src/avl.c@a6184aff5108
src/avl.c
Sat, 28 Oct 2017 15:59:16 +0200
- author
- Mike Becker <universe@uap-core.de>
- date
- Sat, 28 Oct 2017 15:59:16 +0200
- changeset 260
- a6184aff5108
- parent 259
- 2f5dea574a75
- child 287
- 98da78a1e69a
- permissions
- -rw-r--r--
rename LICENSE to COPYING to be distributed by autoconf
1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
3 *
4 * Copyright 2017 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 "ucx/avl.h"
31 #include <limits.h>
33 #define ptrcast(ptr) ((void*)(ptr))
34 #define alloc_tree(al) (UcxAVLTree*) almalloc((al), sizeof(UcxAVLTree))
35 #define alloc_node(al) (UcxAVLNode*) almalloc((al), sizeof(UcxAVLNode))
37 static void ucx_avl_connect(UcxAVLTree *tree,
38 UcxAVLNode *node, UcxAVLNode *child, intptr_t nullkey) {
39 if (child) {
40 child->parent = node;
41 }
42 // if child is NULL, nullkey decides if left or right pointer is cleared
43 if (tree->cmpfunc(
44 ptrcast(child ? child->key : nullkey),
45 ptrcast(node->key), tree->userdata) > 0) {
46 node->right = child;
47 } else {
48 node->left = child;
49 }
50 size_t lh = node->left ? node->left->height : 0;
51 size_t rh = node->right ? node->right->height : 0;
52 node->height = 1 + (lh > rh ? lh : rh);
53 }
55 #define avlheight(node) ((node) ? (node)->height : 0)
57 static UcxAVLNode* avl_rotright(UcxAVLTree *tree, UcxAVLNode *l0) {
58 UcxAVLNode *p = l0->parent;
59 UcxAVLNode *l1 = l0->left;
60 if (p) {
61 ucx_avl_connect(tree, p, l1, 0);
62 } else {
63 l1->parent = NULL;
64 }
65 ucx_avl_connect(tree, l0, l1->right, l1->key);
66 ucx_avl_connect(tree, l1, l0, 0);
67 return l1;
68 }
70 static UcxAVLNode* avl_rotleft(UcxAVLTree *tree, UcxAVLNode *l0) {
71 UcxAVLNode *p = l0->parent;
72 UcxAVLNode *l1 = l0->right;
73 if (p) {
74 ucx_avl_connect(tree, p, l1, 0);
75 } else {
76 l1->parent = NULL;
77 }
78 ucx_avl_connect(tree, l0, l1->left, l1->key);
79 ucx_avl_connect(tree, l1, l0, 0);
80 return l1;
81 }
83 static void ucx_avl_balance(UcxAVLTree *tree, UcxAVLNode *n) {
84 int lh = avlheight(n->left);
85 int rh = avlheight(n->right);
86 n->height = 1 + (lh > rh ? lh : rh);
88 if (lh - rh == 2) {
89 UcxAVLNode *c = n->left;
90 if (avlheight(c->right) - avlheight(c->left) == 1) {
91 avl_rotleft(tree, c);
92 }
93 n = avl_rotright(tree, n);
94 } else if (rh - lh == 2) {
95 UcxAVLNode *c = n->right;
96 if (avlheight(c->left) - avlheight(c->right) == 1) {
97 avl_rotright(tree, c);
98 }
99 n = avl_rotleft(tree, n);
100 }
102 if (n->parent) {
103 ucx_avl_balance(tree, n->parent);
104 } else {
105 tree->root = n;
106 }
107 }
109 UcxAVLTree *ucx_avl_new(cmp_func cmpfunc) {
110 return ucx_avl_new_a(cmpfunc, ucx_default_allocator());
111 }
113 UcxAVLTree *ucx_avl_new_a(cmp_func cmpfunc, UcxAllocator *allocator) {
114 UcxAVLTree* tree = alloc_tree(allocator);
115 if (tree) {
116 tree->allocator = allocator;
117 tree->cmpfunc = cmpfunc;
118 tree->root = NULL;
119 tree->userdata = NULL;
120 }
122 return tree;
123 }
125 static void ucx_avl_free_node(UcxAllocator *al, UcxAVLNode *node) {
126 if (node) {
127 ucx_avl_free_node(al, node->left);
128 ucx_avl_free_node(al, node->right);
129 alfree(al, node);
130 }
131 }
133 void ucx_avl_free(UcxAVLTree *tree) {
134 UcxAllocator *al = tree->allocator;
135 ucx_avl_free_node(al, tree->root);
136 alfree(al, tree);
137 }
139 UcxAVLNode *ucx_avl_get_node(UcxAVLTree *tree, intptr_t key) {
140 UcxAVLNode *n = tree->root;
141 int cmpresult;
142 while (n && (cmpresult = tree->cmpfunc(
143 ptrcast(key), ptrcast(n->key), tree->userdata))) {
144 n = cmpresult > 0 ? n->right : n->left;
145 }
146 return n;
147 }
149 void *ucx_avl_get(UcxAVLTree *tree, intptr_t key) {
150 UcxAVLNode *n = ucx_avl_get_node(tree, key);
151 return n ? n->value : NULL;
152 }
154 UcxAVLNode *ucx_avl_find_node(UcxAVLTree *tree, intptr_t key,
155 distance_func dfnc, int mode) {
156 UcxAVLNode *n = tree->root;
157 UcxAVLNode *closest = NULL;
159 intmax_t cmpresult;
160 intmax_t closest_dist;
161 closest_dist = mode == UCX_AVL_FIND_LOWER_BOUNDED ? INTMAX_MIN : INTMAX_MAX;
163 while (n && (cmpresult = dfnc(
164 ptrcast(key), ptrcast(n->key), tree->userdata))) {
165 if (mode == UCX_AVL_FIND_CLOSEST) {
166 intmax_t dist = cmpresult;
167 if (dist < 0) dist *= -1;
168 if (dist < closest_dist) {
169 closest_dist = dist;
170 closest = n;
171 }
172 } else if (mode == UCX_AVL_FIND_LOWER_BOUNDED && cmpresult <= 0) {
173 if (cmpresult > closest_dist) {
174 closest_dist = cmpresult;
175 closest = n;
176 }
177 } else if (mode == UCX_AVL_FIND_UPPER_BOUNDED && cmpresult >= 0) {
178 if (cmpresult < closest_dist) {
179 closest_dist = cmpresult;
180 closest = n;
181 }
182 }
183 n = cmpresult > 0 ? n->right : n->left;
184 }
185 return n ? n : closest;
186 }
188 void *ucx_avl_find(UcxAVLTree *tree, intptr_t key,
189 distance_func dfnc, int mode) {
190 UcxAVLNode *n = ucx_avl_find_node(tree, key, dfnc, mode);
191 return n ? n->value : NULL;
192 }
194 int ucx_avl_put(UcxAVLTree *tree, intptr_t key, void *value) {
195 return ucx_avl_put_s(tree, key, value, NULL);
196 }
198 int ucx_avl_put_s(UcxAVLTree *tree, intptr_t key, void *value,
199 void **oldvalue) {
200 if (tree->root) {
201 UcxAVLNode *n = tree->root;
202 int cmpresult;
203 while ((cmpresult = tree->cmpfunc(
204 ptrcast(key), ptrcast(n->key), tree->userdata))) {
205 UcxAVLNode *m = cmpresult > 0 ? n->right : n->left;
206 if (m) {
207 n = m;
208 } else {
209 break;
210 }
211 }
213 if (cmpresult) {
214 UcxAVLNode* e = alloc_node(tree->allocator);
215 if (e) {
216 e->key = key; e->value = value; e->height = 1;
217 e->parent = e->left = e->right = NULL;
218 ucx_avl_connect(tree, n, e, 0);
219 ucx_avl_balance(tree, n);
220 return 0;
221 } else {
222 return 1;
223 }
224 } else {
225 if (oldvalue) {
226 *oldvalue = n->value;
227 }
228 n->value = value;
229 return 0;
230 }
231 } else {
232 tree->root = alloc_node(tree->allocator);
233 if (tree->root) {
234 tree->root->key = key; tree->root->value = value;
235 tree->root->height = 1;
236 tree->root->parent = tree->root->left = tree->root->right = NULL;
238 if (oldvalue) {
239 *oldvalue = NULL;
240 }
242 return 0;
243 } else {
244 return 1;
245 }
246 }
247 }
249 int ucx_avl_remove(UcxAVLTree *tree, intptr_t key) {
250 return ucx_avl_remove_s(tree, key, NULL, NULL);
251 }
253 int ucx_avl_remove_node(UcxAVLTree *tree, UcxAVLNode *node) {
254 return ucx_avl_remove_s(tree, node->key, NULL, NULL);
255 }
257 int ucx_avl_remove_s(UcxAVLTree *tree, intptr_t key,
258 intptr_t *oldkey, void **oldvalue) {
260 UcxAVLNode *n = tree->root;
261 int cmpresult;
262 while (n && (cmpresult = tree->cmpfunc(
263 ptrcast(key), ptrcast(n->key), tree->userdata))) {
264 n = cmpresult > 0 ? n->right : n->left;
265 }
266 if (n) {
267 if (oldkey) {
268 *oldkey = n->key;
269 }
270 if (oldvalue) {
271 *oldvalue = n->value;
272 }
274 UcxAVLNode *p = n->parent;
275 if (n->left && n->right) {
276 UcxAVLNode *s = n->right;
277 while (s->left) {
278 s = s->left;
279 }
280 ucx_avl_connect(tree, s->parent, s->right, s->key);
281 n->key = s->key; n->value = s->value;
282 p = s->parent;
283 alfree(tree->allocator, s);
284 } else {
285 if (p) {
286 ucx_avl_connect(tree, p, n->right ? n->right:n->left, n->key);
287 } else {
288 tree->root = n->right ? n->right : n->left;
289 if (tree->root) {
290 tree->root->parent = NULL;
291 }
292 }
293 alfree(tree->allocator, n);
294 }
296 if (p) {
297 ucx_avl_balance(tree, p);
298 }
300 return 0;
301 } else {
302 return 1;
303 }
304 }
306 static size_t ucx_avl_countn(UcxAVLNode *node) {
307 if (node) {
308 return 1 + ucx_avl_countn(node->left) + ucx_avl_countn(node->right);
309 } else {
310 return 0;
311 }
312 }
314 size_t ucx_avl_count(UcxAVLTree *tree) {
315 return ucx_avl_countn(tree->root);
316 }
318 UcxAVLNode* ucx_avl_pred(UcxAVLNode* node) {
319 if (node->left) {
320 UcxAVLNode* n = node->left;
321 while (n->right) {
322 n = n->right;
323 }
324 return n;
325 } else {
326 UcxAVLNode* n = node;
327 while (n->parent) {
328 if (n->parent->right == n) {
329 return n->parent;
330 } else {
331 n = n->parent;
332 }
333 }
334 return NULL;
335 }
336 }
338 UcxAVLNode* ucx_avl_succ(UcxAVLNode* node) {
339 if (node->right) {
340 UcxAVLNode* n = node->right;
341 while (n->left) {
342 n = n->left;
343 }
344 return n;
345 } else {
346 UcxAVLNode* n = node;
347 while (n->parent) {
348 if (n->parent->left == n) {
349 return n->parent;
350 } else {
351 n = n->parent;
352 }
353 }
354 return NULL;
355 }
356 }
