. */
+ nodeleft->balance);
+ }
+ else
+ {
+ /*
+ * h+2
+ / \ / \
+ h+2 h --> h+1 h+1
+ / \ / \ / \
+ h h+1 h L R h
+ / \
+ L R
+
+ */
+ gl_list_node_t L = nodeleft->right = nodeleftright->left;
+ gl_list_node_t R = node->left = nodeleftright->right;
+ nodeleftright->left = nodeleft;
+ nodeleftright->right = node;
+
+ nodeleftright->parent = node->parent;
+ if (L != NULL)
+ L->parent = nodeleft;
+ if (R != NULL)
+ R->parent = node;
+ nodeleft->parent = nodeleftright;
+ node->parent = nodeleftright;
+
+ nodeleft->balance = (nodeleftright->balance > 0 ? -1 : 0);
+ node->balance = (nodeleftright->balance < 0 ? 1 : 0);
+ nodeleftright->balance = 0;
+
+ nodeleft->branch_size =
+ (nodeleft->left != NULL ? nodeleft->left->branch_size : 0)
+ + 1 + (nodeleft->right != NULL ? nodeleft->right->branch_size : 0);
+ node->branch_size =
+ (node->left != NULL ? node->left->branch_size : 0)
+ + 1 + (node->right != NULL ? node->right->branch_size : 0);
+ nodeleftright->branch_size =
+ nodeleft->branch_size + 1 + node->branch_size;
+
+ *nodep = nodeleftright;
+ height_diff = (height_diff < 0
+ ? /* noderight's height had been decremented from
+ h+1 to h. The subtree's height changes from
+ h+3 to h+2. */
+ -1
+ : /* nodeleft's height had been incremented from
+ h+1 to h+2. The subtree's height changes from
+ h+2 to h+2. */
+ 0);
+ }
+ }
+ else
+ {
+ /* node->balance = 2. The subtree is heavier on the right side.
+ Rotate from right to left:
+
+ *
+ / \
+ h h+2
+ */
+ gl_list_node_t noderightleft = noderight->left;
+ gl_list_node_t noderightright = noderight->right;
+ if (noderight->balance >= 0)
+ {
+ /*
+ * h+2|h+3
+ / \ / \
+ h h+2 --> h+1|h+2 \
+ / \ / \ |
+ h|h+1 h+1 h h|h+1 h+1
+ */
+ node->right = noderightleft;
+ noderight->left = node;
+
+ noderight->parent = node->parent;
+ node->parent = noderight;
+ if (noderightleft != NULL)
+ noderightleft->parent = node;
+
+ noderight->balance -= 1;
+ node->balance = - noderight->balance;
+
+ node->branch_size =
+ (nodeleft != NULL ? nodeleft->branch_size : 0)
+ + 1 + (noderightleft != NULL ? noderightleft->branch_size : 0);
+ noderight->branch_size =
+ node->branch_size + 1 + noderightright->branch_size;
+
+ *nodep = noderight;
+ height_diff = (height_diff < 0
+ ? /* nodeleft's height had been decremented from
+ h+1 to h. The subtree's height changes from
+ h+3 to h+2|h+3. */
+ - noderight->balance - 1
+ : /* noderight's height had been incremented from
+ h+1 to h+2. The subtree's height changes from
+ h+2 to h+2|h+3. */
+ - noderight->balance);
+ }
+ else
+ {
+ /*
+ * h+2
+ / \ / \
+ h h+2 --> h+1 h+1
+ / \ / \ / \
+ h+1 h h L R h
+ / \
+ L R
+
+ */
+ gl_list_node_t L = node->right = noderightleft->left;
+ gl_list_node_t R = noderight->left = noderightleft->right;
+ noderightleft->left = node;
+ noderightleft->right = noderight;
+
+ noderightleft->parent = node->parent;
+ if (L != NULL)
+ L->parent = node;
+ if (R != NULL)
+ R->parent = noderight;
+ node->parent = noderightleft;
+ noderight->parent = noderightleft;
+
+ node->balance = (noderightleft->balance > 0 ? -1 : 0);
+ noderight->balance = (noderightleft->balance < 0 ? 1 : 0);
+ noderightleft->balance = 0;
+
+ node->branch_size =
+ (node->left != NULL ? node->left->branch_size : 0)
+ + 1 + (node->right != NULL ? node->right->branch_size : 0);
+ noderight->branch_size =
+ (noderight->left != NULL ? noderight->left->branch_size : 0)
+ + 1 + (noderight->right != NULL ? noderight->right->branch_size : 0);
+ noderightleft->branch_size =
+ node->branch_size + 1 + noderight->branch_size;
+
+ *nodep = noderightleft;
+ height_diff = (height_diff < 0
+ ? /* nodeleft's height had been decremented from
+ h+1 to h. The subtree's height changes from
+ h+3 to h+2. */
+ -1
+ : /* noderight's height had been incremented from
+ h+1 to h+2. The subtree's height changes from
+ h+2 to h+2. */
+ 0);
+ }
+ }
+ node = *nodep;
+ }
+ break;
+ }
+}
+
+static void
+gl_tree_remove_node_from_tree (gl_list_t list, gl_list_node_t node)
+{
+ gl_list_node_t parent = node->parent;
+
+ if (node->left == NULL)
+ {
+ /* Replace node with node->right. */
+ gl_list_node_t child = node->right;
+
+ if (child != NULL)
+ child->parent = parent;
+ if (parent == NULL)
+ list->root = child;
+ else
+ {
+ if (parent->left == node)
+ parent->left = child;
+ else /* parent->right == node */
+ parent->right = child;
+
+ /* Update branch_size fields of the parent nodes. */
+ {
+ gl_list_node_t p;
+
+ for (p = parent; p != NULL; p = p->parent)
+ p->branch_size--;
+ }
+
+ rebalance (list, child, -1, parent);
+ }
+ }
+ else if (node->right == NULL)
+ {
+ /* It is not absolutely necessary to treat this case. But the more
+ general case below is more complicated, hence slower. */
+ /* Replace node with node->left. */
+ gl_list_node_t child = node->left;
+
+ child->parent = parent;
+ if (parent == NULL)
+ list->root = child;
+ else
+ {
+ if (parent->left == node)
+ parent->left = child;
+ else /* parent->right == node */
+ parent->right = child;
+
+ /* Update branch_size fields of the parent nodes. */
+ {
+ gl_list_node_t p;
+
+ for (p = parent; p != NULL; p = p->parent)
+ p->branch_size--;
+ }
+
+ rebalance (list, child, -1, parent);
+ }
+ }
+ else
+ {
+ /* Replace node with the rightmost element of the node->left subtree. */
+ gl_list_node_t subst;
+ gl_list_node_t subst_parent;
+ gl_list_node_t child;
+
+ for (subst = node->left; subst->right != NULL; )
+ subst = subst->right;
+
+ subst_parent = subst->parent;
+
+ child = subst->left;
+
+ /* The case subst_parent == node is special: If we do nothing special,
+ we get confusion about node->left, subst->left and child->parent.
+ subst_parent == node
+ <==> The 'for' loop above terminated immediately.
+ <==> subst == subst_parent->left
+ [otherwise subst == subst_parent->right]
+ In this case, we would need to first set
+ child->parent = node; node->left = child;
+ and later - when we copy subst into node's position - again
+ child->parent = subst; subst->left = child;
+ Altogether a no-op. */
+ if (subst_parent != node)
+ {
+ if (child != NULL)
+ child->parent = subst_parent;
+ subst_parent->right = child;
+ }
+
+ /* Update branch_size fields of the parent nodes. */
+ {
+ gl_list_node_t p;
+
+ for (p = subst_parent; p != NULL; p = p->parent)
+ p->branch_size--;
+ }
+
+ /* Copy subst into node's position.
+ (This is safer than to copy subst's value into node, keep node in
+ place, and free subst.) */
+ if (subst_parent != node)
+ {
+ subst->left = node->left;
+ subst->left->parent = subst;
+ }
+ subst->right = node->right;
+ subst->right->parent = subst;
+ subst->balance = node->balance;
+ subst->branch_size = node->branch_size;
+ subst->parent = parent;
+ if (parent == NULL)
+ list->root = subst;
+ else if (parent->left == node)
+ parent->left = subst;
+ else /* parent->right == node */
+ parent->right = subst;
+
+ /* Rebalancing starts at child's parent, that is subst_parent -
+ except when subst_parent == node. In this case, we need to use
+ its replacement, subst. */
+ rebalance (list, child, -1, subst_parent != node ? subst_parent : subst);
-
-static bool
-gl_tree_remove_node (gl_list_t list, gl_list_node_t node)
-{
- gl_list_node_t parent;
-
-#if WITH_HASHTABLE
- /* Remove node from the hash table.
- Note that this is only possible _before_ the node is removed from the
- tree structure, because remove_from_bucket() uses node_position(). */
- remove_from_bucket (list, node);
-#endif
-
- parent = node->parent;
-
- if (node->left == NULL)
- {
- /* Replace node with node->right. */
- gl_list_node_t child = node->right;
-
- if (child != NULL)
- child->parent = parent;
- if (parent == NULL)
- list->root = child;
- else
- {
- if (parent->left == node)
- parent->left = child;
- else /* parent->right == node */
- parent->right = child;
-
- /* Update branch_size fields of the parent nodes. */
- {
- gl_list_node_t p;
-
- for (p = parent; p != NULL; p = p->parent)
- p->branch_size--;
- }
-
- rebalance (list, child, -1, parent);
- }
- }
- else if (node->right == NULL)
- {
- /* It is not absolutely necessary to treat this case. But the more
- general case below is more complicated, hence slower. */
- /* Replace node with node->left. */
- gl_list_node_t child = node->left;
-
- child->parent = parent;
- if (parent == NULL)
- list->root = child;
- else
- {
- if (parent->left == node)
- parent->left = child;
- else /* parent->right == node */
- parent->right = child;
-
- /* Update branch_size fields of the parent nodes. */
- {
- gl_list_node_t p;
-
- for (p = parent; p != NULL; p = p->parent)
- p->branch_size--;
- }
-
- rebalance (list, child, -1, parent);
- }
- }
- else
- {
- /* Replace node with the rightmost element of the node->left subtree. */
- gl_list_node_t subst;
- gl_list_node_t subst_parent;
- gl_list_node_t child;
-
- for (subst = node->left; subst->right != NULL; )
- subst = subst->right;
-
- subst_parent = subst->parent;
-
- child = subst->left;
-
- /* The case subst_parent == node is special: If we do nothing special,
- we get confusion about node->left, subst->left and child->parent.
- subst_parent == node
- <==> The 'for' loop above terminated immediately.
- <==> subst == subst_parent->left
- [otherwise subst == subst_parent->right]
- In this case, we would need to first set
- child->parent = node; node->left = child;
- and later - when we copy subst into node's position - again
- child->parent = subst; subst->left = child;
- Altogether a no-op. */
- if (subst_parent != node)
- {
- if (child != NULL)
- child->parent = subst_parent;
- subst_parent->right = child;
- }
-
- /* Update branch_size fields of the parent nodes. */
- {
- gl_list_node_t p;
-
- for (p = subst_parent; p != NULL; p = p->parent)
- p->branch_size--;
- }
-
- /* Copy subst into node's position.
- (This is safer than to copy subst's value into node, keep node in
- place, and free subst.) */
- if (subst_parent != node)
- {
- subst->left = node->left;
- subst->left->parent = subst;
- }
- subst->right = node->right;
- subst->right->parent = subst;
- subst->balance = node->balance;
- subst->branch_size = node->branch_size;
- subst->parent = parent;
- if (parent == NULL)
- list->root = subst;
- else if (parent->left == node)
- parent->left = subst;
- else /* parent->right == node */
- parent->right = subst;
-
- /* Rebalancing starts at child's parent, that is subst_parent -
- except when subst_parent == node. In this case, we need to use
- its replacement, subst. */
- rebalance (list, child, -1, subst_parent != node ? subst_parent : subst);
- }
-
- if (list->base.dispose_fn != NULL)
- list->base.dispose_fn (node->value);
- free (node);
- return true;
-}