ucx: src/tree.c@425234b05dff

     1 /*

     2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

     3  *

     4  * Copyright 2024 Mike Becker, Olaf Wintermann All rights reserved.

     5  *

     6  * Redistribution and use in source and binary forms, with or without

     7  * modification, are permitted provided that the following conditions are met:

     8  *

     9  *   1. Redistributions of source code must retain the above copyright

    10  *      notice, this list of conditions and the following disclaimer.

    11  *

    12  *   2. Redistributions in binary form must reproduce the above copyright

    13  *      notice, this list of conditions and the following disclaimer in the

    14  *      documentation and/or other materials provided with the distribution.

    15  *

    16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

    17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

    18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

    19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

    20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

    21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

    22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

    23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

    24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

    25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

    26  * POSSIBILITY OF SUCH DAMAGE.

    27  */

    29 #include "cx/tree.h"

    31 #include <assert.h>

    33 #define CX_TREE_PTR(cur, off) (*(void**)(((char*)(cur))+(off)))

    34 #define CX_TREE_PTR(cur, off) (*(void**)(((char*)(cur))+(off)))

    35 #define tree_parent(node) CX_TREE_PTR(node, loc_parent)

    36 #define tree_children(node) CX_TREE_PTR(node, loc_children)

    37 #define tree_prev(node) CX_TREE_PTR(node, loc_prev)

    38 #define tree_next(node) CX_TREE_PTR(node, loc_next)

    40 void cx_tree_link(

    41         void *restrict parent,

    42         void *restrict node,

    43         ptrdiff_t loc_parent,

    44         ptrdiff_t loc_children,

    45         ptrdiff_t loc_prev,

    46         ptrdiff_t loc_next

    47 ) {

    48     void *current_parent = tree_parent(node);

    49     if (current_parent == parent) return;

    50     if (current_parent != NULL) {

    51         cx_tree_unlink(node, loc_parent, loc_children,

    52                        loc_prev, loc_next);

    53     }

    55     if (tree_children(parent) == NULL) {

    56         tree_children(parent) = node;

    57     } else {

    58         void *children = tree_children(parent);

    59         tree_prev(children) = node;

    60         tree_next(node) = children;

    61         tree_children(parent) = node;

    62     }

    63     tree_parent(node) = parent;

    64 }

    66 void cx_tree_unlink(

    67         void *node,

    68         ptrdiff_t loc_parent,

    69         ptrdiff_t loc_children,

    70         ptrdiff_t loc_prev,

    71         ptrdiff_t loc_next

    72 ) {

    73     if (tree_parent(node) == NULL) return;

    75     void *left = tree_prev(node);

    76     void *right = tree_next(node);

    77     assert(left == NULL || tree_children(tree_parent(node)) != node);

    78     if (left == NULL) {

    79         tree_children(tree_parent(node)) = right;

    80     } else {

    81         tree_next(left) = right;

    82     }

    83     if (right != NULL) tree_prev(right) = left;

    84     tree_parent(node) = NULL;

    85     tree_prev(node) = NULL;

    86     tree_next(node) = NULL;

    87 }

Mercurial > hg > ucx / file revision