comrogue-pi/include/comrogue/internals/rbtree.h
2013-04-23 01:49:58 -06:00

110 lines
5.0 KiB
C

/*
* This file is part of the COMROGUE Operating System for Raspberry Pi
*
* Copyright (c) 2013, Eric J. Bowersox / Erbosoft Enterprises
* All rights reserved.
*
* This program is free for commercial and non-commercial use as long as the following conditions are
* adhered to.
*
* Copyright in this file remains Eric J. Bowersox and/or Erbosoft, and as such any copyright notices
* in the code are not to be removed.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted
* provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this list of conditions and
* the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and
* the following disclaimer in the documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* "Raspberry Pi" is a trademark of the Raspberry Pi Foundation.
*/
#ifndef __RBTREE_H_INCLUDED
#define __RBTREE_H_INCLUDED
#ifndef __ASM__
#include <comrogue/types.h>
#include <comrogue/compiler_macros.h>
/*------------------------------------------------------------------------------------------------------
* An implementation of left-leaning red-black 2-3 trees as detailed in "Left-leaning Red-Black Trees,"
* Robert Sedgwick, Princeton University, 2008 (http://www.cs.princeton.edu/~rs/talks/LLRB/LLRB.pdf).
* See also Java source at https://gist.github.com/741080.
*
* Note that we store the node color as a single bit in the low-order bit of the "right" node pointer.
* This is do-able since, for all cases, pointers to instances of RBTREENODE will be 4-byte aligned.
*------------------------------------------------------------------------------------------------------
*/
/* Generic key and comparison function definitions */
typedef PVOID TREEKEY;
typedef INT32 (*PFNTREECOMPARE)(TREEKEY, TREEKEY);
/* A node may be colored red or black. */
#define RED TRUE
#define BLACK FALSE
/* The basic tree node. */
typedef struct tagRBTREENODE {
struct tagRBTREENODE *ptnLeft; /* pointer to left child */
UINT_PTR ptnRightColor; /* pointer to right child AND color stored in low-order bit */
TREEKEY treekey; /* key value */
} RBTREENODE, *PRBTREENODE;
/* Tree node macros, mostly to access either color or pointer or both from the ptnRightColor field */
#define rbtNodeRight(ptn) ((PRBTREENODE)((ptn)->ptnRightColor & ~1))
#define rbtNodeColor(ptn) ((ptn)->ptnRightColor & 1)
#define rbtIsRed(ptn) ((ptn) ? rbtNodeColor(ptn) : FALSE)
#define rbtSetNodeRight(ptn, ptnR) \
do { (ptn)->ptnRightColor = (((UINT_PTR)(ptnR)) & ~1) | ((ptn)->ptnRightColor & 1); } while (0)
#define rbtSetNodeColor(ptn, clr) \
do { (ptn)->ptnRightColor = ((ptn)->ptnRightColor & ~1) | ((clr) ? 1 : 0); } while (0)
#define rbtToggleColor(ptn) do { if (ptn) (ptn)->ptnRightColor ^= 1; } while (0)
#define rbtInitNode(ptn, ptnL, ptnR, clr, key) \
do { (ptn)->ptnLeft = (ptnL); (ptn)->ptnRightColor = (((UINT_PTR)(ptnR)) & ~1) | ((clr) ? 1 : 0); \
(ptn)->treekey = (TREEKEY)(key); } while (0)
#define rbtNewNode(ptn, key) rbtInitNode(ptn, NULL, NULL, RED, key)
/* The head-of-tree structure. */
typedef struct tagRBTREE {
PFNTREECOMPARE pfnTreeCompare; /* pointer to comparison function */
PRBTREENODE ptnRoot; /* pointer to root of tree */
} RBTREE, *PRBTREE;
/* Tree macros. */
#define rbtInitTree(ptree, pfnCompare) \
do { (ptree)->pfnTreeCompare = (pfnCompare); (ptree)->ptnRoot = NULL; } while (0)
#define rbtIsEmpty(ptree) MAKEBOOL(!((ptree)->ptnRoot))
/* Type of function used by RbtWalk. */
typedef BOOL (*PFNRBTWALK)(PRBTREE, PRBTREENODE, PVOID);
/* Function prototypes. */
CDECL_BEGIN
extern INT32 RbtStdCompareByValue(TREEKEY k1, TREEKEY k2);
extern void RbtInsert(PRBTREE ptree, PRBTREENODE ptnNew);
extern PRBTREENODE RbtFind(PRBTREE ptree, TREEKEY key);
extern PRBTREENODE RbtFindPredecessor(PRBTREE ptree, TREEKEY key);
extern PRBTREENODE RbtFindSuccessor(PRBTREE ptree, TREEKEY key);
extern PRBTREENODE RbtFindMin(PRBTREE ptree);
extern void RbtDelete(PRBTREE ptree, TREEKEY key);
extern BOOL RbtWalk(PRBTREE ptree, PFNRBTWALK pfnWalk, PVOID pData);
CDECL_END
#endif /* __ASM__ */
#endif /* __RBTREE_H_INCLUDED */