From liblavl

libraries/liblutil/avl.c

+/* avl.c - routines to implement an avl tree */
+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 1998-2003 The OpenLDAP Foundation.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ */
+/* Portions Copyright (c) 1993 Regents of the University of Michigan.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that this notice is preserved and that due credit is given
+ * to the University of Michigan at Ann Arbor. The name of the University
+ * may not be used to endorse or promote products derived from this
+ * software without specific prior written permission. This software
+ * is provided ``as is'' without express or implied warranty.
+ */
+/* ACKNOWLEDGEMENTS:
+ * This work was originally developed by the University of Michigan
+ * (as part of U-MICH LDAP).  Additional significant contributors
+ * include:
+ *   Hallvard B. Furuseth
+ *   Kurt D. Zeilenga
+ */
+
+#include "portable.h"
+
+#include <stdio.h>
+#include <ac/stdlib.h>
+
+#ifdef CSRIMALLOC
+#define ber_memalloc malloc
+#define ber_memrealloc realloc
+#define ber_memfree free
+#else
+#include "lber.h"
+#endif
+
+#define AVL_INTERNAL
+#include "avl.h"
+
+#define ROTATERIGHT(x)	{ \
+	Avlnode *tmp;\
+	if ( *(x) == NULL || (*(x))->avl_left == NULL ) {\
+		(void) fputs("RR error\n", stderr); exit( EXIT_FAILURE ); \
+	}\
+	tmp = (*(x))->avl_left;\
+	(*(x))->avl_left = tmp->avl_right;\
+	tmp->avl_right = *(x);\
+	*(x) = tmp;\
+}
+#define ROTATELEFT(x)	{ \
+	Avlnode *tmp;\
+	if ( *(x) == NULL || (*(x))->avl_right == NULL ) {\
+		(void) fputs("RL error\n", stderr); exit( EXIT_FAILURE ); \
+	}\
+	tmp = (*(x))->avl_right;\
+	(*(x))->avl_right = tmp->avl_left;\
+	tmp->avl_left = *(x);\
+	*(x) = tmp;\
+}
+
+/*
+ * ravl_insert - called from avl_insert() to do a recursive insert into
+ * and balance of an avl tree.
+ */
+
+static int
+ravl_insert(
+    Avlnode	**iroot,
+    void*	data,
+    int		*taller,
+    AVL_CMP		fcmp,			/* comparison function */
+    AVL_DUP		fdup,			/* function to call for duplicates */
+    int		depth
+)
+{
+	int	rc, cmp, tallersub;
+	Avlnode	*l, *r;
+
+	if ( *iroot == 0 ) {
+		if ( (*iroot = (Avlnode *) ber_memalloc( sizeof( Avlnode ) ))
+		    == NULL ) {
+			return( -1 );
+		}
+		(*iroot)->avl_left = 0;
+		(*iroot)->avl_right = 0;
+		(*iroot)->avl_bf = 0;
+		(*iroot)->avl_data = data;
+		*taller = 1;
+		return( 0 );
+	}
+
+	cmp = (*fcmp)( data, (*iroot)->avl_data );
+
+	/* equal - duplicate name */
+	if ( cmp == 0 ) {
+		*taller = 0;
+		return( (*fdup)( (*iroot)->avl_data, data ) );
+	}
+
+	/* go right */
+	else if ( cmp > 0 ) {
+		rc = ravl_insert( &((*iroot)->avl_right), data, &tallersub,
+		   fcmp, fdup, depth );
+		if ( tallersub )
+			switch ( (*iroot)->avl_bf ) {
+			case LH	: /* left high - balance is restored */
+				(*iroot)->avl_bf = EH;
+				*taller = 0;
+				break;
+			case EH	: /* equal height - now right heavy */
+				(*iroot)->avl_bf = RH;
+				*taller = 1;
+				break;
+			case RH	: /* right heavy to start - right balance */
+				r = (*iroot)->avl_right;
+				switch ( r->avl_bf ) {
+				case LH	: /* double rotation left */
+					l = r->avl_left;
+					switch ( l->avl_bf ) {
+					case LH	: (*iroot)->avl_bf = EH;
+						  r->avl_bf = RH;
+						  break;
+					case EH	: (*iroot)->avl_bf = EH;
+						  r->avl_bf = EH;
+						  break;
+					case RH	: (*iroot)->avl_bf = LH;
+						  r->avl_bf = EH;
+						  break;
+					}
+					l->avl_bf = EH;
+					ROTATERIGHT( (&r) )
+					(*iroot)->avl_right = r;
+					ROTATELEFT( iroot )
+					*taller = 0;
+					break;
+				case EH	: /* This should never happen */
+					break;
+				case RH	: /* single rotation left */
+					(*iroot)->avl_bf = EH;
+					r->avl_bf = EH;
+					ROTATELEFT( iroot )
+					*taller = 0;
+					break;
+				}
+				break;
+			}
+		else
+			*taller = 0;
+	}
+
+	/* go left */
+	else {
+		rc = ravl_insert( &((*iroot)->avl_left), data, &tallersub,
+		   fcmp, fdup, depth );
+		if ( tallersub )
+			switch ( (*iroot)->avl_bf ) {
+			case LH	: /* left high to start - left balance */
+				l = (*iroot)->avl_left;
+				switch ( l->avl_bf ) {
+				case LH	: /* single rotation right */
+					(*iroot)->avl_bf = EH;
+					l->avl_bf = EH;
+					ROTATERIGHT( iroot )
+					*taller = 0;
+					break;
+				case EH	: /* this should never happen */
+					break;
+				case RH	: /* double rotation right */
+					r = l->avl_right;
+					switch ( r->avl_bf ) {
+					case LH	: (*iroot)->avl_bf = RH;
+						  l->avl_bf = EH;
+						  break;
+					case EH	: (*iroot)->avl_bf = EH;
+						  l->avl_bf = EH;
+						  break;
+					case RH	: (*iroot)->avl_bf = EH;
+						  l->avl_bf = LH;
+						  break;
+					}
+					r->avl_bf = EH;
+					ROTATELEFT( (&l) )
+					(*iroot)->avl_left = l;
+					ROTATERIGHT( iroot )
+					*taller = 0;
+					break;
+				}
+				break;
+			case EH	: /* equal height - now left heavy */
+				(*iroot)->avl_bf = LH;
+				*taller = 1;
+				break;
+			case RH	: /* right high - balance is restored */
+				(*iroot)->avl_bf = EH;
+				*taller = 0;
+				break;
+			}
+		else
+			*taller = 0;
+	}
+
+	return( rc );
+}
+
+/*
+ * avl_insert -- insert a node containing data data into the avl tree
+ * with root root.  fcmp is a function to call to compare the data portion
+ * of two nodes.  it should take two arguments and return <, >, or == 0,
+ * depending on whether its first argument is <, >, or == its second
+ * argument (like strcmp, e.g.).  fdup is a function to call when a duplicate
+ * node is inserted.  it should return 0, or -1 and its return value
+ * will be the return value from avl_insert in the case of a duplicate node.
+ * the function will be called with the original node's data as its first
+ * argument and with the incoming duplicate node's data as its second
+ * argument.  this could be used, for example, to keep a count with each
+ * node.
+ *
+ * NOTE: this routine may malloc memory
+ */
+
+int
+avl_insert( Avlnode **root, void* data, AVL_CMP fcmp, AVL_DUP fdup )
+{
+	int	taller;
+
+	return( ravl_insert( root, data, &taller, fcmp, fdup, 0 ) );
+}
+
+/* 
+ * right_balance() - called from delete when root's right subtree has
+ * been shortened because of a deletion.
+ */
+
+static int
+right_balance( Avlnode **root )
+{
+	int	shorter = -1;
+	Avlnode	*r, *l;
+
+	switch( (*root)->avl_bf ) {
+	case RH:	/* was right high - equal now */
+		(*root)->avl_bf = EH;
+		shorter = 1;
+		break;
+	case EH:	/* was equal - left high now */
+		(*root)->avl_bf = LH;
+		shorter = 0;
+		break;
+	case LH:	/* was right high - balance */
+		l = (*root)->avl_left;
+		switch ( l->avl_bf ) {
+		case RH	: /* double rotation left */
+			r = l->avl_right;
+			switch ( r->avl_bf ) {
+			case RH	:
+				(*root)->avl_bf = EH;
+				l->avl_bf = LH;
+				break;
+			case EH	:
+				(*root)->avl_bf = EH;
+				l->avl_bf = EH;
+				break;
+			case LH	:
+				(*root)->avl_bf = RH;
+				l->avl_bf = EH;
+				break;
+			}
+			r->avl_bf = EH;
+			ROTATELEFT( (&l) )
+			(*root)->avl_left = l;
+			ROTATERIGHT( root )
+			shorter = 1;
+			break;
+		case EH	: /* right rotation */
+			(*root)->avl_bf = LH;
+			l->avl_bf = RH;
+			ROTATERIGHT( root );
+			shorter = 0;
+			break;
+		case LH	: /* single rotation right */
+			(*root)->avl_bf = EH;
+			l->avl_bf = EH;
+			ROTATERIGHT( root )
+			shorter = 1;
+			break;
+		}
+		break;
+	}
+
+	return( shorter );
+}
+
+/* 
+ * left_balance() - called from delete when root's left subtree has
+ * been shortened because of a deletion.
+ */
+
+static int
+left_balance( Avlnode **root )
+{
+	int	shorter = -1;
+	Avlnode	*r, *l;
+
+	switch( (*root)->avl_bf ) {
+	case LH:	/* was left high - equal now */
+		(*root)->avl_bf = EH;
+		shorter = 1;
+		break;
+	case EH:	/* was equal - right high now */
+		(*root)->avl_bf = RH;
+		shorter = 0;
+		break;
+	case RH:	/* was right high - balance */
+		r = (*root)->avl_right;
+		switch ( r->avl_bf ) {
+		case LH	: /* double rotation left */
+			l = r->avl_left;
+			switch ( l->avl_bf ) {
+			case LH	:
+				(*root)->avl_bf = EH;
+				r->avl_bf = RH;
+				break;
+			case EH	:
+				(*root)->avl_bf = EH;
+				r->avl_bf = EH;
+				break;
+			case RH	:
+				(*root)->avl_bf = LH;
+				r->avl_bf = EH;
+				break;
+			}
+			l->avl_bf = EH;
+			ROTATERIGHT( (&r) )
+			(*root)->avl_right = r;
+			ROTATELEFT( root )
+			shorter = 1;
+			break;
+		case EH	: /* single rotation left */
+			(*root)->avl_bf = RH;
+			r->avl_bf = LH;
+			ROTATELEFT( root );
+			shorter = 0;
+			break;
+		case RH	: /* single rotation left */
+			(*root)->avl_bf = EH;
+			r->avl_bf = EH;
+			ROTATELEFT( root )
+			shorter = 1;
+			break;
+		}
+		break;
+	}
+
+	return( shorter );
+}
+
+/*
+ * ravl_delete() - called from avl_delete to do recursive deletion of a
+ * node from an avl tree.  It finds the node recursively, deletes it,
+ * and returns shorter if the tree is shorter after the deletion and
+ * rebalancing.
+ */
+
+static void*
+ravl_delete( Avlnode **root, void* data, AVL_CMP fcmp, int *shorter )
+{
+	int	shortersubtree = 0;
+	int	cmp;
+	void*	savedata;
+	Avlnode	*minnode, *savenode;
+
+	if ( *root == NULLAVL )
+		return( 0 );
+
+	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.
+ */
+
+void*
+avl_find( Avlnode *root, const void* data, AVL_CMP fcmp )
+{
+	int	cmp;
+
+	while ( root != 0 && (cmp = (*fcmp)( data, root->avl_data )) != 0 ) {
+		if ( cmp < 0 )
+			root = root->avl_left;
+		else
+			root = root->avl_right;
+	}
+
+	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 );
+}

libraries/liblutil/testavl.c

+/* testavl.c - Test Tim Howes AVL code */
+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 1998-2003 The OpenLDAP Foundation.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ */
+/* Portions Copyright (c) 1993 Regents of the University of Michigan.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that this notice is preserved and that due credit is given
+ * to the University of Michigan at Ann Arbor. The name of the University
+ * may not be used to endorse or promote products derived from this
+ * software without specific prior written permission. This software
+ * is provided ``as is'' without express or implied warranty.
+ */
+/* ACKNOWLEDGEMENTS:
+ * This work was originally developed by the University of Michigan
+ * (as part of U-MICH LDAP).
+ */
+
+#include "portable.h"
+
+#include <stdio.h>
+
+#include <ac/stdlib.h>
+#include <ac/string.h>
+
+#define AVL_INTERNAL
+#define AVL_NONREENTRANT 
+#include "avl.h"
+
+static void ravl_print LDAP_P(( Avlnode *root, int depth ));
+static void myprint LDAP_P(( Avlnode *root ));
+static int avl_strcmp LDAP_P(( const void *s, const void *t ));
+
+int
+main( int argc, char **argv )
+{
+	Avlnode	*tree = NULL;
+	char	command[ 10 ];
+	char	name[ 80 ];
+	char	*p;
+
+	printf( "> " );
+	while ( fgets( command, sizeof( command ), stdin ) != NULL ) {
+		switch( *command ) {
+		case 'n':	/* new tree */
+			( void ) avl_free( tree, free );
+			tree = NULL;
+			break;
+		case 'p':	/* print */
+			( void ) myprint( tree );
+			break;
+		case 't':	/* traverse with first, next */
+#ifdef AVL_NONREENTRANT
+			printf( "***\n" );
+			for ( p = (char * ) avl_getfirst( tree );
+			    p != NULL;
+				p = (char *) avl_getnext())
+				printf( "%s\n", p );
+			printf( "***\n" );
+#else
+			printf( "*** reentrant interface not implemented ***" );
+#endif
+			break;
+		case 'f':	/* find */
+			printf( "data? " );
+			if ( fgets( name, sizeof( name ), stdin ) == NULL )
+				exit( EXIT_SUCCESS );
+			name[ strlen( name ) - 1 ] = '\0';
+			if ( (p = (char *) avl_find( tree, name, avl_strcmp ))
+			    == NULL )
+				printf( "Not found.\n\n" );
+			else
+				printf( "%s\n\n", p );
+			break;
+		case 'i':	/* insert */
+			printf( "data? " );
+			if ( fgets( name, sizeof( name ), stdin ) == NULL )
+				exit( EXIT_SUCCESS );
+			name[ strlen( name ) - 1 ] = '\0';
+			if ( avl_insert( &tree, strdup( name ), avl_strcmp, 
+			    avl_dup_error ) != 0 )
+				printf( "\nNot inserted!\n" );
+			break;
+		case 'd':	/* delete */
+			printf( "data? " );
+			if ( fgets( name, sizeof( name ), stdin ) == NULL )
+				exit( EXIT_SUCCESS );
+			name[ strlen( name ) - 1 ] = '\0';
+			if ( avl_delete( &tree, name, avl_strcmp ) == NULL )
+				printf( "\nNot found!\n" );
+			break;
+		case 'q':	/* quit */
+			exit( EXIT_SUCCESS );
+			break;
+		case '\n':
+			break;
+		default:
+			printf("Commands: insert, delete, print, new, quit\n");
+		}
+
+		printf( "> " );
+	}
+
+	return( 0 );
+}
+
+static void ravl_print( Avlnode *root, int depth )
+{
+	int	i;
+
+	if ( root == 0 )
+		return;
+
+	ravl_print( root->avl_right, depth+1 );
+
+	for ( i = 0; i < depth; i++ )
+		printf( "   " );
+	printf( "%s %d\n", (char *) root->avl_data, root->avl_bf );
+
+	ravl_print( root->avl_left, depth+1 );
+}
+
+static void myprint( Avlnode *root )
+{
+	printf( "********\n" );
+
+	if ( root == 0 )
+		printf( "\tNULL\n" );
+	else
+		ravl_print( root, 0 );
+
+	printf( "********\n" );
+}
+
+static int avl_strcmp( const void *s, const void *t )
+{
+	return strcmp( s, t );
+}