comparison: src/tree.c
src/tree.c
- changeset 816
- 425234b05dff
- child 826
- 21840975d541
equal
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| 815:b0c4750cecd8 | 816:425234b05dff |
|---|---|
| 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 */ | |
| 28 | |
| 29 #include "cx/tree.h" | |
| 30 | |
| 31 #include <assert.h> | |
| 32 | |
| 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) | |
| 39 | |
| 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 } | |
| 54 | |
| 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 } | |
| 65 | |
| 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; | |
| 74 | |
| 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 } |
