olaf@424: /*
olaf@424:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
olaf@424:  *
olaf@424:  * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
olaf@424:  *
olaf@424:  * Redistribution and use in source and binary forms, with or without
olaf@424:  * modification, are permitted provided that the following conditions are met:
olaf@424:  *
olaf@424:  *   1. Redistributions of source code must retain the above copyright
olaf@424:  *      notice, this list of conditions and the following disclaimer.
olaf@424:  *
olaf@424:  *   2. Redistributions in binary form must reproduce the above copyright
olaf@424:  *      notice, this list of conditions and the following disclaimer in the
olaf@424:  *      documentation and/or other materials provided with the distribution.
olaf@424:  *
olaf@424:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
olaf@424:  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
olaf@424:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
olaf@424:  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
olaf@424:  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
olaf@424:  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
olaf@424:  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
olaf@424:  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
olaf@424:  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
olaf@424:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
olaf@424:  * POSSIBILITY OF SUCH DAMAGE.
olaf@424:  */
olaf@424: 
olaf@424: #include "cx/tree.h"
olaf@431: #include "cx/linked_list.h"
olaf@425: 
olaf@426: #define CX_TR_PTR(cur, off) ((void**)(((char*)cur)+off))
olaf@426: 
olaf@426: void* cx_tree_last(void *node, ptrdiff_t loc_next) {
olaf@426:     void *last;
olaf@426:     do {
olaf@426:         last = node;
olaf@426:     } while ((node = *CX_TR_PTR(node, loc_next)) != NULL);
olaf@426:     return last;
olaf@426: }
olaf@425: 
olaf@425: int cx_tree_add_node(void *node, ptrdiff_t loc_parent, ptrdiff_t loc_prev, ptrdiff_t loc_next, void *new_node) {
olaf@426:     void *last = cx_tree_last(node, loc_next);
olaf@426:     if(!last)
olaf@426:         return 1;
olaf@426:     
olaf@426:     // next pointer must be present
olaf@426:     *CX_TR_PTR(last, loc_next) = new_node;
olaf@426:     
olaf@426:     // optional fields
olaf@426:     if(loc_parent >= 0) {
olaf@426:         *CX_TR_PTR(new_node, loc_parent) = *CX_TR_PTR(node, loc_parent);
olaf@426:     }
olaf@426:     if(loc_prev >= 0) {
olaf@426:         *CX_TR_PTR(new_node, loc_prev) = last;
olaf@426:     }
olaf@426:     
olaf@426:     return 0;
olaf@425: }
olaf@425: 
olaf@425: int cx_tree_add_child_node(
olaf@425:         void *parent,
olaf@425:         ptrdiff_t loc_parent,
olaf@425:         ptrdiff_t loc_prev,
olaf@425:         ptrdiff_t loc_next,
olaf@425:         void **children_begin,
olaf@425:         void **children_end,
olaf@425:         void *new_node)
olaf@425: {
olaf@431:     if(cx_linked_list_add(children_begin, children_end, loc_prev, loc_next, new_node)) {
olaf@431:         return 1;
olaf@431:     }
olaf@431:     // optional field
olaf@431:     if(loc_parent >= 0) {
olaf@431:         *CX_TR_PTR(new_node, loc_parent) = parent;
olaf@431:     }
olaf@431:     return 0;
olaf@425: }