diff options
| -rw-r--r-- | source3/ubi_AVLtree.c | 699 | ||||
| -rw-r--r-- | source3/ubi_AVLtree.h | 340 | ||||
| -rw-r--r-- | source3/ubi_BinTree.c | 1042 | ||||
| -rw-r--r-- | source3/ubi_BinTree.h | 745 | ||||
| -rw-r--r-- | source3/ubi_SplayTree.c | 472 | ||||
| -rw-r--r-- | source3/ubi_SplayTree.h | 339 | ||||
| -rw-r--r-- | source3/ubi_dLinkList.c | 152 | ||||
| -rw-r--r-- | source3/ubi_dLinkList.h | 163 |
8 files changed, 3952 insertions, 0 deletions
diff --git a/source3/ubi_AVLtree.c b/source3/ubi_AVLtree.c new file mode 100644 index 0000000000..730392a472 --- /dev/null +++ b/source3/ubi_AVLtree.c @@ -0,0 +1,699 @@ +/* ========================================================================== ** + * ubi_AVLtree.c + * + * 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 file implements the core of the height-balanced (AVL) tree management + * routines. The header file, ubi_AVLtree.h, contains function prototypes + * for all "exported" functions. + * + * -------------------------------------------------------------------------- ** + * + * 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.c,v $ + * Revision 1.1 1997/10/09 04:09:51 crh + * This is my library of lists and trees. My hope is to replace all of the + * hard coded linked lists that are currently used in Samba with calls to + * these modules. This should make the code simpler, smaller, and (I hope) + * faster. The tree code, in particular, should speed up processing where + * large lists are involved. + * + * Chris -)----- + * + * Revision 2.4 1997/07/26 04:36:20 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 04:41:35 crh + * Changed TRUE and FALSE to ubi_TRUE and ubi_FALSE to avoid causing + * problems. + * + * Revision 2.2 1995/10/03 22:16:01 CRH + * Ubisized! + * + * Revision 2.1 95/03/09 23:45:59 CRH + * Added the ModuleID static string and function. These modules are now + * self-identifying. + * + * Revision 2.0 95/03/05 14:10:51 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 22:58:56 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_AVLtree.h" /* Header for THIS module. */ +#include <stdlib.h> /* Standard C definitions, etc. */ + +/* ========================================================================== ** + * Static data. + */ + +static char ModuleID[] = "ubi_AVLtree\n\ +\t$Revision: 1.1 $\n\ +\t$Date: 1997/10/09 04:09:51 $\n\ +\t$Author: crh $\n"; + +/* ========================================================================== ** + * The next set of functions are the AVL balancing routines. There are left + * and right, single and double rotations. The rotation routines handle the + * rotations and reconnect all tree pointers that might get confused by the + * rotations. A pointer to the new subtree root node is returned. + * + * Note that L1 and R1 are identical, except that all the RIGHTs and LEFTs + * are reversed. The same is true for L2 and R2. I'm sure that there is + * a clever way to reduce the amount of code by combining these functions, + * but it might involve additional overhead, and it would probably be a pain + * to read, debug, etc. + * -------------------------------------------------------------------------- ** + */ + +static ubi_avlNodePtr L1( ubi_avlNodePtr p ) + /* ------------------------------------------------------------------------ ** + * Single rotate left. + * + * Input: p - Pointer to the root of a tree (possibly a subtree). + * Output: A pointer to the new root of the same subtree (now that node + * p has been moved). + * ------------------------------------------------------------------------ ** + */ + { + ubi_avlNodePtr tmp; + + tmp = p->Link[RIGHT]; + p->Link[RIGHT] = tmp->Link[LEFT]; + tmp->Link[LEFT] = p; + + tmp->Link[PARENT] = p->Link[PARENT]; + tmp->gender = p->gender; + if(tmp->Link[PARENT]) + (tmp->Link[PARENT])->Link[(tmp->gender)] = tmp; + p->Link[PARENT] = tmp; + p->gender = LEFT; + if( p->Link[RIGHT] ) + { + p->Link[RIGHT]->Link[PARENT] = p; + (p->Link[RIGHT])->gender = RIGHT; + } + p->balance -= Normalize( tmp->balance ); + (tmp->balance)--; + return( tmp ); + } /* L1 */ + +static ubi_avlNodePtr R1( ubi_avlNodePtr p ) + /* ------------------------------------------------------------------------ ** + * Single rotate right. + * + * Input: p - Pointer to the root of a tree (possibly a subtree). + * Output: A pointer to the new root of the same subtree (now that node + * p has been moved). + * ------------------------------------------------------------------------ ** + */ + { + ubi_avlNodePtr tmp; + + tmp = p->Link[LEFT]; + p->Link[LEFT] = tmp->Link[RIGHT]; + tmp->Link[RIGHT] = p; + + tmp->Link[PARENT] = p->Link[PARENT]; + tmp->gender = p->gender; + if(tmp->Link[PARENT]) + (tmp->Link[PARENT])->Link[(tmp->gender)] = tmp; + p->Link[PARENT] = tmp; + p->gender = RIGHT; + if(p->Link[LEFT]) + { + p->Link[LEFT]->Link[PARENT] = p; + p->Link[LEFT]->gender = LEFT; + } + p->balance -= Normalize( tmp->balance ); + (tmp->balance)++; + return( tmp ); + } /* R1 */ + +static ubi_avlNodePtr L2( ubi_avlNodePtr tree ) + /* ------------------------------------------------------------------------ ** + * Double rotate left. + * + * Input: p - Pointer to the root of a tree (possibly a subtree). + * Output: A pointer to the new root of the same subtree (now that node + * p has been moved). + * ------------------------------------------------------------------------ ** + */ + { + ubi_avlNodePtr tmp, newroot; + + tmp = tree->Link[RIGHT]; + newroot = tmp->Link[LEFT]; + tmp->Link[LEFT] = newroot->Link[RIGHT]; + newroot->Link[RIGHT] = tmp; + tree->Link[RIGHT] = newroot->Link[LEFT]; + newroot->Link[LEFT] = tree; + + newroot->Link[PARENT] = tree->Link[PARENT]; + newroot->gender = tree->gender; + tree->Link[PARENT] = newroot; + tree->gender = LEFT; + tmp->Link[PARENT] = newroot; + tmp->gender = RIGHT; + + if( tree->Link[RIGHT] ) + { + tree->Link[RIGHT]->Link[PARENT] = tree; + tree->Link[RIGHT]->gender = RIGHT; + } + if( tmp->Link[LEFT] ) + { + tmp->Link[LEFT]->Link[PARENT] = tmp; + tmp->Link[LEFT]->gender = LEFT; + } + if(newroot->Link[PARENT]) + newroot->Link[PARENT]->Link[newroot->gender] = newroot; + + switch( newroot->balance ) + { + case LEFT : + tree->balance = EQUAL; tmp->balance = RIGHT; break; + case EQUAL: + tree->balance = EQUAL; tmp->balance = EQUAL; break; + case RIGHT: + tree->balance = LEFT; tmp->balance = EQUAL; break; + } + newroot->balance = EQUAL; + return( newroot ); + } /* L2 */ + +static ubi_avlNodePtr R2( ubi_avlNodePtr tree ) + /* ------------------------------------------------------------------------ ** + * Double rotate right. + * + * Input: p - Pointer to the root of a tree (possibly a subtree). + * Output: A pointer to the new root of the same subtree (now that node + * p has been moved). + * ------------------------------------------------------------------------ ** + */ + { + ubi_avlNodePtr tmp, newroot; + + tmp = tree->Link[LEFT]; + newroot = tmp->Link[RIGHT]; + tmp->Link[RIGHT] = newroot->Link[LEFT]; + newroot->Link[LEFT] = tmp; + tree->Link[LEFT] = newroot->Link[RIGHT]; + newroot->Link[RIGHT] = tree; + + newroot->Link[PARENT] = tree->Link[PARENT]; + newroot->gender = tree->gender; + tree->Link[PARENT] = newroot; + tree->gender = RIGHT; + tmp->Link[PARENT] = newroot; + tmp->gender = LEFT; + + if( tree->Link[LEFT] ) + { + tree->Link[LEFT]->Link[PARENT] = tree; + tree->Link[LEFT]->gender = LEFT; + } + if( tmp->Link[RIGHT] ) + { + tmp->Link[RIGHT]->Link[PARENT] = tmp; + tmp->Link[RIGHT]->gender = RIGHT; + } + if(newroot->Link[PARENT]) + newroot->Link[PARENT]->Link[newroot->gender] = newroot; + + switch( newroot->balance ) + { + case LEFT : + tree->balance = RIGHT; tmp->balance = EQUAL; break; + case EQUAL : + tree->balance = EQUAL; tmp->balance = EQUAL; break; + case RIGHT : + tree->balance = EQUAL; tmp->balance = LEFT; break; + } + newroot->balance = EQUAL; + return( newroot ); + } /* R2 */ + + +static ubi_avlNodePtr Adjust( ubi_avlNodePtr p, char LorR ) + /* ------------------------------------------------------------------------ ** + * Adjust the balance value at node *p. If necessary, rotate the subtree + * rooted at p. + * + * Input: p - A pointer to the node to be adjusted. One of the + * subtrees of this node has changed height, so the + * balance value at this node must be adjusted, possibly + * by rotating the tree at this node. + * LorR - Indicates the TALLER subtree. + * + * Output: A pointer to the (possibly new) root node of the subtree. + * + * Notes: This function may be called after a node has been added *or* + * deleted, so LorR indicates the TALLER subtree. + * ------------------------------------------------------------------------ ** + */ + { + if( p->balance != LorR ) + p->balance += Normalize(LorR); + else + { + char tallerbal; /* Balance value of the root of the taller subtree of p. */ + + tallerbal = p->Link[LorR]->balance; + if( ( EQUAL == tallerbal ) || ( p->balance == tallerbal ) ) + p = ( (LEFT==LorR) ? R1(p) : L1(p) ); /* single rotation */ + else + p = ( (LEFT==LorR) ? R2(p) : L2(p) ); /* double rotation */ + } + return( p ); + } /* Adjust */ + +static ubi_avlNodePtr Rebalance( ubi_avlNodePtr Root, + ubi_avlNodePtr subtree, + char LorR ) + /* ------------------------------------------------------------------------ ** + * Rebalance the tree following an insertion. + * + * Input: Root - A pointer to the root node of the whole tree. + * subtree - A pointer to the node that has just gained a new + * child. + * LorR - Gender of the child that has just been gained. + * + * Output: A pointer to the (possibly new) root of the AVL tree. + * Rebalancing the tree moves nodes around a bit, so the node + * that *was* the root, may not be the root when we're finished. + * + * Notes: Rebalance() must walk up the tree from where we are (which is + * where the latest change occurred), rebalancing the subtrees + * along the way. The rebalancing operation can stop if the + * change at the current subtree root won't affect the rest of + * the tree. In the case of an addition, if a subtree root's + * balance becomes EQUAL, then we know that the height of that + * subtree has not changed, so we can exit. + * ------------------------------------------------------------------------ ** + */ + { + while( subtree ) + { + subtree = Adjust( subtree, LorR ); + if( PARENT == subtree->gender ) + return( subtree ); + if( EQUAL == subtree->balance ) + return( Root ); + LorR = subtree->gender; + subtree = subtree->Link[PARENT]; + } + return( Root ); + } /* Rebalance */ + +static ubi_avlNodePtr Debalance( ubi_avlNodePtr Root, + ubi_avlNodePtr subtree, + char LorR ) + /* ------------------------------------------------------------------------ ** + * Rebalance the tree following a deletion. + * + * Input: Root - A pointer to the root node of the whole tree. + * subtree - A pointer to the node who's child has just "left the + * nest". + * LorR - Gender of the child that left. + * + * Output: A pointer to the (possibly new) root of the AVL tree. + * Rebalancing the tree moves nodes around a bit, so the node + * that *was* the root, may not be the root when we're finished. + * + * Notes: Debalance() is subtly different from Rebalance() (above) in + * two respects. + * * When it calls Adjust(), it passes the *opposite* of LorR. + * This is because LorR, as passed into Debalance() indicates + * the shorter subtree. As we move up the tree, LorR is + * assigned the gender of the node that we are leaving (i.e., + * the subtree that we just rebalanced). + * * We know that a subtree has not changed height if the + * balance becomes LEFT or RIGHT. This is the *opposite* of + * what happens in Rebalance(). + * ------------------------------------------------------------------------ ** + */ + { + while( subtree ) + { + subtree = Adjust( subtree, RevWay(LorR) ); + if( PARENT == subtree->gender ) + return( subtree ); + if( EQUAL != subtree->balance ) + return( Root ); + LorR = subtree->gender; + subtree = subtree->Link[PARENT]; + } + return( Root ); + } /* Debalance */ + + +/* -------------------------------------------------------------------------- ** + * The next two functions are used for general tree manipulation. They are + * each slightly different from their ubi_BinTree counterparts. + * -------------------------------------------------------------------------- ** + */ + +static void ReplaceNode( ubi_avlNodePtr *parent, + ubi_avlNodePtr oldnode, + ubi_avlNodePtr newnode ) + /* ------------------------------------------------------------------------ ** + * Remove node oldnode from the tree, replacing it with node newnode. + * + * Input: + * parent - A pointer to he parent pointer of the node to be + * replaced. <parent> may point to the Link[] field of + * a parent node, or it may indicate the root pointer at + * the top of the tree. + * oldnode - A pointer to the node that is to be replaced. + * newnode - A pointer to the node that is to be installed in the + * place of <*oldnode>. + * + * Notes: Don't forget to free oldnode. + * The only difference between this function and the ubi_bt + * version is that the node size is sizeof( ubi_avlNode ), not + * sizeof( ubi_btNode ). + * ------------------------------------------------------------------------ ** + */ + { + register int i; + register int avlNodeSize = sizeof( ubi_avlNode ); + + for( i = 0; i < avlNodeSize; i++ ) + ((unsigned char *)newnode)[i] = ((unsigned char *)oldnode)[i]; + (*parent) = newnode; + + if(oldnode->Link[LEFT ] ) + (oldnode->Link[LEFT ])->Link[PARENT] = newnode; + if(oldnode->Link[RIGHT] ) + (oldnode->Link[RIGHT])->Link[PARENT] = newnode; + } /* ReplaceNode */ + +static void SwapNodes( ubi_btRootPtr RootPtr, + ubi_avlNodePtr Node1, + ubi_avlNodePtr Node2 ) + /* ------------------------------------------------------------------------ ** + * This function swaps two nodes in the tree. Node1 will take the place of + * Node2, and Node2 will fill in the space left vacant by Node 1. + * + * Input: + * RootPtr - pointer to the tree header structure for this tree. + * Node1 - \ + * > These are the two nodes which are to be swapped. + * Node2 - / + * + * Notes: + * This function does a three step swap, using a dummy node as a place + * holder. This function is used by ubi_avlRemove(). + * The only difference between this function and its ubi_bt counterpart + * is that the nodes are ubi_avlNodes, not ubi_btNodes. + * ------------------------------------------------------------------------ ** + */ + { + ubi_avlNodePtr *Parent; + ubi_avlNode dummy; + ubi_avlNodePtr dummy_p = &dummy; + + if( Node1->Link[PARENT] ) + Parent = &((Node1->Link[PARENT])->Link[Node1->gender]); + else + Parent = (ubi_avlNodePtr *)&(RootPtr->root); + ReplaceNode( Parent, Node1, dummy_p ); + + if( Node2->Link[PARENT] ) + Parent = &((Node2->Link[PARENT])->Link[Node2->gender]); + else + Parent = (ubi_avlNodePtr *)&(RootPtr->root); + ReplaceNode( Parent, Node2, Node1 ); + + if( dummy_p->Link[PARENT] ) + Parent = &((dummy_p->Link[PARENT])->Link[dummy_p->gender]); + else + Parent = (ubi_avlNodePtr *)&(RootPtr->root); + ReplaceNode( Parent, dummy_p, Node2 ); + } /* SwapNodes */ + + +/* ========================================================================== ** + * Public, exported (ie. not static-ly declared) functions... + * -------------------------------------------------------------------------- ** + */ + +ubi_avlNodePtr ubi_avlInitNode( ubi_avlNodePtr NodePtr ) + /* ------------------------------------------------------------------------ ** + * Initialize a tree node. + * + * Input: NodePtr - 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). + * ------------------------------------------------------------------------ ** + */ + { + (void)ubi_btInitNode( (ubi_btNodePtr)NodePtr ); + NodePtr->balance = EQUAL; + return( NodePtr ); + } /* ubi_avlInitNode */ + +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 OtherP; + + if( !(OldNode) ) OldNode = &OtherP; + if( ubi_btInsert( RootPtr, + (ubi_btNodePtr)NewNode, + ItemPtr, + (ubi_btNodePtr *)OldNode ) ) + { + if( (*OldNode) ) + NewNode->balance = (*OldNode)->balance; + else + { + NewNode->balance = EQUAL; + RootPtr->root = (ubi_btNodePtr)Rebalance( (ubi_avlNodePtr)RootPtr->root, + NewNode->Link[PARENT], + NewNode->gender ); + } + return( ubi_trTRUE ); + } + return( ubi_trFALSE ); /* Failure: could not replace an existing node. */ + } /* ubi_avlInsert */ + +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. + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr p, + *parentp; + + /* if the node has both left and right subtrees, then we have to swap + * it with another node. + */ + if( (DeadNode->Link[LEFT]) && (DeadNode->Link[RIGHT]) ) + SwapNodes( RootPtr, DeadNode, ubi_trPrev( DeadNode ) ); + + /* The parent of the node to be deleted may be another node, or it may be + * the root of the tree. Since we're not sure, it's best just to have + * a pointer to the parent pointer, whatever it is. + */ + if( DeadNode->Link[PARENT] ) + parentp = (ubi_btNodePtr *) + &((DeadNode->Link[PARENT])->Link[(DeadNode->gender)]); + else + parentp = &( RootPtr->root ); + + /* Now link the parent to the only grand-child. Patch up the gender and + * such, and rebalance. + */ + if( EQUAL == DeadNode->balance ) + (*parentp) = NULL; + else + { + p = (ubi_btNodePtr)(DeadNode->Link[(DeadNode->balance)]); + p->Link[PARENT] = (ubi_btNodePtr)DeadNode->Link[PARENT]; + p->gender = DeadNode->gender; + (*parentp) = p; + } + RootPtr->root = (ubi_btNodePtr)Debalance( (ubi_avlNodePtr)RootPtr->root, + DeadNode->Link[PARENT], + DeadNode->gender ); + + (RootPtr->count)--; + return( DeadNode ); + } /* ubi_avlRemove */ + +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. + * ------------------------------------------------------------------------ ** + */ + { + if( size > 0 ) + { + list[0] = ModuleID; + if( size > 1 ) + return( 1 + ubi_btModuleID( --size, &(list[1]) ) ); + return( 1 ); + } + return( 0 ); + } /* ubi_avlModuleID */ + +/* ============================== The End ============================== */ diff --git a/source3/ubi_AVLtree.h b/source3/ubi_AVLtree.h new file mode 100644 index 0000000000..27d84a2896 --- /dev/null +++ b/source3/ubi_AVLtree.h @@ -0,0 +1,340 @@ +#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 1997/10/09 04:09:51 crh + * This is my library of lists and trees. My hope is to replace all of the + * hard coded linked lists that are currently used in Samba with calls to + * these modules. This should make the code simpler, smaller, and (I hope) + * faster. The tree code, in particular, should speed up processing where + * large lists are involved. + * + * Chris -)----- + * + * 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 */ diff --git a/source3/ubi_BinTree.c b/source3/ubi_BinTree.c new file mode 100644 index 0000000000..e6db1a4816 --- /dev/null +++ b/source3/ubi_BinTree.c @@ -0,0 +1,1042 @@ +/* ========================================================================== ** + * ubi_BinTree.c + * + * Copyright (C) 1991-1997 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * -------------------------------------------------------------------------- ** + * + * ubi_BinTree manages a simple binary tree. Nothing fancy here. No height + * balancing, no restructuring. Still, a good tool for creating short, low- + * overhead sorted lists of things that need to be found in a hurry. + * + * In addition, this module provides a good basis for creating other types + * of binary tree handling modules. + * + * -------------------------------------------------------------------------- ** + * + * 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_BinTree.c,v $ + * Revision 1.1 1997/10/09 04:09:52 crh + * This is my library of lists and trees. My hope is to replace all of the + * hard coded linked lists that are currently used in Samba with calls to + * these modules. This should make the code simpler, smaller, and (I hope) + * faster. The tree code, in particular, should speed up processing where + * large lists are involved. + * + * Chris -)----- + * + * Revision 2.4 1997/07/26 04:11:10 crh + * + Just to be annoying I changed ubi_TRUE and ubi_FALSE to ubi_trTRUE + * and ubi_trFALSE. + * + There is now a type ubi_trBool to go with ubi_trTRUE and ubi_trFALSE. + * + There used to be something called "ubi_TypeDefs.h". I got rid of it. + * + Added function ubi_btLeafNode(). + * + * Revision 2.3 1997/06/03 05:16:17 crh + * Changed TRUE and FALSE to ubi_TRUE and ubi_FALSE to avoid conflicts. + * Also changed the interface to function InitTree(). See the comments + * for this function for more information. + * + * Revision 2.2 1995/10/03 22:00:07 CRH + * Ubisized! + * + * Revision 2.1 95/03/09 23:37:10 CRH + * Added the ModuleID static string and function. These modules are now + * self-identifying. + * + * Revision 2.0 95/02/27 22:00:17 CRH + * Revision 2.0 of this program includes the following changes: + * + * 1) A fix to a major typo in the RepaceNode() function. + * 2) The addition of the static function Border(). + * 3) The addition of the public functions FirstOf() and LastOf(), which + * use Border(). These functions are used with trees that allow + * duplicate keys. + * 4) A complete rewrite of the Locate() function. Locate() now accepts + * a "comparison" operator. + * 5) Overall enhancements to both code and comments. + * + * I decided to give this a new major rev number because the interface has + * changed. In particular, there are two new functions, and changes to the + * Locate() function. + * + * Revision 1.0 93/10/15 22:44:59 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 - June, 1991 - Written by Christopher R. Hertel (CRH). + * + * ========================================================================== ** + */ + +#include "ubi_BinTree.h" /* Header for this module */ +#include <stdlib.h> /* Standard C definitions. */ + +/* ========================================================================== ** + * Static data. + */ + +static char ModuleID[] = "ubi_BinTree\n\ +\t$Revision: 1.1 $\n\ +\t$Date: 1997/10/09 04:09:52 $\n\ +\t$Author: crh $\n"; + +/* ========================================================================== ** + * Internal (private) functions. + */ + +static ubi_btNodePtr qFind( ubi_btCompFunc cmp, + ubi_btItemPtr FindMe, + register ubi_btNodePtr p ) + /* ------------------------------------------------------------------------ ** + * This function performs a non-recursive search of a tree for a node + * matching a specific key. It is called "qFind()" because it is + * faster that TreeFind (below). + * + * Input: + * cmp - a pointer to the tree's comparison function. + * FindMe - a pointer to the key value for which to search. + * p - a pointer to the starting point of the search. <p> + * is considered to be the root of a subtree, and only + * the subtree will be searched. + * + * Output: + * A pointer to a node with a key that matches the key indicated by + * FindMe, or NULL if no such node was found. + * + * Note: In a tree that allows duplicates, the pointer returned *might + * not* point to the (sequentially) first occurance of the + * desired key. + * ------------------------------------------------------------------------ ** + */ + { + char tmp; + + while( p && (( tmp = AbNormal((*cmp)(FindMe, p)) ) != EQUAL) ) + p = p->Link[tmp]; + + return( p ); + } /* qFind */ + +static ubi_btNodePtr TreeFind( ubi_btItemPtr findme, + ubi_btNodePtr p, + ubi_btNodePtr *parentp, + char *gender, + ubi_btCompFunc CmpFunc ) + /* ------------------------------------------------------------------------ ** + * TreeFind() searches a tree for a given value (findme). It will return a + * pointer to the target node, if found, or NULL if the target node was not + * found. + * + * TreeFind() also returns, via parameters, a pointer to the parent of the + * target node, and a LEFT or RIGHT value indicating which child of the + * parent is the target node. *If the target is not found*, then these + * values indicate the place at which the target *should be found*. This + * is useful when inserting a new node into a tree or searching for nodes + * "near" the target node. + * + * The parameters are: + * + * findme - is a pointer to the key information to be searched for. + * p - points to the root of the tree to be searched. + * parentp - will return a pointer to a pointer to the !parent! of the + * target node, which can be especially usefull if the target + * was not found. + * gender - returns LEFT or RIGHT to indicate which child of *parentp + * was last searched. + * CmpFunc - points to the comparison function. + * + * This function is called by ubi_btLocate() and ubi_btInsert(). + * ------------------------------------------------------------------------ ** + */ + { + register ubi_btNodePtr tmp_p = p; + ubi_btNodePtr tmp_pp = NULL; + char tmp_sex = EQUAL; + char tmp_cmp; + + while( tmp_p && (EQUAL != (tmp_cmp = AbNormal((*CmpFunc)(findme, tmp_p)))) ) + { + tmp_pp = tmp_p; /* Keep track of previous node. */ + tmp_sex = tmp_cmp; /* Keep track of sex of child. */ + tmp_p = tmp_p->Link[tmp_cmp]; /* Go to child. */ + } + *parentp = tmp_pp; /* Return results. */ + *gender = tmp_sex; + return( tmp_p ); + } /* TreeFind */ + +static void ReplaceNode( ubi_btNodePtr *parent, + ubi_btNodePtr oldnode, + ubi_btNodePtr newnode ) + /* ------------------------------------------------------------------ * + * Remove node oldnode from the tree, replacing it with node newnode. + * + * Input: + * parent - A pointer to he parent pointer of the node to be + * replaced. <parent> may point to the Link[] field of + * a parent node, or it may indicate the root pointer at + * the top of the tree. + * oldnode - A pointer to the node that is to be replaced. + * newnode - A pointer to the node that is to be installed in the + * place of <*oldnode>. + * + * Notes: Don't forget to free oldnode. + * Also, this function used to have a really nasty typo + * bug. "oldnode" and "newnode" were swapped in the line + * that now reads: + * ((unsigned char *)newnode)[i] = ((unsigned char *)oldnode)[i]; + * Bleah! + * ------------------------------------------------------------------ * + */ + { + register int i; + register int btNodeSize = sizeof( ubi_btNode ); + + for( i = 0; i < btNodeSize; i++ ) /* Copy node internals to new node. */ + ((unsigned char *)newnode)[i] = ((unsigned char *)oldnode)[i]; + (*parent) = newnode; /* Old node's parent points to new child. */ + /* Now tell the children about their new step-parent. */ + if( oldnode->Link[LEFT ] ) (oldnode->Link[LEFT ])->Link[PARENT] = newnode; + if( oldnode->Link[RIGHT] ) (oldnode->Link[RIGHT])->Link[PARENT] = newnode; + } /* ReplaceNode */ + +static void SwapNodes( ubi_btRootPtr RootPtr, + ubi_btNodePtr Node1, + ubi_btNodePtr Node2 ) + /* ------------------------------------------------------------------------ ** + * This function swaps two nodes in the tree. Node1 will take the place of + * Node2, and Node2 will fill in the space left vacant by Node 1. + * + * Input: + * RootPtr - pointer to the tree header structure for this tree. + * Node1 - \ + * > These are the two nodes which are to be swapped. + * Node2 - / + * + * Notes: + * This function does a three step swap, using a dummy node as a place + * holder. This function is used by ubi_btRemove(). + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr *Parent; + ubi_btNode dummy; + ubi_btNodePtr dummy_p = &dummy; + + /* Replace Node 1 with the dummy, thus removing Node1 from the tree. */ + if( Node1->Link[PARENT] ) + Parent = &((Node1->Link[PARENT])->Link[Node1->gender]); + else + Parent = &(RootPtr->root); + ReplaceNode( Parent, Node1, dummy_p ); + + /* Swap Node 1 with Node 2, placing Node 1 back into the tree. */ + if( Node2->Link[PARENT] ) + Parent = &((Node2->Link[PARENT])->Link[Node2->gender]); + else + Parent = &(RootPtr->root); + ReplaceNode( Parent, Node2, Node1 ); + + /* Swap Node 2 and the dummy, thus placing Node 2 back into the tree. */ + if( dummy_p->Link[PARENT] ) + Parent = &((dummy_p->Link[PARENT])->Link[dummy_p->gender]); + else + Parent = &(RootPtr->root); + ReplaceNode( Parent, dummy_p, Node2 ); + } /* SwapNodes */ + +/* -------------------------------------------------------------------------- ** + * These routines allow you to walk through the tree, forwards or backwards. + */ + +static ubi_btNodePtr SubSlide( register ubi_btNodePtr P, + register char whichway ) + /* ------------------------------------------------------------------------ ** + * Slide down the side of a subtree. + * + * Given a starting node, this function returns a pointer to the LEFT-, or + * RIGHT-most descendent, *or* (if whichway is PARENT) to the tree root. + * + * Input: P - a pointer to a starting place. + * whichway - the direction (LEFT, RIGHT, or PARENT) in which to + * travel. + * Output: A pointer to a node that is either the root, or has no + * whichway-th child but is within the subtree of P. Note that + * the return value may be the same as P. The return value *will + * be* NULL if P is NULL. + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr Q = NULL; + + while( P ) + { + Q = P; + P = P->Link[ whichway ]; + } + return( Q ); + } /* SubSlide */ + +static ubi_btNodePtr Neighbor( register ubi_btNodePtr P, + register char whichway ) + /* ------------------------------------------------------------------------ ** + * Given starting point p, return the (key order) next or preceeding node + * in the tree. + * + * Input: P - Pointer to our starting place node. + * whichway - the direction in which to travel to find the + * neighbor, i.e., the RIGHT neighbor or the LEFT + * neighbor. + * + * Output: A pointer to the neighboring node, or NULL if P was NULL. + * + * Notes: If whichway is PARENT, the results are unpredictable. + * ------------------------------------------------------------------------ ** + */ + { + if( P ) + { + if( P->Link[ whichway ] ) + return( SubSlide( P->Link[ whichway ], (char)RevWay(whichway) ) ); + else + while( P->Link[ PARENT ] ) + { + if( (P->Link[ PARENT ])->Link[ whichway ] == P ) + P = P->Link[ PARENT ]; + else + return( P->Link[ PARENT ] ); + } + } + return( NULL ); + } /* Neighbor */ + +static ubi_btNodePtr Border( ubi_btRootPtr RootPtr, + ubi_btItemPtr FindMe, + ubi_btNodePtr p, + char whichway ) + /* ------------------------------------------------------------------------ ** + * Given starting point p, which has a key value equal to *FindMe, locate + * the first (index order) node with the same key value. + * + * This function is useful in trees that have can have duplicate keys. + * For example, consider the following tree: + * Tree Traversal + * 2 If <p> points to the root and <whichway> is RIGHT, 3 + * / \ then the return value will be a pointer to the / \ + * 2 2 RIGHT child of the root node. The tree on 2 5 + * / / \ the right shows the order of traversal. / / \ + * 1 2 3 1 4 6 + * + * Input: RootPtr - Pointer to the tree root structure. + * FindMe - Key value for comparisons. + * p - Pointer to the starting-point node. + * whichway - the direction in which to travel to find the + * neighbor, i.e., the RIGHT neighbor or the LEFT + * neighbor. + * + * Output: A pointer to the first (index, or "traversal", order) node with + * a Key value that matches *FindMe. + * + * Notes: If whichway is PARENT, or if the tree does not allow duplicate + * keys, this function will return <p>. + * ------------------------------------------------------------------------ ** + */ + { + register ubi_btNodePtr q; + + /* Exit if there's nothing that can be done. */ + if( !Dups_OK( RootPtr ) || (PARENT == whichway) ) + return( p ); + + /* First, if needed, move up the tree. We need to get to the root of the + * subtree that contains all of the matching nodes. + */ + q = p->Link[PARENT]; + while( q && (EQUAL == AbNormal( (*(RootPtr->cmp))(FindMe, q) )) ) + { + p = q; + q = p->Link[PARENT]; + } + + /* Next, move back down in the "whichway" direction. */ + q = p->Link[whichway]; + while( q ) + { + if( q = qFind( RootPtr->cmp, FindMe, q ) ) + { + p = q; + q = p->Link[whichway]; + } + } + return( p ); + } /* Border */ + + +/* ========================================================================== ** + * Exported utilities. + */ + +long ubi_btSgn( register long x ) + /* ------------------------------------------------------------------------ ** + * Return the sign of x; {negative,zero,positive} ==> {-1, 0, 1}. + * + * Input: x - a signed long integer value. + * + * Output: the "sign" of x, represented as follows: + * -1 == negative + * 0 == zero (no sign) + * 1 == positive + * + * Note: This utility is provided in order to facilitate the conversion + * of C comparison function return values into BinTree direction + * values: {LEFT, PARENT, EQUAL}. It is INCORPORATED into the + * AbNormal() conversion macro! + * + * ------------------------------------------------------------------------ ** + */ + { + return( (x)?((x>0)?(1):(-1)):(0) ); + } /* ubi_btSgn */ + +ubi_btNodePtr ubi_btInitNode( ubi_btNodePtr NodePtr ) + /* ------------------------------------------------------------------------ ** + * Initialize a tree node. + * + * Input: a pointer to a ubi_btNode structure to be initialized. + * Output: a pointer to the initialized ubi_btNode structure (ie. the + * same as the input pointer). + * ------------------------------------------------------------------------ ** + */ + { + NodePtr->Link[ LEFT ] = NULL; + NodePtr->Link[ PARENT ] = NULL; + NodePtr->Link[ RIGHT ] = NULL; + NodePtr->gender = EQUAL; + return( NodePtr ); + } /* ubi_btInitNode */ + +ubi_btRootPtr ubi_btInitTree( ubi_btRootPtr RootPtr, + ubi_btCompFunc CompFunc, + unsigned char Flags ) + /* ------------------------------------------------------------------------ ** + * Initialize the fields of a Tree Root header structure. + * + * Input: RootPtr - a pointer to an ubi_btRoot structure to be + * initialized. + * CompFunc - a pointer to a comparison function that will be used + * whenever nodes in the tree must be compared against + * outside values. + * Flags - One bytes worth of flags. Flags include + * ubi_trOVERWRITE and ubi_trDUPKEY. See the header + * file for more info. + * + * Output: a pointer to the initialized ubi_btRoot structure (ie. the + * same value as RootPtr). + * + * Note: The interface to this function has changed from that of + * previous versions. The <Flags> parameter replaces two + * boolean parameters that had the same basic effect. + * + * ------------------------------------------------------------------------ ** + */ + { + if( RootPtr ) + { + RootPtr->root = NULL; + RootPtr->count = 0L; + RootPtr->cmp = CompFunc; + RootPtr->flags = (Flags & ubi_trDUPKEY) ? ubi_trDUPKEY : Flags; + } /* There are only two supported flags, and they are + * mutually exclusive. ubi_trDUPKEY takes precedence + * over ubi_trOVERWRITE. + */ + return( RootPtr ); + } /* ubi_btInitTree */ + +ubi_trBool ubi_btInsert( ubi_btRootPtr RootPtr, + ubi_btNodePtr NewNode, + ubi_btItemPtr ItemPtr, + ubi_btNodePtr *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_btNode 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_btNodePtr OtherP, + parent = NULL; + char tmp; + + if( !(OldNode) ) /* If they didn't give us a pointer, supply our own. */ + OldNode = &OtherP; + + (void)ubi_btInitNode( NewNode ); /* Init the new node's BinTree fields. */ + + /* Find a place for the new node. */ + *OldNode = TreeFind(ItemPtr, (RootPtr->root), &parent, &tmp, (RootPtr->cmp)); + + /* Now add the node to the tree... */ + if (!(*OldNode)) /* The easy one: we have a space for a new node! */ + { + if (!(parent)) + RootPtr->root = NewNode; + else + { + parent->Link[tmp] = NewNode; + NewNode->Link[PARENT] = parent; + NewNode->gender = tmp; + } + (RootPtr->count)++; + return( ubi_trTRUE ); + } + + /* If we reach this point, we know that a duplicate node exists. This + * section adds the node to the tree if duplicate keys are allowed. + */ + if( Dups_OK(RootPtr) ) /* Key exists, add duplicate */ + { + ubi_btNodePtr q; + + tmp = RIGHT; + q = (*OldNode); + *OldNode = NULL; + while( q ) + { + parent = q; + if( tmp == EQUAL ) tmp = RIGHT; + q = q->Link[tmp]; + if ( q ) + tmp = AbNormal( (*(RootPtr->cmp))(ItemPtr, q) ); + } + parent->Link[tmp] = NewNode; + NewNode->Link[PARENT] = parent; + NewNode->gender = tmp; + (RootPtr->count)++; + return( ubi_trTRUE ); + } + + /* If we get to *this* point, we know that we are not allowed to have + * duplicate nodes, but our node keys match, so... may we replace the + * old one? + */ + if( Ovwt_OK(RootPtr) ) /* Key exists, we replace */ + { + if (!(parent)) + ReplaceNode( &(RootPtr->root), *OldNode, NewNode ); + else + ReplaceNode( &(parent->Link[(*OldNode)->gender]), *OldNode, NewNode ); + return( ubi_trTRUE ); + } + + return( ubi_trFALSE ); /* Failure: could not replace an existing node. */ + } /* ubi_btInsert */ + +ubi_btNodePtr ubi_btRemove( ubi_btRootPtr RootPtr, + ubi_btNodePtr DeadNode ) + /* ------------------------------------------------------------------------ ** + * This function removes the indicated node from the tree. + * + * 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. + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr p, + *parentp; + char tmp; + + /* if the node has both left and right subtrees, then we have to swap + * it with another node. The other node we choose will be the Prev()ious + * node, which is garunteed to have no RIGHT child. + */ + if( (DeadNode->Link[LEFT]) && (DeadNode->Link[RIGHT]) ) + SwapNodes( RootPtr, DeadNode, ubi_btPrev( DeadNode ) ); + + /* The parent of the node to be deleted may be another node, or it may be + * the root of the tree. Since we're not sure, it's best just to have + * a pointer to the parent pointer, whatever it is. + */ + if (DeadNode->Link[PARENT]) + parentp = &((DeadNode->Link[PARENT])->Link[DeadNode->gender]); + else + parentp = &( RootPtr->root ); + + /* Now link the parent to the only grand-child and patch up the gender. */ + tmp = ((DeadNode->Link[LEFT])?LEFT:RIGHT); + + p = (DeadNode->Link[tmp]); + if( p ) + { + p->Link[PARENT] = DeadNode->Link[PARENT]; + p->gender = DeadNode->gender; + } + (*parentp) = p; + + /* Finished, reduce the node count and return. */ + (RootPtr->count)--; + return( DeadNode ); + } /* ubi_btRemove */ + +ubi_btNodePtr ubi_btLocate( ubi_btRootPtr RootPtr, + ubi_btItemPtr FindMe, + ubi_trCompOps CompOp ) + /* ------------------------------------------------------------------------ ** + * The purpose of ubi_btLocate() is to find a node or set of nodes given + * a target value and a "comparison operator". The Locate() function is + * more flexible and (in the case of trees that may contain dupicate keys) + * more precise than the ubi_btFind() function. The latter is faster, + * but it only searches for exact matches and, if the tree contains + * duplicates, Find() may return a pointer to any one of the duplicate- + * keyed records. + * + * Input: + * RootPtr - A pointer to the header of the tree to be searched. + * FindMe - An ubi_btItemPtr that indicates the key for which to + * search. + * CompOp - One of the following: + * CompOp Return a pointer to the node with + * ------ --------------------------------- + * ubi_trLT - the last key value that is less + * than FindMe. + * ubi_trLE - the first key matching FindMe, or + * the last key that is less than + * FindMe. + * ubi_trEQ - the first key matching FindMe. + * ubi_trGE - the first key matching FindMe, or the + * first key greater than FindMe. + * ubi_trGT - the first key greater than FindMe. + * Output: + * A pointer to the node matching the criteria listed above under + * CompOp, or NULL if no node matched the criteria. + * + * Notes: + * In the case of trees with duplicate keys, Locate() will behave as + * follows: + * + * Find: 3 Find: 3 + * Keys: 1 2 2 2 3 3 3 3 3 4 4 Keys: 1 1 2 2 2 4 4 5 5 5 6 + * ^ ^ ^ ^ ^ + * LT EQ GT LE GE + * + * That is, when returning a pointer to a node with a key that is LESS + * THAN the target key (FindMe), Locate() will return a pointer to the + * LAST matching node. + * When returning a pointer to a node with a key that is GREATER + * THAN the target key (FindMe), Locate() will return a pointer to the + * FIRST matching node. + * + * See Also: ubi_btFind(), ubi_btFirstOf(), ubi_btLastOf(). + * ------------------------------------------------------------------------ ** + */ + { + register ubi_btNodePtr p; + ubi_btNodePtr parent; + char whichkid; + + /* Start by searching for a matching node. */ + p = TreeFind( FindMe, + RootPtr->root, + &parent, + &whichkid, + RootPtr->cmp ); + + if( p ) /* If we have found a match, we can resolve as follows: */ + { + switch( CompOp ) + { + case ubi_trLT: /* It's just a jump to the left... */ + p = Border( RootPtr, FindMe, p, LEFT ); + return( Neighbor( p, LEFT ) ); + case ubi_trGT: /* ...and then a jump to the right. */ + p = Border( RootPtr, FindMe, p, RIGHT ); + return( Neighbor( p, RIGHT ) ); + } + p = Border( RootPtr, FindMe, p, LEFT ); + return( p ); + } + + /* Else, no match. */ + if( ubi_trEQ == CompOp ) /* If we were looking for an exact match... */ + return( NULL ); /* ...forget it. */ + + /* We can still return a valid result for GT, GE, LE, and LT. + * <parent> points to a node with a value that is either just before or + * just after the target value. + * Remaining possibilities are LT and GT (including LE & GE). + */ + if( (ubi_trLT == CompOp) || (ubi_trLE == CompOp) ) + return( (LEFT == whichkid) ? Neighbor( parent, whichkid ) : parent ); + else + return( (RIGHT == whichkid) ? Neighbor( parent, whichkid ) : parent ); + } /* ubi_btLocate */ + +ubi_btNodePtr ubi_btFind( ubi_btRootPtr RootPtr, + ubi_btItemPtr FindMe ) + /* ------------------------------------------------------------------------ ** + * This function performs a non-recursive search of a tree for any node + * matching a specific key. + * + * Input: + * RootPtr - a pointer to the header of the tree to be searched. + * FindMe - a pointer to the key value for which to search. + * + * Output: + * A pointer to a node with a key that matches the key indicated by + * FindMe, or NULL if no such node was found. + * + * Note: In a tree that allows duplicates, the pointer returned *might + * not* point to the (sequentially) first occurance of the + * desired key. In such a tree, it may be more useful to use + * ubi_btLocate(). + * ------------------------------------------------------------------------ ** + */ + { + return( qFind( RootPtr->cmp, FindMe, RootPtr->root ) ); + } /* ubi_btFind */ + +ubi_btNodePtr ubi_btNext( ubi_btNodePtr P ) + /* ------------------------------------------------------------------------ ** + * Given the node indicated by P, find the (sorted order) Next node in the + * tree. + * Input: P - a pointer to a node that exists in a binary tree. + * Output: A pointer to the "next" node in the tree, or NULL if P pointed + * to the "last" node in the tree or was NULL. + * ------------------------------------------------------------------------ ** + */ + { + return( Neighbor( P, RIGHT ) ); + } /* ubi_btNext */ + +ubi_btNodePtr ubi_btPrev( ubi_btNodePtr P ) + /* ------------------------------------------------------------------------ ** + * Given the node indicated by P, find the (sorted order) Previous node in + * the tree. + * Input: P - a pointer to a node that exists in a binary tree. + * Output: A pointer to the "previous" node in the tree, or NULL if P + * pointed to the "first" node in the tree or was NULL. + * ------------------------------------------------------------------------ ** + */ + { + return( Neighbor( P, LEFT ) ); + } /* ubi_btPrev */ + +ubi_btNodePtr ubi_btFirst( ubi_btNodePtr P ) + /* ------------------------------------------------------------------------ ** + * Given the node indicated by P, find the (sorted order) First node in the + * subtree of which *P is the root. + * Input: P - a pointer to a node that exists in a binary tree. + * Output: A pointer to the "first" node in a subtree that has *P as its + * root. This function will return NULL only if P is NULL. + * Note: In general, you will be passing in the value of the root field + * of an ubi_btRoot structure. + * ------------------------------------------------------------------------ ** + */ + { + return( SubSlide( P, LEFT ) ); + } /* ubi_btFirst */ + +ubi_btNodePtr ubi_btLast( ubi_btNodePtr P ) + /* ------------------------------------------------------------------------ ** + * Given the node indicated by P, find the (sorted order) Last node in the + * subtree of which *P is the root. + * Input: P - a pointer to a node that exists in a binary tree. + * Output: A pointer to the "last" node in a subtree that has *P as its + * root. This function will return NULL only if P is NULL. + * Note: In general, you will be passing in the value of the root field + * of an ubi_btRoot structure. + * ------------------------------------------------------------------------ ** + */ + { + return( SubSlide( P, RIGHT ) ); + } /* ubi_btLast */ + +ubi_btNodePtr ubi_btFirstOf( ubi_btRootPtr RootPtr, + ubi_btItemPtr MatchMe, + ubi_btNodePtr p ) + /* ------------------------------------------------------------------------ ** + * Given a tree that a allows duplicate keys, and a pointer to a node in + * the tree, this function will return a pointer to the first (traversal + * order) node with the same key value. + * + * Input: RootPtr - A pointer to the root of the tree. + * MatchMe - A pointer to the key value. This should probably + * point to the key within node *p. + * p - A pointer to a node in the tree. + * Output: A pointer to the first node in the set of nodes with keys + * matching <FindMe>. + * Notes: Node *p MUST be in the set of nodes with keys matching + * <FindMe>. If not, this function will return NULL. + * ------------------------------------------------------------------------ ** + */ + { + /* If our starting point is invalid, return NULL. */ + if( !p || AbNormal( (*(RootPtr->cmp))( MatchMe, p ) != EQUAL ) ) + return( NULL ); + return( Border( RootPtr, MatchMe, p, LEFT ) ); + } /* ubi_btFirstOf */ + +ubi_btNodePtr ubi_btLastOf( ubi_btRootPtr RootPtr, + ubi_btItemPtr MatchMe, + ubi_btNodePtr p ) + /* ------------------------------------------------------------------------ ** + * Given a tree that a allows duplicate keys, and a pointer to a node in + * the tree, this function will return a pointer to the last (traversal + * order) node with the same key value. + * + * Input: RootPtr - A pointer to the root of the tree. + * MatchMe - A pointer to the key value. This should probably + * point to the key within node *p. + * p - A pointer to a node in the tree. + * Output: A pointer to the last node in the set of nodes with keys + * matching <FindMe>. + * Notes: Node *p MUST be in the set of nodes with keys matching + * <FindMe>. If not, this function will return NULL. + * ------------------------------------------------------------------------ ** + */ + { + /* If our starting point is invalid, return NULL. */ + if( !p || AbNormal( (*(RootPtr->cmp))( MatchMe, p ) != EQUAL ) ) + return( NULL ); + return( Border( RootPtr, MatchMe, p, RIGHT ) ); + } /* ubi_btLastOf */ + +ubi_trBool ubi_btTraverse( ubi_btRootPtr RootPtr, + ubi_btActionRtn EachNode, + void *UserData ) + /* ------------------------------------------------------------------------ ** + * Traverse a tree in sorted order (non-recursively). At each node, call + * (*EachNode)(), passing a pointer to the current node, and UserData as the + * second parameter. + * Input: RootPtr - a pointer to an ubi_btRoot structure that indicates + * the tree to be traversed. + * EachNode - a pointer to a function to be called at each node + * as the node is visited. + * UserData - a generic pointer that may point to anything that + * you choose. + * Output: A boolean value. FALSE if the tree is empty, otherwise TRUE. + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr p; + + if( !(p = ubi_btFirst( RootPtr->root )) ) return( ubi_trFALSE ); + + while( p ) + { + EachNode( p, UserData ); + p = ubi_btNext( p ); + } + return( ubi_trTRUE ); + } /* ubi_btTraverse */ + +ubi_trBool ubi_btKillTree( ubi_btRootPtr RootPtr, + ubi_btKillNodeRtn FreeNode ) + /* ------------------------------------------------------------------------ ** + * Delete an entire tree (non-recursively) and reinitialize the ubi_btRoot + * structure. Note that this function will return FALSE if either parameter + * is NULL. + * + * Input: RootPtr - a pointer to an ubi_btRoot structure that indicates + * the root of the tree to delete. + * FreeNode - a function that will be called for each node in the + * tree to deallocate the memory used by the node. + * + * Output: A boolean value. FALSE if either input parameter was NULL, else + * TRUE. + * + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr p, q; + + if( !(RootPtr) || !(FreeNode) ) + return( ubi_trFALSE ); + + p = ubi_btFirst( RootPtr->root ); + while( p ) + { + q = p; + while( q->Link[RIGHT] ) + q = SubSlide( q->Link[RIGHT], LEFT ); + p = q->Link[PARENT]; + if( p ) + p->Link[ ((p->Link[LEFT] == q)?LEFT:RIGHT) ] = NULL; + FreeNode((void *)q); + } + + (void)ubi_btInitTree( RootPtr, + RootPtr->cmp, + RootPtr->flags ); + return( ubi_trTRUE ); + } /* ubi_btKillTree */ + +ubi_btNodePtr ubi_btLeafNode( ubi_btNodePtr leader ) + /* ------------------------------------------------------------------------ ** + * Returns a pointer to a leaf node. + * + * Input: leader - Pointer to a node at which to start the descent. + * + * Output: A pointer to a leaf node selected in a somewhat arbitrary + * manner. + * + * Notes: I wrote this function because I was using splay trees as a + * database cache. The cache had a maximum size on it, and I + * needed a way of choosing a node to sacrifice if the cache + * became full. In a splay tree, less recently accessed nodes + * tend toward the bottom of the tree, meaning that leaf nodes + * are good candidates for removal. (I really can't think of + * any other reason to use this function.) + * + In a simple binary tree or an AVL tree, the most recently + * added nodes tend to be nearer the bottom, making this a *bad* + * way to choose which node to remove from the cache. + * + Randomizing the traversal order is probably a good idea. You + * can improve the randomization of leaf node selection by passing + * in pointers to nodes other than the root node each time. A + * pointer to any node in the tree will do. Of course, if you + * pass a pointer to a leaf node you'll get the same thing back. + * + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr follower = NULL; + int whichway = LEFT; + + while( NULL != leader ) + { + follower = leader; + leader = follower->Link[ whichway ]; + if( NULL == leader ) + { + whichway = RevWay( whichway ); + leader = follower->Link[ whichway ]; + } + } + + return( follower ); + } /* ubi_btLeafNode */ + +int ubi_btModuleID( 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. + * ------------------------------------------------------------------------ ** + */ + { + if( size > 0 ) + { + list[0] = ModuleID; + if( size > 1 ) + list[1] = NULL; + return( 1 ); + } + return( 0 ); + } /* ubi_btModuleID */ + + +/* ========================================================================== */ diff --git a/source3/ubi_BinTree.h b/source3/ubi_BinTree.h new file mode 100644 index 0000000000..1be8cba877 --- /dev/null +++ b/source3/ubi_BinTree.h @@ -0,0 +1,745 @@ +#ifndef ubi_BinTree_H +#define ubi_BinTree_H +/* ========================================================================== ** + * ubi_BinTree.h + * + * Copyright (C) 1991-1997 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * -------------------------------------------------------------------------- ** + * + * ubi_BinTree manages a simple binary tree. Nothing fancy here. No height + * balancing, no restructuring. Still, a good tool for creating short, low- + * overhead sorted lists of things that need to be found in a hurry. + * + * In addition, this module provides a good basis for creating other types + * of binary tree handling modules. + * + * -------------------------------------------------------------------------- ** + * + * 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_BinTree.h,v $ + * Revision 1.1 1997/10/09 04:09:52 crh + * This is my library of lists and trees. My hope is to replace all of the + * hard coded linked lists that are currently used in Samba with calls to + * these modules. This should make the code simpler, smaller, and (I hope) + * faster. The tree code, in particular, should speed up processing where + * large lists are involved. + * + * Chris -)----- + * + * Revision 2.4 1997/07/26 04:11:14 crh + * + Just to be annoying I changed ubi_TRUE and ubi_FALSE to ubi_trTRUE + * and ubi_trFALSE. + * + There is now a type ubi_trBool to go with ubi_trTRUE and ubi_trFALSE. + * + There used to be something called "ubi_TypeDefs.h". I got rid of it. + * + Added function ubi_btLeafNode(). + * + * Revision 2.3 1997/06/03 05:15:27 crh + * Changed TRUE and FALSE to ubi_TRUE and ubi_FALSE to avoid conflicts. + * Also changed the interface to function InitTree(). See the comments + * for this function for more information. + * + * Revision 2.2 1995/10/03 22:00:40 CRH + * Ubisized! + * + * Revision 2.1 95/03/09 23:43:46 CRH + * Added the ModuleID static string and function. These modules are now + * self-identifying. + * + * Revision 2.0 95/02/27 22:00:33 CRH + * Revision 2.0 of this program includes the following changes: + * + * 1) A fix to a major typo in the RepaceNode() function. + * 2) The addition of the static function Border(). + * 3) The addition of the public functions FirstOf() and LastOf(), which + * use Border(). These functions are used with trees that allow + * duplicate keys. + * 4) A complete rewrite of the Locate() function. Locate() now accepts + * a "comparison" operator. + * 5) Overall enhancements to both code and comments. + * + * I decided to give this a new major rev number because the interface has + * changed. In particular, there are two new functions, and changes to the + * Locate() function. + * + * Revision 1.0 93/10/15 22:55:04 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 - June, 1991 - Written by Christopher R. Hertel (CRH). + * + * ========================================================================== ** + */ + +/* -------------------------------------------------------------------------- ** + * Macros and constants. + * + * General purpose: + * ubi_trTRUE - Boolean TRUE. + * ubi_trFALSE - Boolean FALSE. + * + * Flags used in the tree header: + * ubi_trOVERWRITE - This flag indicates that an existing node may be + * overwritten by a new node with a matching key. + * ubi_trDUPKEY - This flag indicates that the tree allows duplicate + * keys. If the tree does allow duplicates, the + * overwrite flag is ignored. + * + * Node link array index constants: (Each node has an array of three + * pointers. One to the left, one to the right, and one back to the + * parent.) + * LEFT - Left child pointer. + * PARENT - Parent pointer. + * RIGHT - Right child pointer. + * EQUAL - Synonym for PARENT. + * + * ubi_trCompOps: These values are used in the ubi_trLocate() function. + * ubi_trLT - request the first instance of the greatest key less than + * the search key. + * ubi_trLE - request the first instance of the greatest key that is less + * than or equal to the search key. + * ubi_trEQ - request the first instance of key that is equal to the + * search key. + * ubi_trGE - request the first instance of a key that is greater than + * or equal to the search key. + * ubi_trGT - request the first instance of the first key that is greater + * than the search key. + * -------------------------------------------------------------------------- ** + */ + +#define ubi_trTRUE 0xFF +#define ubi_trFALSE 0x00 + +#define ubi_trOVERWRITE 0x01 /* Turn on allow overwrite */ +#define ubi_trDUPKEY 0x02 /* Turn on allow duplicate keys */ + +/* Pointer array index constants... */ +#define LEFT 0x00 +#define PARENT 0x01 +#define RIGHT 0x02 +#define EQUAL PARENT + +typedef enum { + ubi_trLT = 1, + ubi_trLE, + ubi_trEQ, + ubi_trGE, + ubi_trGT + } ubi_trCompOps; + +/* -------------------------------------------------------------------------- ** + * These three macros allow simple manipulation of pointer index values (LEFT, + * RIGHT, and PARENT). + * + * Normalize() - converts {LEFT, PARENT, RIGHT} into {-1, 0 ,1}. C + * uses {negative, zero, positive} values to indicate + * {less than, equal to, greater than}. + * AbNormal() - converts {negative, zero, positive} to {LEFT, PARENT, + * RIGHT} (opposite of Normalize()). Note: C comparison + * functions, such as strcmp(), return {negative, zero, + * positive} values, which are not necessarily {-1, 0, + * 1}. This macro uses the the ubi_btSgn() function to + * compensate. + * RevWay() - converts LEFT to RIGHT and RIGHT to LEFT. PARENT (EQUAL) + * is left as is. + * -------------------------------------------------------------------------- ** + */ +#define Normalize(W) ((char)((W)-EQUAL)) +#define AbNormal(W) ((char)( EQUAL+((char)ubi_btSgn( (W) )) )) +#define RevWay(W) ((char)((W)==LEFT?RIGHT:((W)==RIGHT?LEFT:EQUAL))) + +/* -------------------------------------------------------------------------- ** + * These macros allow us to quickly read the values of the OVERWRITE and + * DUPlicate KEY bits of the tree root flags field. + * -------------------------------------------------------------------------- ** + */ +#define Dups_OK(A) ((ubi_trDUPKEY & ((A)->flags))?(ubi_trTRUE):(ubi_trFALSE)) +#define Ovwt_OK(A) ((ubi_trOVERWRITE & ((A)->flags))?(ubi_trTRUE):(ubi_trFALSE)) + +/* -------------------------------------------------------------------------- ** + * Typedefs... + * + * ubi_trBool - Your typcial true or false... + * + * Item Pointer: The ubi_btItemPtr is a generic pointer. It is used to + * indicate a key that is being searched for within the tree. + * Searching occurs whenever the ubi_trFind(), ubi_trLocate(), + * or ubi_trInsert() functions are called. + * -------------------------------------------------------------------------- ** + */ + +typedef unsigned char ubi_trBool; + +typedef void *ubi_btItemPtr; /* A pointer to data within a node. */ + +/* ------------------------------------------------------------------------- ** + * Binary Tree Node Structure: This structure defines the basic elements of + * the 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 it as a building block. + * + * The fields are as follows: + * Link - an array of pointers. These pointers are manipulated by + * the BT routines. The pointers indicate the left and right + * child nodes and 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 - a one-byte field indicating whether the node is the RIGHT or + * LEFT child of its parent. If the node is the root of the + * tree, gender will be PARENT. + * ------------------------------------------------------------------------- ** + */ +typedef struct ubi_btNodeStruct { + struct ubi_btNodeStruct *Link[ 3 ]; + char gender; + } ubi_btNode; + +typedef ubi_btNode *ubi_btNodePtr; /* Pointer to an ubi_btNode structure. */ + +/* ------------------------------------------------------------------------- ** + * The next three typedefs define standard function types used by the binary + * tree management routines. In particular: + * + * ubi_btCompFunc is a pointer to a comparison function. Comparison + * functions are passed an ubi_btItemPtr and an + * ubi_btNodePtr. They return a value that is (<0), 0, + * or (>0) to indicate that the Item is (respectively) + * "less than", "equal to", or "greater than" the Item + * contained within the node. (See ubi_btInitTree()). + * ubi_btActionRtn is a pointer to a function that may be called for each + * node visited when performing a tree traversal (see + * ubi_btTraverse()). The function will be passed two + * parameters: the first is a pointer to a node in the + * tree, the second is a generic pointer that may point to + * anything that you like. + * ubi_btKillNodeRtn is a pointer to a function that will deallocate the + * memory used by a node (see ubi_btKillTree()). Since + * memory management is left up to you, deallocation may + * mean anything that you want it to mean. Just remember + * that the tree *will* be destroyed and that none of the + * node pointers will be valid any more. + * ------------------------------------------------------------------------- ** + */ + +typedef int (*ubi_btCompFunc)( ubi_btItemPtr, ubi_btNodePtr ); + +typedef void (*ubi_btActionRtn)( ubi_btNodePtr, void * ); + +typedef void (*ubi_btKillNodeRtn)( ubi_btNodePtr ); + +/* -------------------------------------------------------------------------- ** + * Tree Root Structure: This structure gives us a convenient handle for + * accessing whole AVL trees. The fields are: + * root - A pointer to the root node of the AVL tree. + * count - A count of the number of nodes stored in the tree. + * cmp - A pointer to the comparison routine to be used when building or + * searching the tree. + * flags - A set of bit flags. Two flags are currently defined: + * + * ubi_trOVERWRITE - If set, this flag indicates that a new node should + * (bit 0x01) overwrite an old node if the two have identical + * keys (ie., the keys are equal). + * ubi_trDUPKEY - If set, this flag indicates that the tree is + * (bit 0x02) allowed to contain nodes with duplicate keys. + * + * NOTE: ubi_trInsert() tests ubi_trDUPKEY before ubi_trOVERWRITE. + * + * All of these values are set when you initialize the root structure by + * calling ubi_trInitTree(). + * -------------------------------------------------------------------------- ** + */ + +typedef struct { + ubi_btNodePtr root; /* A pointer to the root node of the tree */ + unsigned long count; /* A count of the number of nodes in the tree */ + ubi_btCompFunc cmp; /* A pointer to the tree's comparison function */ + unsigned char flags; /* Overwrite Y|N, Duplicate keys Y|N... */ + } ubi_btRoot; + +typedef ubi_btRoot *ubi_btRootPtr; /* Pointer to an ubi_btRoot structure. */ + + +/* -------------------------------------------------------------------------- ** + * Function Prototypes. + */ + +long ubi_btSgn( long x ); + /* ------------------------------------------------------------------------ ** + * Return the sign of x; {negative,zero,positive} ==> {-1, 0, 1}. + * + * Input: x - a signed long integer value. + * + * Output: the "sign" of x, represented as follows: + * -1 == negative + * 0 == zero (no sign) + * 1 == positive + * + * Note: This utility is provided in order to facilitate the conversion + * of C comparison function return values into BinTree direction + * values: {LEFT, PARENT, EQUAL}. It is INCORPORATED into the + * AbNormal() conversion macro! + * + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btInitNode( ubi_btNodePtr NodePtr ); + /* ------------------------------------------------------------------------ ** + * Initialize a tree node. + * + * Input: a pointer to a ubi_btNode structure to be initialized. + * Output: a pointer to the initialized ubi_btNode structure (ie. the + * same as the input pointer). + * ------------------------------------------------------------------------ ** + */ + +ubi_btRootPtr ubi_btInitTree( ubi_btRootPtr RootPtr, + ubi_btCompFunc CompFunc, + unsigned char Flags ); + /* ------------------------------------------------------------------------ ** + * Initialize the fields of a Tree Root header structure. + * + * Input: RootPtr - a pointer to an ubi_btRoot structure to be + * initialized. + * CompFunc - a pointer to a comparison function that will be used + * whenever nodes in the tree must be compared against + * outside values. + * Flags - One bytes worth of flags. Flags include + * ubi_trOVERWRITE and ubi_trDUPKEY. See the header + * file for more info. + * + * Output: a pointer to the initialized ubi_btRoot structure (ie. the + * same value as RootPtr). + * + * Note: The interface to this function has changed from that of + * previous versions. The <Flags> parameter replaces two + * boolean parameters that had the same basic effect. + * ------------------------------------------------------------------------ ** + */ + +ubi_trBool ubi_btInsert( ubi_btRootPtr RootPtr, + ubi_btNodePtr NewNode, + ubi_btItemPtr ItemPtr, + ubi_btNodePtr *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_btNode 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_btNodePtr ubi_btRemove( ubi_btRootPtr RootPtr, + ubi_btNodePtr DeadNode ); + /* ------------------------------------------------------------------------ ** + * This function removes the indicated node from the tree. + * + * 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. + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btLocate( ubi_btRootPtr RootPtr, + ubi_btItemPtr FindMe, + ubi_trCompOps CompOp ); + /* ------------------------------------------------------------------------ ** + * The purpose of ubi_btLocate() is to find a node or set of nodes given + * a target value and a "comparison operator". The Locate() function is + * more flexible and (in the case of trees that may contain dupicate keys) + * more precise than the ubi_btFind() function. The latter is faster, + * but it only searches for exact matches and, if the tree contains + * duplicates, Find() may return a pointer to any one of the duplicate- + * keyed records. + * + * Input: + * RootPtr - A pointer to the header of the tree to be searched. + * FindMe - An ubi_btItemPtr that indicates the key for which to + * search. + * CompOp - One of the following: + * CompOp Return a pointer to the node with + * ------ --------------------------------- + * ubi_trLT - the last key value that is less + * than FindMe. + * ubi_trLE - the first key matching FindMe, or + * the last key that is less than + * FindMe. + * ubi_trEQ - the first key matching FindMe. + * ubi_trGE - the first key matching FindMe, or the + * first key greater than FindMe. + * ubi_trGT - the first key greater than FindMe. + * Output: + * A pointer to the node matching the criteria listed above under + * CompOp, or NULL if no node matched the criteria. + * + * Notes: + * In the case of trees with duplicate keys, Locate() will behave as + * follows: + * + * Find: 3 Find: 3 + * Keys: 1 2 2 2 3 3 3 3 3 4 4 Keys: 1 1 2 2 2 4 4 5 5 5 6 + * ^ ^ ^ ^ ^ + * LT EQ GT LE GE + * + * That is, when returning a pointer to a node with a key that is LESS + * THAN the target key (FindMe), Locate() will return a pointer to the + * LAST matching node. + * When returning a pointer to a node with a key that is GREATER + * THAN the target key (FindMe), Locate() will return a pointer to the + * FIRST matching node. + * + * See Also: ubi_btFind(), ubi_btFirstOf(), ubi_btLastOf(). + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btFind( ubi_btRootPtr RootPtr, + ubi_btItemPtr FindMe ); + /* ------------------------------------------------------------------------ ** + * This function performs a non-recursive search of a tree for any node + * matching a specific key. + * + * Input: + * RootPtr - a pointer to the header of the tree to be searched. + * FindMe - a pointer to the key value for which to search. + * + * Output: + * A pointer to a node with a key that matches the key indicated by + * FindMe, or NULL if no such node was found. + * + * Note: In a tree that allows duplicates, the pointer returned *might + * not* point to the (sequentially) first occurance of the + * desired key. In such a tree, it may be more useful to use + * ubi_btLocate(). + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btNext( ubi_btNodePtr P ); + /* ------------------------------------------------------------------------ ** + * Given the node indicated by P, find the (sorted order) Next node in the + * tree. + * Input: P - a pointer to a node that exists in a binary tree. + * Output: A pointer to the "next" node in the tree, or NULL if P pointed + * to the "last" node in the tree or was NULL. + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btPrev( ubi_btNodePtr P ); + /* ------------------------------------------------------------------------ ** + * Given the node indicated by P, find the (sorted order) Previous node in + * the tree. + * Input: P - a pointer to a node that exists in a binary tree. + * Output: A pointer to the "previous" node in the tree, or NULL if P + * pointed to the "first" node in the tree or was NULL. + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btFirst( ubi_btNodePtr P ); + /* ------------------------------------------------------------------------ ** + * Given the node indicated by P, find the (sorted order) First node in the + * subtree of which *P is the root. + * Input: P - a pointer to a node that exists in a binary tree. + * Output: A pointer to the "first" node in a subtree that has *P as its + * root. This function will return NULL only if P is NULL. + * Note: In general, you will be passing in the value of the root field + * of an ubi_btRoot structure. + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btLast( ubi_btNodePtr P ); + /* ------------------------------------------------------------------------ ** + * Given the node indicated by P, find the (sorted order) Last node in the + * subtree of which *P is the root. + * Input: P - a pointer to a node that exists in a binary tree. + * Output: A pointer to the "last" node in a subtree that has *P as its + * root. This function will return NULL only if P is NULL. + * Note: In general, you will be passing in the value of the root field + * of an ubi_btRoot structure. + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btFirstOf( ubi_btRootPtr RootPtr, + ubi_btItemPtr MatchMe, + ubi_btNodePtr p ); + /* ------------------------------------------------------------------------ ** + * Given a tree that a allows duplicate keys, and a pointer to a node in + * the tree, this function will return a pointer to the first (traversal + * order) node with the same key value. + * + * Input: RootPtr - A pointer to the root of the tree. + * MatchMe - A pointer to the key value. This should probably + * point to the key within node *p. + * p - A pointer to a node in the tree. + * Output: A pointer to the first node in the set of nodes with keys + * matching <FindMe>. + * Notes: Node *p MUST be in the set of nodes with keys matching + * <FindMe>. If not, this function will return NULL. + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btLastOf( ubi_btRootPtr RootPtr, + ubi_btItemPtr MatchMe, + ubi_btNodePtr p ); + /* ------------------------------------------------------------------------ ** + * Given a tree that a allows duplicate keys, and a pointer to a node in + * the tree, this function will return a pointer to the last (traversal + * order) node with the same key value. + * + * Input: RootPtr - A pointer to the root of the tree. + * MatchMe - A pointer to the key value. This should probably + * point to the key within node *p. + * p - A pointer to a node in the tree. + * Output: A pointer to the last node in the set of nodes with keys + * matching <FindMe>. + * Notes: Node *p MUST be in the set of nodes with keys matching + * <FindMe>. If not, this function will return NULL. + * ------------------------------------------------------------------------ ** + */ + +ubi_trBool ubi_btTraverse( ubi_btRootPtr RootPtr, + ubi_btActionRtn EachNode, + void *UserData ); + /* ------------------------------------------------------------------------ ** + * Traverse a tree in sorted order (non-recursively). At each node, call + * (*EachNode)(), passing a pointer to the current node, and UserData as the + * second parameter. + * Input: RootPtr - a pointer to an ubi_btRoot structure that indicates + * the tree to be traversed. + * EachNode - a pointer to a function to be called at each node + * as the node is visited. + * UserData - a generic pointer that may point to anything that + * you choose. + * Output: A boolean value. FALSE if the tree is empty, otherwise TRUE. + * ------------------------------------------------------------------------ ** + */ + +ubi_trBool ubi_btKillTree( ubi_btRootPtr RootPtr, + ubi_btKillNodeRtn FreeNode ); + /* ------------------------------------------------------------------------ ** + * Delete an entire tree (non-recursively) and reinitialize the ubi_btRoot + * structure. Note that this function will return FALSE if either parameter + * is NULL. + * + * Input: RootPtr - a pointer to an ubi_btRoot structure that indicates + * the root of the tree to delete. + * FreeNode - a function that will be called for each node in the + * tree to deallocate the memory used by the node. + * + * Output: A boolean value. FALSE if either input parameter was NULL, else + * TRUE. + * + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_btLeafNode( ubi_btNodePtr leader ); + /* ------------------------------------------------------------------------ ** + * Returns a pointer to a leaf node. + * + * Input: leader - Pointer to a node at which to start the descent. + * + * Output: A pointer to a leaf node selected in a somewhat arbitrary + * manner. + * + * Notes: I wrote this function because I was using splay trees as a + * database cache. The cache had a maximum size on it, and I + * needed a way of choosing a node to sacrifice if the cache + * became full. In a splay tree, less recently accessed nodes + * tend toward the bottom of the tree, meaning that leaf nodes + * are good candidates for removal. (I really can't think of + * any other reason to use this function.) + * + In a simple binary tree or an AVL tree, the most recently + * added nodes tend to be nearer the bottom, making this a *bad* + * way to choose which node to remove from the cache. + * + Randomizing the traversal order is probably a good idea. You + * can improve the randomization of leaf node selection by passing + * in pointers to nodes other than the root node each time. A + * pointer to any node in the tree will do. Of course, if you + * pass a pointer to a leaf node you'll get the same thing back. + * + * ------------------------------------------------------------------------ ** + */ + + +int ubi_btModuleID( 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_bt..., use ubi_tr..., and select the tree type by + * including the appropriate module header. + */ + +#define ubi_trItemPtr ubi_btItemPtr + +#define ubi_trNode ubi_btNode +#define ubi_trNodePtr ubi_btNodePtr + +#define ubi_trRoot ubi_btRoot +#define ubi_trRootPtr ubi_btRootPtr + +#define ubi_trCompFunc ubi_btCompFunc +#define ubi_trActionRtn ubi_btActionRtn +#define ubi_trKillNodeRtn ubi_btKillNodeRtn + +#define ubi_trSgn( x ) ubi_btSgn( x ) + +#define ubi_trInitNode( Np ) ubi_btInitNode( (ubi_btNodePtr)(Np) ) + +#define ubi_trInitTree( Rp, Cf, Fl ) \ + ubi_btInitTree( (ubi_btRootPtr)(Rp), (ubi_btCompFunc)(Cf), (Fl) ) + +#define ubi_trInsert( Rp, Nn, Ip, On ) \ + ubi_btInsert( (ubi_btRootPtr)(Rp), (ubi_btNodePtr)(Nn), \ + (ubi_btItemPtr)(Ip), (ubi_btNodePtr *)(On) ) + +#define ubi_trRemove( Rp, Dn ) \ + ubi_btRemove( (ubi_btRootPtr)(Rp), (ubi_btNodePtr)(Dn) ) + +#define ubi_trLocate( Rp, Ip, Op ) \ + ubi_btLocate( (ubi_btRootPtr)(Rp), \ + (ubi_btItemPtr)(Ip), \ + (ubi_trCompOps)(Op) ) + +#define ubi_trFind( Rp, Ip ) \ + ubi_btFind( (ubi_btRootPtr)(Rp), (ubi_btItemPtr)(Ip) ) + +#define ubi_trNext( P ) ubi_btNext( (ubi_btNodePtr)(P) ) + +#define ubi_trPrev( P ) ubi_btPrev( (ubi_btNodePtr)(P) ) + +#define ubi_trFirst( P ) ubi_btFirst( (ubi_btNodePtr)(P) ) + +#define ubi_trLast( P ) ubi_btLast( (ubi_btNodePtr)(P) ) + +#define ubi_trFirstOf( Rp, Ip, P ) \ + ubi_btFirstOf( (ubi_btRootPtr)(Rp), \ + (ubi_btItemPtr)(Ip), \ + (ubi_btNodePtr)(P) ) + +#define ubi_trLastOf( Rp, Ip, P ) \ + ubi_btLastOf( (ubi_btRootPtr)(Rp), \ + (ubi_btItemPtr)(Ip), \ + (ubi_btNodePtr)(P) ) + +#define ubi_trTraverse( Rp, En, Ud ) \ + ubi_btTraverse((ubi_btRootPtr)(Rp), (ubi_btActionRtn)(En), (void *)(Ud)) + +#define ubi_trKillTree( Rp, Fn ) \ + ubi_btKillTree( (ubi_btRootPtr)(Rp), (ubi_btKillNodeRtn)(Fn) ) + +#define ubi_trLeafNode( Nd ) \ + ubi_btLeafNode( (ubi_btNodePtr)(Nd) ) + +#define ubi_trModuleID( s, l ) ubi_btModuleID( s, l ) + +/* ========================================================================== */ +#endif /* ubi_BinTree_H */ diff --git a/source3/ubi_SplayTree.c b/source3/ubi_SplayTree.c new file mode 100644 index 0000000000..d38e383d96 --- /dev/null +++ b/source3/ubi_SplayTree.c @@ -0,0 +1,472 @@ +/* ========================================================================== ** + * ubi_SplayTree.c + * + * Copyright (C) 1993-1995 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * -------------------------------------------------------------------------- ** + * + * This module implements "splay" trees. Splay trees are binary trees + * that are rearranged (splayed) whenever a node is accessed. The + * splaying process *tends* to make the tree bushier (improves balance), + * and the nodes that are accessed most frequently *tend* to be closer to + * the top. + * + * References: "Self-Adjusting Binary Search Trees", by Daniel Sleator and + * Robert Tarjan. Journal of the Association for Computing + * Machinery Vol 32, No. 3, July 1985 pp. 652-686 + * + * -------------------------------------------------------------------------- ** + * + * 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_SplayTree.c,v $ + * Revision 1.1 1997/10/09 04:09:54 crh + * This is my library of lists and trees. My hope is to replace all of the + * hard coded linked lists that are currently used in Samba with calls to + * these modules. This should make the code simpler, smaller, and (I hope) + * faster. The tree code, in particular, should speed up processing where + * large lists are involved. + * + * Chris -)----- + * + * Revision 2.5 1997/07/26 04:15:42 crh + * + Cleaned up a few minor syntax annoyances that gcc discovered for me. + * + Changed ubi_TRUE and ubi_FALSE to ubi_trTRUE and ubi_trFALSE. + * + * Revision 2.4 1997/06/03 04:42:21 crh + * Changed TRUE and FALSE to ubi_TRUE and ubi_FALSE to avoid causing + * problems. + * + * Revision 2.3 1995/10/03 22:19:07 CRH + * Ubisized! + * Also, added the function ubi_sptSplay(). + * + * Revision 2.1 95/03/09 23:54:42 CRH + * Added the ModuleID static string and function. These modules are now + * self-identifying. + * + * Revision 2.0 95/02/27 22:34:46 CRH + * This module was updated to match the interface changes made to the + * ubi_BinTree module. In particular, the interface to the Locate() function + * has changed. See ubi_BinTree for more information on changes and new + * functions. + * + * The revision number was also upped to match ubi_BinTree. + * + * Revision 1.1 93/10/18 20:35:16 CRH + * I removed the hard-coded logical device names from the include file + * specifications. CRH + * + * Revision 1.0 93/10/15 23:00:15 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 + * + * Revision 0.1 93/04/25 22:03:32 CRH + * Simply changed the <exec/types.h> #include reference the .c file to + * use <stdlib.h> instead. The latter is portable, the former is not. + * + * Revision 0.0 93/04/21 23:05:52 CRH + * Initial version, written by Christopher R. Hertel. + * This module implements Splay Trees using the ubi_BinTree module as a basis. + * + * ========================================================================== ** + */ + +#include <stdlib.h> /* Defines NULL for us. */ +#include "ubi_SplayTree.h" /* Header for THIS module. */ + +/* ========================================================================== ** + * Static data. + */ + +static char ModuleID[] = "ubi_SplayTree\n\ +\t$Revision: 1.1 $\n\ +\t$Date: 1997/10/09 04:09:54 $\n\ +\t$Author: crh $\n"; + + +/* ========================================================================== ** + * Private functions... + */ + +static void Rotate( ubi_btNodePtr p ) + /* ------------------------------------------------------------------------ ** + * This function performs a single rotation, moving node *p up one level + * in the tree. + * + * Input: p - a pointer to an ubi_btNode in a tree. + * + * Output: None. + * + * Notes: This implements a single rotation in either direction (left + * or right). This is the basic building block of all splay + * tree rotations. + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr parentp; + ubi_btNodePtr tmp; + char way; + char revway; + + parentp = p->Link[PARENT]; /* Find parent. */ + + if( parentp ) /* If no parent, then we're already the root. */ + { + way = p->gender; + revway = RevWay(way); + tmp = p->Link[revway]; + + parentp->Link[way] = tmp; + if( tmp ) + { + tmp->Link[PARENT] = parentp; + tmp->gender = way; + } + + tmp = parentp->Link[PARENT]; + p->Link[PARENT] = tmp; + p->gender = parentp->gender; + if( tmp ) + tmp->Link[p->gender] = p; + + parentp->Link[PARENT] = p; + parentp->gender = revway; + p->Link[revway] = parentp; + } + } /* Rotate */ + +static ubi_btNodePtr Splay( ubi_btNodePtr SplayWithMe ) + /* ------------------------------------------------------------------------ ** + * Move the node indicated by SplayWithMe to the root of the tree by + * splaying the tree. + * + * Input: SplayWithMe - A pointer to an ubi_btNode within a tree. + * + * Output: A pointer to the root of the splay tree (i.e., the same as + * SplayWithMe). + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr parent; + + while( (parent = SplayWithMe->Link[PARENT]) ) + { + if( parent->gender == SplayWithMe->gender ) /* Zig-Zig */ + Rotate( parent ); + else + { + if( EQUAL != parent->gender ) /* Zig-Zag */ + Rotate( SplayWithMe ); + } + Rotate( SplayWithMe ); /* Zig */ + } /* while */ + return( SplayWithMe ); + } /* Splay */ + +/* ========================================================================== ** + * Exported utilities. + */ + +ubi_trBool ubi_sptInsert( ubi_btRootPtr RootPtr, + ubi_btNodePtr NewNode, + ubi_btItemPtr ItemPtr, + ubi_btNodePtr *OldNode ) + /* ------------------------------------------------------------------------ ** + * This function uses a non-recursive algorithm to add a new element to the + * splay 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_btNode 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_btNodePtr OtherP; + + if( !(OldNode) ) + OldNode = &OtherP; + + if( ubi_btInsert( RootPtr, NewNode, ItemPtr, OldNode ) ) + { + RootPtr->root = Splay( NewNode ); + return( ubi_trTRUE ); + } + + /* Splay the unreplacable, duplicate keyed, unique, old node. */ + RootPtr->root = Splay( (*OldNode) ); + return( ubi_trFALSE ); + } /* ubi_sptInsert */ + +ubi_btNodePtr ubi_sptRemove( ubi_btRootPtr RootPtr, ubi_btNodePtr DeadNode ) + /* ------------------------------------------------------------------------ ** + * This function removes the indicated node from the tree. + * + * 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. + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr p; + + (void)Splay( DeadNode ); /* Move dead node to root. */ + if( (p = DeadNode->Link[LEFT]) ) /* If left subtree exists... */ + { + ubi_btNodePtr q = DeadNode->Link[RIGHT]; + + p->Link[PARENT] = NULL; /* Left subtree node becomes root.*/ + p->gender = PARENT; + p = ubi_btLast( p ); /* Find rightmost left tree node..*/ + p->Link[RIGHT] = q; /* ...attach right tree. */ + if( q ) + q->Link[PARENT] = p; + RootPtr->root = Splay( p ); /* Resplay at p. */ + } + else + { + if( (p = DeadNode->Link[RIGHT]) ) /* No left, but right subtree... */ + { /* ...exists... */ + p->Link[PARENT] = NULL; /* Right subtree root becomes... */ + p->gender = PARENT; /* ...overall tree root. */ + RootPtr->root = p; + } + else + RootPtr->root = NULL; /* No subtrees => empty tree. */ + } + + (RootPtr->count)--; /* Decrement node count. */ + return( DeadNode ); /* Return pointer to pruned node. */ + } /* ubi_sptRemove */ + +ubi_btNodePtr ubi_sptLocate( ubi_btRootPtr RootPtr, + ubi_btItemPtr FindMe, + ubi_trCompOps CompOp ) + /* ------------------------------------------------------------------------ ** + * The purpose of ubi_btLocate() is to find a node or set of nodes given + * a target value and a "comparison operator". The Locate() function is + * more flexible and (in the case of trees that may contain dupicate keys) + * more precise than the ubi_btFind() function. The latter is faster, + * but it only searches for exact matches and, if the tree contains + * duplicates, Find() may return a pointer to any one of the duplicate- + * keyed records. + * + * Input: + * RootPtr - A pointer to the header of the tree to be searched. + * FindMe - An ubi_btItemPtr that indicates the key for which to + * search. + * CompOp - One of the following: + * CompOp Return a pointer to the node with + * ------ --------------------------------- + * ubi_trLT - the last key value that is less + * than FindMe. + * ubi_trLE - the first key matching FindMe, or + * the last key that is less than + * FindMe. + * ubi_trEQ - the first key matching FindMe. + * ubi_trGE - the first key matching FindMe, or the + * first key greater than FindMe. + * ubi_trGT - the first key greater than FindMe. + * Output: + * A pointer to the node matching the criteria listed above under + * CompOp, or NULL if no node matched the criteria. + * + * Notes: + * In the case of trees with duplicate keys, Locate() will behave as + * follows: + * + * Find: 3 Find: 3 + * Keys: 1 2 2 2 3 3 3 3 3 4 4 Keys: 1 1 2 2 2 4 4 5 5 5 6 + * ^ ^ ^ ^ ^ + * LT EQ GT LE GE + * + * That is, when returning a pointer to a node with a key that is LESS + * THAN the target key (FindMe), Locate() will return a pointer to the + * LAST matching node. + * When returning a pointer to a node with a key that is GREATER + * THAN the target key (FindMe), Locate() will return a pointer to the + * FIRST matching node. + * + * See Also: ubi_btFind(), ubi_btFirstOf(), ubi_btLastOf(). + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr p; + + p = ubi_btLocate( RootPtr, FindMe, CompOp ); + if( p ) + RootPtr->root = Splay( p ); + return( p ); + } /* ubi_sptLocate */ + +ubi_btNodePtr ubi_sptFind( ubi_btRootPtr RootPtr, + ubi_btItemPtr FindMe ) + /* ------------------------------------------------------------------------ ** + * This function performs a non-recursive search of a tree for any node + * matching a specific key. + * + * Input: + * RootPtr - a pointer to the header of the tree to be searched. + * FindMe - a pointer to the key value for which to search. + * + * Output: + * A pointer to a node with a key that matches the key indicated by + * FindMe, or NULL if no such node was found. + * + * Note: In a tree that allows duplicates, the pointer returned *might + * not* point to the (sequentially) first occurance of the + * desired key. In such a tree, it may be more useful to use + * ubi_sptLocate(). + * ------------------------------------------------------------------------ ** + */ + { + ubi_btNodePtr p; + + p = ubi_btFind( RootPtr, FindMe ); + if( p ) + RootPtr->root = Splay( p ); + return( p ); + } /* ubi_sptFind */ + +void ubi_sptSplay( ubi_btRootPtr RootPtr, + ubi_btNodePtr SplayMe ) + /* ------------------------------------------------------------------------ ** + * This function allows you to splay the tree at a given node, thus moving + * the node to the top of the tree. + * + * Input: + * RootPtr - a pointer to the header of the tree to be splayed. + * SplayMe - a pointer to a node within the tree. This will become + * the new root node. + * Output: None. + * + * Notes: This is an uncharacteristic function for this group of modules + * in that it provides access to the internal balancing routines, + * which would normally be hidden. + * Splaying the tree will not damage it (assuming that I've done + * *my* job), but there is overhead involved. I don't recommend + * that you use this function unless you understand the underlying + * Splay Tree principles involved. + * ------------------------------------------------------------------------ ** + */ + { + RootPtr->root = Splay( SplayMe ); + } /* ubi_sptSplay */ + +int ubi_sptModuleID( 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. + * ------------------------------------------------------------------------ ** + */ + { + if( size > 0 ) + { + list[0] = ModuleID; + if( size > 1 ) + return( 1 + ubi_btModuleID( --size, &(list[1]) ) ); + return( 1 ); + } + return( 0 ); + } /* ubi_sptModuleID */ + +/* ================================ The End ================================= */ diff --git a/source3/ubi_SplayTree.h b/source3/ubi_SplayTree.h new file mode 100644 index 0000000000..6a17a19ec4 --- /dev/null +++ b/source3/ubi_SplayTree.h @@ -0,0 +1,339 @@ +#ifndef ubi_SplayTree_H +#define ubi_SplayTree_H +/* ========================================================================== ** + * ubi_SplayTree.h + * + * Copyright (C) 1993,1995 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * -------------------------------------------------------------------------- ** + * + * This module implements "splay" trees. Splay trees are binary trees + * that are rearranged (splayed) whenever a node is accessed. The + * splaying process *tends* to make the tree bushier (improves balance), + * and the nodes that are accessed most frequently *tend* to be closer to + * the top. + * + * References: "Self-Adjusting Binary Search Trees", by Daniel Sleator and + * Robert Tarjan. Journal of the Association for Computing + * Machinery Vol 32, No. 3, July 1985 pp. 652-686 + * + * -------------------------------------------------------------------------- ** + * + * 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_SplayTree.h,v $ + * Revision 1.1 1997/10/09 04:09:55 crh + * This is my library of lists and trees. My hope is to replace all of the + * hard coded linked lists that are currently used in Samba with calls to + * these modules. This should make the code simpler, smaller, and (I hope) + * faster. The tree code, in particular, should speed up processing where + * large lists are involved. + * + * Chris -)----- + * + * Revision 2.5 1997/07/26 04:15:46 crh + * + Cleaned up a few minor syntax annoyances that gcc discovered for me. + * + Changed ubi_TRUE and ubi_FALSE to ubi_trTRUE and ubi_trFALSE. + * + * Revision 2.4 1997/06/03 05:22:56 crh + * Changed TRUE and FALSE to ubi_TRUE and ubi_FALSE to avoid causing + * problems. + * + * Revision 2.3 1995/10/03 22:19:37 CRH + * Ubisized! + * Also, added the function ubi_sptSplay(). + * + * Revision 2.1 95/03/09 23:55:04 CRH + * Added the ModuleID static string and function. These modules are now + * self-identifying. + * + * Revision 2.0 95/02/27 22:34:55 CRH + * This module was updated to match the interface changes made to the + * ubi_BinTree module. In particular, the interface to the Locate() function + * has changed. See ubi_BinTree for more information on changes and new + * functions. + * + * The revision number was also upped to match ubi_BinTree. + * + * + * Revision 1.0 93/10/15 22:59:36 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 + * + * Revision 0.0 93/04/21 23:07:13 CRH + * Initial version, written by Christopher R. Hertel. + * This module implements Splay Trees using the ubi_BinTree module as a basis. + * + * ========================================================================== ** + */ + +#include "ubi_BinTree.h" /* Base binary tree functions, types, etc. */ + +/* ========================================================================== ** + * Function prototypes... + */ + +ubi_trBool ubi_sptInsert( ubi_btRootPtr RootPtr, + ubi_btNodePtr NewNode, + ubi_btItemPtr ItemPtr, + ubi_btNodePtr *OldNode ); + /* ------------------------------------------------------------------------ ** + * This function uses a non-recursive algorithm to add a new element to the + * splay 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_btNode 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_btNodePtr ubi_sptRemove( ubi_btRootPtr RootPtr, ubi_btNodePtr DeadNode ); + /* ------------------------------------------------------------------------ ** + * This function removes the indicated node from the tree. + * + * 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. + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_sptLocate( ubi_btRootPtr RootPtr, + ubi_btItemPtr FindMe, + ubi_trCompOps CompOp ); + /* ------------------------------------------------------------------------ ** + * The purpose of ubi_btLocate() is to find a node or set of nodes given + * a target value and a "comparison operator". The Locate() function is + * more flexible and (in the case of trees that may contain dupicate keys) + * more precise than the ubi_btFind() function. The latter is faster, + * but it only searches for exact matches and, if the tree contains + * duplicates, Find() may return a pointer to any one of the duplicate- + * keyed records. + * + * Input: + * RootPtr - A pointer to the header of the tree to be searched. + * FindMe - An ubi_btItemPtr that indicates the key for which to + * search. + * CompOp - One of the following: + * CompOp Return a pointer to the node with + * ------ --------------------------------- + * ubi_trLT - the last key value that is less + * than FindMe. + * ubi_trLE - the first key matching FindMe, or + * the last key that is less than + * FindMe. + * ubi_trEQ - the first key matching FindMe. + * ubi_trGE - the first key matching FindMe, or the + * first key greater than FindMe. + * ubi_trGT - the first key greater than FindMe. + * Output: + * A pointer to the node matching the criteria listed above under + * CompOp, or NULL if no node matched the criteria. + * + * Notes: + * In the case of trees with duplicate keys, Locate() will behave as + * follows: + * + * Find: 3 Find: 3 + * Keys: 1 2 2 2 3 3 3 3 3 4 4 Keys: 1 1 2 2 2 4 4 5 5 5 6 + * ^ ^ ^ ^ ^ + * LT EQ GT LE GE + * + * That is, when returning a pointer to a node with a key that is LESS + * THAN the target key (FindMe), Locate() will return a pointer to the + * LAST matching node. + * When returning a pointer to a node with a key that is GREATER + * THAN the target key (FindMe), Locate() will return a pointer to the + * FIRST matching node. + * + * See Also: ubi_btFind(), ubi_btFirstOf(), ubi_btLastOf(). + * ------------------------------------------------------------------------ ** + */ + +ubi_btNodePtr ubi_sptFind( ubi_btRootPtr RootPtr, + ubi_btItemPtr FindMe ); + /* ------------------------------------------------------------------------ ** + * This function performs a non-recursive search of a tree for any node + * matching a specific key. + * + * Input: + * RootPtr - a pointer to the header of the tree to be searched. + * FindMe - a pointer to the key value for which to search. + * + * Output: + * A pointer to a node with a key that matches the key indicated by + * FindMe, or NULL if no such node was found. + * + * Note: In a tree that allows duplicates, the pointer returned *might + * not* point to the (sequentially) first occurance of the + * desired key. In such a tree, it may be more useful to use + * ubi_sptLocate(). + * ------------------------------------------------------------------------ ** + */ + +void ubi_sptSplay( ubi_btRootPtr RootPtr, + ubi_btNodePtr SplayMe ); + /* ------------------------------------------------------------------------ ** + * This function allows you to splay the tree at a given node, thus moving + * the node to the top of the tree. + * + * Input: + * RootPtr - a pointer to the header of the tree to be splayed. + * SplayMe - a pointer to a node within the tree. This will become + * the new root node. + * Output: None. + * + * Notes: This is an uncharacteristic function for this group of modules + * in that it provides access to the internal balancing routines, + * which would normally be hidden. + * Splaying the tree will not damage it (assuming that I've done + * *my* job), but there is overhead involved. I don't recommend + * that you use this function unless you understand the underlying + * Splay Tree principles involved. + * ------------------------------------------------------------------------ ** + */ + +int ubi_sptModuleID( 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_bt..., use ubi_tr..., and select the tree type by + * including the appropriate module header. + */ + +#undef ubi_trInsert +#undef ubi_trRemove +#undef ubi_trLocate +#undef ubi_trFind +#undef ubi_trModuleID + +#define ubi_trInsert( Rp, Nn, Ip, On ) \ + ubi_sptInsert( (ubi_btRootPtr)(Rp), (ubi_btNodePtr)(Nn), \ + (ubi_btItemPtr)(Ip), (ubi_btNodePtr *)(On) ) + +#define ubi_trRemove( Rp, Dn ) \ + ubi_sptRemove( (ubi_btRootPtr)(Rp), (ubi_btNodePtr)(Dn) ) + +#define ubi_trLocate( Rp, Ip, Op ) \ + ubi_sptLocate( (ubi_btRootPtr)(Rp), \ + (ubi_btItemPtr)(Ip), \ + (ubi_trCompOps)(Op) ) + +#define ubi_trFind( Rp, Ip ) \ + ubi_sptFind( (ubi_btRootPtr)(Rp), (ubi_btItemPtr)(Ip) ) + +#define ubi_trModuleID( s, l ) ubi_sptModuleID( s, l ) + +/* ================================ The End ================================= */ +#endif /* ubi_SplayTree_H */ + + + + + diff --git a/source3/ubi_dLinkList.c b/source3/ubi_dLinkList.c new file mode 100644 index 0000000000..9c9ef3a73d --- /dev/null +++ b/source3/ubi_dLinkList.c @@ -0,0 +1,152 @@ +/* ========================================================================== ** + * ubi_dLinkList.c + * + * Copyright (C) 1997 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * -------------------------------------------------------------------------- ** + * This module implements simple doubly-linked lists. + * -------------------------------------------------------------------------- ** + * + * 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_dLinkList.c,v $ + * Revision 1.1 1997/10/09 04:09:55 crh + * This is my library of lists and trees. My hope is to replace all of the + * hard coded linked lists that are currently used in Samba with calls to + * these modules. This should make the code simpler, smaller, and (I hope) + * faster. The tree code, in particular, should speed up processing where + * large lists are involved. + * + * Chris -)----- + * + * Revision 0.2 1997/10/08 03:07:21 crh + * Fixed a few forgotten link-ups in Insert(), and fixed the AddHead() + * macro, which was passing the wrong value for <After> to Insert(). + * + * Revision 0.1 1997/10/07 04:34:07 crh + * Initial Revision. + * + * + * ========================================================================== ** + */ + +#include "ubi_dLinkList.h" + +/* ========================================================================== ** + * Functions... + */ + +ubi_dlListPtr ubi_dlInitList( ubi_dlListPtr ListPtr ) + /* ------------------------------------------------------------------------ ** + * Initialize a doubly-linked list header. + * + * Input: ListPtr - A pointer to the list structure that is to be + * initialized for use. + * + * Output: A pointer to the initialized list header (i.e., same as + * <ListPtr>). + * + * ------------------------------------------------------------------------ ** + */ + { + ListPtr->Head = NULL; + ListPtr->Tail = NULL; + ListPtr->count = 0; + return( ListPtr ); + } /* ubi_dlInitList */ + +ubi_dlNodePtr ubi_dlInsert( ubi_dlListPtr ListPtr, + ubi_dlNodePtr New, + ubi_dlNodePtr After ) + /* ------------------------------------------------------------------------ ** + * Insert a new node into the list. + * + * Input: ListPtr - A pointer to the list into which the node is to + * be inserted. + * New - Pointer to the new node. + * After - NULL, or a pointer to a node that is already in the + * list. + * If NULL, then <New> will be added at the head of the + * list, else it will be added following <After>. + * + * Output: A pointer to the node that was inserted into the list (i.e., + * the same as <New>). + * + * ------------------------------------------------------------------------ ** + */ + { + if( NULL == After ) + { + New->Next = ListPtr->Head; + New->Prev = NULL; + if( NULL != ListPtr->Head ) + ListPtr->Head->Prev = New; + else + ListPtr->Tail = New; + ListPtr->Head = New; + } + else + { + New->Next = After->Next; + New->Prev = After; + if( NULL != After->Next ) + After->Next->Prev = New; + else + ListPtr->Tail = New; + After->Next = New; + } + + ++(ListPtr->count); + + return( New ); + } /* ubi_dlInsert */ + +ubi_dlNodePtr ubi_dlRemove( ubi_dlListPtr ListPtr, ubi_dlNodePtr Old ) + /* ------------------------------------------------------------------------ ** + * Remove a node from the list. + * + * Input: ListPtr - A pointer to the list from which <Old> is to be + * removed. + * Old - A pointer to the node that is to be removed from the + * list. + * + * Output: A pointer to the node that was removed (i.e., <Old>). + * + * ------------------------------------------------------------------------ ** + */ + { + if( NULL != Old ) + { + if( Old->Next ) + Old->Next->Prev = Old->Prev; + else + ListPtr->Tail = Old->Prev; + + if( Old->Prev ) + Old->Prev->Next = Old->Next; + else + ListPtr->Head = Old->Next; + + --(ListPtr->count); + } + + return( Old ); + } /* ubi_dlRemove */ + + +/* ================================ The End ================================= */ diff --git a/source3/ubi_dLinkList.h b/source3/ubi_dLinkList.h new file mode 100644 index 0000000000..8aafd99704 --- /dev/null +++ b/source3/ubi_dLinkList.h @@ -0,0 +1,163 @@ +#ifndef ubi_dLinkList_H +#define ubi_dLinkList_H +/* ========================================================================== ** + * ubi_dLinkList.h + * + * Copyright (C) 1997 by Christopher R. Hertel + * + * Email: crh@ubiqx.mn.org + * -------------------------------------------------------------------------- ** + * This module implements simple doubly-linked lists. + * -------------------------------------------------------------------------- ** + * + * 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_dLinkList.h,v $ + * Revision 1.1 1997/10/09 04:09:56 crh + * This is my library of lists and trees. My hope is to replace all of the + * hard coded linked lists that are currently used in Samba with calls to + * these modules. This should make the code simpler, smaller, and (I hope) + * faster. The tree code, in particular, should speed up processing where + * large lists are involved. + * + * Chris -)----- + * + * Revision 0.2 1997/10/08 03:08:16 crh + * Fixed a few forgotten link-ups in Insert(), and fixed the AddHead() + * macro, which was passing the wrong value for <After> to Insert(). + * + * Revision 0.1 1997/10/07 04:34:38 crh + * Initial Revision. + * + * + * ========================================================================== ** + */ + +#include <stdlib.h> + + +/* ========================================================================== ** + * Typedefs... + * + * ubi_dlNode - This is the basic node structure. + * ubi_dlNodePtr - Pointer to a node. + * ubi_dlList - This is the list header structure. + * ubi_dlListPtr - Pointer to a List (i.e., a list header structure). + * + */ + +typedef struct ubi_dlListNode + { + struct ubi_dlListNode *Next; + struct ubi_dlListNode *Prev; + } ubi_dlNode; + +typedef ubi_dlNode *ubi_dlNodePtr; + +typedef struct + { + ubi_dlNodePtr Head; + ubi_dlNodePtr Tail; + unsigned long count; + } ubi_dlList; + +typedef ubi_dlList *ubi_dlListPtr; + +/* ========================================================================== ** + * Macros... + * + * ubi_dlAddHead - Add a new node at the head of the list. + * ubi_dlAddTail - Add a new node at the tail of the list. + * ubi_dlRemHead - Remove the node at the head of the list, if any. + * ubi_dlRemTail - Remove the node at the tail of the list, if any. + * ubi_dlFirst - Return a pointer to the first node in the list, if any. + * ubi_dlLast - Return a pointer to the last node in the list, if any. + * ubi_dlNext - Given a node, return a pointer to the next node. + * ubi_dlPrev - Given a node, return a pointer to the previous node. + */ + +#define ubi_dlAddHead( L, N ) ubi_dlInsert( (L), (N), NULL ) + +#define ubi_dlAddTail( L, N ) ubi_dlInsert( (L), (N), ((L)->Tail) ) + +#define ubi_dlRemHead( L ) ubi_dlRemove( (L), ((L)->Head) ) + +#define ubi_dlRemTail( L ) ubi_dlRemove( (L), ((L)->Tail) ) + +#define ubi_dlFirst( L ) ((L)->Head) + +#define ubi_dlLast( L ) ((L)->Tail) + +#define ubi_dlNext( N ) ((N)->Next) + +#define ubi_dlPrev( N ) ((N)->Prev) + + +/* ========================================================================== ** + * Function prototypes... + */ + +ubi_dlListPtr ubi_dlInitList( ubi_dlListPtr ListPtr ); + /* ------------------------------------------------------------------------ ** + * Initialize a doubly-linked list header. + * + * Input: ListPtr - A pointer to the list structure that is to be + * initialized for use. + * + * Output: A pointer to the initialized list header (i.e., same as + * <ListPtr>). + * + * ------------------------------------------------------------------------ ** + */ + +ubi_dlNodePtr ubi_dlInsert( ubi_dlListPtr ListPtr, + ubi_dlNodePtr New, + ubi_dlNodePtr After ); + /* ------------------------------------------------------------------------ ** + * Insert a new node into the list. + * + * Input: ListPtr - A pointer to the list into which the node is to + * be inserted. + * New - Pointer to the new node. + * After - NULL, or a pointer to a node that is already in the + * list. + * If NULL, then <New> will be added at the head of the + * list, else it will be added following <After>. + * + * Output: A pointer to the node that was inserted into the list (i.e., + * the same as <New>). + * + * ------------------------------------------------------------------------ ** + */ + +ubi_dlNodePtr ubi_dlRemove( ubi_dlListPtr ListPtr, ubi_dlNodePtr Old ); + /* ------------------------------------------------------------------------ ** + * Remove a node from the list. + * + * Input: ListPtr - A pointer to the list from which <Old> is to be + * removed. + * Old - A pointer to the node that is to be removed from the + * list. + * + * Output: A pointer to the node that was removed (i.e., <Old>). + * + * ------------------------------------------------------------------------ ** + */ + + +/* ================================ The End ================================= */ +#endif /* ubi_dLinkList_H */ |