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0823efed | 1 | /* A type-safe hash table template. |
23a5b65a | 2 | Copyright (C) 2012-2014 Free Software Foundation, Inc. |
0823efed DN |
3 | Contributed by Lawrence Crowl <crowl@google.com> |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
9 | Software Foundation; either version 3, or (at your option) any later | |
10 | version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING3. If not see | |
19 | <http://www.gnu.org/licenses/>. */ | |
20 | ||
21 | ||
22 | /* This file implements a typed hash table. | |
5831a5f0 LC |
23 | The implementation borrows from libiberty's htab_t in hashtab.h. |
24 | ||
25 | ||
26 | INTRODUCTION TO TYPES | |
27 | ||
28 | Users of the hash table generally need to be aware of three types. | |
29 | ||
30 | 1. The type being placed into the hash table. This type is called | |
31 | the value type. | |
32 | ||
33 | 2. The type used to describe how to handle the value type within | |
34 | the hash table. This descriptor type provides the hash table with | |
35 | several things. | |
36 | ||
37 | - A typedef named 'value_type' to the value type (from above). | |
38 | ||
39 | - A static member function named 'hash' that takes a value_type | |
40 | pointer and returns a hashval_t value. | |
41 | ||
42 | - A typedef named 'compare_type' that is used to test when an value | |
43 | is found. This type is the comparison type. Usually, it will be the | |
44 | same as value_type. If it is not the same type, you must generally | |
45 | explicitly compute hash values and pass them to the hash table. | |
46 | ||
47 | - A static member function named 'equal' that takes a value_type | |
48 | pointer and a compare_type pointer, and returns a bool. | |
49 | ||
50 | - A static function named 'remove' that takes an value_type pointer | |
51 | and frees the memory allocated by it. This function is used when | |
52 | individual elements of the table need to be disposed of (e.g., | |
53 | when deleting a hash table, removing elements from the table, etc). | |
54 | ||
55 | 3. The type of the hash table itself. (More later.) | |
56 | ||
57 | In very special circumstances, users may need to know about a fourth type. | |
58 | ||
59 | 4. The template type used to describe how hash table memory | |
60 | is allocated. This type is called the allocator type. It is | |
61 | parameterized on the value type. It provides four functions. | |
62 | ||
5831a5f0 LC |
63 | - A static member function named 'data_alloc'. This function |
64 | allocates the data elements in the table. | |
65 | ||
66 | - A static member function named 'data_free'. This function | |
67 | deallocates the data elements in the table. | |
68 | ||
69 | Hash table are instantiated with two type arguments. | |
70 | ||
71 | * The descriptor type, (2) above. | |
72 | ||
73 | * The allocator type, (4) above. In general, you will not need to | |
74 | provide your own allocator type. By default, hash tables will use | |
75 | the class template xcallocator, which uses malloc/free for allocation. | |
76 | ||
77 | ||
78 | DEFINING A DESCRIPTOR TYPE | |
79 | ||
80 | The first task in using the hash table is to describe the element type. | |
81 | We compose this into a few steps. | |
82 | ||
83 | 1. Decide on a removal policy for values stored in the table. | |
84 | This header provides class templates for the two most common | |
85 | policies. | |
86 | ||
87 | * typed_free_remove implements the static 'remove' member function | |
88 | by calling free(). | |
89 | ||
90 | * typed_noop_remove implements the static 'remove' member function | |
91 | by doing nothing. | |
92 | ||
93 | You can use these policies by simply deriving the descriptor type | |
94 | from one of those class template, with the appropriate argument. | |
95 | ||
96 | Otherwise, you need to write the static 'remove' member function | |
97 | in the descriptor class. | |
98 | ||
99 | 2. Choose a hash function. Write the static 'hash' member function. | |
100 | ||
101 | 3. Choose an equality testing function. In most cases, its two | |
102 | arguments will be value_type pointers. If not, the first argument must | |
103 | be a value_type pointer, and the second argument a compare_type pointer. | |
104 | ||
105 | ||
106 | AN EXAMPLE DESCRIPTOR TYPE | |
107 | ||
108 | Suppose you want to put some_type into the hash table. You could define | |
109 | the descriptor type as follows. | |
110 | ||
111 | struct some_type_hasher : typed_noop_remove <some_type> | |
112 | // Deriving from typed_noop_remove means that we get a 'remove' that does | |
113 | // nothing. This choice is good for raw values. | |
114 | { | |
115 | typedef some_type value_type; | |
116 | typedef some_type compare_type; | |
117 | static inline hashval_t hash (const value_type *); | |
118 | static inline bool equal (const value_type *, const compare_type *); | |
119 | }; | |
120 | ||
121 | inline hashval_t | |
122 | some_type_hasher::hash (const value_type *e) | |
123 | { ... compute and return a hash value for E ... } | |
124 | ||
125 | inline bool | |
126 | some_type_hasher::equal (const value_type *p1, const compare_type *p2) | |
127 | { ... compare P1 vs P2. Return true if they are the 'same' ... } | |
128 | ||
129 | ||
130 | AN EXAMPLE HASH_TABLE DECLARATION | |
131 | ||
132 | To instantiate a hash table for some_type: | |
133 | ||
134 | hash_table <some_type_hasher> some_type_hash_table; | |
135 | ||
136 | There is no need to mention some_type directly, as the hash table will | |
137 | obtain it using some_type_hasher::value_type. | |
138 | ||
139 | You can then used any of the functions in hash_table's public interface. | |
140 | See hash_table for details. The interface is very similar to libiberty's | |
141 | htab_t. | |
142 | ||
143 | ||
144 | EASY DESCRIPTORS FOR POINTERS | |
145 | ||
146 | The class template pointer_hash provides everything you need to hash | |
147 | pointers (as opposed to what they point to). So, to instantiate a hash | |
148 | table over pointers to whatever_type, | |
149 | ||
150 | hash_table <pointer_hash <whatever_type>> whatever_type_hash_table; | |
151 | ||
bf190e8d LC |
152 | |
153 | HASH TABLE ITERATORS | |
154 | ||
155 | The hash table provides standard C++ iterators. For example, consider a | |
156 | hash table of some_info. We wish to consume each element of the table: | |
157 | ||
158 | extern void consume (some_info *); | |
159 | ||
160 | We define a convenience typedef and the hash table: | |
161 | ||
162 | typedef hash_table <some_info_hasher> info_table_type; | |
163 | info_table_type info_table; | |
164 | ||
165 | Then we write the loop in typical C++ style: | |
166 | ||
167 | for (info_table_type::iterator iter = info_table.begin (); | |
168 | iter != info_table.end (); | |
169 | ++iter) | |
170 | if ((*iter).status == INFO_READY) | |
171 | consume (&*iter); | |
172 | ||
173 | Or with common sub-expression elimination: | |
174 | ||
175 | for (info_table_type::iterator iter = info_table.begin (); | |
176 | iter != info_table.end (); | |
177 | ++iter) | |
178 | { | |
179 | some_info &elem = *iter; | |
180 | if (elem.status == INFO_READY) | |
181 | consume (&elem); | |
182 | } | |
183 | ||
184 | One can also use a more typical GCC style: | |
185 | ||
186 | typedef some_info *some_info_p; | |
187 | some_info *elem_ptr; | |
188 | info_table_type::iterator iter; | |
189 | FOR_EACH_HASH_TABLE_ELEMENT (info_table, elem_ptr, some_info_p, iter) | |
190 | if (elem_ptr->status == INFO_READY) | |
191 | consume (elem_ptr); | |
192 | ||
5831a5f0 | 193 | */ |
0823efed DN |
194 | |
195 | ||
196 | #ifndef TYPED_HASHTAB_H | |
197 | #define TYPED_HASHTAB_H | |
198 | ||
b086d530 | 199 | #include "ggc.h" |
0823efed DN |
200 | #include "hashtab.h" |
201 | ||
b086d530 TS |
202 | template<typename, typename, typename> class hash_map; |
203 | template<typename, typename> class hash_set; | |
0823efed DN |
204 | |
205 | /* The ordinary memory allocator. */ | |
206 | /* FIXME (crowl): This allocator may be extracted for wider sharing later. */ | |
207 | ||
208 | template <typename Type> | |
209 | struct xcallocator | |
210 | { | |
0823efed | 211 | static Type *data_alloc (size_t count); |
0823efed DN |
212 | static void data_free (Type *memory); |
213 | }; | |
214 | ||
215 | ||
5831a5f0 | 216 | /* Allocate memory for COUNT data blocks. */ |
0823efed DN |
217 | |
218 | template <typename Type> | |
219 | inline Type * | |
220 | xcallocator <Type>::data_alloc (size_t count) | |
221 | { | |
222 | return static_cast <Type *> (xcalloc (count, sizeof (Type))); | |
223 | } | |
224 | ||
225 | ||
0823efed DN |
226 | /* Free memory for data blocks. */ |
227 | ||
228 | template <typename Type> | |
229 | inline void | |
230 | xcallocator <Type>::data_free (Type *memory) | |
231 | { | |
232 | return ::free (memory); | |
233 | } | |
234 | ||
235 | ||
5831a5f0 | 236 | /* Helpful type for removing with free. */ |
0823efed | 237 | |
5831a5f0 | 238 | template <typename Type> |
5deac340 | 239 | struct typed_free_remove |
0823efed | 240 | { |
5831a5f0 | 241 | static inline void remove (Type *p); |
5deac340 | 242 | }; |
0823efed | 243 | |
0823efed | 244 | |
5831a5f0 LC |
245 | /* Remove with free. */ |
246 | ||
247 | template <typename Type> | |
248 | inline void | |
249 | typed_free_remove <Type>::remove (Type *p) | |
250 | { | |
251 | free (p); | |
252 | } | |
253 | ||
254 | ||
255 | /* Helpful type for a no-op remove. */ | |
256 | ||
257 | template <typename Type> | |
5deac340 | 258 | struct typed_noop_remove |
0823efed | 259 | { |
5831a5f0 | 260 | static inline void remove (Type *p); |
5deac340 | 261 | }; |
0823efed DN |
262 | |
263 | ||
5831a5f0 LC |
264 | /* Remove doing nothing. */ |
265 | ||
266 | template <typename Type> | |
267 | inline void | |
268 | typed_noop_remove <Type>::remove (Type *p ATTRIBUTE_UNUSED) | |
269 | { | |
270 | } | |
271 | ||
272 | ||
5deac340 | 273 | /* Pointer hash with a no-op remove method. */ |
0823efed | 274 | |
5831a5f0 LC |
275 | template <typename Type> |
276 | struct pointer_hash : typed_noop_remove <Type> | |
0823efed | 277 | { |
84baa4b9 TS |
278 | typedef Type *value_type; |
279 | typedef Type *compare_type; | |
280 | typedef int store_values_directly; | |
0823efed | 281 | |
84baa4b9 | 282 | static inline hashval_t hash (const value_type &); |
0823efed | 283 | |
84baa4b9 | 284 | static inline bool equal (const value_type &existing, const compare_type &candidate); |
5deac340 | 285 | }; |
0823efed | 286 | |
5831a5f0 | 287 | template <typename Type> |
5deac340 | 288 | inline hashval_t |
84baa4b9 | 289 | pointer_hash <Type>::hash (const value_type &candidate) |
5deac340 RG |
290 | { |
291 | /* This is a really poor hash function, but it is what the current code uses, | |
292 | so I am reusing it to avoid an additional axis in testing. */ | |
293 | return (hashval_t) ((intptr_t)candidate >> 3); | |
294 | } | |
295 | ||
5831a5f0 | 296 | template <typename Type> |
84baa4b9 TS |
297 | inline bool |
298 | pointer_hash <Type>::equal (const value_type &existing, | |
299 | const compare_type &candidate) | |
0823efed | 300 | { |
5deac340 | 301 | return existing == candidate; |
0823efed DN |
302 | } |
303 | ||
304 | ||
305 | /* Table of primes and their inversion information. */ | |
306 | ||
307 | struct prime_ent | |
308 | { | |
309 | hashval_t prime; | |
310 | hashval_t inv; | |
311 | hashval_t inv_m2; /* inverse of prime-2 */ | |
312 | hashval_t shift; | |
313 | }; | |
314 | ||
315 | extern struct prime_ent const prime_tab[]; | |
316 | ||
317 | ||
318 | /* Functions for computing hash table indexes. */ | |
319 | ||
320 | extern unsigned int hash_table_higher_prime_index (unsigned long n); | |
321 | extern hashval_t hash_table_mod1 (hashval_t hash, unsigned int index); | |
322 | extern hashval_t hash_table_mod2 (hashval_t hash, unsigned int index); | |
323 | ||
84baa4b9 TS |
324 | /* The below is some template meta programming to decide if we should use the |
325 | hash table partial specialization that directly stores value_type instead of | |
326 | pointers to value_type. If the Descriptor type defines the type | |
327 | Descriptor::store_values_directly then values are stored directly otherwise | |
328 | pointers to them are stored. */ | |
329 | template<typename T> struct notype { typedef void type; }; | |
330 | ||
331 | template<typename T, typename = void> | |
332 | struct storage_tester | |
333 | { | |
334 | static const bool value = false; | |
335 | }; | |
336 | ||
337 | template<typename T> | |
338 | struct storage_tester<T, typename notype<typename | |
339 | T::store_values_directly>::type> | |
340 | { | |
341 | static const bool value = true; | |
342 | }; | |
343 | ||
344 | template<typename Traits> | |
345 | struct has_is_deleted | |
346 | { | |
347 | template<typename U, bool (*)(U &)> struct helper {}; | |
348 | template<typename U> static char test (helper<U, U::is_deleted> *); | |
349 | template<typename U> static int test (...); | |
350 | static const bool value = sizeof (test<Traits> (0)) == sizeof (char); | |
351 | }; | |
352 | ||
353 | template<typename Type, typename Traits, bool = has_is_deleted<Traits>::value> | |
354 | struct is_deleted_helper | |
355 | { | |
356 | static inline bool | |
357 | call (Type &v) | |
358 | { | |
359 | return Traits::is_deleted (v); | |
360 | } | |
361 | }; | |
362 | ||
363 | template<typename Type, typename Traits> | |
364 | struct is_deleted_helper<Type *, Traits, false> | |
365 | { | |
366 | static inline bool | |
367 | call (Type *v) | |
368 | { | |
369 | return v == HTAB_DELETED_ENTRY; | |
370 | } | |
371 | }; | |
372 | ||
373 | template<typename Traits> | |
374 | struct has_is_empty | |
375 | { | |
376 | template<typename U, bool (*)(U &)> struct helper {}; | |
377 | template<typename U> static char test (helper<U, U::is_empty> *); | |
378 | template<typename U> static int test (...); | |
379 | static const bool value = sizeof (test<Traits> (0)) == sizeof (char); | |
380 | }; | |
381 | ||
382 | template<typename Type, typename Traits, bool = has_is_deleted<Traits>::value> | |
383 | struct is_empty_helper | |
384 | { | |
385 | static inline bool | |
386 | call (Type &v) | |
387 | { | |
388 | return Traits::is_empty (v); | |
389 | } | |
390 | }; | |
391 | ||
392 | template<typename Type, typename Traits> | |
393 | struct is_empty_helper<Type *, Traits, false> | |
394 | { | |
395 | static inline bool | |
396 | call (Type *v) | |
397 | { | |
398 | return v == HTAB_EMPTY_ENTRY; | |
399 | } | |
400 | }; | |
401 | ||
402 | template<typename Traits> | |
403 | struct has_mark_deleted | |
404 | { | |
405 | template<typename U, void (*)(U &)> struct helper {}; | |
406 | template<typename U> static char test (helper<U, U::mark_deleted> *); | |
407 | template<typename U> static int test (...); | |
408 | static const bool value = sizeof (test<Traits> (0)) == sizeof (char); | |
409 | }; | |
410 | ||
411 | template<typename Type, typename Traits, bool = has_is_deleted<Traits>::value> | |
412 | struct mark_deleted_helper | |
413 | { | |
414 | static inline void | |
415 | call (Type &v) | |
416 | { | |
417 | Traits::mark_deleted (v); | |
418 | } | |
419 | }; | |
420 | ||
421 | template<typename Type, typename Traits> | |
422 | struct mark_deleted_helper<Type *, Traits, false> | |
423 | { | |
424 | static inline void | |
425 | call (Type *&v) | |
426 | { | |
427 | v = static_cast<Type *> (HTAB_DELETED_ENTRY); | |
428 | } | |
429 | }; | |
430 | ||
431 | template<typename Traits> | |
432 | struct has_mark_empty | |
433 | { | |
434 | template<typename U, void (*)(U &)> struct helper {}; | |
435 | template<typename U> static char test (helper<U, U::mark_empty> *); | |
436 | template<typename U> static int test (...); | |
437 | static const bool value = sizeof (test<Traits> (0)) == sizeof (char); | |
438 | }; | |
439 | ||
440 | template<typename Type, typename Traits, bool = has_is_deleted<Traits>::value> | |
441 | struct mark_empty_helper | |
442 | { | |
443 | static inline void | |
444 | call (Type &v) | |
445 | { | |
446 | Traits::mark_empty (v); | |
447 | } | |
448 | }; | |
449 | ||
450 | template<typename Type, typename Traits> | |
451 | struct mark_empty_helper<Type *, Traits, false> | |
452 | { | |
453 | static inline void | |
454 | call (Type *&v) | |
455 | { | |
456 | v = static_cast<Type *> (HTAB_EMPTY_ENTRY); | |
457 | } | |
458 | }; | |
0823efed | 459 | |
0823efed DN |
460 | /* User-facing hash table type. |
461 | ||
84baa4b9 TS |
462 | The table stores elements of type Descriptor::value_type, or pointers to |
463 | objects of type value_type if the descriptor does not define the type | |
464 | store_values_directly. | |
0823efed | 465 | |
5831a5f0 | 466 | It hashes values with the hash member function. |
0823efed | 467 | The table currently works with relatively weak hash functions. |
5831a5f0 | 468 | Use typed_pointer_hash <Value> when hashing pointers instead of objects. |
0823efed | 469 | |
5831a5f0 | 470 | It compares elements with the equal member function. |
0823efed | 471 | Two elements with the same hash may not be equal. |
5831a5f0 | 472 | Use typed_pointer_equal <Value> when hashing pointers instead of objects. |
0823efed | 473 | |
5831a5f0 | 474 | It removes elements with the remove member function. |
0823efed | 475 | This feature is useful for freeing memory. |
5831a5f0 LC |
476 | Derive from typed_null_remove <Value> when not freeing objects. |
477 | Derive from typed_free_remove <Value> when doing a simple object free. | |
0823efed | 478 | |
5831a5f0 | 479 | Specify the template Allocator to allocate and free memory. |
0823efed DN |
480 | The default is xcallocator. |
481 | ||
84baa4b9 TS |
482 | Storage is an implementation detail and should not be used outside the |
483 | hash table code. | |
484 | ||
0823efed | 485 | */ |
5831a5f0 | 486 | template <typename Descriptor, |
84baa4b9 TS |
487 | template<typename Type> class Allocator= xcallocator, |
488 | bool Storage = storage_tester<Descriptor>::value> | |
0823efed | 489 | class hash_table |
84baa4b9 TS |
490 | { |
491 | }; | |
492 | ||
493 | template <typename Descriptor, | |
494 | template<typename Type> class Allocator> | |
495 | class hash_table<Descriptor, Allocator, false> | |
0823efed | 496 | { |
5831a5f0 LC |
497 | typedef typename Descriptor::value_type value_type; |
498 | typedef typename Descriptor::compare_type compare_type; | |
0823efed | 499 | |
0823efed | 500 | public: |
c203e8a7 TS |
501 | hash_table (size_t); |
502 | ~hash_table (); | |
bf190e8d | 503 | |
c203e8a7 TS |
504 | /* Current size (in entries) of the hash table. */ |
505 | size_t size () const { return m_size; } | |
0823efed | 506 | |
c203e8a7 TS |
507 | /* Return the current number of elements in this hash table. */ |
508 | size_t elements () const { return m_n_elements - m_n_deleted; } | |
0823efed | 509 | |
c203e8a7 TS |
510 | /* Return the current number of elements in this hash table. */ |
511 | size_t elements_with_deleted () const { return m_n_elements; } | |
0823efed | 512 | |
c203e8a7 TS |
513 | /* This function clears all entries in the given hash table. */ |
514 | void empty (); | |
0823efed | 515 | |
c203e8a7 TS |
516 | /* This function clears a specified SLOT in a hash table. It is |
517 | useful when you've already done the lookup and don't want to do it | |
518 | again. */ | |
0823efed | 519 | |
c203e8a7 | 520 | void clear_slot (value_type **); |
0823efed | 521 | |
c203e8a7 TS |
522 | /* This function searches for a hash table entry equal to the given |
523 | COMPARABLE element starting with the given HASH value. It cannot | |
524 | be used to insert or delete an element. */ | |
525 | value_type *find_with_hash (const compare_type *, hashval_t); | |
0823efed | 526 | |
c203e8a7 TS |
527 | /* Like find_slot_with_hash, but compute the hash value from the element. */ |
528 | value_type *find (const value_type *value) | |
529 | { | |
530 | return find_with_hash (value, Descriptor::hash (value)); | |
531 | } | |
0823efed | 532 | |
c203e8a7 TS |
533 | value_type **find_slot (const value_type *value, insert_option insert) |
534 | { | |
535 | return find_slot_with_hash (value, Descriptor::hash (value), insert); | |
536 | } | |
0823efed | 537 | |
c203e8a7 TS |
538 | /* This function searches for a hash table slot containing an entry |
539 | equal to the given COMPARABLE element and starting with the given | |
540 | HASH. To delete an entry, call this with insert=NO_INSERT, then | |
541 | call clear_slot on the slot returned (possibly after doing some | |
542 | checks). To insert an entry, call this with insert=INSERT, then | |
543 | write the value you want into the returned slot. When inserting an | |
544 | entry, NULL may be returned if memory allocation fails. */ | |
545 | value_type **find_slot_with_hash (const compare_type *comparable, | |
546 | hashval_t hash, enum insert_option insert); | |
0823efed | 547 | |
c203e8a7 TS |
548 | /* This function deletes an element with the given COMPARABLE value |
549 | from hash table starting with the given HASH. If there is no | |
550 | matching element in the hash table, this function does nothing. */ | |
551 | void remove_elt_with_hash (const compare_type *, hashval_t); | |
0823efed | 552 | |
c203e8a7 TS |
553 | /* Like remove_elt_with_hash, but compute the hash value from the element. */ |
554 | void remove_elt (const value_type *value) | |
555 | { | |
556 | remove_elt_with_hash (value, Descriptor::hash (value)); | |
557 | } | |
0823efed | 558 | |
c203e8a7 TS |
559 | /* This function scans over the entire hash table calling CALLBACK for |
560 | each live entry. If CALLBACK returns false, the iteration stops. | |
561 | ARGUMENT is passed as CALLBACK's second argument. */ | |
562 | template <typename Argument, | |
563 | int (*Callback) (value_type **slot, Argument argument)> | |
564 | void traverse_noresize (Argument argument); | |
0823efed | 565 | |
c203e8a7 TS |
566 | /* Like traverse_noresize, but does resize the table when it is too empty |
567 | to improve effectivity of subsequent calls. */ | |
568 | template <typename Argument, | |
569 | int (*Callback) (value_type **slot, Argument argument)> | |
570 | void traverse (Argument argument); | |
0823efed | 571 | |
c203e8a7 TS |
572 | class iterator |
573 | { | |
574 | public: | |
575 | iterator () : m_slot (NULL), m_limit (NULL) {} | |
0823efed | 576 | |
c203e8a7 TS |
577 | iterator (value_type **slot, value_type **limit) : |
578 | m_slot (slot), m_limit (limit) {} | |
0823efed | 579 | |
84baa4b9 | 580 | inline value_type *operator * () { return *m_slot; } |
c203e8a7 TS |
581 | void slide (); |
582 | inline iterator &operator ++ (); | |
583 | bool operator != (const iterator &other) const | |
584 | { | |
585 | return m_slot != other.m_slot || m_limit != other.m_limit; | |
586 | } | |
0823efed | 587 | |
c203e8a7 TS |
588 | private: |
589 | value_type **m_slot; | |
590 | value_type **m_limit; | |
591 | }; | |
0823efed | 592 | |
c203e8a7 TS |
593 | iterator begin () const |
594 | { | |
595 | iterator iter (m_entries, m_entries + m_size); | |
596 | iter.slide (); | |
597 | return iter; | |
598 | } | |
0823efed | 599 | |
c203e8a7 | 600 | iterator end () const { return iterator (); } |
0823efed | 601 | |
c203e8a7 TS |
602 | double collisions () const |
603 | { | |
604 | return m_searches ? static_cast <double> (m_collisions) / m_searches : 0; | |
605 | } | |
0823efed | 606 | |
c203e8a7 | 607 | private: |
0823efed | 608 | |
c203e8a7 TS |
609 | value_type **find_empty_slot_for_expand (hashval_t); |
610 | void expand (); | |
bf190e8d | 611 | |
c203e8a7 TS |
612 | /* Table itself. */ |
613 | typename Descriptor::value_type **m_entries; | |
bf190e8d | 614 | |
c203e8a7 | 615 | size_t m_size; |
bf190e8d | 616 | |
c203e8a7 TS |
617 | /* Current number of elements including also deleted elements. */ |
618 | size_t m_n_elements; | |
0823efed | 619 | |
c203e8a7 TS |
620 | /* Current number of deleted elements in the table. */ |
621 | size_t m_n_deleted; | |
0823efed | 622 | |
c203e8a7 TS |
623 | /* The following member is used for debugging. Its value is number |
624 | of all calls of `htab_find_slot' for the hash table. */ | |
625 | unsigned int m_searches; | |
0823efed | 626 | |
c203e8a7 TS |
627 | /* The following member is used for debugging. Its value is number |
628 | of collisions fixed for time of work with the hash table. */ | |
629 | unsigned int m_collisions; | |
0823efed | 630 | |
c203e8a7 TS |
631 | /* Current size (in entries) of the hash table, as an index into the |
632 | table of primes. */ | |
633 | unsigned int m_size_prime_index; | |
634 | }; | |
0823efed | 635 | |
c203e8a7 | 636 | template<typename Descriptor, template<typename Type> class Allocator> |
84baa4b9 | 637 | hash_table<Descriptor, Allocator, false>::hash_table (size_t size) : |
c203e8a7 | 638 | m_n_elements (0), m_n_deleted (0), m_searches (0), m_collisions (0) |
0823efed DN |
639 | { |
640 | unsigned int size_prime_index; | |
641 | ||
642 | size_prime_index = hash_table_higher_prime_index (size); | |
643 | size = prime_tab[size_prime_index].prime; | |
644 | ||
c203e8a7 TS |
645 | m_entries = Allocator <value_type*> ::data_alloc (size); |
646 | gcc_assert (m_entries != NULL); | |
647 | m_size = size; | |
648 | m_size_prime_index = size_prime_index; | |
0823efed DN |
649 | } |
650 | ||
c203e8a7 | 651 | template<typename Descriptor, template<typename Type> class Allocator> |
84baa4b9 | 652 | hash_table<Descriptor, Allocator, false>::~hash_table () |
0823efed | 653 | { |
c203e8a7 TS |
654 | for (size_t i = m_size - 1; i < m_size; i--) |
655 | if (m_entries[i] != HTAB_EMPTY_ENTRY && m_entries[i] != HTAB_DELETED_ENTRY) | |
656 | Descriptor::remove (m_entries[i]); | |
0823efed | 657 | |
c203e8a7 | 658 | Allocator <value_type *> ::data_free (m_entries); |
0823efed DN |
659 | } |
660 | ||
0823efed | 661 | /* Similar to find_slot, but without several unwanted side effects: |
5deac340 | 662 | - Does not call equal when it finds an existing entry. |
0823efed DN |
663 | - Does not change the count of elements/searches/collisions in the |
664 | hash table. | |
665 | This function also assumes there are no deleted entries in the table. | |
666 | HASH is the hash value for the element to be inserted. */ | |
667 | ||
c203e8a7 | 668 | template<typename Descriptor, template<typename Type> class Allocator> |
e4e01495 | 669 | typename hash_table<Descriptor, Allocator, false>::value_type ** |
84baa4b9 TS |
670 | hash_table<Descriptor, Allocator, false> |
671 | ::find_empty_slot_for_expand (hashval_t hash) | |
0823efed | 672 | { |
c203e8a7 TS |
673 | hashval_t index = hash_table_mod1 (hash, m_size_prime_index); |
674 | size_t size = m_size; | |
675 | value_type **slot = m_entries + index; | |
0823efed DN |
676 | hashval_t hash2; |
677 | ||
678 | if (*slot == HTAB_EMPTY_ENTRY) | |
679 | return slot; | |
680 | else if (*slot == HTAB_DELETED_ENTRY) | |
681 | abort (); | |
682 | ||
c203e8a7 | 683 | hash2 = hash_table_mod2 (hash, m_size_prime_index); |
0823efed DN |
684 | for (;;) |
685 | { | |
686 | index += hash2; | |
687 | if (index >= size) | |
688 | index -= size; | |
689 | ||
c203e8a7 | 690 | slot = m_entries + index; |
0823efed DN |
691 | if (*slot == HTAB_EMPTY_ENTRY) |
692 | return slot; | |
693 | else if (*slot == HTAB_DELETED_ENTRY) | |
694 | abort (); | |
695 | } | |
696 | } | |
697 | ||
0823efed DN |
698 | /* The following function changes size of memory allocated for the |
699 | entries and repeatedly inserts the table elements. The occupancy | |
700 | of the table after the call will be about 50%. Naturally the hash | |
701 | table must already exist. Remember also that the place of the | |
702 | table entries is changed. If memory allocation fails, this function | |
703 | will abort. */ | |
704 | ||
c203e8a7 | 705 | template<typename Descriptor, template<typename Type> class Allocator> |
0823efed | 706 | void |
84baa4b9 | 707 | hash_table<Descriptor, Allocator, false>::expand () |
0823efed | 708 | { |
c203e8a7 TS |
709 | value_type **oentries = m_entries; |
710 | unsigned int oindex = m_size_prime_index; | |
711 | size_t osize = size (); | |
712 | value_type **olimit = oentries + osize; | |
713 | size_t elts = elements (); | |
0823efed DN |
714 | |
715 | /* Resize only when table after removal of unused elements is either | |
716 | too full or too empty. */ | |
c203e8a7 TS |
717 | unsigned int nindex; |
718 | size_t nsize; | |
0823efed DN |
719 | if (elts * 2 > osize || (elts * 8 < osize && osize > 32)) |
720 | { | |
721 | nindex = hash_table_higher_prime_index (elts * 2); | |
722 | nsize = prime_tab[nindex].prime; | |
723 | } | |
724 | else | |
725 | { | |
726 | nindex = oindex; | |
727 | nsize = osize; | |
728 | } | |
729 | ||
c203e8a7 | 730 | value_type **nentries = Allocator <value_type *> ::data_alloc (nsize); |
0823efed | 731 | gcc_assert (nentries != NULL); |
c203e8a7 TS |
732 | m_entries = nentries; |
733 | m_size = nsize; | |
734 | m_size_prime_index = nindex; | |
735 | m_n_elements -= m_n_deleted; | |
736 | m_n_deleted = 0; | |
0823efed | 737 | |
c203e8a7 | 738 | value_type **p = oentries; |
0823efed DN |
739 | do |
740 | { | |
5831a5f0 | 741 | value_type *x = *p; |
0823efed DN |
742 | |
743 | if (x != HTAB_EMPTY_ENTRY && x != HTAB_DELETED_ENTRY) | |
744 | { | |
5831a5f0 | 745 | value_type **q = find_empty_slot_for_expand (Descriptor::hash (x)); |
0823efed DN |
746 | |
747 | *q = x; | |
748 | } | |
749 | ||
750 | p++; | |
751 | } | |
752 | while (p < olimit); | |
753 | ||
5831a5f0 | 754 | Allocator <value_type *> ::data_free (oentries); |
0823efed DN |
755 | } |
756 | ||
c203e8a7 TS |
757 | template<typename Descriptor, template<typename Type> class Allocator> |
758 | void | |
84baa4b9 | 759 | hash_table<Descriptor, Allocator, false>::empty () |
c203e8a7 TS |
760 | { |
761 | size_t size = m_size; | |
762 | value_type **entries = m_entries; | |
763 | int i; | |
764 | ||
765 | for (i = size - 1; i >= 0; i--) | |
766 | if (entries[i] != HTAB_EMPTY_ENTRY && entries[i] != HTAB_DELETED_ENTRY) | |
767 | Descriptor::remove (entries[i]); | |
768 | ||
769 | /* Instead of clearing megabyte, downsize the table. */ | |
770 | if (size > 1024*1024 / sizeof (PTR)) | |
771 | { | |
772 | int nindex = hash_table_higher_prime_index (1024 / sizeof (PTR)); | |
773 | int nsize = prime_tab[nindex].prime; | |
774 | ||
775 | Allocator <value_type *> ::data_free (m_entries); | |
776 | m_entries = Allocator <value_type *> ::data_alloc (nsize); | |
777 | m_size = nsize; | |
778 | m_size_prime_index = nindex; | |
779 | } | |
780 | else | |
781 | memset (entries, 0, size * sizeof (value_type *)); | |
782 | m_n_deleted = 0; | |
783 | m_n_elements = 0; | |
784 | } | |
785 | ||
786 | /* This function clears a specified SLOT in a hash table. It is | |
787 | useful when you've already done the lookup and don't want to do it | |
788 | again. */ | |
789 | ||
790 | template<typename Descriptor, template<typename Type> class Allocator> | |
791 | void | |
84baa4b9 | 792 | hash_table<Descriptor, Allocator, false>::clear_slot (value_type **slot) |
c203e8a7 TS |
793 | { |
794 | if (slot < m_entries || slot >= m_entries + size () | |
795 | || *slot == HTAB_EMPTY_ENTRY || *slot == HTAB_DELETED_ENTRY) | |
796 | abort (); | |
797 | ||
798 | Descriptor::remove (*slot); | |
799 | ||
800 | *slot = static_cast <value_type *> (HTAB_DELETED_ENTRY); | |
801 | m_n_deleted++; | |
802 | } | |
0823efed DN |
803 | |
804 | /* This function searches for a hash table entry equal to the given | |
805 | COMPARABLE element starting with the given HASH value. It cannot | |
806 | be used to insert or delete an element. */ | |
807 | ||
c203e8a7 | 808 | template<typename Descriptor, template<typename Type> class Allocator> |
e4e01495 | 809 | typename hash_table<Descriptor, Allocator, false>::value_type * |
84baa4b9 | 810 | hash_table<Descriptor, Allocator, false> |
5831a5f0 | 811 | ::find_with_hash (const compare_type *comparable, hashval_t hash) |
0823efed | 812 | { |
c203e8a7 TS |
813 | m_searches++; |
814 | size_t size = m_size; | |
815 | hashval_t index = hash_table_mod1 (hash, m_size_prime_index); | |
0823efed | 816 | |
c203e8a7 | 817 | value_type *entry = m_entries[index]; |
0823efed | 818 | if (entry == HTAB_EMPTY_ENTRY |
5831a5f0 | 819 | || (entry != HTAB_DELETED_ENTRY && Descriptor::equal (entry, comparable))) |
0823efed DN |
820 | return entry; |
821 | ||
c203e8a7 | 822 | hashval_t hash2 = hash_table_mod2 (hash, m_size_prime_index); |
0823efed DN |
823 | for (;;) |
824 | { | |
c203e8a7 | 825 | m_collisions++; |
0823efed DN |
826 | index += hash2; |
827 | if (index >= size) | |
828 | index -= size; | |
829 | ||
c203e8a7 | 830 | entry = m_entries[index]; |
0823efed | 831 | if (entry == HTAB_EMPTY_ENTRY |
5831a5f0 LC |
832 | || (entry != HTAB_DELETED_ENTRY |
833 | && Descriptor::equal (entry, comparable))) | |
0823efed DN |
834 | return entry; |
835 | } | |
836 | } | |
837 | ||
0823efed DN |
838 | /* This function searches for a hash table slot containing an entry |
839 | equal to the given COMPARABLE element and starting with the given | |
840 | HASH. To delete an entry, call this with insert=NO_INSERT, then | |
841 | call clear_slot on the slot returned (possibly after doing some | |
842 | checks). To insert an entry, call this with insert=INSERT, then | |
843 | write the value you want into the returned slot. When inserting an | |
844 | entry, NULL may be returned if memory allocation fails. */ | |
845 | ||
c203e8a7 | 846 | template<typename Descriptor, template<typename Type> class Allocator> |
e4e01495 | 847 | typename hash_table<Descriptor, Allocator, false>::value_type ** |
84baa4b9 | 848 | hash_table<Descriptor, Allocator, false> |
5831a5f0 | 849 | ::find_slot_with_hash (const compare_type *comparable, hashval_t hash, |
0823efed DN |
850 | enum insert_option insert) |
851 | { | |
c203e8a7 TS |
852 | if (insert == INSERT && m_size * 3 <= m_n_elements * 4) |
853 | expand (); | |
0823efed | 854 | |
c203e8a7 | 855 | m_searches++; |
0823efed | 856 | |
c203e8a7 TS |
857 | value_type **first_deleted_slot = NULL; |
858 | hashval_t index = hash_table_mod1 (hash, m_size_prime_index); | |
859 | hashval_t hash2 = hash_table_mod2 (hash, m_size_prime_index); | |
860 | value_type *entry = m_entries[index]; | |
861 | size_t size = m_size; | |
0823efed DN |
862 | if (entry == HTAB_EMPTY_ENTRY) |
863 | goto empty_entry; | |
864 | else if (entry == HTAB_DELETED_ENTRY) | |
c203e8a7 | 865 | first_deleted_slot = &m_entries[index]; |
5831a5f0 | 866 | else if (Descriptor::equal (entry, comparable)) |
c203e8a7 | 867 | return &m_entries[index]; |
5831a5f0 | 868 | |
0823efed DN |
869 | for (;;) |
870 | { | |
c203e8a7 | 871 | m_collisions++; |
0823efed DN |
872 | index += hash2; |
873 | if (index >= size) | |
874 | index -= size; | |
5831a5f0 | 875 | |
c203e8a7 | 876 | entry = m_entries[index]; |
0823efed DN |
877 | if (entry == HTAB_EMPTY_ENTRY) |
878 | goto empty_entry; | |
879 | else if (entry == HTAB_DELETED_ENTRY) | |
880 | { | |
881 | if (!first_deleted_slot) | |
c203e8a7 | 882 | first_deleted_slot = &m_entries[index]; |
0823efed | 883 | } |
5831a5f0 | 884 | else if (Descriptor::equal (entry, comparable)) |
c203e8a7 | 885 | return &m_entries[index]; |
0823efed DN |
886 | } |
887 | ||
888 | empty_entry: | |
889 | if (insert == NO_INSERT) | |
890 | return NULL; | |
891 | ||
892 | if (first_deleted_slot) | |
893 | { | |
c203e8a7 | 894 | m_n_deleted--; |
5831a5f0 | 895 | *first_deleted_slot = static_cast <value_type *> (HTAB_EMPTY_ENTRY); |
0823efed DN |
896 | return first_deleted_slot; |
897 | } | |
898 | ||
c203e8a7 TS |
899 | m_n_elements++; |
900 | return &m_entries[index]; | |
0823efed DN |
901 | } |
902 | ||
0823efed DN |
903 | /* This function deletes an element with the given COMPARABLE value |
904 | from hash table starting with the given HASH. If there is no | |
905 | matching element in the hash table, this function does nothing. */ | |
906 | ||
c203e8a7 | 907 | template<typename Descriptor, template<typename Type> class Allocator> |
0823efed | 908 | void |
84baa4b9 | 909 | hash_table<Descriptor, Allocator, false> |
5831a5f0 | 910 | ::remove_elt_with_hash (const compare_type *comparable, hashval_t hash) |
0823efed | 911 | { |
c203e8a7 | 912 | value_type **slot = find_slot_with_hash (comparable, hash, NO_INSERT); |
0823efed DN |
913 | if (*slot == HTAB_EMPTY_ENTRY) |
914 | return; | |
915 | ||
5831a5f0 | 916 | Descriptor::remove (*slot); |
0823efed | 917 | |
5831a5f0 | 918 | *slot = static_cast <value_type *> (HTAB_DELETED_ENTRY); |
c203e8a7 | 919 | m_n_deleted++; |
0823efed DN |
920 | } |
921 | ||
0823efed DN |
922 | /* This function scans over the entire hash table calling CALLBACK for |
923 | each live entry. If CALLBACK returns false, the iteration stops. | |
924 | ARGUMENT is passed as CALLBACK's second argument. */ | |
925 | ||
84baa4b9 | 926 | template<typename Descriptor, template<typename Type> class Allocator> |
c203e8a7 | 927 | template<typename Argument, |
e4e01495 TS |
928 | int (*Callback) (typename hash_table<Descriptor, Allocator, |
929 | false>::value_type **slot, | |
930 | Argument argument)> | |
0823efed | 931 | void |
84baa4b9 | 932 | hash_table<Descriptor, Allocator, false>::traverse_noresize (Argument argument) |
0823efed | 933 | { |
c203e8a7 TS |
934 | value_type **slot = m_entries; |
935 | value_type **limit = slot + size (); | |
0823efed DN |
936 | |
937 | do | |
938 | { | |
5831a5f0 | 939 | value_type *x = *slot; |
0823efed DN |
940 | |
941 | if (x != HTAB_EMPTY_ENTRY && x != HTAB_DELETED_ENTRY) | |
942 | if (! Callback (slot, argument)) | |
943 | break; | |
944 | } | |
945 | while (++slot < limit); | |
946 | } | |
947 | ||
0823efed DN |
948 | /* Like traverse_noresize, but does resize the table when it is too empty |
949 | to improve effectivity of subsequent calls. */ | |
950 | ||
5831a5f0 | 951 | template <typename Descriptor, |
0823efed DN |
952 | template <typename Type> class Allocator> |
953 | template <typename Argument, | |
e4e01495 TS |
954 | int (*Callback) (typename hash_table<Descriptor, Allocator, |
955 | false>::value_type **slot, | |
5831a5f0 | 956 | Argument argument)> |
0823efed | 957 | void |
84baa4b9 | 958 | hash_table<Descriptor, Allocator, false>::traverse (Argument argument) |
0823efed | 959 | { |
c203e8a7 | 960 | size_t size = m_size; |
0823efed DN |
961 | if (elements () * 8 < size && size > 32) |
962 | expand (); | |
963 | ||
964 | traverse_noresize <Argument, Callback> (argument); | |
965 | } | |
966 | ||
bf190e8d LC |
967 | /* Slide down the iterator slots until an active entry is found. */ |
968 | ||
c203e8a7 | 969 | template<typename Descriptor, template<typename Type> class Allocator> |
bf190e8d | 970 | void |
84baa4b9 | 971 | hash_table<Descriptor, Allocator, false>::iterator::slide () |
bf190e8d | 972 | { |
65d3284b | 973 | for ( ; m_slot < m_limit; ++m_slot ) |
bf190e8d | 974 | { |
65d3284b | 975 | value_type *x = *m_slot; |
bf190e8d LC |
976 | if (x != HTAB_EMPTY_ENTRY && x != HTAB_DELETED_ENTRY) |
977 | return; | |
978 | } | |
65d3284b RS |
979 | m_slot = NULL; |
980 | m_limit = NULL; | |
bf190e8d LC |
981 | } |
982 | ||
983 | /* Bump the iterator. */ | |
984 | ||
c203e8a7 | 985 | template<typename Descriptor, template<typename Type> class Allocator> |
84baa4b9 TS |
986 | inline typename hash_table<Descriptor, Allocator, false>::iterator & |
987 | hash_table<Descriptor, Allocator, false>::iterator::operator ++ () | |
988 | { | |
989 | ++m_slot; | |
990 | slide (); | |
991 | return *this; | |
992 | } | |
993 | ||
994 | /* A partial specialization used when values should be stored directly. */ | |
995 | ||
996 | template <typename Descriptor, | |
997 | template<typename Type> class Allocator> | |
998 | class hash_table<Descriptor, Allocator, true> | |
999 | { | |
1000 | typedef typename Descriptor::value_type value_type; | |
1001 | typedef typename Descriptor::compare_type compare_type; | |
1002 | ||
1003 | public: | |
b086d530 | 1004 | explicit hash_table (size_t, bool ggc = false); |
84baa4b9 TS |
1005 | ~hash_table (); |
1006 | ||
1007 | /* Current size (in entries) of the hash table. */ | |
1008 | size_t size () const { return m_size; } | |
1009 | ||
1010 | /* Return the current number of elements in this hash table. */ | |
1011 | size_t elements () const { return m_n_elements - m_n_deleted; } | |
1012 | ||
1013 | /* Return the current number of elements in this hash table. */ | |
1014 | size_t elements_with_deleted () const { return m_n_elements; } | |
1015 | ||
1016 | /* This function clears all entries in the given hash table. */ | |
1017 | void empty (); | |
1018 | ||
1019 | /* This function clears a specified SLOT in a hash table. It is | |
1020 | useful when you've already done the lookup and don't want to do it | |
1021 | again. */ | |
1022 | ||
1023 | void clear_slot (value_type *); | |
1024 | ||
1025 | /* This function searches for a hash table entry equal to the given | |
1026 | COMPARABLE element starting with the given HASH value. It cannot | |
1027 | be used to insert or delete an element. */ | |
1028 | value_type &find_with_hash (const compare_type &, hashval_t); | |
1029 | ||
1030 | /* Like find_slot_with_hash, but compute the hash value from the element. */ | |
1031 | value_type &find (const value_type &value) | |
1032 | { | |
1033 | return find_with_hash (value, Descriptor::hash (value)); | |
1034 | } | |
1035 | ||
1036 | value_type *find_slot (const value_type &value, insert_option insert) | |
1037 | { | |
1038 | return find_slot_with_hash (value, Descriptor::hash (value), insert); | |
1039 | } | |
1040 | ||
1041 | /* This function searches for a hash table slot containing an entry | |
1042 | equal to the given COMPARABLE element and starting with the given | |
1043 | HASH. To delete an entry, call this with insert=NO_INSERT, then | |
1044 | call clear_slot on the slot returned (possibly after doing some | |
1045 | checks). To insert an entry, call this with insert=INSERT, then | |
1046 | write the value you want into the returned slot. When inserting an | |
1047 | entry, NULL may be returned if memory allocation fails. */ | |
1048 | value_type *find_slot_with_hash (const compare_type &comparable, | |
1049 | hashval_t hash, enum insert_option insert); | |
1050 | ||
1051 | /* This function deletes an element with the given COMPARABLE value | |
1052 | from hash table starting with the given HASH. If there is no | |
1053 | matching element in the hash table, this function does nothing. */ | |
1054 | void remove_elt_with_hash (const compare_type &, hashval_t); | |
1055 | ||
1056 | /* Like remove_elt_with_hash, but compute the hash value from the element. */ | |
1057 | void remove_elt (const value_type &value) | |
1058 | { | |
1059 | remove_elt_with_hash (value, Descriptor::hash (value)); | |
1060 | } | |
1061 | ||
1062 | /* This function scans over the entire hash table calling CALLBACK for | |
1063 | each live entry. If CALLBACK returns false, the iteration stops. | |
1064 | ARGUMENT is passed as CALLBACK's second argument. */ | |
1065 | template <typename Argument, | |
1066 | int (*Callback) (value_type *slot, Argument argument)> | |
1067 | void traverse_noresize (Argument argument); | |
1068 | ||
1069 | /* Like traverse_noresize, but does resize the table when it is too empty | |
1070 | to improve effectivity of subsequent calls. */ | |
1071 | template <typename Argument, | |
1072 | int (*Callback) (value_type *slot, Argument argument)> | |
1073 | void traverse (Argument argument); | |
1074 | ||
1075 | class iterator | |
1076 | { | |
1077 | public: | |
1078 | iterator () : m_slot (NULL), m_limit (NULL) {} | |
1079 | ||
1080 | iterator (value_type *slot, value_type *limit) : | |
1081 | m_slot (slot), m_limit (limit) {} | |
1082 | ||
1083 | inline value_type &operator * () { return *m_slot; } | |
1084 | void slide (); | |
1085 | inline iterator &operator ++ (); | |
1086 | bool operator != (const iterator &other) const | |
1087 | { | |
1088 | return m_slot != other.m_slot || m_limit != other.m_limit; | |
1089 | } | |
1090 | ||
1091 | private: | |
1092 | value_type *m_slot; | |
1093 | value_type *m_limit; | |
1094 | }; | |
1095 | ||
1096 | iterator begin () const | |
1097 | { | |
1098 | iterator iter (m_entries, m_entries + m_size); | |
1099 | iter.slide (); | |
1100 | return iter; | |
1101 | } | |
1102 | ||
1103 | iterator end () const { return iterator (); } | |
1104 | ||
1105 | double collisions () const | |
1106 | { | |
1107 | return m_searches ? static_cast <double> (m_collisions) / m_searches : 0; | |
1108 | } | |
1109 | ||
1110 | private: | |
b086d530 TS |
1111 | template<typename T> friend void gt_ggc_mx (hash_table<T> *); |
1112 | template<typename T> friend void gt_pch_nx (hash_table<T> *); | |
1113 | template<typename T> friend void hashtab_entry_note_pointers (void *, void *, gt_pointer_operator, void *); | |
1114 | template<typename T, typename U, typename V> friend void gt_pch_nx (hash_map<T, U, V> *, gt_pointer_operator, void *); | |
1115 | template<typename T, typename U> friend void gt_pch_nx (hash_set<T, U> *, gt_pointer_operator, void *); | |
84baa4b9 TS |
1116 | |
1117 | value_type *find_empty_slot_for_expand (hashval_t); | |
1118 | void expand (); | |
1119 | static bool is_deleted (value_type &v) | |
1120 | { | |
1121 | return is_deleted_helper<value_type, Descriptor>::call (v); | |
1122 | } | |
1123 | static bool is_empty (value_type &v) | |
1124 | { | |
1125 | return is_empty_helper<value_type, Descriptor>::call (v); | |
1126 | } | |
1127 | ||
1128 | static void mark_deleted (value_type &v) | |
1129 | { | |
1130 | return mark_deleted_helper<value_type, Descriptor>::call (v); | |
1131 | } | |
1132 | ||
1133 | static void mark_empty (value_type &v) | |
1134 | { | |
1135 | return mark_empty_helper<value_type, Descriptor>::call (v); | |
1136 | } | |
1137 | ||
1138 | /* Table itself. */ | |
1139 | typename Descriptor::value_type *m_entries; | |
1140 | ||
1141 | size_t m_size; | |
1142 | ||
1143 | /* Current number of elements including also deleted elements. */ | |
1144 | size_t m_n_elements; | |
1145 | ||
1146 | /* Current number of deleted elements in the table. */ | |
1147 | size_t m_n_deleted; | |
1148 | ||
1149 | /* The following member is used for debugging. Its value is number | |
1150 | of all calls of `htab_find_slot' for the hash table. */ | |
1151 | unsigned int m_searches; | |
1152 | ||
1153 | /* The following member is used for debugging. Its value is number | |
1154 | of collisions fixed for time of work with the hash table. */ | |
1155 | unsigned int m_collisions; | |
1156 | ||
1157 | /* Current size (in entries) of the hash table, as an index into the | |
1158 | table of primes. */ | |
1159 | unsigned int m_size_prime_index; | |
b086d530 TS |
1160 | |
1161 | /* if m_entries is stored in ggc memory. */ | |
1162 | bool m_ggc; | |
84baa4b9 TS |
1163 | }; |
1164 | ||
1165 | template<typename Descriptor, template<typename Type> class Allocator> | |
b086d530 TS |
1166 | hash_table<Descriptor, Allocator, true>::hash_table (size_t size, bool ggc) : |
1167 | m_n_elements (0), m_n_deleted (0), m_searches (0), m_collisions (0), | |
1168 | m_ggc (ggc) | |
84baa4b9 TS |
1169 | { |
1170 | unsigned int size_prime_index; | |
1171 | ||
1172 | size_prime_index = hash_table_higher_prime_index (size); | |
1173 | size = prime_tab[size_prime_index].prime; | |
1174 | ||
b086d530 TS |
1175 | if (!m_ggc) |
1176 | m_entries = Allocator <value_type> ::data_alloc (size); | |
1177 | else | |
1178 | m_entries = ggc_cleared_vec_alloc<value_type> (size); | |
1179 | ||
84baa4b9 TS |
1180 | gcc_assert (m_entries != NULL); |
1181 | m_size = size; | |
1182 | m_size_prime_index = size_prime_index; | |
1183 | } | |
1184 | ||
1185 | template<typename Descriptor, template<typename Type> class Allocator> | |
1186 | hash_table<Descriptor, Allocator, true>::~hash_table () | |
1187 | { | |
1188 | for (size_t i = m_size - 1; i < m_size; i--) | |
1189 | if (!is_empty (m_entries[i]) && !is_deleted (m_entries[i])) | |
1190 | Descriptor::remove (m_entries[i]); | |
1191 | ||
b086d530 TS |
1192 | if (!m_ggc) |
1193 | Allocator <value_type> ::data_free (m_entries); | |
1194 | else | |
1195 | ggc_free (m_entries); | |
84baa4b9 TS |
1196 | } |
1197 | ||
1198 | /* Similar to find_slot, but without several unwanted side effects: | |
1199 | - Does not call equal when it finds an existing entry. | |
1200 | - Does not change the count of elements/searches/collisions in the | |
1201 | hash table. | |
1202 | This function also assumes there are no deleted entries in the table. | |
1203 | HASH is the hash value for the element to be inserted. */ | |
1204 | ||
1205 | template<typename Descriptor, template<typename Type> class Allocator> | |
e4e01495 | 1206 | typename hash_table<Descriptor, Allocator, true>::value_type * |
84baa4b9 TS |
1207 | hash_table<Descriptor, Allocator, true> |
1208 | ::find_empty_slot_for_expand (hashval_t hash) | |
1209 | { | |
1210 | hashval_t index = hash_table_mod1 (hash, m_size_prime_index); | |
1211 | size_t size = m_size; | |
1212 | value_type *slot = m_entries + index; | |
1213 | hashval_t hash2; | |
1214 | ||
1215 | if (is_empty (*slot)) | |
1216 | return slot; | |
1217 | else if (is_deleted (*slot)) | |
1218 | abort (); | |
1219 | ||
1220 | hash2 = hash_table_mod2 (hash, m_size_prime_index); | |
1221 | for (;;) | |
1222 | { | |
1223 | index += hash2; | |
1224 | if (index >= size) | |
1225 | index -= size; | |
1226 | ||
1227 | slot = m_entries + index; | |
1228 | if (is_empty (*slot)) | |
1229 | return slot; | |
1230 | else if (is_deleted (*slot)) | |
1231 | abort (); | |
1232 | } | |
1233 | } | |
1234 | ||
1235 | /* The following function changes size of memory allocated for the | |
1236 | entries and repeatedly inserts the table elements. The occupancy | |
1237 | of the table after the call will be about 50%. Naturally the hash | |
1238 | table must already exist. Remember also that the place of the | |
1239 | table entries is changed. If memory allocation fails, this function | |
1240 | will abort. */ | |
1241 | ||
1242 | template<typename Descriptor, template<typename Type> class Allocator> | |
1243 | void | |
1244 | hash_table<Descriptor, Allocator, true>::expand () | |
1245 | { | |
1246 | value_type *oentries = m_entries; | |
1247 | unsigned int oindex = m_size_prime_index; | |
1248 | size_t osize = size (); | |
1249 | value_type *olimit = oentries + osize; | |
1250 | size_t elts = elements (); | |
1251 | ||
1252 | /* Resize only when table after removal of unused elements is either | |
1253 | too full or too empty. */ | |
1254 | unsigned int nindex; | |
1255 | size_t nsize; | |
1256 | if (elts * 2 > osize || (elts * 8 < osize && osize > 32)) | |
1257 | { | |
1258 | nindex = hash_table_higher_prime_index (elts * 2); | |
1259 | nsize = prime_tab[nindex].prime; | |
1260 | } | |
1261 | else | |
1262 | { | |
1263 | nindex = oindex; | |
1264 | nsize = osize; | |
1265 | } | |
1266 | ||
b086d530 TS |
1267 | value_type *nentries; |
1268 | if (!m_ggc) | |
1269 | nentries = Allocator <value_type> ::data_alloc (nsize); | |
1270 | else | |
1271 | nentries = ggc_cleared_vec_alloc<value_type> (nsize); | |
1272 | ||
84baa4b9 TS |
1273 | gcc_assert (nentries != NULL); |
1274 | m_entries = nentries; | |
1275 | m_size = nsize; | |
1276 | m_size_prime_index = nindex; | |
1277 | m_n_elements -= m_n_deleted; | |
1278 | m_n_deleted = 0; | |
1279 | ||
1280 | value_type *p = oentries; | |
1281 | do | |
1282 | { | |
1283 | value_type &x = *p; | |
1284 | ||
1285 | if (!is_empty (x) && !is_deleted (x)) | |
1286 | { | |
1287 | value_type *q = find_empty_slot_for_expand (Descriptor::hash (x)); | |
1288 | ||
1289 | *q = x; | |
1290 | } | |
1291 | ||
1292 | p++; | |
1293 | } | |
1294 | while (p < olimit); | |
1295 | ||
b086d530 TS |
1296 | if (!m_ggc) |
1297 | Allocator <value_type> ::data_free (oentries); | |
1298 | else | |
1299 | ggc_free (oentries); | |
84baa4b9 TS |
1300 | } |
1301 | ||
1302 | template<typename Descriptor, template<typename Type> class Allocator> | |
1303 | void | |
1304 | hash_table<Descriptor, Allocator, true>::empty () | |
1305 | { | |
1306 | size_t size = m_size; | |
1307 | value_type *entries = m_entries; | |
1308 | int i; | |
1309 | ||
1310 | for (i = size - 1; i >= 0; i--) | |
1311 | if (!is_empty (entries[i]) && !is_deleted (entries[i])) | |
1312 | Descriptor::remove (entries[i]); | |
1313 | ||
1314 | /* Instead of clearing megabyte, downsize the table. */ | |
1315 | if (size > 1024*1024 / sizeof (PTR)) | |
1316 | { | |
1317 | int nindex = hash_table_higher_prime_index (1024 / sizeof (PTR)); | |
1318 | int nsize = prime_tab[nindex].prime; | |
1319 | ||
b086d530 TS |
1320 | if (!m_ggc) |
1321 | { | |
1322 | Allocator <value_type> ::data_free (m_entries); | |
1323 | m_entries = Allocator <value_type> ::data_alloc (nsize); | |
1324 | } | |
1325 | else | |
1326 | { | |
1327 | ggc_free (m_entries); | |
1328 | m_entries = ggc_cleared_vec_alloc<value_type> (nsize); | |
1329 | } | |
1330 | ||
84baa4b9 TS |
1331 | m_size = nsize; |
1332 | m_size_prime_index = nindex; | |
1333 | } | |
1334 | else | |
1335 | memset (entries, 0, size * sizeof (value_type)); | |
1336 | m_n_deleted = 0; | |
1337 | m_n_elements = 0; | |
1338 | } | |
1339 | ||
1340 | /* This function clears a specified SLOT in a hash table. It is | |
1341 | useful when you've already done the lookup and don't want to do it | |
1342 | again. */ | |
1343 | ||
1344 | template<typename Descriptor, template<typename Type> class Allocator> | |
1345 | void | |
1346 | hash_table<Descriptor, Allocator, true>::clear_slot (value_type *slot) | |
1347 | { | |
1348 | if (slot < m_entries || slot >= m_entries + size () | |
1349 | || is_empty (*slot) || is_deleted (*slot)) | |
1350 | abort (); | |
1351 | ||
1352 | Descriptor::remove (*slot); | |
1353 | ||
1354 | mark_deleted (*slot); | |
1355 | m_n_deleted++; | |
1356 | } | |
1357 | ||
1358 | /* This function searches for a hash table entry equal to the given | |
1359 | COMPARABLE element starting with the given HASH value. It cannot | |
1360 | be used to insert or delete an element. */ | |
1361 | ||
1362 | template<typename Descriptor, template<typename Type> class Allocator> | |
e4e01495 | 1363 | typename hash_table<Descriptor, Allocator, true>::value_type & |
84baa4b9 TS |
1364 | hash_table<Descriptor, Allocator, true> |
1365 | ::find_with_hash (const compare_type &comparable, hashval_t hash) | |
1366 | { | |
1367 | m_searches++; | |
1368 | size_t size = m_size; | |
1369 | hashval_t index = hash_table_mod1 (hash, m_size_prime_index); | |
1370 | ||
1371 | value_type *entry = &m_entries[index]; | |
1372 | if (is_empty (*entry) | |
1373 | || (!is_deleted (*entry) && Descriptor::equal (*entry, comparable))) | |
1374 | return *entry; | |
1375 | ||
1376 | hashval_t hash2 = hash_table_mod2 (hash, m_size_prime_index); | |
1377 | for (;;) | |
1378 | { | |
1379 | m_collisions++; | |
1380 | index += hash2; | |
1381 | if (index >= size) | |
1382 | index -= size; | |
1383 | ||
1384 | entry = &m_entries[index]; | |
1385 | if (is_empty (*entry) | |
1386 | || (!is_deleted (*entry) && Descriptor::equal (*entry, comparable))) | |
1387 | return *entry; | |
1388 | } | |
1389 | } | |
1390 | ||
1391 | /* This function searches for a hash table slot containing an entry | |
1392 | equal to the given COMPARABLE element and starting with the given | |
1393 | HASH. To delete an entry, call this with insert=NO_INSERT, then | |
1394 | call clear_slot on the slot returned (possibly after doing some | |
1395 | checks). To insert an entry, call this with insert=INSERT, then | |
1396 | write the value you want into the returned slot. When inserting an | |
1397 | entry, NULL may be returned if memory allocation fails. */ | |
1398 | ||
1399 | template<typename Descriptor, template<typename Type> class Allocator> | |
e4e01495 | 1400 | typename hash_table<Descriptor, Allocator, true>::value_type * |
84baa4b9 TS |
1401 | hash_table<Descriptor, Allocator, true> |
1402 | ::find_slot_with_hash (const compare_type &comparable, hashval_t hash, | |
1403 | enum insert_option insert) | |
1404 | { | |
1405 | if (insert == INSERT && m_size * 3 <= m_n_elements * 4) | |
1406 | expand (); | |
1407 | ||
1408 | m_searches++; | |
1409 | ||
1410 | value_type *first_deleted_slot = NULL; | |
1411 | hashval_t index = hash_table_mod1 (hash, m_size_prime_index); | |
1412 | hashval_t hash2 = hash_table_mod2 (hash, m_size_prime_index); | |
1413 | value_type *entry = &m_entries[index]; | |
1414 | size_t size = m_size; | |
1415 | if (is_empty (*entry)) | |
1416 | goto empty_entry; | |
1417 | else if (is_deleted (*entry)) | |
1418 | first_deleted_slot = &m_entries[index]; | |
1419 | else if (Descriptor::equal (*entry, comparable)) | |
1420 | return &m_entries[index]; | |
1421 | ||
1422 | for (;;) | |
1423 | { | |
1424 | m_collisions++; | |
1425 | index += hash2; | |
1426 | if (index >= size) | |
1427 | index -= size; | |
1428 | ||
1429 | entry = &m_entries[index]; | |
1430 | if (is_empty (*entry)) | |
1431 | goto empty_entry; | |
1432 | else if (is_deleted (*entry)) | |
1433 | { | |
1434 | if (!first_deleted_slot) | |
1435 | first_deleted_slot = &m_entries[index]; | |
1436 | } | |
1437 | else if (Descriptor::equal (*entry, comparable)) | |
1438 | return &m_entries[index]; | |
1439 | } | |
1440 | ||
1441 | empty_entry: | |
1442 | if (insert == NO_INSERT) | |
1443 | return NULL; | |
1444 | ||
1445 | if (first_deleted_slot) | |
1446 | { | |
1447 | m_n_deleted--; | |
1448 | mark_empty (*first_deleted_slot); | |
1449 | return first_deleted_slot; | |
1450 | } | |
1451 | ||
1452 | m_n_elements++; | |
1453 | return &m_entries[index]; | |
1454 | } | |
1455 | ||
1456 | /* This function deletes an element with the given COMPARABLE value | |
1457 | from hash table starting with the given HASH. If there is no | |
1458 | matching element in the hash table, this function does nothing. */ | |
1459 | ||
1460 | template<typename Descriptor, template<typename Type> class Allocator> | |
1461 | void | |
1462 | hash_table<Descriptor, Allocator, true> | |
1463 | ::remove_elt_with_hash (const compare_type &comparable, hashval_t hash) | |
1464 | { | |
1465 | value_type *slot = find_slot_with_hash (comparable, hash, NO_INSERT); | |
1466 | if (is_empty (*slot)) | |
1467 | return; | |
1468 | ||
1469 | Descriptor::remove (*slot); | |
1470 | ||
1471 | mark_deleted (*slot); | |
1472 | m_n_deleted++; | |
1473 | } | |
1474 | ||
1475 | /* This function scans over the entire hash table calling CALLBACK for | |
1476 | each live entry. If CALLBACK returns false, the iteration stops. | |
1477 | ARGUMENT is passed as CALLBACK's second argument. */ | |
1478 | ||
1479 | template<typename Descriptor, | |
1480 | template<typename Type> class Allocator> | |
1481 | template<typename Argument, | |
e4e01495 TS |
1482 | int (*Callback) (typename hash_table<Descriptor, Allocator, |
1483 | true>::value_type *slot, | |
84baa4b9 TS |
1484 | Argument argument)> |
1485 | void | |
1486 | hash_table<Descriptor, Allocator, true>::traverse_noresize (Argument argument) | |
1487 | { | |
1488 | value_type *slot = m_entries; | |
1489 | value_type *limit = slot + size (); | |
1490 | ||
1491 | do | |
1492 | { | |
1493 | value_type &x = *slot; | |
1494 | ||
1495 | if (!is_empty (x) && !is_deleted (x)) | |
1496 | if (! Callback (slot, argument)) | |
1497 | break; | |
1498 | } | |
1499 | while (++slot < limit); | |
1500 | } | |
1501 | ||
1502 | /* Like traverse_noresize, but does resize the table when it is too empty | |
1503 | to improve effectivity of subsequent calls. */ | |
1504 | ||
1505 | template <typename Descriptor, | |
1506 | template <typename Type> class Allocator> | |
1507 | template <typename Argument, | |
e4e01495 TS |
1508 | int (*Callback) (typename hash_table<Descriptor, Allocator, |
1509 | true>::value_type *slot, | |
84baa4b9 TS |
1510 | Argument argument)> |
1511 | void | |
1512 | hash_table<Descriptor, Allocator, true>::traverse (Argument argument) | |
1513 | { | |
1514 | size_t size = m_size; | |
1515 | if (elements () * 8 < size && size > 32) | |
1516 | expand (); | |
1517 | ||
1518 | traverse_noresize <Argument, Callback> (argument); | |
1519 | } | |
1520 | ||
1521 | /* Slide down the iterator slots until an active entry is found. */ | |
1522 | ||
1523 | template<typename Descriptor, template<typename Type> class Allocator> | |
1524 | void | |
1525 | hash_table<Descriptor, Allocator, true>::iterator::slide () | |
1526 | { | |
1527 | for ( ; m_slot < m_limit; ++m_slot ) | |
1528 | { | |
1529 | value_type &x = *m_slot; | |
1530 | if (!is_empty (x) && !is_deleted (x)) | |
1531 | return; | |
1532 | } | |
1533 | m_slot = NULL; | |
1534 | m_limit = NULL; | |
1535 | } | |
1536 | ||
1537 | /* Bump the iterator. */ | |
1538 | ||
1539 | template<typename Descriptor, template<typename Type> class Allocator> | |
1540 | inline typename hash_table<Descriptor, Allocator, true>::iterator & | |
1541 | hash_table<Descriptor, Allocator, true>::iterator::operator ++ () | |
bf190e8d | 1542 | { |
65d3284b | 1543 | ++m_slot; |
bf190e8d LC |
1544 | slide (); |
1545 | return *this; | |
1546 | } | |
1547 | ||
bf190e8d LC |
1548 | |
1549 | /* Iterate through the elements of hash_table HTAB, | |
1550 | using hash_table <....>::iterator ITER, | |
3fadf78a | 1551 | storing each element in RESULT, which is of type TYPE. */ |
bf190e8d LC |
1552 | |
1553 | #define FOR_EACH_HASH_TABLE_ELEMENT(HTAB, RESULT, TYPE, ITER) \ | |
1554 | for ((ITER) = (HTAB).begin (); \ | |
84baa4b9 | 1555 | (ITER) != (HTAB).end () ? (RESULT = *(ITER) , true) : false; \ |
bf190e8d LC |
1556 | ++(ITER)) |
1557 | ||
b086d530 TS |
1558 | /* ggc walking routines. */ |
1559 | ||
1560 | template<typename E> | |
1561 | static inline void | |
1562 | gt_ggc_mx (hash_table<E> *h) | |
1563 | { | |
1564 | typedef hash_table<E> table; | |
1565 | ||
1566 | if (!ggc_test_and_set_mark (h->m_entries)) | |
1567 | return; | |
1568 | ||
1569 | for (size_t i = 0; i < h->m_size; i++) | |
1570 | { | |
1571 | if (table::is_empty (h->m_entries[i]) | |
1572 | || table::is_deleted (h->m_entries[i])) | |
1573 | continue; | |
1574 | ||
1575 | E::ggc_mx (h->m_entries[i]); | |
1576 | } | |
1577 | } | |
1578 | ||
1579 | template<typename D> | |
1580 | static inline void | |
1581 | hashtab_entry_note_pointers (void *obj, void *h, gt_pointer_operator op, | |
1582 | void *cookie) | |
1583 | { | |
1584 | hash_table<D> *map = static_cast<hash_table<D> *> (h); | |
1585 | gcc_checking_assert (map->m_entries == obj); | |
1586 | for (size_t i = 0; i < map->m_size; i++) | |
1587 | { | |
1588 | typedef hash_table<D> table; | |
1589 | if (table::is_empty (map->m_entries[i]) | |
1590 | || table::is_deleted (map->m_entries[i])) | |
1591 | continue; | |
1592 | ||
1593 | D::pch_nx (map->m_entries[i], op, cookie); | |
1594 | } | |
1595 | } | |
1596 | ||
1597 | template<typename D> | |
1598 | static void | |
1599 | gt_pch_nx (hash_table<D> *h) | |
1600 | { | |
4b49af15 TS |
1601 | bool success ATTRIBUTE_UNUSED |
1602 | = gt_pch_note_object (h->m_entries, h, hashtab_entry_note_pointers<D>); | |
1603 | gcc_checking_assert (success); | |
b086d530 TS |
1604 | for (size_t i = 0; i < h->m_size; i++) |
1605 | { | |
1606 | if (hash_table<D>::is_empty (h->m_entries[i]) | |
1607 | || hash_table<D>::is_deleted (h->m_entries[i])) | |
1608 | continue; | |
1609 | ||
1610 | D::pch_nx (h->m_entries[i]); | |
1611 | } | |
1612 | } | |
1613 | ||
0823efed | 1614 | #endif /* TYPED_HASHTAB_H */ |