Line | Count | Source |
1 | | /*************************************************************************** |
2 | | * _ _ ____ _ |
3 | | * Project ___| | | | _ \| | |
4 | | * / __| | | | |_) | | |
5 | | * | (__| |_| | _ <| |___ |
6 | | * \___|\___/|_| \_\_____| |
7 | | * |
8 | | * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. |
9 | | * |
10 | | * This software is licensed as described in the file COPYING, which |
11 | | * you should have received as part of this distribution. The terms |
12 | | * are also available at https://curl.se/docs/copyright.html. |
13 | | * |
14 | | * You may opt to use, copy, modify, merge, publish, distribute and/or sell |
15 | | * copies of the Software, and permit persons to whom the Software is |
16 | | * furnished to do so, under the terms of the COPYING file. |
17 | | * |
18 | | * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY |
19 | | * KIND, either express or implied. |
20 | | * |
21 | | * SPDX-License-Identifier: curl |
22 | | * |
23 | | ***************************************************************************/ |
24 | | #include "curl_setup.h" |
25 | | |
26 | | #include "urldata.h" |
27 | | #include "splay.h" |
28 | | |
29 | | static struct Curl_tree *splay(timediff_t key, |
30 | | struct Curl_tree *root); |
31 | | |
32 | | #ifdef UNITTESTS |
33 | | uint32_t Curl_splayget(struct Curl_tree *node) |
34 | 0 | { |
35 | 0 | DEBUGASSERT(node); |
36 | 0 | return node->id; |
37 | 0 | } |
38 | | |
39 | | #endif |
40 | | |
41 | | void Curl_timeouts_init(struct Curl_timeouts *timeouts, |
42 | | const struct curltime *ptime_base) |
43 | 17.2k | { |
44 | 17.2k | struct curltime time_base = ptime_base ? *ptime_base : curlx_now(); |
45 | 17.2k | timeouts->tree = NULL; |
46 | 17.2k | timeouts->time_base_sec = time_base.tv_sec; |
47 | 17.2k | } |
48 | | |
49 | | bool Curl_timeouts_has(struct Curl_easy *data) |
50 | 195k | { |
51 | 195k | struct Curl_tree *node = data ? &data->state.timeouts.splaynode : NULL; |
52 | 195k | return node && node->registered; |
53 | 195k | } |
54 | | |
55 | | timediff_t Curl_timeouts_offset_us(struct Curl_timeouts *timeouts, |
56 | | const struct curltime *pts) |
57 | 477k | { |
58 | 477k | struct curltime time_base; |
59 | 477k | time_base.tv_sec = timeouts->time_base_sec; |
60 | 477k | time_base.tv_usec = 0; |
61 | 477k | return curlx_ptimediff_us(pts, &time_base); |
62 | 477k | } |
63 | | |
64 | | int Curl_timeouts_next_ms(struct Curl_timeouts *timeouts, |
65 | | const struct curltime *pnow, |
66 | | timediff_t *pexpire_offset_us, |
67 | | uint32_t *pmid) |
68 | 8.24k | { |
69 | 8.24k | if(timeouts->tree) { /* splay the lowest key to the root */ |
70 | 8.24k | timeouts->tree = splay(TIMEDIFF_T_MIN, timeouts->tree); |
71 | 8.24k | } |
72 | | |
73 | 8.24k | if(timeouts->tree) { |
74 | 8.24k | timediff_t elapsed_us = Curl_timeouts_offset_us(timeouts, pnow); |
75 | 8.24k | timediff_t delta_us = timeouts->tree->key - elapsed_us; |
76 | 8.24k | if(pmid) |
77 | 8.24k | *pmid = timeouts->tree->id; |
78 | 8.24k | if(pexpire_offset_us) |
79 | 0 | *pexpire_offset_us = timeouts->tree->key; |
80 | 8.24k | if(delta_us > 0) { /* expires in the future */ |
81 | 8.19k | timediff_t ms = curlx_us_to_ceil_ms(delta_us); |
82 | 8.19k | return (ms > INT_MAX) ? INT_MAX : (int)ms; |
83 | 8.19k | } |
84 | 45 | else /* has expired */ |
85 | 45 | return 0; |
86 | 8.24k | } |
87 | 0 | if(pmid) |
88 | 0 | *pmid = UINT32_MAX; |
89 | 0 | if(pexpire_offset_us) |
90 | 0 | *pexpire_offset_us = 0; |
91 | 0 | return -1; |
92 | 8.24k | } |
93 | | |
94 | | /* |
95 | | * Splay using the key i (which may or may not be in the tree). |
96 | | * This rotates the tree, so: |
97 | | * - root->smaller has all nodes smaller than `key` |
98 | | * - root->larger has all nodes larger than `key` |
99 | | * - root->key may equal `key` or not |
100 | | * <https://en.wikipedia.org/wiki/Splay_tree> |
101 | | */ |
102 | | struct Curl_tree *splay(timediff_t key, |
103 | | struct Curl_tree *root) |
104 | 500k | { |
105 | 500k | struct Curl_tree N, *l, *r, *y; |
106 | | |
107 | 500k | if(!root) |
108 | 0 | return NULL; |
109 | 500k | N.smaller = N.larger = NULL; |
110 | 500k | l = r = &N; |
111 | | |
112 | 514k | for(;;) { |
113 | 514k | if(key < root->key) { |
114 | | /* key is somewhere in root->smaller branch */ |
115 | 419k | if(!root->smaller) /* which is empty, done */ |
116 | 406k | break; |
117 | 12.9k | if(key < root->smaller->key) { |
118 | | /* key is somewhere in root->smaller->smaller, make a "Zig step" */ |
119 | 12.3k | y = root->smaller; |
120 | 12.3k | root->smaller = y->larger; |
121 | 12.3k | y->larger = root; |
122 | 12.3k | root = y; |
123 | 12.3k | if(!root->smaller) |
124 | 12.3k | break; |
125 | 12.3k | } |
126 | | /* Making root->smaller the new root, the old root is no longer |
127 | | * referenced. Remember it in the N tree's `r`ight/larger side. |
128 | | * Everything in old root is smaller than what the right side |
129 | | * of N already has, so it gets added to r->smaller. */ |
130 | 620 | r->smaller = root; |
131 | 620 | r = root; |
132 | 620 | root = root->smaller; |
133 | 620 | } |
134 | 94.9k | else if(key > root->key) { |
135 | | /* key is somewhere in root->larger branch */ |
136 | 38.2k | if(!root->larger) /* which is empty, done */ |
137 | 25.6k | break; |
138 | 12.6k | if(key > root->larger->key) { |
139 | | /* key is somewhere in root->larger->larger, make a "Zig step" */ |
140 | 0 | y = root->larger; |
141 | 0 | root->larger = y->smaller; |
142 | 0 | y->smaller = root; |
143 | 0 | root = y; |
144 | 0 | if(!root->larger) |
145 | 0 | break; |
146 | 0 | } |
147 | | /* Making root->larger the new root, the old root is no longer |
148 | | * referenced. Remember it in the N tree's `l`eft/smaller side. |
149 | | * Everything in old root is larger than what the left side |
150 | | * of N already has, so it gets added to l->larger. */ |
151 | 12.6k | l->larger = root; |
152 | 12.6k | l = root; |
153 | 12.6k | root = root->larger; |
154 | 12.6k | } |
155 | 56.7k | else /* exact match, root is key, done */ |
156 | 56.7k | break; |
157 | 514k | } |
158 | | |
159 | | /* Put it all together again. |
160 | | * root->smaller has everything larger than current `l`. |
161 | | * root->larger has everything smaller than current `r`. */ |
162 | 500k | l->larger = root->smaller; |
163 | 500k | r->smaller = root->larger; |
164 | 500k | root->smaller = N.larger; |
165 | 500k | root->larger = N.smaller; |
166 | | |
167 | 500k | return root; |
168 | 500k | } |
169 | | |
170 | | /* Insert key i into the tree t. Return a pointer to the resulting tree or |
171 | | * NULL if something went wrong. |
172 | | * |
173 | | * @unittest 1309 |
174 | | */ |
175 | | UNITTEST struct Curl_tree *splayinsert(timediff_t key, |
176 | | struct Curl_tree *root, |
177 | | struct Curl_tree *node, |
178 | | uint32_t id); |
179 | | UNITTEST struct Curl_tree *splayinsert(timediff_t key, |
180 | | struct Curl_tree *root, |
181 | | struct Curl_tree *node, |
182 | | uint32_t id) |
183 | 57.3k | { |
184 | 57.3k | DEBUGASSERT(node); |
185 | | |
186 | 57.3k | node->key = key; |
187 | 57.3k | node->id = id; |
188 | 57.3k | node->same = NULL; |
189 | 57.3k | node->registered = TRUE; |
190 | 57.3k | if(root) { |
191 | 15.1k | root = splay(key, root); |
192 | 15.1k | DEBUGASSERT(root); |
193 | 15.1k | if(key == root->key) { |
194 | | /* There already exists a node in the tree with the same key. |
195 | | Append the new node to the `same` list. */ |
196 | 0 | struct Curl_tree **panchor = &root->same; |
197 | 0 | while(*panchor) |
198 | 0 | panchor = &(*panchor)->same; |
199 | 0 | *panchor = node; |
200 | 0 | return root; /* the root node always stays the same */ |
201 | 0 | } |
202 | 15.1k | } |
203 | | |
204 | | /* node becomes the new root. Insert old root as sub-branch. */ |
205 | 57.3k | if(!root) { |
206 | 42.1k | node->smaller = node->larger = NULL; |
207 | 42.1k | } |
208 | 15.1k | else if(key < root->key) { |
209 | 2.15k | node->smaller = root->smaller; |
210 | 2.15k | node->larger = root; |
211 | 2.15k | root->smaller = NULL; |
212 | 2.15k | } |
213 | 12.9k | else { |
214 | 12.9k | node->larger = root->larger; |
215 | 12.9k | node->smaller = root; |
216 | 12.9k | root->larger = NULL; |
217 | 12.9k | } |
218 | | |
219 | 57.3k | return node; |
220 | 57.3k | } |
221 | | |
222 | | void Curl_timeouts_add(struct Curl_timeouts *timeouts, |
223 | | struct Curl_easy *data, |
224 | | timediff_t offset_us) |
225 | 57.3k | { |
226 | 57.3k | struct Curl_tree *node = &data->state.timeouts.splaynode; |
227 | 57.3k | DEBUGASSERT(!node->registered); |
228 | 57.3k | timeouts->tree = splayinsert(offset_us, timeouts->tree, |
229 | 57.3k | node, data->mid); |
230 | 57.3k | } |
231 | | |
232 | | /* Finds and deletes the best-fit node from the tree. Return a pointer to the |
233 | | resulting tree. best-fit means the smallest node if it is not larger than |
234 | | the key |
235 | | |
236 | | @unittest 1309 |
237 | | */ |
238 | | UNITTEST struct Curl_tree *splaygetbest(timediff_t key, |
239 | | struct Curl_tree *root, |
240 | | struct Curl_tree **removed); |
241 | | UNITTEST struct Curl_tree *splaygetbest(timediff_t key, |
242 | | struct Curl_tree *root, |
243 | | struct Curl_tree **removed) |
244 | 408k | { |
245 | 408k | struct Curl_tree *x; |
246 | | |
247 | 408k | if(!root) { |
248 | 0 | *removed = NULL; /* none removed since there was no root */ |
249 | 0 | return NULL; |
250 | 0 | } |
251 | | |
252 | | /* find smallest */ |
253 | 408k | root = splay(TIMEDIFF_T_MIN, root); |
254 | 408k | DEBUGASSERT(root); |
255 | 408k | if(key < root->key) { |
256 | | /* even the smallest is too big */ |
257 | 408k | *removed = NULL; |
258 | 408k | return root; |
259 | 408k | } |
260 | | |
261 | | /* FIRST! Check if there is a list with identical keys */ |
262 | 22 | if(root->same) { |
263 | 0 | x = root->same; |
264 | 0 | DEBUGASSERT(x->key == root->key); |
265 | | /* 'x' becomes the new root node */ |
266 | 0 | x->larger = root->larger; |
267 | 0 | x->smaller = root->smaller; |
268 | 0 | root->same = NULL; |
269 | 0 | root->registered = FALSE; |
270 | 0 | *removed = root; |
271 | 0 | return x; /* new root */ |
272 | 0 | } |
273 | | |
274 | | /* we splayed the tree to the smallest element, there is no smaller */ |
275 | 22 | x = root->larger; |
276 | 22 | root->registered = FALSE; |
277 | 22 | *removed = root; |
278 | | |
279 | 22 | return x; |
280 | 22 | } |
281 | | |
282 | | bool Curl_timeouts_remove_expired(struct Curl_timeouts *timeouts, |
283 | | const struct curltime *ts, |
284 | | uint32_t *pmid) |
285 | 425k | { |
286 | 425k | if(timeouts->tree) { |
287 | 408k | struct Curl_tree *t = NULL; |
288 | 408k | timediff_t elapsed_us = Curl_timeouts_offset_us(timeouts, ts); |
289 | 408k | timeouts->tree = splaygetbest(elapsed_us, timeouts->tree, &t); |
290 | 408k | if(t) { |
291 | 22 | *pmid = t->id; |
292 | 22 | return TRUE; |
293 | 22 | } |
294 | 408k | } |
295 | 425k | *pmid = UINT32_MAX; |
296 | 425k | return FALSE; |
297 | 425k | } |
298 | | |
299 | | /* Deletes the node we point out from the tree if it is there. Stores a |
300 | | * pointer to the new resulting tree in 'newroot'. |
301 | | * |
302 | | * Returns zero on success and non-zero on errors! |
303 | | * When returning error, it does not touch the 'newroot' pointer. |
304 | | * |
305 | | * NOTE: when the last node of the tree is removed, there is no tree left so |
306 | | * 'newroot' will be made to point to NULL. |
307 | | * |
308 | | * @unittest 1309 |
309 | | */ |
310 | | UNITTEST int splayremove(struct Curl_tree *root, |
311 | | struct Curl_tree *removenode, |
312 | | struct Curl_tree **newroot); |
313 | | UNITTEST int splayremove(struct Curl_tree *root, |
314 | | struct Curl_tree *removenode, |
315 | | struct Curl_tree **newroot) |
316 | 56.7k | { |
317 | 56.7k | struct Curl_tree *x; |
318 | | |
319 | 56.7k | if(!root) |
320 | 0 | return 1; |
321 | | |
322 | 56.7k | DEBUGASSERT(removenode); |
323 | 56.7k | if(!removenode->registered) |
324 | 0 | return 2; |
325 | | |
326 | 56.7k | root = splay(removenode->key, root); |
327 | 56.7k | DEBUGASSERT(root); |
328 | | |
329 | | /* First make sure that we got the same root key as the one we want |
330 | | to remove, as otherwise we might be trying to remove a node that |
331 | | is not actually in the tree. */ |
332 | 56.7k | if(root->key != removenode->key) { |
333 | 0 | DEBUGASSERT(0); |
334 | 0 | return 2; |
335 | 0 | } |
336 | | |
337 | 56.7k | if(root != removenode) { |
338 | | /* Should be in the root->same list then */ |
339 | 0 | struct Curl_tree **panchor; |
340 | 0 | for(panchor = &root->same; *panchor; panchor = &(*panchor)->same) { |
341 | 0 | if(*panchor == removenode) { |
342 | 0 | *panchor = removenode->same; |
343 | 0 | removenode->same = NULL; |
344 | 0 | removenode->registered = FALSE; |
345 | 0 | *newroot = root; |
346 | 0 | return 0; |
347 | 0 | } |
348 | 0 | } |
349 | | /* not found in same list, error */ |
350 | 0 | DEBUGASSERT(0); |
351 | 0 | return 2; |
352 | 0 | } |
353 | | /* removing the root node */ |
354 | 56.7k | if(root->same) { |
355 | | /* 'x' is the new root node, we make it use the root node's |
356 | | smaller/larger links */ |
357 | 0 | x = root->same; |
358 | 0 | x->larger = root->larger; |
359 | 0 | x->smaller = root->smaller; |
360 | 0 | root->same = NULL; |
361 | 0 | } |
362 | 56.7k | else { |
363 | | /* Remove the root node */ |
364 | 56.7k | if(!root->smaller) |
365 | 44.0k | x = root->larger; |
366 | 12.6k | else { |
367 | 12.6k | x = splay(removenode->key, root->smaller); |
368 | 12.6k | DEBUGASSERT(x); |
369 | 12.6k | x->larger = root->larger; |
370 | 12.6k | } |
371 | 56.7k | } |
372 | 56.7k | removenode->registered = FALSE; |
373 | 56.7k | *newroot = x; /* return new root */ |
374 | 56.7k | return 0; |
375 | 56.7k | } |
376 | | |
377 | | bool Curl_timeouts_remove(struct Curl_timeouts *timeouts, |
378 | | struct Curl_easy *data) |
379 | 73.9k | { |
380 | 73.9k | struct Curl_tree *node = &data->state.timeouts.splaynode; |
381 | 73.9k | if(node->registered) { |
382 | 56.7k | int rc = splayremove(timeouts->tree, node, &timeouts->tree); |
383 | 56.7k | #ifdef DEBUGBUILD |
384 | 56.7k | if(rc) |
385 | 0 | curl_mfprintf(stderr, "Internal error removing splay node = %d\n", rc); |
386 | | #else |
387 | | (void)rc; |
388 | | #endif |
389 | 56.7k | return TRUE; |
390 | 56.7k | } |
391 | 17.2k | return FALSE; |
392 | 73.9k | } |