1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 1.2 +++ b/src/tree.c Mon Jan 22 19:34:38 2024 +0100 1.3 @@ -0,0 +1,87 @@ 1.4 +/* 1.5 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. 1.6 + * 1.7 + * Copyright 2024 Mike Becker, Olaf Wintermann All rights reserved. 1.8 + * 1.9 + * Redistribution and use in source and binary forms, with or without 1.10 + * modification, are permitted provided that the following conditions are met: 1.11 + * 1.12 + * 1. Redistributions of source code must retain the above copyright 1.13 + * notice, this list of conditions and the following disclaimer. 1.14 + * 1.15 + * 2. Redistributions in binary form must reproduce the above copyright 1.16 + * notice, this list of conditions and the following disclaimer in the 1.17 + * documentation and/or other materials provided with the distribution. 1.18 + * 1.19 + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 1.20 + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1.21 + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1.22 + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 1.23 + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 1.24 + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 1.25 + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 1.26 + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 1.27 + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 1.28 + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 1.29 + * POSSIBILITY OF SUCH DAMAGE. 1.30 + */ 1.31 + 1.32 +#include "cx/tree.h" 1.33 + 1.34 +#include <assert.h> 1.35 + 1.36 +#define CX_TREE_PTR(cur, off) (*(void**)(((char*)(cur))+(off))) 1.37 +#define CX_TREE_PTR(cur, off) (*(void**)(((char*)(cur))+(off))) 1.38 +#define tree_parent(node) CX_TREE_PTR(node, loc_parent) 1.39 +#define tree_children(node) CX_TREE_PTR(node, loc_children) 1.40 +#define tree_prev(node) CX_TREE_PTR(node, loc_prev) 1.41 +#define tree_next(node) CX_TREE_PTR(node, loc_next) 1.42 + 1.43 +void cx_tree_link( 1.44 + void *restrict parent, 1.45 + void *restrict node, 1.46 + ptrdiff_t loc_parent, 1.47 + ptrdiff_t loc_children, 1.48 + ptrdiff_t loc_prev, 1.49 + ptrdiff_t loc_next 1.50 +) { 1.51 + void *current_parent = tree_parent(node); 1.52 + if (current_parent == parent) return; 1.53 + if (current_parent != NULL) { 1.54 + cx_tree_unlink(node, loc_parent, loc_children, 1.55 + loc_prev, loc_next); 1.56 + } 1.57 + 1.58 + if (tree_children(parent) == NULL) { 1.59 + tree_children(parent) = node; 1.60 + } else { 1.61 + void *children = tree_children(parent); 1.62 + tree_prev(children) = node; 1.63 + tree_next(node) = children; 1.64 + tree_children(parent) = node; 1.65 + } 1.66 + tree_parent(node) = parent; 1.67 +} 1.68 + 1.69 +void cx_tree_unlink( 1.70 + void *node, 1.71 + ptrdiff_t loc_parent, 1.72 + ptrdiff_t loc_children, 1.73 + ptrdiff_t loc_prev, 1.74 + ptrdiff_t loc_next 1.75 +) { 1.76 + if (tree_parent(node) == NULL) return; 1.77 + 1.78 + void *left = tree_prev(node); 1.79 + void *right = tree_next(node); 1.80 + assert(left == NULL || tree_children(tree_parent(node)) != node); 1.81 + if (left == NULL) { 1.82 + tree_children(tree_parent(node)) = right; 1.83 + } else { 1.84 + tree_next(left) = right; 1.85 + } 1.86 + if (right != NULL) tree_prev(right) = left; 1.87 + tree_parent(node) = NULL; 1.88 + tree_prev(node) = NULL; 1.89 + tree_next(node) = NULL; 1.90 +}