/// \brief Delete a tree node.
///
- /// When a node is deleted, a process called node fusion occurs
- /// where nodes that satisfy some conditions are combined together
- /// into a new node, and the old nodes are deleted from the
- /// tree. From the DomainTree user's perspective, such node fusion
- /// will not cause any disturbance in the content of the DomainTree
- /// itself, but any existing pointers that the user code contains to
- /// DomainTreeNodes may be invalidated. In this case, the user code
- /// is required to re-lookup the node using \c find() and other seek
- /// methods.
- ///
/// \throw none.
///
/// \param mem_sgmt The \c MemorySegment object used to insert the nodes
const isc::dns::LabelSequence& new_prefix,
const isc::dns::LabelSequence& new_suffix);
- /// Try to replace the upper node and its down node into a single
- /// new node, deleting the old nodes in the process. This happens
- /// iteratively up the tree until no pair of nodes can be fused
- /// anymore. Note that after deletion operation, a pointer to a node
- /// may be invalid.
- void tryNodeFusion(util::MemorySegment& mem_sgmt,
- DomainTreeNode<T>* upper_node);
-
//@}
typename DomainTreeNode<T>::DomainTreeNodePtr root_;
deleteHelper(mem_sgmt, node->getDown(), deleter);
}
- tryNodeFusion(mem_sgmt, upper_node);
-
// Finally, destroy the node.
deleter(node->data_.get());
DomainTreeNode<T>::destroy(mem_sgmt, node);
root_ = NULL;
}
-template <typename T>
-void
-DomainTree<T>::tryNodeFusion(util::MemorySegment& mem_sgmt,
- DomainTreeNode<T>* upper_node)
-{
- // Keep doing node fusion up the tree until it's no longer possible.
- while (upper_node) {
- DomainTreeNode<T>* subtree_root = upper_node->getDown();
-
- // If the node deletion caused the subtree root to disappear
- // completely, return early.
- if (!subtree_root) {
- if (upper_node->isSubTreeRoot()) {
- upper_node = upper_node->getParent();
- continue;
- } else {
- break;
- }
- }
-
- // If the subtree root has left or right children, the subtree
- // has more than 1 nodes, so fusion cannot be done.
- if (subtree_root->getLeft() || subtree_root->getRight()) {
- break;
- }
-
- // If the upper node is not empty, fusion cannot be done.
- if (!upper_node->isEmpty()) {
- break;
- }
-
- // If upper node is the root node (.), don't attempt node fusion
- // with it. The root node must always exist.
- if (upper_node == root_.get()) {
- break;
- }
-
- // Create a new label sequence with (subtree_root+upper_node)
- // labels.
- uint8_t buf[isc::dns::LabelSequence::MAX_SERIALIZED_LENGTH];
- isc::dns::LabelSequence ls(subtree_root->getLabels(), buf);
- ls.extend(upper_node->getLabels(), buf);
-
- // We create a new node to replace subtree_root and
- // upper_node. subtree_root and upper_node will be deleted at
- // the end.
- DomainTreeNode<T>* new_node = DomainTreeNode<T>::create(mem_sgmt, ls);
-
- new_node->parent_ = upper_node->getParent();
-
- upper_node->setParentChild(upper_node, new_node, &root_, new_node);
-
- new_node->left_ = upper_node->getLeft();
- if (new_node->getLeft() != NULL) {
- new_node->getLeft()->parent_ = new_node;
- }
-
- new_node->right_ = upper_node->getRight();
- if (new_node->getRight() != NULL) {
- new_node->getRight()->parent_ = new_node;
- }
-
- new_node->down_ = subtree_root->getDown();
- if (new_node->getDown() != NULL) {
- new_node->getDown()->parent_ = new_node;
- }
-
- // The color of the new node is the same as the upper node's.
- new_node->setColor(upper_node->getColor());
-
- new_node->setSubTreeRoot(upper_node->isSubTreeRoot());
-
- // The flags of the new node are the same as the upper node's.
- new_node->setFlag(DomainTreeNode<T>::FLAG_CALLBACK,
- upper_node->getFlag(DomainTreeNode<T>::FLAG_CALLBACK));
- new_node->setFlag(DomainTreeNode<T>::FLAG_USER1,
- upper_node->getFlag(DomainTreeNode<T>::FLAG_USER1));
- new_node->setFlag(DomainTreeNode<T>::FLAG_USER2,
- upper_node->getFlag(DomainTreeNode<T>::FLAG_USER2));
- new_node->setFlag(DomainTreeNode<T>::FLAG_USER3,
- upper_node->getFlag(DomainTreeNode<T>::FLAG_USER3));
-
- // The data on the new node is the same as the subtree
- // root's. Note that the upper node must be empty (contains no
- // data).
- T* data = subtree_root->setData(NULL);
- new_node->setData(data);
-
- // Destroy the old nodes (without destroying any data).
- DomainTreeNode<T>::destroy(mem_sgmt, upper_node);
- DomainTreeNode<T>::destroy(mem_sgmt, subtree_root);
-
- // We added 1 node and deleted 2.
- --node_count_;
-
- // Ascend one level up and iterate the whole process again if
- // the conditions exist to fuse more nodes.
- if (new_node->isSubTreeRoot()) {
- upper_node = new_node->getParent();
- } else {
- break;
- }
- }
-}
-
template <typename T>
void
DomainTree<T>::nodeFission(util::MemorySegment& mem_sgmt,
checkTree(tree, names);
}
-TEST_F(DomainTreeTest, nodeFusion) {
- // Test that node fusion occurs when conditions permit.
-
- /* Original tree:
- * .
- * |
- * b
- * / \
- * a d.e.f
- * / | \
- * c | g.h
- * | |
- * w.y i
- * / | \ \
- * x | z k
- * | |
- * p j
- * / \
- * o q
- *
- */
-
- // First, check that "d.e.f" and "w.y" exist independently.
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("d.e.f"), &cdtnode));
- EXPECT_EQ(Name("d.e.f"), cdtnode->getName());
-
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("w.y.d.e.f"), &cdtnode));
- EXPECT_EQ(Name("w.y"), cdtnode->getName());
-
- // Now, delete "x" node.
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("x.d.e.f"), &dtnode));
- dtree_expose_empty_node.remove(mem_sgmt_, dtnode, deleteData);
-
- // "d.e.f" should still exist independently as "w.y" still has a
- // left or right child.
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("d.e.f"), &cdtnode));
- EXPECT_EQ(Name("d.e.f"), cdtnode->getName());
-
- // Now, delete "z" node.
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("z.d.e.f"), &dtnode));
- dtree_expose_empty_node.remove(mem_sgmt_, dtnode, deleteData);
-
- /* Deleting 'x' and 'z' should cause "w.y" to be fused with "d.e.f":
- * .
- * |
- * b
- * / \
- * a w.y.d.e.f
- * / | \
- * c | g.h
- * | |
- * p i
- * / \ \
- * o q k
- */
-
- // Check that "w.y" got fused with "d.e.f"
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("w.y.d.e.f"), &cdtnode));
- EXPECT_EQ(Name("w.y.d.e.f"), cdtnode->getName());
-
- // Check that "p" exists independently. This also checks that the
- // down pointer got saved correctly during the last fusion.
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("p.w.y.d.e.f"), &cdtnode));
- EXPECT_EQ(Name("p"), cdtnode->getName());
-
- // Now, delete "o" and "q" nodes.
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("o.w.y.d.e.f"), &dtnode));
- dtree_expose_empty_node.remove(mem_sgmt_, dtnode, deleteData);
-
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("q.w.y.d.e.f"), &dtnode));
- dtree_expose_empty_node.remove(mem_sgmt_, dtnode, deleteData);
-
- /* Deleting 'o' and 'q' should cause "p" to be fused with "w.y.d.e.f":
- * .
- * |
- * b
- * / \
- * a p.w.y.d.e.f
- * / \
- * c g.h
- * |
- * i
- * \
- * k
- */
-
- // Check that "p" got fused with "w.y.d.e.f"
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("p.w.y.d.e.f"), &cdtnode));
- EXPECT_EQ(Name("p.w.y.d.e.f"), cdtnode->getName());
-}
-
-TEST_F(DomainTreeTest, nodeFusionWithData) {
- // Test that node fusion does not occur when there is data in the
- // parent node.
-
- /* Original tree:
- * .
- * |
- * b
- * / \
- * a d.e.f
- * / | \
- * c | g.h
- * | |
- * w.y i
- * / | \ \
- * x | z k
- * | |
- * p j
- * / \
- * o q
- *
- */
-
- // First, check that "d.e.f" and "w.y" exist independently.
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("d.e.f"), &cdtnode));
- EXPECT_EQ(Name("d.e.f"), cdtnode->getName());
-
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("w.y.d.e.f"), &cdtnode));
- EXPECT_EQ(Name("w.y"), cdtnode->getName());
-
- // Set data (some value 42) in the "d.e.f" node
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("d.e.f"), &dtnode));
- EXPECT_EQ(static_cast<int*>(NULL),
- dtnode->setData(new int(42)));
-
- // Now, delete "x" and "z" nodes.
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("x.d.e.f"), &dtnode));
- dtree_expose_empty_node.remove(mem_sgmt_, dtnode, deleteData);
-
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("z.d.e.f"), &dtnode));
- dtree_expose_empty_node.remove(mem_sgmt_, dtnode, deleteData);
-
- /* Deleting 'x' and 'z' should not cause "w.y" to be fused with
- * "d.e.f" because "d.e.f" is not empty (has data) in this case.
- * .
- * |
- * b
- * / \
- * a d.e.f
- * / | \
- * c | g.h
- * | |
- * w.y i
- * | \
- * | k
- * |
- * p
- * / \
- * o q
- *
- */
-
- // Check that "w.y" did not get fused with "d.e.f"
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("d.e.f"), &cdtnode));
- EXPECT_EQ(Name("d.e.f"), cdtnode->getName());
-
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("w.y.d.e.f"), &cdtnode));
- EXPECT_EQ(Name("w.y"), cdtnode->getName());
-}
-
-TEST_F(DomainTreeTest, nodeFusionMultiple) {
- // Test that node fusion occurs up the tree multiple times when
- // conditions permit.
-
- /* Original tree:
- * .
- * |
- * b
- * / \
- * a d.e.f
- * / | \
- * c | g.h
- * | |
- * w.y i
- * / | \ \
- * x | z k
- * | |
- * p j
- * / \
- * o q
- *
- */
-
- // Set data (some value 42) in the "d.e.f" node
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("d.e.f"), &dtnode));
- EXPECT_EQ(static_cast<int*>(NULL),
- dtnode->setData(new int(42)));
-
- // Now, delete "x" and "z" nodes.
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("x.d.e.f"), &dtnode));
- dtree_expose_empty_node.remove(mem_sgmt_, dtnode, deleteData);
-
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("z.d.e.f"), &dtnode));
- dtree_expose_empty_node.remove(mem_sgmt_, dtnode, deleteData);
-
- /* Deleting 'x' and 'z' should not cause "w.y" to be fused with
- * "d.e.f" because "d.e.f" is not empty (has data) in this case.
- * .
- * |
- * b
- * / \
- * a d.e.f
- * / | \
- * c | g.h
- * | |
- * w.y i
- * | \
- * | k
- * |
- * p
- * / \
- * o q
- *
- */
-
- // Check that "w.y" did not get fused with "d.e.f"
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("d.e.f"), &cdtnode));
- EXPECT_EQ(Name("d.e.f"), cdtnode->getName());
-
- // Now, clear the data on "d.e.f". (Ideally, this itself should
- // cause fusion of "d.e.f" and "w.y" to occur, but we only do fusion
- // during deletion in our DomainTree implementation.)
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("d.e.f"), &dtnode));
- delete dtnode->setData(NULL);
-
- // Check that "p" exists independently.
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("p.w.y.d.e.f"), &cdtnode));
- EXPECT_EQ(Name("p"), cdtnode->getName());
-
- // Now, delete "o" and "q" nodes.
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("o.w.y.d.e.f"), &dtnode));
- dtree_expose_empty_node.remove(mem_sgmt_, dtnode, deleteData);
-
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("q.w.y.d.e.f"), &dtnode));
- dtree_expose_empty_node.remove(mem_sgmt_, dtnode, deleteData);
-
- // The deletion of "o" and "q" should cause "p" to fuse with "w.y"
- // to form "p.w.y". Then, as "d.e.f" is now empty and conditions
- // permit, for a second time up the forest, "p.w.y" is fused with
- // "d.e.f" to form "p.w.y.d.e.f".
- EXPECT_EQ(TestDomainTree::EXACTMATCH,
- dtree_expose_empty_node.find(Name("p.w.y.d.e.f"), &cdtnode));
- EXPECT_EQ(Name("p.w.y.d.e.f"), cdtnode->getName());
-}
-
TEST_F(DomainTreeTest, subTreeRoot) {
// This is a testcase for a particular issue that went unchecked in
// #2089's implementation, but was fixed in #2092. The issue was
projects / thirdparty / kea.git / commitdiff
