]>
Commit | Line | Data |
---|---|---|
064af421 | 1 | /* |
bc8d7dfa | 2 | * Copyright (c) 2008, 2009, 2010, 2012, 2013, 2015, 2016 Nicira, Inc. |
064af421 | 3 | * |
a14bc59f BP |
4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
5 | * you may not use this file except in compliance with the License. | |
6 | * You may obtain a copy of the License at: | |
064af421 | 7 | * |
a14bc59f BP |
8 | * http://www.apache.org/licenses/LICENSE-2.0 |
9 | * | |
10 | * Unless required by applicable law or agreed to in writing, software | |
11 | * distributed under the License is distributed on an "AS IS" BASIS, | |
12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
13 | * See the License for the specific language governing permissions and | |
14 | * limitations under the License. | |
064af421 BP |
15 | */ |
16 | ||
17 | #ifndef HMAP_H | |
18 | #define HMAP_H 1 | |
19 | ||
20 | #include <stdbool.h> | |
21 | #include <stdlib.h> | |
ee89ea7b | 22 | #include "openvswitch/util.h" |
064af421 | 23 | |
0b64afd6 BP |
24 | #ifdef __cplusplus |
25 | extern "C" { | |
26 | #endif | |
27 | ||
064af421 BP |
28 | /* A hash map node, to be embedded inside the data structure being mapped. */ |
29 | struct hmap_node { | |
30 | size_t hash; /* Hash value. */ | |
31 | struct hmap_node *next; /* Next in linked list. */ | |
32 | }; | |
33 | ||
34 | /* Returns the hash value embedded in 'node'. */ | |
35 | static inline size_t hmap_node_hash(const struct hmap_node *node) | |
36 | { | |
37 | return node->hash; | |
38 | } | |
39 | ||
1e68c073 | 40 | #define HMAP_NODE_NULL ((struct hmap_node *) 1) |
6c2e425e | 41 | #define HMAP_NODE_NULL_INITIALIZER { 0, HMAP_NODE_NULL } |
1e68c073 BP |
42 | |
43 | /* Returns true if 'node' has been set to null by hmap_node_nullify() and has | |
44 | * not been un-nullified by being inserted into an hmap. */ | |
45 | static inline bool | |
46 | hmap_node_is_null(const struct hmap_node *node) | |
47 | { | |
48 | return node->next == HMAP_NODE_NULL; | |
49 | } | |
50 | ||
51 | /* Marks 'node' with a distinctive value that can be tested with | |
52 | * hmap_node_is_null(). */ | |
53 | static inline void | |
54 | hmap_node_nullify(struct hmap_node *node) | |
55 | { | |
56 | node->next = HMAP_NODE_NULL; | |
57 | } | |
58 | ||
064af421 BP |
59 | /* A hash map. */ |
60 | struct hmap { | |
baa8f41b | 61 | struct hmap_node **buckets; /* Must point to 'one' iff 'mask' == 0. */ |
064af421 BP |
62 | struct hmap_node *one; |
63 | size_t mask; | |
64 | size_t n; | |
65 | }; | |
66 | ||
67 | /* Initializer for an empty hash map. */ | |
e37726e4 BP |
68 | #define HMAP_INITIALIZER(HMAP) \ |
69 | { (struct hmap_node **const) &(HMAP)->one, NULL, 0, 0 } | |
064af421 | 70 | |
64982ba2 BP |
71 | /* Initializer for an immutable struct hmap 'HMAP' that contains 'N' nodes |
72 | * linked together starting at 'NODE'. The hmap only has a single chain of | |
73 | * hmap_nodes, so 'N' should be small. */ | |
74 | #define HMAP_CONST(HMAP, N, NODE) { \ | |
75 | CONST_CAST(struct hmap_node **, &(HMAP)->one), NODE, 0, N } | |
aaf881c6 | 76 | |
064af421 BP |
77 | /* Initialization. */ |
78 | void hmap_init(struct hmap *); | |
79 | void hmap_destroy(struct hmap *); | |
f3099647 | 80 | void hmap_clear(struct hmap *); |
064af421 | 81 | void hmap_swap(struct hmap *a, struct hmap *b); |
a4af0040 | 82 | void hmap_moved(struct hmap *hmap); |
064af421 BP |
83 | static inline size_t hmap_count(const struct hmap *); |
84 | static inline bool hmap_is_empty(const struct hmap *); | |
85 | ||
86 | /* Adjusting capacity. */ | |
0c5e05bf | 87 | void hmap_expand_at(struct hmap *, const char *where); |
8f3676cf | 88 | #define hmap_expand(HMAP) hmap_expand_at(HMAP, OVS_SOURCE_LOCATOR) |
0c5e05bf BP |
89 | |
90 | void hmap_shrink_at(struct hmap *, const char *where); | |
8f3676cf | 91 | #define hmap_shrink(HMAP) hmap_shrink_at(HMAP, OVS_SOURCE_LOCATOR) |
0c5e05bf BP |
92 | |
93 | void hmap_reserve_at(struct hmap *, size_t capacity, const char *where); | |
94 | #define hmap_reserve(HMAP, CAPACITY) \ | |
8f3676cf | 95 | hmap_reserve_at(HMAP, CAPACITY, OVS_SOURCE_LOCATOR) |
064af421 BP |
96 | |
97 | /* Insertion and deletion. */ | |
0c5e05bf BP |
98 | static inline void hmap_insert_at(struct hmap *, struct hmap_node *, |
99 | size_t hash, const char *where); | |
100 | #define hmap_insert(HMAP, NODE, HASH) \ | |
8f3676cf | 101 | hmap_insert_at(HMAP, NODE, HASH, OVS_SOURCE_LOCATOR) |
0c5e05bf | 102 | |
064af421 BP |
103 | static inline void hmap_insert_fast(struct hmap *, |
104 | struct hmap_node *, size_t hash); | |
064af421 | 105 | static inline void hmap_remove(struct hmap *, struct hmap_node *); |
064af421 | 106 | |
63e60b86 | 107 | void hmap_node_moved(struct hmap *, struct hmap_node *, struct hmap_node *); |
064af421 | 108 | static inline void hmap_replace(struct hmap *, const struct hmap_node *old, |
43d1478b | 109 | struct hmap_node *new_node); |
064af421 | 110 | |
f2f7be86 BP |
111 | struct hmap_node *hmap_random_node(const struct hmap *); |
112 | ||
3adb8bf0 BP |
113 | /* Search. |
114 | * | |
115 | * HMAP_FOR_EACH_WITH_HASH iterates NODE over all of the nodes in HMAP that | |
116 | * have hash value equal to HASH. HMAP_FOR_EACH_IN_BUCKET iterates NODE over | |
4e8e4213 BP |
117 | * all of the nodes in HMAP that would fall in the same bucket as HASH. MEMBER |
118 | * must be the name of the 'struct hmap_node' member within NODE. | |
3adb8bf0 BP |
119 | * |
120 | * These macros may be used interchangeably to search for a particular value in | |
121 | * an hmap, see, e.g. shash_find() for an example. Usually, using | |
122 | * HMAP_FOR_EACH_WITH_HASH provides an optimization, because comparing a hash | |
123 | * value is usually cheaper than comparing an entire hash map key. But for | |
124 | * simple hash map keys, it makes sense to use HMAP_FOR_EACH_IN_BUCKET because | |
125 | * it avoids doing two comparisons when a single simple comparison suffices. | |
126 | * | |
127 | * The loop should not change NODE to point to a different node or insert or | |
128 | * delete nodes in HMAP (unless it "break"s out of the loop to terminate | |
129 | * iteration). | |
130 | * | |
131 | * HASH is only evaluated once. | |
48627758 | 132 | * |
f0b12cd7 RB |
133 | * When the loop terminates normally, meaning the iteration has completed |
134 | * without using 'break', NODE will be NULL. This is true for all of the | |
135 | * HMAP_FOR_EACH_*() macros. | |
3adb8bf0 | 136 | */ |
4e8e4213 | 137 | #define HMAP_FOR_EACH_WITH_HASH(NODE, MEMBER, HASH, HMAP) \ |
f17e8ad6 | 138 | for (INIT_CONTAINER(NODE, hmap_first_with_hash(HMAP, HASH), MEMBER); \ |
f0b12cd7 | 139 | (NODE != OBJECT_CONTAINING(NULL, NODE, MEMBER)) || (NODE = NULL); \ |
772ec52b BP |
140 | ASSIGN_CONTAINER(NODE, hmap_next_with_hash(&(NODE)->MEMBER), \ |
141 | MEMBER)) | |
4e8e4213 | 142 | #define HMAP_FOR_EACH_IN_BUCKET(NODE, MEMBER, HASH, HMAP) \ |
f17e8ad6 | 143 | for (INIT_CONTAINER(NODE, hmap_first_in_bucket(HMAP, HASH), MEMBER); \ |
f0b12cd7 | 144 | (NODE != OBJECT_CONTAINING(NULL, NODE, MEMBER)) || (NODE = NULL); \ |
772ec52b | 145 | ASSIGN_CONTAINER(NODE, hmap_next_in_bucket(&(NODE)->MEMBER), MEMBER)) |
064af421 BP |
146 | |
147 | static inline struct hmap_node *hmap_first_with_hash(const struct hmap *, | |
148 | size_t hash); | |
149 | static inline struct hmap_node *hmap_next_with_hash(const struct hmap_node *); | |
3adb8bf0 BP |
150 | static inline struct hmap_node *hmap_first_in_bucket(const struct hmap *, |
151 | size_t hash); | |
152 | static inline struct hmap_node *hmap_next_in_bucket(const struct hmap_node *); | |
064af421 | 153 | |
e39e5b9d BP |
154 | bool hmap_contains(const struct hmap *, const struct hmap_node *); |
155 | ||
bc8d7dfa BP |
156 | /* Iteration. |
157 | * | |
158 | * The *_INIT variants of these macros additionally evaluate the expressions | |
159 | * supplied following the HMAP argument once during the loop initialization. | |
160 | * This makes it possible for data structures that wrap around hmaps to insert | |
161 | * additional initialization into their iteration macros without having to | |
162 | * completely rewrite them. In particular, it can be a good idea to insert | |
163 | * BUILD_ASSERT_TYPE checks for map and node types that wrap hmap, since | |
164 | * otherwise it is possible for clients to accidentally confuse two derived | |
165 | * data structures that happen to use the same member names for struct hmap and | |
166 | * struct hmap_node. */ | |
633d7b90 BP |
167 | |
168 | /* Iterates through every node in HMAP. */ | |
bc8d7dfa BP |
169 | #define HMAP_FOR_EACH(NODE, MEMBER, HMAP) \ |
170 | HMAP_FOR_EACH_INIT(NODE, MEMBER, HMAP, (void) 0) | |
171 | #define HMAP_FOR_EACH_INIT(NODE, MEMBER, HMAP, ...) \ | |
172 | for (INIT_CONTAINER(NODE, hmap_first(HMAP), MEMBER), __VA_ARGS__; \ | |
f0b12cd7 | 173 | (NODE != OBJECT_CONTAINING(NULL, NODE, MEMBER)) || (NODE = NULL); \ |
772ec52b | 174 | ASSIGN_CONTAINER(NODE, hmap_next(HMAP, &(NODE)->MEMBER), MEMBER)) |
4e8e4213 | 175 | |
633d7b90 BP |
176 | /* Safe when NODE may be freed (not needed when NODE may be removed from the |
177 | * hash map but its members remain accessible and intact). */ | |
bc8d7dfa BP |
178 | #define HMAP_FOR_EACH_SAFE(NODE, NEXT, MEMBER, HMAP) \ |
179 | HMAP_FOR_EACH_SAFE_INIT(NODE, NEXT, MEMBER, HMAP, (void) 0) | |
180 | #define HMAP_FOR_EACH_SAFE_INIT(NODE, NEXT, MEMBER, HMAP, ...) \ | |
181 | for (INIT_CONTAINER(NODE, hmap_first(HMAP), MEMBER), __VA_ARGS__; \ | |
f0b12cd7 | 182 | ((NODE != OBJECT_CONTAINING(NULL, NODE, MEMBER)) || (NODE = NULL) \ |
f17e8ad6 | 183 | ? INIT_CONTAINER(NEXT, hmap_next(HMAP, &(NODE)->MEMBER), MEMBER), 1 \ |
4e8e4213 | 184 | : 0); \ |
064af421 BP |
185 | (NODE) = (NEXT)) |
186 | ||
633d7b90 | 187 | /* Continues an iteration from just after NODE. */ |
bc8d7dfa BP |
188 | #define HMAP_FOR_EACH_CONTINUE(NODE, MEMBER, HMAP) \ |
189 | HMAP_FOR_EACH_CONTINUE_INIT(NODE, MEMBER, HMAP, (void) 0) | |
190 | #define HMAP_FOR_EACH_CONTINUE_INIT(NODE, MEMBER, HMAP, ...) \ | |
191 | for (ASSIGN_CONTAINER(NODE, hmap_next(HMAP, &(NODE)->MEMBER), MEMBER), \ | |
192 | __VA_ARGS__; \ | |
f0b12cd7 | 193 | (NODE != OBJECT_CONTAINING(NULL, NODE, MEMBER)) || (NODE = NULL); \ |
772ec52b | 194 | ASSIGN_CONTAINER(NODE, hmap_next(HMAP, &(NODE)->MEMBER), MEMBER)) |
633d7b90 | 195 | |
4ec3d7c7 DDP |
196 | static inline struct hmap_node * |
197 | hmap_pop_helper__(struct hmap *hmap, size_t *bucket) { | |
198 | ||
199 | for (; *bucket <= hmap->mask; (*bucket)++) { | |
200 | struct hmap_node *node = hmap->buckets[*bucket]; | |
201 | ||
202 | if (node) { | |
203 | hmap_remove(hmap, node); | |
204 | return node; | |
205 | } | |
206 | } | |
207 | ||
208 | return NULL; | |
209 | } | |
210 | ||
211 | #define HMAP_FOR_EACH_POP(NODE, MEMBER, HMAP) \ | |
212 | for (size_t bucket__ = 0; \ | |
213 | INIT_CONTAINER(NODE, hmap_pop_helper__(HMAP, &bucket__), MEMBER), \ | |
214 | (NODE != OBJECT_CONTAINING(NULL, NODE, MEMBER)) || (NODE = NULL);) | |
215 | ||
064af421 BP |
216 | static inline struct hmap_node *hmap_first(const struct hmap *); |
217 | static inline struct hmap_node *hmap_next(const struct hmap *, | |
218 | const struct hmap_node *); | |
219 | ||
bfbcebc2 DDP |
220 | struct hmap_position { |
221 | unsigned int bucket; | |
222 | unsigned int offset; | |
223 | }; | |
224 | ||
ee114c23 | 225 | struct hmap_node *hmap_at_position(const struct hmap *, |
bfbcebc2 | 226 | struct hmap_position *); |
ee114c23 | 227 | |
064af421 BP |
228 | /* Returns the number of nodes currently in 'hmap'. */ |
229 | static inline size_t | |
230 | hmap_count(const struct hmap *hmap) | |
231 | { | |
232 | return hmap->n; | |
233 | } | |
234 | ||
72865317 BP |
235 | /* Returns the maximum number of nodes that 'hmap' may hold before it should be |
236 | * rehashed. */ | |
237 | static inline size_t | |
238 | hmap_capacity(const struct hmap *hmap) | |
239 | { | |
240 | return hmap->mask * 2 + 1; | |
241 | } | |
242 | ||
064af421 | 243 | /* Returns true if 'hmap' currently contains no nodes, |
7614e5d0 JR |
244 | * false otherwise. |
245 | * Note: While hmap in general is not thread-safe without additional locking, | |
246 | * hmap_is_empty() is. */ | |
064af421 BP |
247 | static inline bool |
248 | hmap_is_empty(const struct hmap *hmap) | |
249 | { | |
250 | return hmap->n == 0; | |
251 | } | |
252 | ||
253 | /* Inserts 'node', with the given 'hash', into 'hmap'. 'hmap' is never | |
254 | * expanded automatically. */ | |
255 | static inline void | |
256 | hmap_insert_fast(struct hmap *hmap, struct hmap_node *node, size_t hash) | |
257 | { | |
258 | struct hmap_node **bucket = &hmap->buckets[hash & hmap->mask]; | |
259 | node->hash = hash; | |
260 | node->next = *bucket; | |
261 | *bucket = node; | |
262 | hmap->n++; | |
263 | } | |
264 | ||
265 | /* Inserts 'node', with the given 'hash', into 'hmap', and expands 'hmap' if | |
0c5e05bf BP |
266 | * necessary to optimize search performance. |
267 | * | |
268 | * ('where' is used in debug logging. Commonly one would use hmap_insert() to | |
269 | * automatically provide the caller's source file and line number for | |
270 | * 'where'.) */ | |
064af421 | 271 | static inline void |
0c5e05bf BP |
272 | hmap_insert_at(struct hmap *hmap, struct hmap_node *node, size_t hash, |
273 | const char *where) | |
064af421 BP |
274 | { |
275 | hmap_insert_fast(hmap, node, hash); | |
276 | if (hmap->n / 2 > hmap->mask) { | |
0c5e05bf | 277 | hmap_expand_at(hmap, where); |
064af421 BP |
278 | } |
279 | } | |
280 | ||
281 | /* Removes 'node' from 'hmap'. Does not shrink the hash table; call | |
282 | * hmap_shrink() directly if desired. */ | |
283 | static inline void | |
284 | hmap_remove(struct hmap *hmap, struct hmap_node *node) | |
285 | { | |
286 | struct hmap_node **bucket = &hmap->buckets[node->hash & hmap->mask]; | |
287 | while (*bucket != node) { | |
288 | bucket = &(*bucket)->next; | |
289 | } | |
290 | *bucket = node->next; | |
291 | hmap->n--; | |
292 | } | |
293 | ||
0b64afd6 BP |
294 | /* Puts 'new_node' in the position in 'hmap' currently occupied by 'old_node'. |
295 | * The 'new_node' must hash to the same value as 'old_node'. The client is | |
296 | * responsible for ensuring that the replacement does not violate any | |
297 | * client-imposed invariants (e.g. uniqueness of keys within a map). | |
064af421 | 298 | * |
0b64afd6 BP |
299 | * Afterward, 'old_node' is not part of 'hmap', and the client is responsible |
300 | * for freeing it (if this is desirable). */ | |
064af421 BP |
301 | static inline void |
302 | hmap_replace(struct hmap *hmap, | |
0b64afd6 | 303 | const struct hmap_node *old_node, struct hmap_node *new_node) |
064af421 | 304 | { |
0b64afd6 BP |
305 | struct hmap_node **bucket = &hmap->buckets[old_node->hash & hmap->mask]; |
306 | while (*bucket != old_node) { | |
064af421 BP |
307 | bucket = &(*bucket)->next; |
308 | } | |
0b64afd6 BP |
309 | *bucket = new_node; |
310 | new_node->hash = old_node->hash; | |
a4af0040 | 311 | new_node->next = old_node->next; |
064af421 BP |
312 | } |
313 | ||
314 | static inline struct hmap_node * | |
315 | hmap_next_with_hash__(const struct hmap_node *node, size_t hash) | |
316 | { | |
317 | while (node != NULL && node->hash != hash) { | |
318 | node = node->next; | |
319 | } | |
ebc56baa | 320 | return CONST_CAST(struct hmap_node *, node); |
064af421 BP |
321 | } |
322 | ||
323 | /* Returns the first node in 'hmap' with the given 'hash', or a null pointer if | |
324 | * no nodes have that hash value. */ | |
325 | static inline struct hmap_node * | |
326 | hmap_first_with_hash(const struct hmap *hmap, size_t hash) | |
327 | { | |
328 | return hmap_next_with_hash__(hmap->buckets[hash & hmap->mask], hash); | |
329 | } | |
330 | ||
3adb8bf0 BP |
331 | /* Returns the first node in 'hmap' in the bucket in which the given 'hash' |
332 | * would land, or a null pointer if that bucket is empty. */ | |
333 | static inline struct hmap_node * | |
334 | hmap_first_in_bucket(const struct hmap *hmap, size_t hash) | |
335 | { | |
336 | return hmap->buckets[hash & hmap->mask]; | |
337 | } | |
338 | ||
339 | /* Returns the next node in the same bucket as 'node', or a null pointer if | |
340 | * there are no more nodes in that bucket. | |
341 | * | |
342 | * If the hash map has been reallocated since 'node' was visited, some nodes | |
343 | * may be skipped; if new nodes with the same hash value have been added, they | |
344 | * will be skipped. (Removing 'node' from the hash map does not prevent | |
345 | * calling this function, since node->next is preserved, although freeing | |
346 | * 'node' of course does.) */ | |
347 | static inline struct hmap_node * | |
348 | hmap_next_in_bucket(const struct hmap_node *node) | |
349 | { | |
350 | return node->next; | |
351 | } | |
352 | ||
064af421 BP |
353 | /* Returns the next node in the same hash map as 'node' with the same hash |
354 | * value, or a null pointer if no more nodes have that hash value. | |
355 | * | |
356 | * If the hash map has been reallocated since 'node' was visited, some nodes | |
357 | * may be skipped; if new nodes with the same hash value have been added, they | |
358 | * will be skipped. (Removing 'node' from the hash map does not prevent | |
359 | * calling this function, since node->next is preserved, although freeing | |
360 | * 'node' of course does.) */ | |
361 | static inline struct hmap_node * | |
362 | hmap_next_with_hash(const struct hmap_node *node) | |
363 | { | |
364 | return hmap_next_with_hash__(node->next, node->hash); | |
365 | } | |
366 | ||
367 | static inline struct hmap_node * | |
368 | hmap_next__(const struct hmap *hmap, size_t start) | |
369 | { | |
370 | size_t i; | |
371 | for (i = start; i <= hmap->mask; i++) { | |
372 | struct hmap_node *node = hmap->buckets[i]; | |
373 | if (node) { | |
374 | return node; | |
375 | } | |
376 | } | |
377 | return NULL; | |
378 | } | |
379 | ||
380 | /* Returns the first node in 'hmap', in arbitrary order, or a null pointer if | |
381 | * 'hmap' is empty. */ | |
382 | static inline struct hmap_node * | |
383 | hmap_first(const struct hmap *hmap) | |
384 | { | |
385 | return hmap_next__(hmap, 0); | |
386 | } | |
387 | ||
388 | /* Returns the next node in 'hmap' following 'node', in arbitrary order, or a | |
389 | * null pointer if 'node' is the last node in 'hmap'. | |
390 | * | |
391 | * If the hash map has been reallocated since 'node' was visited, some nodes | |
392 | * may be skipped or visited twice. (Removing 'node' from the hash map does | |
393 | * not prevent calling this function, since node->next is preserved, although | |
394 | * freeing 'node' of course does.) */ | |
395 | static inline struct hmap_node * | |
396 | hmap_next(const struct hmap *hmap, const struct hmap_node *node) | |
397 | { | |
398 | return (node->next | |
399 | ? node->next | |
400 | : hmap_next__(hmap, (node->hash & hmap->mask) + 1)); | |
401 | } | |
402 | ||
0b64afd6 BP |
403 | #ifdef __cplusplus |
404 | } | |
405 | #endif | |
406 | ||
064af421 | 407 | #endif /* hmap.h */ |