Subversion Repositories PlanixRsrch.SVN

/*
 * Copyright 2019, The PLANIX Project
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/**
 *@file
 *@brief Implementation of mavliter_next
 */

#include "mavl.h"

/**
 * Get the next element within an AVL Tree.
 * @param i pointer to AVL Iterator
 * @return the element or NULL if there is no next elemeent.
 */

void *
mavliter_next ( struct mavliter *i )
{
        while ( i->stack_ptr ) {
                i->stack_ptr--;
                i->cur = i->stack[i->stack_ptr];
                
                if ( !i->cur )
                        continue;
                        
                if ( ( i->stack_ptr ) & 1 ) 
                        return mavlnode_dataptr ( i->cur );
                
                break;
        }


        if ( !i->cur ) 
                return NULL;

        while ( i->cur->s[0] ) {

                /* push s[1] branch */
                i->stack[i->stack_ptr++] = i->cur->s[1];
                
                /* push node */
                i->stack[i->stack_ptr++] = i->cur;
                
                i->cur = i->cur->s[0];
        }
        
        i->stack[i->stack_ptr++] = i->cur->s[1];
        
        return mavlnode_dataptr ( i->cur );
        
}