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5c193dec AJ |
1 | /* |
2 | * Copyright (C) 1996-2014 The Squid Software Foundation and contributors | |
3 | * | |
4 | * Squid software is distributed under GPLv2+ license and includes | |
5 | * contributions from numerous individuals and organizations. | |
6 | * Please see the COPYING and CONTRIBUTORS files for details. | |
7 | */ | |
8 | ||
b5638623 | 9 | #ifndef SQUID_SPLAY_H |
10 | #define SQUID_SPLAY_H | |
3c01c392 | 11 | |
3b359328 | 12 | #if defined(__cplusplus) |
b67e2c8c | 13 | |
cfb88efb AR |
14 | #include "fatal.h" |
15 | ||
16 | #include <stack> | |
29b17d63 | 17 | |
fb3eae94 FC |
18 | |
19 | // private class of Splay. Do not use directly | |
b67e2c8c | 20 | template <class V> |
42a503bd | 21 | class SplayNode |
22 | { | |
23 | ||
24 | public: | |
b67e2c8c | 25 | typedef V Value; |
29b17d63 | 26 | typedef int SPLAYCMP(Value const &a, Value const &b); |
27 | typedef void SPLAYFREE(Value &); | |
28 | typedef void SPLAYWALKEE(Value const & nodedata, void *state); | |
00d77d6b | 29 | static void DefaultFree (Value &aValue) {delete aValue;} |
42a503bd | 30 | |
2bcafc95 | 31 | SplayNode<V> (Value const &); |
29b17d63 | 32 | Value data; |
33 | mutable SplayNode<V> *left; | |
34 | mutable SplayNode<V> *right; | |
fb3eae94 | 35 | void destroy(SPLAYFREE * = DefaultFree); |
29b17d63 | 36 | void walk(SPLAYWALKEE *, void *callerState); |
4c50505b | 37 | SplayNode<V> const * start() const; |
ccd33084 | 38 | SplayNode<V> const * finish() const; |
42a503bd | 39 | |
6ca34f6f | 40 | SplayNode<V> * remove(const Value data, SPLAYCMP * compare); |
42a503bd | 41 | |
29b17d63 | 42 | SplayNode<V> * insert(Value data, SPLAYCMP * compare); |
42a503bd | 43 | |
fb3eae94 FC |
44 | /// look in the splay for data for where compare(data,candidate) == true. |
45 | /// return NULL if not found, a pointer to the sought data if found. | |
b001e822 | 46 | template <class FindValue> SplayNode<V> * splay(const FindValue &data, int( * compare)(FindValue const &a, Value const &b)) const; |
97754f5a AR |
47 | |
48 | /// recursively visit left nodes, this node, and then right nodes | |
49 | template <class Visitor> void visit(Visitor &v) const; | |
b67e2c8c | 50 | }; |
51 | ||
29b17d63 | 52 | typedef SplayNode<void *> splayNode; |
53 | ||
54 | template <class V> | |
b8bad68c | 55 | class SplayConstIterator; |
56 | ||
57 | template <class V> | |
ccd33084 | 58 | class SplayIterator; |
59 | ||
60 | template <class V> | |
42a503bd | 61 | class Splay |
62 | { | |
63 | ||
64 | public: | |
29b17d63 | 65 | typedef V Value; |
66 | typedef int SPLAYCMP(Value const &a, Value const &b); | |
42a503bd | 67 | typedef void SPLAYFREE(Value &); |
b8bad68c | 68 | typedef SplayIterator<V> iterator; |
69 | typedef const SplayConstIterator<V> const_iterator; | |
c5dd4956 | 70 | Splay():head(NULL), elements (0) {} |
42a503bd | 71 | |
29b17d63 | 72 | mutable SplayNode<V> * head; |
b001e822 | 73 | template <class FindValue> Value const *find (FindValue const &, int( * compare)(FindValue const &a, Value const &b)) const; |
fb3eae94 | 74 | |
0353e724 | 75 | void insert(Value const &, SPLAYCMP *compare); |
42a503bd | 76 | |
6ca34f6f | 77 | void remove(Value const &, SPLAYCMP *compare); |
42a503bd | 78 | |
fb3eae94 | 79 | void destroy(SPLAYFREE * = SplayNode<V>::DefaultFree); |
42a503bd | 80 | |
4c50505b | 81 | SplayNode<V> const * start() const; |
42a503bd | 82 | |
ccd33084 | 83 | SplayNode<V> const * finish() const; |
42a503bd | 84 | |
85 | size_t size() const; | |
86 | ||
4a0199ee | 87 | bool empty() const { return size() == 0; } |
fb3eae94 | 88 | |
b8bad68c | 89 | const_iterator begin() const; |
90 | ||
91 | const_iterator end() const; | |
92 | ||
97754f5a AR |
93 | /// recursively visit all nodes, in left-to-right order |
94 | template <class Visitor> void visit(Visitor &v) const; | |
95 | ||
0353e724 | 96 | size_t elements; |
29b17d63 | 97 | }; |
b67e2c8c | 98 | |
b67e2c8c | 99 | SQUIDCEXTERN int splayLastResult; |
100 | ||
29b17d63 | 101 | template<class V> |
2bcafc95 | 102 | SplayNode<V>::SplayNode (Value const &someData) : data(someData), left(NULL), right (NULL) {} |
103 | ||
87c692d7 | 104 | template<class V> |
29b17d63 | 105 | void |
106 | SplayNode<V>::walk(SPLAYWALKEE * walkee, void *state) | |
107 | { | |
0c9ed72a FC |
108 | if (this == NULL) |
109 | return; | |
110 | ||
29b17d63 | 111 | if (left) |
42a503bd | 112 | left->walk(walkee, state); |
113 | ||
29b17d63 | 114 | walkee(data, state); |
42a503bd | 115 | |
29b17d63 | 116 | if (right) |
42a503bd | 117 | right->walk(walkee, state); |
29b17d63 | 118 | } |
119 | ||
4c50505b | 120 | template<class V> |
121 | SplayNode<V> const * | |
122 | SplayNode<V>::start() const | |
123 | { | |
e45bad43 | 124 | if (left) |
42a503bd | 125 | return left->start(); |
126 | ||
127 | return this; | |
128 | } | |
129 | ||
130 | template<class V> | |
131 | SplayNode<V> const * | |
ccd33084 | 132 | SplayNode<V>::finish() const |
42a503bd | 133 | { |
e45bad43 | 134 | if (right) |
ccd33084 | 135 | return right->finish(); |
42a503bd | 136 | |
4c50505b | 137 | return this; |
138 | } | |
139 | ||
29b17d63 | 140 | template<class V> |
141 | void | |
142 | SplayNode<V>::destroy(SPLAYFREE * free_func) | |
143 | { | |
0c9ed72a FC |
144 | if (!this) |
145 | return; | |
146 | ||
29b17d63 | 147 | if (left) |
42a503bd | 148 | left->destroy(free_func); |
149 | ||
29b17d63 | 150 | if (right) |
42a503bd | 151 | right->destroy(free_func); |
152 | ||
29b17d63 | 153 | free_func(data); |
42a503bd | 154 | |
29b17d63 | 155 | delete this; |
156 | } | |
157 | ||
158 | template<class V> | |
159 | SplayNode<V> * | |
6ca34f6f | 160 | SplayNode<V>::remove(Value const dataToRemove, SPLAYCMP * compare) |
29b17d63 | 161 | { |
e45bad43 | 162 | assert(this != NULL); |
0c9ed72a | 163 | |
626e1f97 | 164 | SplayNode<V> *result = splay(dataToRemove, compare); |
42a503bd | 165 | |
f53969cc | 166 | if (splayLastResult == 0) { /* found it */ |
42a503bd | 167 | SplayNode<V> *newTop; |
168 | ||
169 | if (result->left == NULL) { | |
170 | newTop = result->right; | |
171 | } else { | |
172 | newTop = result->left->splay(dataToRemove, compare); | |
173 | /* temporary */ | |
174 | newTop->right = result->right; | |
175 | result->right = NULL; | |
176 | } | |
177 | ||
178 | delete result; | |
179 | return newTop; | |
29b17d63 | 180 | } |
42a503bd | 181 | |
f53969cc | 182 | return result; /* It wasn't there */ |
29b17d63 | 183 | } |
b67e2c8c | 184 | |
29b17d63 | 185 | template<class V> |
186 | SplayNode<V> * | |
626e1f97 | 187 | SplayNode<V>::insert(Value dataToInsert, SPLAYCMP * compare) |
29b17d63 | 188 | { |
189 | /* create node to insert */ | |
2bcafc95 | 190 | SplayNode<V> *newNode = new SplayNode<V>(dataToInsert); |
42a503bd | 191 | |
e45bad43 | 192 | assert(this != NULL); |
0c9ed72a | 193 | |
626e1f97 | 194 | SplayNode<V> *newTop = splay(dataToInsert, compare); |
42a503bd | 195 | |
29b17d63 | 196 | if (splayLastResult < 0) { |
42a503bd | 197 | newNode->left = newTop->left; |
198 | newNode->right = newTop; | |
199 | newTop->left = NULL; | |
200 | return newNode; | |
29b17d63 | 201 | } else if (splayLastResult > 0) { |
42a503bd | 202 | newNode->right = newTop->right; |
203 | newNode->left = newTop; | |
204 | newTop->right = NULL; | |
205 | return newNode; | |
29b17d63 | 206 | } else { |
42a503bd | 207 | /* duplicate entry */ |
208 | delete newNode; | |
209 | return newTop; | |
29b17d63 | 210 | } |
211 | } | |
212 | ||
213 | template<class V> | |
b001e822 | 214 | template<class FindValue> |
29b17d63 | 215 | SplayNode<V> * |
b001e822 | 216 | SplayNode<V>::splay(FindValue const &dataToFind, int( * compare)(FindValue const &a, Value const &b)) const |
29b17d63 | 217 | { |
e45bad43 | 218 | assert(this != NULL); |
0c9ed72a | 219 | |
b001e822 | 220 | Value temp = Value(); |
221 | SplayNode<V> N(temp); | |
29b17d63 | 222 | SplayNode<V> *l; |
223 | SplayNode<V> *r; | |
224 | SplayNode<V> *y; | |
225 | N.left = N.right = NULL; | |
226 | l = r = &N; | |
227 | ||
228 | SplayNode<V> *top = const_cast<SplayNode<V> *>(this); | |
42a503bd | 229 | |
29b17d63 | 230 | for (;;) { |
42a503bd | 231 | splayLastResult = compare(dataToFind, top->data); |
232 | ||
233 | if (splayLastResult < 0) { | |
234 | if (top->left == NULL) | |
235 | break; | |
236 | ||
237 | if ((splayLastResult = compare(dataToFind, top->left->data)) < 0) { | |
f53969cc | 238 | y = top->left; /* rotate right */ |
42a503bd | 239 | top->left = y->right; |
240 | y->right = top; | |
241 | top = y; | |
242 | ||
243 | if (top->left == NULL) | |
244 | break; | |
245 | } | |
246 | ||
f53969cc | 247 | r->left = top; /* link right */ |
42a503bd | 248 | r = top; |
249 | top = top->left; | |
250 | } else if (splayLastResult > 0) { | |
251 | if (top->right == NULL) | |
252 | break; | |
253 | ||
254 | if ((splayLastResult = compare(dataToFind, top->right->data)) > 0) { | |
f53969cc | 255 | y = top->right; /* rotate left */ |
42a503bd | 256 | top->right = y->left; |
257 | y->left = top; | |
258 | top = y; | |
259 | ||
260 | if (top->right == NULL) | |
261 | break; | |
262 | } | |
263 | ||
f53969cc | 264 | l->right = top; /* link left */ |
42a503bd | 265 | l = top; |
266 | top = top->right; | |
267 | } else { | |
268 | break; | |
269 | } | |
29b17d63 | 270 | } |
42a503bd | 271 | |
f53969cc | 272 | l->right = top->left; /* assemble */ |
29b17d63 | 273 | r->left = top->right; |
274 | top->left = N.right; | |
275 | top->right = N.left; | |
276 | return top; | |
277 | } | |
278 | ||
97754f5a AR |
279 | template <class V> |
280 | template <class Visitor> | |
281 | void | |
2da4bfe6 A |
282 | SplayNode<V>::visit(Visitor &visitor) const |
283 | { | |
97754f5a AR |
284 | if (left) |
285 | left->visit(visitor); | |
286 | visitor(data); | |
287 | if (right) | |
288 | right->visit(visitor); | |
289 | } | |
290 | ||
291 | template <class V> | |
292 | template <class Visitor> | |
293 | void | |
2da4bfe6 A |
294 | Splay<V>::visit(Visitor &visitor) const |
295 | { | |
97754f5a AR |
296 | if (head) |
297 | head->visit(visitor); | |
298 | } | |
299 | ||
29b17d63 | 300 | template <class V> |
b001e822 | 301 | template <class FindValue> |
29b17d63 | 302 | typename Splay<V>::Value const * |
b001e822 | 303 | Splay<V>::find (FindValue const &value, int( * compare)(FindValue const &a, Value const &b)) const |
29b17d63 | 304 | { |
e45bad43 FC |
305 | if (head == NULL) |
306 | return NULL; | |
307 | ||
29b17d63 | 308 | head = head->splay(value, compare); |
42a503bd | 309 | |
29b17d63 | 310 | if (splayLastResult != 0) |
42a503bd | 311 | return NULL; |
312 | ||
29b17d63 | 313 | return &head->data; |
314 | } | |
b67e2c8c | 315 | |
0353e724 | 316 | template <class V> |
317 | void | |
318 | Splay<V>::insert(Value const &value, SPLAYCMP *compare) | |
319 | { | |
320 | assert (!find (value, compare)); | |
321 | head = head->insert(value, compare); | |
322 | ++elements; | |
323 | } | |
324 | ||
325 | template <class V> | |
326 | void | |
6ca34f6f | 327 | Splay<V>::remove(Value const &value, SPLAYCMP *compare) |
0353e724 | 328 | { |
329 | assert (find (value, compare)); | |
42a503bd | 330 | |
6ca34f6f | 331 | head = head->remove(value, compare); |
42a503bd | 332 | |
0353e724 | 333 | --elements; |
334 | } | |
335 | ||
4c50505b | 336 | template <class V> |
42a503bd | 337 | SplayNode<V> const * |
338 | Splay<V>:: start() const | |
339 | { | |
340 | if (head) | |
341 | return head->start(); | |
342 | ||
343 | return NULL; | |
344 | } | |
345 | ||
346 | template <class V> | |
347 | SplayNode<V> const * | |
ccd33084 | 348 | Splay<V>:: finish() const |
42a503bd | 349 | { |
4c50505b | 350 | if (head) |
ccd33084 | 351 | return head->finish(); |
42a503bd | 352 | |
4c50505b | 353 | return NULL; |
354 | } | |
355 | ||
42a503bd | 356 | template <class V> |
357 | void | |
358 | Splay<V>:: destroy(SPLAYFREE *free_func) | |
359 | { | |
360 | if (head) | |
361 | head->destroy(free_func); | |
362 | ||
363 | head = NULL; | |
364 | ||
365 | elements = 0; | |
366 | } | |
367 | ||
368 | template <class V> | |
369 | size_t | |
370 | Splay<V>::size() const | |
371 | { | |
372 | return elements; | |
373 | } | |
374 | ||
b8bad68c | 375 | template <class V> |
411c6ea3 | 376 | const SplayConstIterator<V> |
b8bad68c | 377 | Splay<V>::begin() const |
378 | { | |
379 | return const_iterator(head); | |
380 | } | |
381 | ||
382 | template <class V> | |
411c6ea3 | 383 | const SplayConstIterator<V> |
b8bad68c | 384 | Splay<V>::end() const |
385 | { | |
386 | return const_iterator(NULL); | |
387 | } | |
388 | ||
97754f5a | 389 | // XXX: This does not seem to iterate the whole thing in some cases. |
b8bad68c | 390 | template <class V> |
b8bad68c | 391 | class SplayConstIterator |
392 | { | |
393 | ||
394 | public: | |
395 | typedef const V value_type; | |
396 | SplayConstIterator (SplayNode<V> *aNode); | |
397 | bool operator == (SplayConstIterator const &right) const; | |
398 | SplayConstIterator operator ++ (int dummy); | |
399 | SplayConstIterator &operator ++ (); | |
400 | V const & operator * () const; | |
401 | ||
402 | private: | |
403 | void advance(); | |
404 | void addLeftPath(SplayNode<V> *aNode); | |
405 | void init(SplayNode<V> *); | |
cfb88efb | 406 | std::stack<SplayNode<V> *> toVisit; |
b8bad68c | 407 | }; |
408 | ||
409 | template <class V> | |
410 | SplayConstIterator<V>::SplayConstIterator (SplayNode<V> *aNode) | |
411 | { | |
412 | init(aNode); | |
413 | } | |
414 | ||
415 | template <class V> | |
416 | bool | |
417 | SplayConstIterator<V>::operator == (SplayConstIterator const &right) const | |
418 | { | |
cfb88efb AR |
419 | if (toVisit.empty() && right.toVisit.empty()) |
420 | return true; | |
421 | if (!toVisit.empty() && !right.toVisit.empty()) | |
422 | return toVisit.top() == right.toVisit.top(); | |
423 | // only one of the two is empty | |
424 | return false; | |
b8bad68c | 425 | } |
426 | ||
427 | template <class V> | |
428 | SplayConstIterator<V> & | |
429 | SplayConstIterator<V>::operator ++ () | |
430 | { | |
431 | advance(); | |
432 | return *this; | |
433 | } | |
434 | ||
435 | template <class V> | |
436 | SplayConstIterator<V> | |
437 | SplayConstIterator<V>::operator ++ (int dummy) | |
438 | { | |
439 | SplayConstIterator<V> result = *this; | |
440 | advance(); | |
441 | return result; | |
442 | } | |
443 | ||
444 | /* advance is simple enough: | |
445 | * if the stack is empty, we're done. | |
446 | * otherwise, pop the last visited node | |
447 | * then, pop the next node to visit | |
448 | * if that has a right child, add it and it's | |
449 | * left-to-end path. | |
450 | * then add the node back. | |
451 | */ | |
452 | template <class V> | |
453 | void | |
454 | SplayConstIterator<V>::advance() | |
455 | { | |
cfb88efb | 456 | if (toVisit.empty()) |
b8bad68c | 457 | return; |
458 | ||
459 | toVisit.pop(); | |
460 | ||
cfb88efb | 461 | if (toVisit.empty()) |
b8bad68c | 462 | return; |
463 | ||
cfb88efb AR |
464 | // not empty |
465 | SplayNode<V> *currentNode = toVisit.top(); | |
466 | toVisit.pop(); | |
b8bad68c | 467 | |
468 | addLeftPath(currentNode->right); | |
469 | ||
cfb88efb | 470 | toVisit.push(currentNode); |
b8bad68c | 471 | } |
472 | ||
473 | template <class V> | |
474 | void | |
475 | SplayConstIterator<V>::addLeftPath(SplayNode<V> *aNode) | |
476 | { | |
477 | if (aNode == NULL) | |
478 | return; | |
479 | ||
480 | do { | |
cfb88efb | 481 | toVisit.push(aNode); |
b8bad68c | 482 | aNode = aNode->left; |
483 | } while (aNode != NULL); | |
484 | } | |
485 | ||
486 | template <class V> | |
487 | void | |
488 | SplayConstIterator<V>::init(SplayNode<V> *head) | |
489 | { | |
490 | addLeftPath(head); | |
491 | } | |
492 | ||
493 | template <class V> | |
494 | V const & | |
495 | SplayConstIterator<V>::operator * () const | |
496 | { | |
497 | /* can't dereference when past the end */ | |
498 | ||
499 | if (toVisit.size() == 0) | |
500 | fatal ("Attempt to dereference SplayConstIterator past-the-end\n"); | |
501 | ||
502 | return toVisit.top()->data; | |
503 | } | |
504 | ||
505 | #endif /* cplusplus */ | |
bdffbfa5 | 506 | |
b5638623 | 507 | #endif /* SQUID_SPLAY_H */ |
f53969cc | 508 |