gecko-dev/xpcom/ds/nsRBTree.h
1999-05-26 01:38:36 +00:00

224 lines
4.1 KiB
C++

/**
* This file defines the binary tree class and its
* nsNode child class.
*
* This simple version stores nodes, and the
* nodes store void* ptrs.
*
* @update gess 4/11/98
* @param
* @return
*/
/**
* MODULE NOTES
* @update gess 4/11/98
*
* This file declares the nsRBTree (red/black tree).
* Red/black trees are auto-balancing binary trees.
*
* To use this class, define a subclass of nsNode
* which stores your data type. It's important that
* you overload the following methods:
*
* virtual PRBool operator<()
* virtual PRBool operator==()
*
*/
#ifndef _nsRBTree
#define _nsRBTree
#include "nsBTree.h"
/**
* Here comes the main event: our nsRBTree (red/black tree).
* Red/Black trees are autobalancing binary trees.
*
* @update gess4/20/98
*/
class NS_COM nsRBTree : public nsBTree {
public:
friend class NS_COM nsRBTreeIterator;
/**
* nsRBTree constructor
*
* @update gess 4/11/98
*/
nsRBTree();
/**
* nsRBTree constructor
*
* @update gess 4/11/98
*/
nsRBTree(const nsRBTree& aCopy);
/**
* nsRBTree destructor
*
* @update gess 4/11/98
*/
virtual ~nsRBTree();
/**
* Given a node, we're supposed to add it into
* our tree.
*
* @update gess 4/11/98
* @param
* @return
*/
nsNode* Add(nsNode& aNode);
/**
* Retrive the first node in the tree
*
* @update gess 4/11/98
* @param
* @return
*/
nsNode* First(void);
/**
* Retrieve the first node given a starting node
*
* @update gess 4/11/98
* @param aNode --
* @return node ptr or null
*/
nsNode* First(nsNode& aNode);
/**
* Find the last node in the tree
*
* @update gess 4/11/98
* @param
* @return node ptr or null
*/
nsNode* Last(void);
/**
* Find the last node from a given node
*
* @update gess 4/11/98
* @param aNode -- node ptr to start from
* @return node ptr or null
*/
nsNode* Last(nsNode& aNode);
/**
* Retrieve the node that preceeds the given node
*
* @update gess 4/11/98
* @param aNode -- node to find precedent of
* @return preceeding node ptr, or null
*/
nsNode* Before(nsNode& aNode);
/**
* Retrieve a ptr to the node following the given node
*
* @update gess 4/11/98
* @param aNode -- node to find successor node from
* @return node ptr or null
*/
nsNode* After(nsNode& aNode);
/**
* Find a (given) node in the tree
*
* @update gess 4/11/98
* @param node to find in the tree
* @return node ptr (if found) or null
*/
nsNode* Find(nsNode& aNode);
private:
/**
* Causes a shift to the left, to keep the
* underlying RB data in balance
*
* @update gess 4/11/98
* @param
* @return this
*/
nsRBTree& ShiftLeft(nsNode& aNode);
/**
* Causes a shift right to occur, to keep the
* underlying RB data in balance
*
* @update gess 4/11/98
* @param aNode -- node at which to perform shift
* @return this
*/
nsRBTree& ShiftRight(nsNode& aNode);
/**
* Rebalances tree around the given node. This only
* needs to be called after a node is deleted.
*
* @update gess 4/11/98
* @param aNode -- node to balance around
* @return this
*/
virtual nsBTree& ReBalance(nsNode& aNode);
};
class NS_COM nsRBTreeIterator {
public:
/**
* TreeIterator constructor
*
* @update gess 4/11/98
* @param
* @return
*/
nsRBTreeIterator(const nsRBTree& aTree);
/**
* TreeIterator constructor
*
* @update gess 4/11/98
* @param
* @return
*/
nsRBTreeIterator(const nsRBTreeIterator& aCopy);
/**
* tree iterator destructor
*
* @update gess 4/11/98
* @param
* @return
*/
~nsRBTreeIterator();
/**
* This method iterates over the tree, calling
* aFunctor for each node.
*
* @update gess 4/11/98
* @param aFunctor -- object to call for each node
* @param aNode -- node at which to start iteration
* @return this
*/
const nsRBTreeIterator& ForEach(nsNodeFunctor& aFunctor) const;
protected:
const nsRBTree& mTree;
};
#endif