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Diffstat (limited to 'source3/ubi_AVLtree.c')
| -rw-r--r-- | source3/ubi_AVLtree.c | 699 |
1 files changed, 699 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 ============================== */ |