diff options
Diffstat (limited to 'source3/ubiqx/ubi_AVLtree.h')
| -rw-r--r-- | source3/ubiqx/ubi_AVLtree.h | 336 |
1 files changed, 336 insertions, 0 deletions
diff --git a/source3/ubiqx/ubi_AVLtree.h b/source3/ubiqx/ubi_AVLtree.h new file mode 100644 index 0000000000..be6fe03212 --- /dev/null +++ b/source3/ubiqx/ubi_AVLtree.h @@ -0,0 +1,336 @@ +#ifndef ubi_AVLtree_H +#define ubi_AVLtree_H +/* ========================================================================== ** + * ubi_AVLtree.h + * + * Copyright (C) 1991-1997 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * -------------------------------------------------------------------------- ** + * + * This module provides an implementation of AVL height balanced binary + * trees. (Adelson-Velskii, Landis 1962) + * + * This header file contains the basic AVL structure and pointer typedefs + * as well as the prototypes needed to access the functions in the AVL + * module ubi_AVLtree. The .c file implements the low-level height balancing + * routines that manage the AVL tree, plus all of the basic primops for + * adding, searching for, and deleting nodes. + * + * -------------------------------------------------------------------------- ** + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library 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 + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * -------------------------------------------------------------------------- ** + * $Log: ubi_AVLtree.h,v $ + * Revision 1.1 1997/10/10 14:46:37 crh + * This is the ubiqx binary tree and linked list library. + * This library is being included as part of the Samba distribution. + * (Hurray!) + * + * Revision 2.4 1997/07/26 04:36:23 crh + * Andrew Leppard, aka "Grazgur", discovered that I still had my brains tied + * on backwards with respect to node deletion. I did some more digging and + * discovered that I was not changing the balance values correctly in the + * single rotation functions. Double rotation was working correctly because + * the formula for changing the balance values is the same for insertion or + * deletion. Not so for single rotation. + * + * I have tested the fix by loading the tree with over 44 thousand names, + * deleting 2,629 of them (all those in which the second character is 'u') + * and then walking the tree recursively to verify that the balance factor of + * each node is correct. Passed. + * + * Thanks Andrew! + * + * Also: + * + Changed ubi_TRUE and ubi_FALSE to ubi_trTRUE and ubi_trFALSE. + * + Rewrote the ubi_tr<func> macros because they weren't doing what I'd + * hoped they would do (see the bottom of the header file). They work now. + * + * Revision 2.3 1997/06/03 05:22:07 crh + * Changed TRUE and FALSE to ubi_TRUE and ubi_FALSE to avoid causing + * problems. + * + * Revision 2.2 1995/10/03 22:15:47 CRH + * Ubisized! + * + * Revision 2.1 95/03/09 23:46:44 CRH + * Added the ModuleID static string and function. These modules are now + * self-identifying. + * + * Revision 2.0 95/03/05 14:11:22 CRH + * This revision of ubi_AVLtree coincides with revision 2.0 of ubi_BinTree, + * and so includes all of the changes to that module. In addition, a bug in + * the node deletion process has been fixed. + * + * After rewriting the Locate() function in ubi_BinTree, I decided that it was + * time to overhaul this module. In the process, I discovered a bug related + * to node deletion. To fix the bug, I wrote function Debalance(). A quick + * glance will show that it is very similar to the Rebalance() function. In + * previous versions of this module, I tried to include the functionality of + * Debalance() within Rebalance(), with poor results. + * + * Revision 1.0 93/10/15 22:58:48 CRH + * With this revision, I have added a set of #define's that provide a single, + * standard API to all existing tree modules. Until now, each of the three + * existing modules had a different function and typedef prefix, as follows: + * + * Module Prefix + * ubi_BinTree ubi_bt + * ubi_AVLtree ubi_avl + * ubi_SplayTree ubi_spt + * + * To further complicate matters, only those portions of the base module + * (ubi_BinTree) that were superceeded in the new module had the new names. + * For example, if you were using ubi_AVLtree, the AVL node structure was + * named "ubi_avlNode", but the root structure was still "ubi_btRoot". Using + * SplayTree, the locate function was called "ubi_sptLocate", but the next + * and previous functions remained "ubi_btNext" and "ubi_btPrev". + * + * This was not too terrible if you were familiar with the modules and knew + * exactly which tree model you wanted to use. If you wanted to be able to + * change modules (for speed comparisons, etc), things could get messy very + * quickly. + * + * So, I have added a set of defined names that get redefined in any of the + * descendant modules. To use this standardized interface in your code, + * simply replace all occurances of "ubi_bt", "ubi_avl", and "ubi_spt" with + * "ubi_tr". The "ubi_tr" names will resolve to the correct function or + * datatype names for the module that you are using. Just remember to + * include the header for that module in your program file. Because these + * names are handled by the preprocessor, there is no added run-time + * overhead. + * + * Note that the original names do still exist, and can be used if you wish + * to write code directly to a specific module. This should probably only be + * done if you are planning to implement a new descendant type, such as + * red/black trees. CRH + * + * V0.0 - May, 1990 - Written by Christopher R. Hertel (CRH). + * + * ========================================================================= ** + */ + +#include "ubi_BinTree.h" /* Base erg binary tree support. */ + +/* ------------------------------------------------------------------------- ** + * AVL Tree Node Structure: This structure defines the basic elements of + * the AVL tree nodes. In general you *SHOULD NOT PLAY WITH THESE + * FIELDS*! But, of course, I have to put the structure into this + * header so that you can use the structure as a building block. + * + * The fields are as follows: + * Link - An array of pointers. These pointers are manipulated by the + * BT and AVL routines, and indicate the left and right child + * nodes, plus the parent node. By keeping track of the parent + * pointer, we avoid the need for recursive routines or hand- + * tooled stacks to keep track of our path back to the root. + * The use of these pointers is subject to change without + * notice. + * gender - For tree rebalancing purposes, it is necessary that each node + * know whether it is the left or right child of its parent, or + * if it is the root. This information is stored in this field. + * balance - This field is also needed for AVL balancing purposes. It + * indicates which subtree of the current node is longer, or if + * the subtrees are, in fact, balanced with respect to each + * other. + * ------------------------------------------------------------------------- ** + */ + +typedef struct ubi_avlNodeStruct { + struct ubi_avlNodeStruct + *Link[3]; /* Normal Binary Tree Node type. */ + char gender; /* The node is either the RIGHT or LEFT child of its */ + /* parent, or is the root node. */ + char balance; /* In an AVL tree, each node is the root of a subtree */ + /* that may be balanced, or be one node longer to the */ + /* right or left. This field keeps track of the */ + /* balance value of each node. */ + } ubi_avlNode; /* Typedef'd name for an avl tree node. */ + +typedef ubi_avlNode *ubi_avlNodePtr; /* a Pointer to an AVL node */ + +/* -------------------------------------------------------------------------- ** + * Function prototypes. + * -------------------------------------------------------------------------- ** + */ + +ubi_avlNodePtr ubi_avlInitNode( ubi_avlNodePtr NodePtr ); + /* ------------------------------------------------------------------------ ** + * Initialize a tree node. + * + * Input: NodePtr - a pointer to a ubi_btNode structure to be + * initialized. + * Output: a pointer to the initialized ubi_avlNode structure (ie. the + * same as the input pointer). + * ------------------------------------------------------------------------ ** + */ + +ubi_trBool ubi_avlInsert( ubi_btRootPtr RootPtr, + ubi_avlNodePtr NewNode, + ubi_btItemPtr ItemPtr, + ubi_avlNodePtr *OldNode ); + /* ------------------------------------------------------------------------ ** + * This function uses a non-recursive algorithm to add a new element to + * the tree. + * + * Input: RootPtr - a pointer to the ubi_btRoot structure that indicates + * the root of the tree to which NewNode is to be added. + * NewNode - a pointer to an ubi_avlNode structure that is NOT + * part of any tree. + * ItemPtr - A pointer to the sort key that is stored within + * *NewNode. ItemPtr MUST point to information stored + * in *NewNode or an EXACT DUPLICATE. The key data + * indicated by ItemPtr is used to place the new node + * into the tree. + * OldNode - a pointer to an ubi_btNodePtr. When searching + * the tree, a duplicate node may be found. If + * duplicates are allowed, then the new node will + * be simply placed into the tree. If duplicates + * are not allowed, however, then one of two things + * may happen. + * 1) if overwritting *is not* allowed, this + * function will return FALSE (indicating that + * the new node could not be inserted), and + * *OldNode will point to the duplicate that is + * still in the tree. + * 2) if overwritting *is* allowed, then this + * function will swap **OldNode for *NewNode. + * In this case, *OldNode will point to the node + * that was removed (thus allowing you to free + * the node). + * ** If you are using overwrite mode, ALWAYS ** + * ** check the return value of this parameter! ** + * Note: You may pass NULL in this parameter, the + * function knows how to cope. If you do this, + * however, there will be no way to return a + * pointer to an old (ie. replaced) node (which is + * a problem if you are using overwrite mode). + * + * Output: a boolean value indicating success or failure. The function + * will return FALSE if the node could not be added to the tree. + * Such failure will only occur if duplicates are not allowed, + * nodes cannot be overwritten, AND a duplicate key was found + * within the tree. + * ------------------------------------------------------------------------ ** + */ + +ubi_avlNodePtr ubi_avlRemove( ubi_btRootPtr RootPtr, + ubi_avlNodePtr DeadNode ); + /* ------------------------------------------------------------------------ ** + * This function removes the indicated node from the tree, after which the + * tree is rebalanced. + * + * Input: RootPtr - A pointer to the header of the tree that contains + * the node to be removed. + * DeadNode - A pointer to the node that will be removed. + * + * Output: This function returns a pointer to the node that was removed + * from the tree (ie. the same as DeadNode). + * + * Note: The node MUST be in the tree indicated by RootPtr. If not, + * strange and evil things will happen to your trees. + * ------------------------------------------------------------------------ ** + */ + +int ubi_avlModuleID( int size, char *list[] ); + /* ------------------------------------------------------------------------ ** + * Returns a set of strings that identify the module. + * + * Input: size - The number of elements in the array <list>. + * list - An array of pointers of type (char *). This array + * should, initially, be empty. This function will fill + * in the array with pointers to strings. + * Output: The number of elements of <list> that were used. If this value + * is less than <size>, the values of the remaining elements are + * not guaranteed. + * + * Notes: Please keep in mind that the pointers returned indicate strings + * stored in static memory. Don't free() them, don't write over + * them, etc. Just read them. + * ------------------------------------------------------------------------ ** + */ + +/* -------------------------------------------------------------------------- ** + * Masquarade... + * + * This set of defines allows you to write programs that will use any of the + * implemented binary tree modules (currently BinTree, AVLtree, and SplayTree). + * Instead of using ubi_avl... or ubi_bt, use ubi_tr... and select the tree + * type by including the appropriate module header. + */ + +#undef ubi_trNode +#undef ubi_trNodePtr +#define ubi_trNode ubi_avlNode +#define ubi_trNodePtr ubi_avlNodePtr + +#undef ubi_trInitNode +#define ubi_trInitNode( Np ) ubi_avlInitNode( (ubi_avlNodePtr)(Np) ) + +#undef ubi_trInsert +#define ubi_trInsert( Rp, Nn, Ip, On ) \ + ubi_avlInsert( (ubi_btRootPtr)(Rp), (ubi_avlNodePtr)(Nn), \ + (ubi_btItemPtr)(Ip), (ubi_avlNodePtr *)(On) ) + +#undef ubi_trRemove +#define ubi_trRemove( Rp, Dn ) \ + ubi_avlRemove( (ubi_btRootPtr)(Rp), (ubi_avlNodePtr)(Dn) ) + +#undef ubi_trLocate +#define ubi_trLocate( Rp, Ip, Op ) \ + (ubi_avlNodePtr)ubi_btLocate( (ubi_btRootPtr)(Rp), \ + (ubi_btItemPtr)(Ip), \ + (ubi_trCompOps)(Op) ) + +#undef ubi_trFind +#define ubi_trFind( Rp, Ip ) \ + (ubi_avlNodePtr)ubi_btFind( (ubi_btRootPtr)(Rp), (ubi_btItemPtr)(Ip) ) + +#undef ubi_trNext +#define ubi_trNext( P ) (ubi_avlNodePtr)ubi_btNext( (ubi_btNodePtr)(P) ) + +#undef ubi_trPrev +#define ubi_trPrev( P ) (ubi_avlNodePtr)ubi_btPrev( (ubi_btNodePtr)(P) ) + +#undef ubi_trFirst +#define ubi_trFirst( P ) (ubi_avlNodePtr)ubi_btFirst( (ubi_btNodePtr)(P) ) + +#undef ubi_trLast +#define ubi_trLast( P ) (ubi_avlNodePtr)ubi_btLast( (ubi_btNodePtr)(P) ) + +#undef ubi_trFirstOf +#define ubi_trFirstOf( Rp, Ip, P ) \ + (ubi_avlNodePtr)ubi_btFirstOf( (ubi_btRootPtr)(Rp), \ + (ubi_btItemPtr)(Ip), \ + (ubi_btNodePtr)(P) ) + +#undef ubi_trLastOf +#define ubi_trLastOf( Rp, Ip, P ) \ + (ubi_avlNodePtr)ubi_btLastOf( (ubi_btRootPtr)(Rp), \ + (ubi_btItemPtr)(Ip), \ + (ubi_btNodePtr)(P) ) + +#undef ubi_trLeafNode +#define ubi_trLeafNode( Nd ) \ + (ubi_avlNodePtr)ubi_btLeafNode( (ubi_btNodePtr)(Nd) ) + +#undef ubi_trModuleID +#define ubi_trModuleID( s, l ) ubi_avlModuleID( s, l ) + + +/* =========================== End ubi_AVLtree.h =========================== */ +#endif /* ubi_AVLtree_H */ |