More juggling

git-svn-id: http://svn.drobilla.net/lad/grauph@15 a436a847-0d15-0410-975c-d299462d15a1

1 files changed, 410 insertions, 0 deletions

diff --git a/src/libs/engine/TreeImplementation.h b/src/libs/engine/TreeImplementation.h
new file mode 100644
index 00000000..a61ec407
--- /dev/null
+++ b/src/libs/engine/TreeImplementation.h
@@ -0,0 +1,410 @@
+/* This file is part of Om.  Copyright (C) 2006 Dave Robillard.
+ * 
+ * Om is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2 of the License, or (at your option) any later
+ * version.
+ * 
+ * Om is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "Tree.h"
+#include <cstdlib>
+#include <iostream>
+#include <cassert>
+using std::cerr; using std::endl;
+
+
+/* FIXME: this is all in horrible need of a rewrite. */
+
+
+/** Destroy the tree.
+ *
+ * Note that this does not delete any TreeNodes still inside the tree,
+ * that is the user's responsibility.
+ */
+template <typename T>
+Tree<T>::~Tree()
+{
+}
+
+
+/** Insert a node into the tree.  Realtime safe.
+ *
+ * @a n will be inserted using the key() field for searches.
+ * n->key() must not be the empty string.
+ */
+template<typename T>
+void
+Tree<T>::insert(TreeNode<T>* const n)
+{
+	assert(n != NULL);
+	assert(n->left_child() == NULL);
+	assert(n->right_child() == NULL);
+	assert(n->parent() == NULL);
+	assert(n->key().length() > 0);
+	assert(find_treenode(n->key()) == NULL);
+
+	if (m_root == NULL) {
+		m_root = n;
+	} else {
+		bool left = false; // which child to insert at
+		bool right = false;
+		TreeNode<T>* i = m_root;
+		while (true) {
+			assert(i != NULL);
+			if (n->key() <= i->key()) {
+				if (i->left_child() == NULL) {
+					left = true;
+					break;
+				} else {
+					i = i->left_child();
+				}
+			} else {
+				if (i->right_child() == NULL) {
+					right = true;
+					break;
+				} else {
+					i = i->right_child();
+				}
+			}
+		}
+		
+		assert(i != NULL);
+		assert(left || right);
+		assert( ! (left && right) );
+		
+		if (left) {
+			assert(i->left_child() == NULL);
+			i->left_child(n);
+		} else if (right) {
+			assert(i->right_child() == NULL);
+			i->right_child(n);
+		} 
+		n->parent(i);
+	}
+	++m_size;
+}
+
+
+/** Remove a node from the tree.
+ *
+ * Realtime safe, caller is responsible to delete returned value.
+ *
+ * @return NULL if object with @a key is not in tree.
+ */
+template<typename T>
+TreeNode<T>*
+Tree<T>::remove(const string& key)
+{
+	TreeNode<T>* node      = find_treenode(key);
+	TreeNode<T>* n         = node;
+	TreeNode<T>* swap      = NULL;
+	T            temp_node;
+	string       temp_key;
+
+	if (node == NULL)
+		return NULL;
+	
+	// Node is not even in tree
+	if (node->parent() == NULL && m_root != node)
+		return NULL;
+	// FIXME: What if the node is in a different tree?  Check for this?
+
+#ifndef NDEBUG
+	const T& remove_node = node->node(); // for error checking
+#endif // NDEBUG
+	
+	// n has two children
+	if (n->left_child() != NULL && n->right_child() != NULL) {
+		if (rand()%2)
+			swap = m_find_largest(n->left_child());
+		else
+			swap = m_find_smallest(n->right_child());
+		
+		// Swap node's elements
+		temp_node = swap->m_node;
+		swap->m_node = n->m_node;
+		n->m_node = temp_node;
+		
+		// Swap node's keys
+		temp_key = swap->m_key;
+		swap->m_key = n->m_key;
+		n->m_key = temp_key;
+
+		n = swap;
+		assert(n != NULL);
+	}
+
+	// be sure we swapped correctly (ie right node is getting removed)
+	assert(n->node() == remove_node);
+	
+	// n now has at most one child
+	assert(n->left_child() == NULL || n->right_child() == NULL);
+
+	if (n->is_leaf()) {
+		if (n->is_left_child())
+			n->parent()->left_child(NULL);
+		else if (n->is_right_child())
+			n->parent()->right_child(NULL);
+		
+		if (m_root == n) m_root = NULL;
+	} else {  // has a single child
+		TreeNode<T>* child = NULL;
+		if (n->left_child() != NULL)
+			child = n->left_child();
+		else if (n->right_child() != NULL)
+			child = n->right_child();
+		else
+			exit(EXIT_FAILURE);
+
+		assert(child != n);
+		assert(child != NULL);
+		assert(n->parent() != n);
+
+		if (n->is_left_child()) {
+			assert(n->parent() != child);
+			n->parent()->left_child(child);
+			child->parent(n->parent());
+		} else if (n->is_right_child()) {
+			assert(n->parent() != child);
+			n->parent()->right_child(child);
+			child->parent(n->parent());
+		} else {
+			child->parent(NULL);
+		}
+		if (m_root == n) m_root = child;	
+	}
+	
+	// Be sure node is cut off completely
+	assert(n != NULL);
+	assert(n->parent() == NULL || n->parent()->left_child() != n);
+	assert(n->parent() == NULL || n->parent()->right_child() != n);
+	assert(n->left_child() == NULL || n->left_child()->parent() != n);
+	assert(n->right_child() == NULL || n->right_child()->parent() != n);
+	assert(m_root != n);
+
+	n->parent(NULL);
+	n->left_child(NULL);
+	n->right_child(NULL);
+
+	--m_size;
+
+	if (m_size == 0) m_root = NULL;
+
+	// Be sure right node is being removed
+	assert(n->node() == remove_node);
+			
+	return n;
+}
+
+
+template<typename T>
+T
+Tree<T>::find(const string& name) const
+{
+	TreeNode<T>* tn = find_treenode(name);
+
+	return (tn == NULL) ? NULL : tn->node();
+}
+
+
+template<typename T>
+TreeNode<T>*
+Tree<T>::find_treenode(const string& name) const
+{
+	TreeNode<T>* i = m_root;
+	int cmp = 0;
+	
+	while (i != NULL) {
+		cmp = name.compare(i->key());
+		if (cmp < 0)
+			i = i->left_child();
+		else if (cmp > 0)
+			i = i->right_child();
+		else
+			break;
+	}
+
+	return i;
+}
+
+
+/// Private ///
+template<typename T>
+void
+Tree<T>::m_set_all_traversed_recursive(TreeNode<T>* root, bool b)
+{
+	assert(root != NULL);
+	
+	// Preorder traversal
+	root->node()->traversed(b);
+	if (root->left_child() != NULL)
+		m_set_all_traversed_recursive(root->left_child(), b);
+	if (root->right_child() != NULL)
+		m_set_all_traversed_recursive(root->right_child(), b);
+}
+
+
+/** Finds the smallest (key) node in the subtree rooted at "root"
+ */
+template<typename T>
+TreeNode<T>*
+Tree<T>::m_find_smallest(TreeNode<T>* root)
+{
+	TreeNode<T>* r = root;
+
+	while (r->left_child() != NULL)
+		r = r->left_child();
+
+	return r;
+}
+
+
+/** Finds the largest (key) node in the subtree rooted at "root".
+ */
+template<typename T>
+TreeNode<T>*
+Tree<T>::m_find_largest(TreeNode<T>* root)
+{
+	TreeNode<T>* r = root;
+
+	while (r->right_child() != NULL)
+		r = r->right_child();
+
+	return r;
+
+}
+
+
+
+//// Iterator Stuff ////
+
+
+
+template<typename T>
+Tree<T>::iterator::iterator(const Tree *tree, size_t size)
+: m_depth(-1),
+  m_size(size),
+  m_stack(NULL),
+  m_tree(tree)
+{
+	if (size > 0)
+		m_stack = new TreeNode<T>*[size];
+}
+
+
+template<typename T>
+Tree<T>::iterator::~iterator()
+{
+	delete[] m_stack;
+}
+
+
+/* FIXME: Make these next two not memcpy (possibly have to force a single
+ * iterator existing at any given time) for speed.
+ */
+
+// Copy constructor (for the typical for loop usage)
+template<typename T>
+Tree<T>::iterator::iterator(const Tree<T>::iterator& copy)
+: m_depth(copy.m_depth),
+  m_size(copy.m_size),
+  m_tree(copy.m_tree)
+{
+	if (m_size > 0) {
+		m_stack = new TreeNode<T>*[m_size];
+		memcpy(m_stack, copy.m_stack, m_size * sizeof(TreeNode<T>*));
+	}
+}
+
+
+// Assignment operator
+template<typename T>
+typename Tree<T>::iterator&
+Tree<T>::iterator::operator=(const Tree<T>::iterator& copy) {
+	m_depth = copy.m_depth;
+	m_size = copy.m_size;
+	m_tree = copy.m_tree;
+	
+	if (m_size > 0) {
+		m_stack = new TreeNode<T>*[m_size];
+		memcpy(m_stack, copy.m_stack, m_size * sizeof(TreeNode<T>*));
+	}
+	return *this;
+}
+
+
+template<typename T>
+T
+Tree<T>::iterator::operator*() const
+{
+	assert(m_depth >= 0);
+	return m_stack[m_depth]->node();
+}
+
+
+template<typename T>
+typename Tree<T>::iterator&
+Tree<T>::iterator::operator++()
+{
+	assert(m_depth >= 0);
+
+	TreeNode<T>* tn = m_stack[m_depth];
+	--m_depth;
+
+	tn = tn->right_child();
+	while (tn != NULL) {
+		++m_depth;
+		m_stack[m_depth] = tn;
+		tn = tn->left_child();
+	}
+
+	return *this;
+}
+
+
+template<typename T>
+bool
+Tree<T>::iterator::operator!=(const Tree<T>::iterator& iter) const
+{
+	// (DeMorgan's Law)
+	return (m_tree != iter.m_tree || m_depth != iter.m_depth);
+}
+
+
+template<typename T>
+typename Tree<T>::iterator
+Tree<T>::begin() const
+{
+	typename Tree<T>::iterator iter(this, m_size);
+	iter.m_depth = -1;
+	
+	TreeNode<T> *ptr = m_root;
+	while (ptr != NULL) {
+		iter.m_depth++;
+		iter.m_stack[iter.m_depth] = ptr;
+		ptr = ptr->left_child();
+	}
+
+	return iter;
+}
+
+
+template<typename T>
+typename Tree<T>::iterator
+Tree<T>::end() const
+{
+	typename Tree<T>::iterator iter(this, 0);
+	iter.m_depth = -1;
+
+	return iter;
+}
+
+