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Diffstat (limited to 'source3/ubiqx/ubi_SplayTree.c')
| -rw-r--r-- | source3/ubiqx/ubi_SplayTree.c | 512 |
1 files changed, 0 insertions, 512 deletions
diff --git a/source3/ubiqx/ubi_SplayTree.c b/source3/ubiqx/ubi_SplayTree.c deleted file mode 100644 index 222506bd06..0000000000 --- a/source3/ubiqx/ubi_SplayTree.c +++ /dev/null @@ -1,512 +0,0 @@ -/* ========================================================================== ** - * ubi_SplayTree.c - * - * Copyright (C) 1993-1998 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 - * - * See also: http://www.cs.cmu.edu/~sleator/ - * - * -------------------------------------------------------------------------- ** - * - * 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 4.5 2000/01/08 23:26:49 crh - * Added ubi_trSplay() macro, which does a type cast for us. - * - * Revision 4.4 1998/06/04 21:29:27 crh - * Upper-cased defined constants (eg UBI_BINTREE_H) in some header files. - * This is more "standard", and is what people expect. Weird, eh? - * - * Revision 4.3 1998/06/03 17:45:05 crh - * Further fiddling with sys_include.h. It's now in ubi_BinTree.h which is - * included by all of the binary tree files. - * - * Also fixed some warnings produced by lint on Irix 6.2, which doesn't seem - * to like syntax like this: - * - * if( (a = b) ) - * - * The fix was to change lines like the above to: - * - * if( 0 != (a=b) ) - * - * Which means the same thing. - * - * Reminder: Some of the ubi_tr* macros in ubi_BinTree.h are redefined in - * ubi_AVLtree.h and ubi_SplayTree.h. This allows easy swapping - * of tree types by simply changing a header. Unfortunately, the - * macro redefinitions in ubi_AVLtree.h and ubi_SplayTree.h will - * conflict if used together. You must either choose a single tree - * type, or use the underlying function calls directly. Compare - * the two header files for more information. - * - * Revision 4.2 1998/06/02 01:29:14 crh - * Changed ubi_null.h to sys_include.h to make it more generic. - * - * Revision 4.1 1998/05/20 04:37:54 crh - * The C file now includes ubi_null.h. See ubi_null.h for more info. - * - * Revision 4.0 1998/03/10 03:41:33 crh - * Minor comment changes. The revision number is now 4.0 to match the - * BinTree and AVLtree modules. - * - * Revision 2.7 1998/01/24 06:37:08 crh - * Added a URL for more information. - * - * Revision 2.6 1997/12/23 04:01:12 crh - * In this version, all constants & macros defined in the header file have - * the ubi_tr prefix. Also cleaned up anything that gcc complained about - * when run with '-pedantic -fsyntax-only -Wall'. - * - * 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_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 "ubi_SplayTree.h" /* Header for THIS module. */ - -/* ========================================================================== ** - * Static data. - */ - -static char ModuleID[] = "ubi_SplayTree\n\ -\tRevision: 4.5 \n\ -\tDate: 2000/01/08 23:26:49 \n\ -\tAuthor: 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[ubi_trPARENT]; /* Find parent. */ - - if( parentp ) /* If no parent, then we're already the root. */ - { - way = p->gender; - revway = ubi_trRevWay(way); - tmp = p->Link[(int)revway]; - - parentp->Link[(int)way] = tmp; - if( tmp ) - { - tmp->Link[ubi_trPARENT] = parentp; - tmp->gender = way; - } - - tmp = parentp->Link[ubi_trPARENT]; - p->Link[ubi_trPARENT] = tmp; - p->gender = parentp->gender; - if( tmp ) - tmp->Link[(int)(p->gender)] = p; - - parentp->Link[ubi_trPARENT] = p; - parentp->gender = revway; - p->Link[(int)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( NULL != (parent = SplayWithMe->Link[ubi_trPARENT]) ) - { - if( parent->gender == SplayWithMe->gender ) /* Zig-Zig */ - Rotate( parent ); - else - { - if( ubi_trEQUAL != 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( NULL != (p = DeadNode->Link[ubi_trLEFT]) ) - { /* If left subtree exists... */ - ubi_btNodePtr q = DeadNode->Link[ubi_trRIGHT]; - - p->Link[ubi_trPARENT] = NULL; /* Left subtree node becomes root.*/ - p->gender = ubi_trPARENT; - p = ubi_btLast( p ); /* Find rightmost left node... */ - p->Link[ubi_trRIGHT] = q; /* ...attach right tree. */ - if( q ) - q->Link[ubi_trPARENT] = p; - RootPtr->root = Splay( p ); /* Resplay at p. */ - } - else - { - if( NULL != (p = DeadNode->Link[ubi_trRIGHT]) ) - { /* No left, but right subtree exists... */ - p->Link[ubi_trPARENT] = NULL; /* Right subtree root becomes... */ - p->gender = ubi_trPARENT; /* ...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 ================================= */ - |