2003-11-27 06:32:36 +08:00
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/* avl.c - routines to implement an avl tree */
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/* $OpenLDAP$ */
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/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
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*
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2004-01-02 03:15:16 +08:00
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* Copyright 1998-2004 The OpenLDAP Foundation.
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2003-11-27 06:32:36 +08:00
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted only as authorized by the OpenLDAP
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* Public License.
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*
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* A copy of this license is available in the file LICENSE in the
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* top-level directory of the distribution or, alternatively, at
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* <http://www.OpenLDAP.org/license.html>.
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*/
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/* Portions Copyright (c) 1993 Regents of the University of Michigan.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms are permitted
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* provided that this notice is preserved and that due credit is given
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* to the University of Michigan at Ann Arbor. The name of the University
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* may not be used to endorse or promote products derived from this
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* software without specific prior written permission. This software
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* is provided ``as is'' without express or implied warranty.
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*/
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/* ACKNOWLEDGEMENTS:
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* This work was originally developed by the University of Michigan
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* (as part of U-MICH LDAP). Additional significant contributors
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* include:
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* Hallvard B. Furuseth
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* Kurt D. Zeilenga
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*/
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#include "portable.h"
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#include <stdio.h>
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#include <ac/stdlib.h>
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#ifdef CSRIMALLOC
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#define ber_memalloc malloc
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#define ber_memrealloc realloc
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#define ber_memfree free
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#else
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#include "lber.h"
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#endif
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#define AVL_INTERNAL
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#include "avl.h"
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#define ROTATERIGHT(x) { \
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Avlnode *tmp;\
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if ( *(x) == NULL || (*(x))->avl_left == NULL ) {\
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(void) fputs("RR error\n", stderr); exit( EXIT_FAILURE ); \
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}\
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tmp = (*(x))->avl_left;\
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(*(x))->avl_left = tmp->avl_right;\
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tmp->avl_right = *(x);\
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*(x) = tmp;\
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}
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#define ROTATELEFT(x) { \
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Avlnode *tmp;\
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if ( *(x) == NULL || (*(x))->avl_right == NULL ) {\
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(void) fputs("RL error\n", stderr); exit( EXIT_FAILURE ); \
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}\
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tmp = (*(x))->avl_right;\
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(*(x))->avl_right = tmp->avl_left;\
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tmp->avl_left = *(x);\
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*(x) = tmp;\
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}
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/*
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* ravl_insert - called from avl_insert() to do a recursive insert into
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* and balance of an avl tree.
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*/
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static int
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ravl_insert(
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Avlnode **iroot,
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void* data,
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int *taller,
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AVL_CMP fcmp, /* comparison function */
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AVL_DUP fdup, /* function to call for duplicates */
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int depth
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)
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{
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int rc, cmp, tallersub;
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Avlnode *l, *r;
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if ( *iroot == 0 ) {
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if ( (*iroot = (Avlnode *) ber_memalloc( sizeof( Avlnode ) ))
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== NULL ) {
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return( -1 );
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}
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(*iroot)->avl_left = 0;
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(*iroot)->avl_right = 0;
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(*iroot)->avl_bf = 0;
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(*iroot)->avl_data = data;
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*taller = 1;
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return( 0 );
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}
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cmp = (*fcmp)( data, (*iroot)->avl_data );
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/* equal - duplicate name */
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if ( cmp == 0 ) {
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*taller = 0;
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return( (*fdup)( (*iroot)->avl_data, data ) );
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}
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/* go right */
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else if ( cmp > 0 ) {
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rc = ravl_insert( &((*iroot)->avl_right), data, &tallersub,
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fcmp, fdup, depth );
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if ( tallersub )
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switch ( (*iroot)->avl_bf ) {
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case LH : /* left high - balance is restored */
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(*iroot)->avl_bf = EH;
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*taller = 0;
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break;
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case EH : /* equal height - now right heavy */
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(*iroot)->avl_bf = RH;
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*taller = 1;
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break;
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case RH : /* right heavy to start - right balance */
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r = (*iroot)->avl_right;
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switch ( r->avl_bf ) {
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case LH : /* double rotation left */
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l = r->avl_left;
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switch ( l->avl_bf ) {
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case LH : (*iroot)->avl_bf = EH;
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r->avl_bf = RH;
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break;
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case EH : (*iroot)->avl_bf = EH;
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r->avl_bf = EH;
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break;
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case RH : (*iroot)->avl_bf = LH;
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r->avl_bf = EH;
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break;
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}
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l->avl_bf = EH;
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ROTATERIGHT( (&r) )
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(*iroot)->avl_right = r;
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ROTATELEFT( iroot )
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*taller = 0;
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break;
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case EH : /* This should never happen */
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break;
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case RH : /* single rotation left */
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(*iroot)->avl_bf = EH;
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r->avl_bf = EH;
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ROTATELEFT( iroot )
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*taller = 0;
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break;
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}
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break;
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}
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else
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*taller = 0;
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}
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/* go left */
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else {
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rc = ravl_insert( &((*iroot)->avl_left), data, &tallersub,
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fcmp, fdup, depth );
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if ( tallersub )
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switch ( (*iroot)->avl_bf ) {
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case LH : /* left high to start - left balance */
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l = (*iroot)->avl_left;
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switch ( l->avl_bf ) {
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case LH : /* single rotation right */
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(*iroot)->avl_bf = EH;
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l->avl_bf = EH;
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ROTATERIGHT( iroot )
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*taller = 0;
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break;
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case EH : /* this should never happen */
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break;
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case RH : /* double rotation right */
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r = l->avl_right;
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switch ( r->avl_bf ) {
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case LH : (*iroot)->avl_bf = RH;
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l->avl_bf = EH;
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break;
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case EH : (*iroot)->avl_bf = EH;
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l->avl_bf = EH;
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break;
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case RH : (*iroot)->avl_bf = EH;
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l->avl_bf = LH;
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break;
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}
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r->avl_bf = EH;
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ROTATELEFT( (&l) )
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(*iroot)->avl_left = l;
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ROTATERIGHT( iroot )
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*taller = 0;
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break;
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}
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break;
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case EH : /* equal height - now left heavy */
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(*iroot)->avl_bf = LH;
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*taller = 1;
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break;
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case RH : /* right high - balance is restored */
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(*iroot)->avl_bf = EH;
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*taller = 0;
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break;
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}
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else
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*taller = 0;
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}
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return( rc );
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}
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/*
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* avl_insert -- insert a node containing data data into the avl tree
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* with root root. fcmp is a function to call to compare the data portion
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* of two nodes. it should take two arguments and return <, >, or == 0,
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* depending on whether its first argument is <, >, or == its second
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* argument (like strcmp, e.g.). fdup is a function to call when a duplicate
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* node is inserted. it should return 0, or -1 and its return value
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* will be the return value from avl_insert in the case of a duplicate node.
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* the function will be called with the original node's data as its first
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* argument and with the incoming duplicate node's data as its second
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* argument. this could be used, for example, to keep a count with each
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* node.
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*
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* NOTE: this routine may malloc memory
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*/
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int
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avl_insert( Avlnode **root, void* data, AVL_CMP fcmp, AVL_DUP fdup )
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{
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int taller;
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return( ravl_insert( root, data, &taller, fcmp, fdup, 0 ) );
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}
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/*
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* right_balance() - called from delete when root's right subtree has
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* been shortened because of a deletion.
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*/
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static int
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right_balance( Avlnode **root )
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{
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int shorter = -1;
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Avlnode *r, *l;
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switch( (*root)->avl_bf ) {
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case RH: /* was right high - equal now */
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(*root)->avl_bf = EH;
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shorter = 1;
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break;
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case EH: /* was equal - left high now */
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(*root)->avl_bf = LH;
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shorter = 0;
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break;
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case LH: /* was right high - balance */
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l = (*root)->avl_left;
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switch ( l->avl_bf ) {
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case RH : /* double rotation left */
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r = l->avl_right;
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switch ( r->avl_bf ) {
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case RH :
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(*root)->avl_bf = EH;
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l->avl_bf = LH;
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break;
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case EH :
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(*root)->avl_bf = EH;
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l->avl_bf = EH;
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break;
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case LH :
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(*root)->avl_bf = RH;
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l->avl_bf = EH;
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break;
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}
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r->avl_bf = EH;
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ROTATELEFT( (&l) )
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(*root)->avl_left = l;
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ROTATERIGHT( root )
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shorter = 1;
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break;
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case EH : /* right rotation */
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(*root)->avl_bf = LH;
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l->avl_bf = RH;
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ROTATERIGHT( root );
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shorter = 0;
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break;
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case LH : /* single rotation right */
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(*root)->avl_bf = EH;
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l->avl_bf = EH;
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ROTATERIGHT( root )
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shorter = 1;
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break;
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}
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break;
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}
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return( shorter );
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}
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/*
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* left_balance() - called from delete when root's left subtree has
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* been shortened because of a deletion.
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*/
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static int
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left_balance( Avlnode **root )
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{
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int shorter = -1;
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Avlnode *r, *l;
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switch( (*root)->avl_bf ) {
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case LH: /* was left high - equal now */
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(*root)->avl_bf = EH;
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shorter = 1;
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break;
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case EH: /* was equal - right high now */
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(*root)->avl_bf = RH;
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shorter = 0;
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break;
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case RH: /* was right high - balance */
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r = (*root)->avl_right;
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switch ( r->avl_bf ) {
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case LH : /* double rotation left */
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l = r->avl_left;
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switch ( l->avl_bf ) {
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case LH :
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(*root)->avl_bf = EH;
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r->avl_bf = RH;
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break;
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case EH :
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(*root)->avl_bf = EH;
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r->avl_bf = EH;
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break;
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case RH :
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(*root)->avl_bf = LH;
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r->avl_bf = EH;
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break;
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}
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l->avl_bf = EH;
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ROTATERIGHT( (&r) )
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(*root)->avl_right = r;
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ROTATELEFT( root )
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shorter = 1;
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break;
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case EH : /* single rotation left */
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(*root)->avl_bf = RH;
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r->avl_bf = LH;
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ROTATELEFT( root );
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shorter = 0;
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break;
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case RH : /* single rotation left */
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(*root)->avl_bf = EH;
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r->avl_bf = EH;
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ROTATELEFT( root )
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shorter = 1;
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break;
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}
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break;
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}
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return( shorter );
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}
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/*
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* ravl_delete() - called from avl_delete to do recursive deletion of a
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* node from an avl tree. It finds the node recursively, deletes it,
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* and returns shorter if the tree is shorter after the deletion and
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* rebalancing.
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*/
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static void*
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ravl_delete( Avlnode **root, void* data, AVL_CMP fcmp, int *shorter )
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{
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int shortersubtree = 0;
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int cmp;
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void* savedata;
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Avlnode *minnode, *savenode;
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if ( *root == NULLAVL )
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return( 0 );
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|
cmp = (*fcmp)( data, (*root)->avl_data );
|
|
|
|
|
|
|
|
/* found it! */
|
|
|
|
if ( cmp == 0 ) {
|
|
|
|
savenode = *root;
|
|
|
|
savedata = savenode->avl_data;
|
|
|
|
|
|
|
|
/* simple cases: no left child */
|
|
|
|
if ( (*root)->avl_left == 0 ) {
|
|
|
|
*root = (*root)->avl_right;
|
|
|
|
*shorter = 1;
|
|
|
|
ber_memfree( (char *) savenode );
|
|
|
|
return( savedata );
|
|
|
|
/* no right child */
|
|
|
|
} else if ( (*root)->avl_right == 0 ) {
|
|
|
|
*root = (*root)->avl_left;
|
|
|
|
*shorter = 1;
|
|
|
|
ber_memfree( (char *) savenode );
|
|
|
|
return( savedata );
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* avl_getmin will return to us the smallest node greater
|
|
|
|
* than the one we are trying to delete. deleting this node
|
|
|
|
* from the right subtree is guaranteed to end in one of the
|
|
|
|
* simple cases above.
|
|
|
|
*/
|
|
|
|
|
|
|
|
minnode = (*root)->avl_right;
|
|
|
|
while ( minnode->avl_left != NULLAVL )
|
|
|
|
minnode = minnode->avl_left;
|
|
|
|
|
|
|
|
/* swap the data */
|
|
|
|
(*root)->avl_data = minnode->avl_data;
|
|
|
|
minnode->avl_data = savedata;
|
|
|
|
|
|
|
|
savedata = ravl_delete( &(*root)->avl_right, data, fcmp,
|
|
|
|
&shortersubtree );
|
|
|
|
|
|
|
|
if ( shortersubtree )
|
|
|
|
*shorter = right_balance( root );
|
|
|
|
else
|
|
|
|
*shorter = 0;
|
|
|
|
/* go left */
|
|
|
|
} else if ( cmp < 0 ) {
|
|
|
|
if ( (savedata = ravl_delete( &(*root)->avl_left, data, fcmp,
|
|
|
|
&shortersubtree )) == 0 ) {
|
|
|
|
*shorter = 0;
|
|
|
|
return( 0 );
|
|
|
|
}
|
|
|
|
|
|
|
|
/* left subtree shorter? */
|
|
|
|
if ( shortersubtree )
|
|
|
|
*shorter = left_balance( root );
|
|
|
|
else
|
|
|
|
*shorter = 0;
|
|
|
|
/* go right */
|
|
|
|
} else {
|
|
|
|
if ( (savedata = ravl_delete( &(*root)->avl_right, data, fcmp,
|
|
|
|
&shortersubtree )) == 0 ) {
|
|
|
|
*shorter = 0;
|
|
|
|
return( 0 );
|
|
|
|
}
|
|
|
|
|
|
|
|
if ( shortersubtree )
|
|
|
|
*shorter = right_balance( root );
|
|
|
|
else
|
|
|
|
*shorter = 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
return( savedata );
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* avl_delete() - deletes the node containing data (according to fcmp) from
|
|
|
|
* the avl tree rooted at root.
|
|
|
|
*/
|
|
|
|
|
|
|
|
void*
|
|
|
|
avl_delete( Avlnode **root, void* data, AVL_CMP fcmp )
|
|
|
|
{
|
|
|
|
int shorter;
|
|
|
|
|
|
|
|
return( ravl_delete( root, data, fcmp, &shorter ) );
|
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
|
|
|
avl_inapply( Avlnode *root, AVL_APPLY fn, void* arg, int stopflag )
|
|
|
|
{
|
|
|
|
if ( root == 0 )
|
|
|
|
return( AVL_NOMORE );
|
|
|
|
|
|
|
|
if ( root->avl_left != 0 )
|
|
|
|
if ( avl_inapply( root->avl_left, fn, arg, stopflag )
|
|
|
|
== stopflag )
|
|
|
|
return( stopflag );
|
|
|
|
|
|
|
|
if ( (*fn)( root->avl_data, arg ) == stopflag )
|
|
|
|
return( stopflag );
|
|
|
|
|
|
|
|
if ( root->avl_right == 0 )
|
|
|
|
return( AVL_NOMORE );
|
|
|
|
else
|
|
|
|
return( avl_inapply( root->avl_right, fn, arg, stopflag ) );
|
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
|
|
|
avl_postapply( Avlnode *root, AVL_APPLY fn, void* arg, int stopflag )
|
|
|
|
{
|
|
|
|
if ( root == 0 )
|
|
|
|
return( AVL_NOMORE );
|
|
|
|
|
|
|
|
if ( root->avl_left != 0 )
|
|
|
|
if ( avl_postapply( root->avl_left, fn, arg, stopflag )
|
|
|
|
== stopflag )
|
|
|
|
return( stopflag );
|
|
|
|
|
|
|
|
if ( root->avl_right != 0 )
|
|
|
|
if ( avl_postapply( root->avl_right, fn, arg, stopflag )
|
|
|
|
== stopflag )
|
|
|
|
return( stopflag );
|
|
|
|
|
|
|
|
return( (*fn)( root->avl_data, arg ) );
|
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
|
|
|
avl_preapply( Avlnode *root, AVL_APPLY fn, void* arg, int stopflag )
|
|
|
|
{
|
|
|
|
if ( root == 0 )
|
|
|
|
return( AVL_NOMORE );
|
|
|
|
|
|
|
|
if ( (*fn)( root->avl_data, arg ) == stopflag )
|
|
|
|
return( stopflag );
|
|
|
|
|
|
|
|
if ( root->avl_left != 0 )
|
|
|
|
if ( avl_preapply( root->avl_left, fn, arg, stopflag )
|
|
|
|
== stopflag )
|
|
|
|
return( stopflag );
|
|
|
|
|
|
|
|
if ( root->avl_right == 0 )
|
|
|
|
return( AVL_NOMORE );
|
|
|
|
else
|
|
|
|
return( avl_preapply( root->avl_right, fn, arg, stopflag ) );
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* avl_apply -- avl tree root is traversed, function fn is called with
|
|
|
|
* arguments arg and the data portion of each node. if fn returns stopflag,
|
|
|
|
* the traversal is cut short, otherwise it continues. Do not use -6 as
|
|
|
|
* a stopflag, as this is what is used to indicate the traversal ran out
|
|
|
|
* of nodes.
|
|
|
|
*/
|
|
|
|
|
|
|
|
int
|
|
|
|
avl_apply( Avlnode *root, AVL_APPLY fn, void* arg, int stopflag, int type )
|
|
|
|
{
|
|
|
|
switch ( type ) {
|
|
|
|
case AVL_INORDER:
|
|
|
|
return( avl_inapply( root, fn, arg, stopflag ) );
|
|
|
|
case AVL_PREORDER:
|
|
|
|
return( avl_preapply( root, fn, arg, stopflag ) );
|
|
|
|
case AVL_POSTORDER:
|
|
|
|
return( avl_postapply( root, fn, arg, stopflag ) );
|
|
|
|
default:
|
|
|
|
fprintf( stderr, "Invalid traversal type %d\n", type );
|
|
|
|
return( -1 );
|
|
|
|
}
|
|
|
|
|
|
|
|
/* NOTREACHED */
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* avl_prefixapply - traverse avl tree root, applying function fprefix
|
|
|
|
* to any nodes that match. fcmp is called with data as its first arg
|
|
|
|
* and the current node's data as its second arg. it should return
|
|
|
|
* 0 if they match, < 0 if data is less, and > 0 if data is greater.
|
|
|
|
* the idea is to efficiently find all nodes that are prefixes of
|
|
|
|
* some key... Like avl_apply, this routine also takes a stopflag
|
|
|
|
* and will return prematurely if fmatch returns this value. Otherwise,
|
|
|
|
* AVL_NOMORE is returned.
|
|
|
|
*/
|
|
|
|
|
|
|
|
int
|
|
|
|
avl_prefixapply(
|
|
|
|
Avlnode *root,
|
|
|
|
void* data,
|
|
|
|
AVL_CMP fmatch,
|
|
|
|
void* marg,
|
|
|
|
AVL_CMP fcmp,
|
|
|
|
void* carg,
|
|
|
|
int stopflag
|
|
|
|
)
|
|
|
|
{
|
|
|
|
int cmp;
|
|
|
|
|
|
|
|
if ( root == 0 )
|
|
|
|
return( AVL_NOMORE );
|
|
|
|
|
|
|
|
cmp = (*fcmp)( data, root->avl_data /* , carg */);
|
|
|
|
if ( cmp == 0 ) {
|
|
|
|
if ( (*fmatch)( root->avl_data, marg ) == stopflag )
|
|
|
|
return( stopflag );
|
|
|
|
|
|
|
|
if ( root->avl_left != 0 )
|
|
|
|
if ( avl_prefixapply( root->avl_left, data, fmatch,
|
|
|
|
marg, fcmp, carg, stopflag ) == stopflag )
|
|
|
|
return( stopflag );
|
|
|
|
|
|
|
|
if ( root->avl_right != 0 )
|
|
|
|
return( avl_prefixapply( root->avl_right, data, fmatch,
|
|
|
|
marg, fcmp, carg, stopflag ) );
|
|
|
|
else
|
|
|
|
return( AVL_NOMORE );
|
|
|
|
|
|
|
|
} else if ( cmp < 0 ) {
|
|
|
|
if ( root->avl_left != 0 )
|
|
|
|
return( avl_prefixapply( root->avl_left, data, fmatch,
|
|
|
|
marg, fcmp, carg, stopflag ) );
|
|
|
|
} else {
|
|
|
|
if ( root->avl_right != 0 )
|
|
|
|
return( avl_prefixapply( root->avl_right, data, fmatch,
|
|
|
|
marg, fcmp, carg, stopflag ) );
|
|
|
|
}
|
|
|
|
|
|
|
|
return( AVL_NOMORE );
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* avl_free -- traverse avltree root, freeing the memory it is using.
|
|
|
|
* the dfree() is called to free the data portion of each node. The
|
|
|
|
* number of items actually freed is returned.
|
|
|
|
*/
|
|
|
|
|
|
|
|
int
|
|
|
|
avl_free( Avlnode *root, AVL_FREE dfree )
|
|
|
|
{
|
|
|
|
int nleft, nright;
|
|
|
|
|
|
|
|
if ( root == 0 )
|
|
|
|
return( 0 );
|
|
|
|
|
|
|
|
nleft = nright = 0;
|
|
|
|
if ( root->avl_left != 0 )
|
|
|
|
nleft = avl_free( root->avl_left, dfree );
|
|
|
|
|
|
|
|
if ( root->avl_right != 0 )
|
|
|
|
nright = avl_free( root->avl_right, dfree );
|
|
|
|
|
|
|
|
if ( dfree )
|
|
|
|
(*dfree)( root->avl_data );
|
|
|
|
ber_memfree( root );
|
|
|
|
|
|
|
|
return( nleft + nright + 1 );
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* avl_find -- search avltree root for a node with data data. the function
|
|
|
|
* cmp is used to compare things. it is called with data as its first arg
|
|
|
|
* and the current node data as its second. it should return 0 if they match,
|
|
|
|
* < 0 if arg1 is less than arg2 and > 0 if arg1 is greater than arg2.
|
|
|
|
*/
|
|
|
|
|
2004-11-20 07:33:46 +08:00
|
|
|
Avlnode *
|
|
|
|
avl_find2( Avlnode *root, const void *data, AVL_CMP fcmp )
|
2003-11-27 06:32:36 +08:00
|
|
|
{
|
|
|
|
int cmp;
|
|
|
|
|
|
|
|
while ( root != 0 && (cmp = (*fcmp)( data, root->avl_data )) != 0 ) {
|
|
|
|
if ( cmp < 0 )
|
|
|
|
root = root->avl_left;
|
|
|
|
else
|
|
|
|
root = root->avl_right;
|
|
|
|
}
|
2004-11-20 07:33:46 +08:00
|
|
|
return root;
|
|
|
|
}
|
|
|
|
|
|
|
|
void*
|
|
|
|
avl_find( Avlnode *root, const void* data, AVL_CMP fcmp )
|
|
|
|
{
|
|
|
|
root = avl_find2( root, data, fcmp );
|
2003-11-27 06:32:36 +08:00
|
|
|
|
|
|
|
return( root ? root->avl_data : 0 );
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* avl_find_lin -- search avltree root linearly for a node with data data.
|
|
|
|
* the function cmp is used to compare things. it is called with data as its
|
|
|
|
* first arg and the current node data as its second. it should return 0 if
|
|
|
|
* they match, non-zero otherwise.
|
|
|
|
*/
|
|
|
|
|
|
|
|
void*
|
|
|
|
avl_find_lin( Avlnode *root, const void* data, AVL_CMP fcmp )
|
|
|
|
{
|
|
|
|
void* res;
|
|
|
|
|
|
|
|
if ( root == 0 )
|
|
|
|
return( NULL );
|
|
|
|
|
|
|
|
if ( (*fcmp)( data, root->avl_data ) == 0 )
|
|
|
|
return( root->avl_data );
|
|
|
|
|
|
|
|
if ( root->avl_left != 0 )
|
|
|
|
if ( (res = avl_find_lin( root->avl_left, data, fcmp ))
|
|
|
|
!= NULL )
|
|
|
|
return( res );
|
|
|
|
|
|
|
|
if ( root->avl_right == 0 )
|
|
|
|
return( NULL );
|
|
|
|
else
|
|
|
|
return( avl_find_lin( root->avl_right, data, fcmp ) );
|
|
|
|
}
|
|
|
|
|
|
|
|
/* NON-REENTRANT INTERFACE */
|
|
|
|
|
|
|
|
static void* *avl_list;
|
|
|
|
static int avl_maxlist;
|
|
|
|
static int avl_nextlist;
|
|
|
|
|
|
|
|
#define AVL_GRABSIZE 100
|
|
|
|
|
|
|
|
/* ARGSUSED */
|
|
|
|
static int
|
|
|
|
avl_buildlist( void* data, void* arg )
|
|
|
|
{
|
|
|
|
static int slots;
|
|
|
|
|
|
|
|
if ( avl_list == (void* *) 0 ) {
|
|
|
|
avl_list = (void* *) ber_memalloc(AVL_GRABSIZE * sizeof(void*));
|
|
|
|
slots = AVL_GRABSIZE;
|
|
|
|
avl_maxlist = 0;
|
|
|
|
} else if ( avl_maxlist == slots ) {
|
|
|
|
slots += AVL_GRABSIZE;
|
|
|
|
avl_list = (void* *) ber_memrealloc( (char *) avl_list,
|
|
|
|
(unsigned) slots * sizeof(void*));
|
|
|
|
}
|
|
|
|
|
|
|
|
avl_list[ avl_maxlist++ ] = data;
|
|
|
|
|
|
|
|
return( 0 );
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* avl_getfirst() and avl_getnext() are provided as alternate tree
|
|
|
|
* traversal methods, to be used when a single function cannot be
|
|
|
|
* provided to be called with every node in the tree. avl_getfirst()
|
|
|
|
* traverses the tree and builds a linear list of all the nodes,
|
|
|
|
* returning the first node. avl_getnext() returns the next thing
|
|
|
|
* on the list built by avl_getfirst(). This means that avl_getfirst()
|
|
|
|
* can take a while, and that the tree should not be messed with while
|
|
|
|
* being traversed in this way, and that multiple traversals (even of
|
|
|
|
* different trees) cannot be active at once.
|
|
|
|
*/
|
|
|
|
|
|
|
|
void*
|
|
|
|
avl_getfirst( Avlnode *root )
|
|
|
|
{
|
|
|
|
if ( avl_list ) {
|
|
|
|
ber_memfree( (char *) avl_list);
|
|
|
|
avl_list = (void* *) 0;
|
|
|
|
}
|
|
|
|
avl_maxlist = 0;
|
|
|
|
avl_nextlist = 0;
|
|
|
|
|
|
|
|
if ( root == 0 )
|
|
|
|
return( 0 );
|
|
|
|
|
|
|
|
(void) avl_apply( root, avl_buildlist, (void*) 0, -1, AVL_INORDER );
|
|
|
|
|
|
|
|
return( avl_list[ avl_nextlist++ ] );
|
|
|
|
}
|
|
|
|
|
|
|
|
void*
|
|
|
|
avl_getnext( void )
|
|
|
|
{
|
|
|
|
if ( avl_list == 0 )
|
|
|
|
return( 0 );
|
|
|
|
|
|
|
|
if ( avl_nextlist == avl_maxlist ) {
|
|
|
|
ber_memfree( (void*) avl_list);
|
|
|
|
avl_list = (void* *) 0;
|
|
|
|
return( 0 );
|
|
|
|
}
|
|
|
|
|
|
|
|
return( avl_list[ avl_nextlist++ ] );
|
|
|
|
}
|
|
|
|
|
|
|
|
/* end non-reentrant code */
|
|
|
|
|
|
|
|
|
|
|
|
int
|
|
|
|
avl_dup_error( void* left, void* right )
|
|
|
|
{
|
|
|
|
return( -1 );
|
|
|
|
}
|
|
|
|
|
|
|
|
int
|
|
|
|
avl_dup_ok( void* left, void* right )
|
|
|
|
{
|
|
|
|
return( 0 );
|
|
|
|
}
|