1 /* SPDX-License-Identifier: LGPL-2.1+ */
8 #include "alloc-util.h"
13 #include "process-util.h"
14 #include "random-util.h"
16 #include "siphash24.h"
17 #include "string-util.h"
21 #if ENABLE_DEBUG_HASHMAP
27 * Implementation of hashmaps.
29 * - uses less RAM compared to closed addressing (chaining), because
30 * our entries are small (especially in Sets, which tend to contain
31 * the majority of entries in systemd).
32 * Collision resolution: Robin Hood
33 * - tends to equalize displacement of entries from their optimal buckets.
34 * Probe sequence: linear
35 * - though theoretically worse than random probing/uniform hashing/double
36 * hashing, it is good for cache locality.
39 * Celis, P. 1986. Robin Hood Hashing.
40 * Ph.D. Dissertation. University of Waterloo, Waterloo, Ont., Canada, Canada.
41 * https://cs.uwaterloo.ca/research/tr/1986/CS-86-14.pdf
42 * - The results are derived for random probing. Suggests deletion with
43 * tombstones and two mean-centered search methods. None of that works
44 * well for linear probing.
46 * Janson, S. 2005. Individual displacements for linear probing hashing with different insertion policies.
47 * ACM Trans. Algorithms 1, 2 (October 2005), 177-213.
48 * DOI=10.1145/1103963.1103964 http://doi.acm.org/10.1145/1103963.1103964
49 * http://www.math.uu.se/~svante/papers/sj157.pdf
50 * - Applies to Robin Hood with linear probing. Contains remarks on
51 * the unsuitability of mean-centered search with linear probing.
53 * Viola, A. 2005. Exact distribution of individual displacements in linear probing hashing.
54 * ACM Trans. Algorithms 1, 2 (October 2005), 214-242.
55 * DOI=10.1145/1103963.1103965 http://doi.acm.org/10.1145/1103963.1103965
56 * - Similar to Janson. Note that Viola writes about C_{m,n} (number of probes
57 * in a successful search), and Janson writes about displacement. C = d + 1.
59 * Goossaert, E. 2013. Robin Hood hashing: backward shift deletion.
60 * http://codecapsule.com/2013/11/17/robin-hood-hashing-backward-shift-deletion/
61 * - Explanation of backward shift deletion with pictures.
63 * Khuong, P. 2013. The Other Robin Hood Hashing.
64 * http://www.pvk.ca/Blog/2013/11/26/the-other-robin-hood-hashing/
65 * - Short summary of random vs. linear probing, and tombstones vs. backward shift.
69 * XXX Ideas for improvement:
70 * For unordered hashmaps, randomize iteration order, similarly to Perl:
71 * http://blog.booking.com/hardening-perls-hash-function.html
74 /* INV_KEEP_FREE = 1 / (1 - max_load_factor)
75 * e.g. 1 / (1 - 0.8) = 5 ... keep one fifth of the buckets free. */
76 #define INV_KEEP_FREE 5U
78 /* Fields common to entries of all hashmap/set types */
79 struct hashmap_base_entry
{
83 /* Entry types for specific hashmap/set types
84 * hashmap_base_entry must be at the beginning of each entry struct. */
86 struct plain_hashmap_entry
{
87 struct hashmap_base_entry b
;
91 struct ordered_hashmap_entry
{
92 struct plain_hashmap_entry p
;
93 unsigned iterate_next
, iterate_previous
;
97 struct hashmap_base_entry b
;
100 /* In several functions it is advantageous to have the hash table extended
101 * virtually by a couple of additional buckets. We reserve special index values
102 * for these "swap" buckets. */
103 #define _IDX_SWAP_BEGIN (UINT_MAX - 3)
104 #define IDX_PUT (_IDX_SWAP_BEGIN + 0)
105 #define IDX_TMP (_IDX_SWAP_BEGIN + 1)
106 #define _IDX_SWAP_END (_IDX_SWAP_BEGIN + 2)
108 #define IDX_FIRST (UINT_MAX - 1) /* special index for freshly initialized iterators */
109 #define IDX_NIL UINT_MAX /* special index value meaning "none" or "end" */
111 assert_cc(IDX_FIRST
== _IDX_SWAP_END
);
112 assert_cc(IDX_FIRST
== _IDX_ITERATOR_FIRST
);
114 /* Storage space for the "swap" buckets.
115 * All entry types can fit into a ordered_hashmap_entry. */
116 struct swap_entries
{
117 struct ordered_hashmap_entry e
[_IDX_SWAP_END
- _IDX_SWAP_BEGIN
];
120 /* Distance from Initial Bucket */
121 typedef uint8_t dib_raw_t
;
122 #define DIB_RAW_OVERFLOW ((dib_raw_t)0xfdU) /* indicates DIB value is greater than representable */
123 #define DIB_RAW_REHASH ((dib_raw_t)0xfeU) /* entry yet to be rehashed during in-place resize */
124 #define DIB_RAW_FREE ((dib_raw_t)0xffU) /* a free bucket */
125 #define DIB_RAW_INIT ((char)DIB_RAW_FREE) /* a byte to memset a DIB store with when initializing */
127 #define DIB_FREE UINT_MAX
129 #if ENABLE_DEBUG_HASHMAP
130 struct hashmap_debug_info
{
131 LIST_FIELDS(struct hashmap_debug_info
, debug_list
);
132 unsigned max_entries
; /* high watermark of n_entries */
134 /* who allocated this hashmap */
139 /* fields to detect modification while iterating */
140 unsigned put_count
; /* counts puts into the hashmap */
141 unsigned rem_count
; /* counts removals from hashmap */
142 unsigned last_rem_idx
; /* remembers last removal index */
145 /* Tracks all existing hashmaps. Get at it from gdb. See sd_dump_hashmaps.py */
146 static LIST_HEAD(struct hashmap_debug_info
, hashmap_debug_list
);
147 static pthread_mutex_t hashmap_debug_list_mutex
= PTHREAD_MUTEX_INITIALIZER
;
149 #define HASHMAP_DEBUG_FIELDS struct hashmap_debug_info debug;
151 #else /* !ENABLE_DEBUG_HASHMAP */
152 #define HASHMAP_DEBUG_FIELDS
153 #endif /* ENABLE_DEBUG_HASHMAP */
157 HASHMAP_TYPE_ORDERED
,
162 struct _packed_ indirect_storage
{
163 void *storage
; /* where buckets and DIBs are stored */
164 uint8_t hash_key
[HASH_KEY_SIZE
]; /* hash key; changes during resize */
166 unsigned n_entries
; /* number of stored entries */
167 unsigned n_buckets
; /* number of buckets */
169 unsigned idx_lowest_entry
; /* Index below which all buckets are free.
170 Makes "while(hashmap_steal_first())" loops
171 O(n) instead of O(n^2) for unordered hashmaps. */
172 uint8_t _pad
[3]; /* padding for the whole HashmapBase */
173 /* The bitfields in HashmapBase complete the alignment of the whole thing. */
176 struct direct_storage
{
177 /* This gives us 39 bytes on 64bit, or 35 bytes on 32bit.
178 * That's room for 4 set_entries + 4 DIB bytes + 3 unused bytes on 64bit,
179 * or 7 set_entries + 7 DIB bytes + 0 unused bytes on 32bit. */
180 uint8_t storage
[sizeof(struct indirect_storage
)];
183 #define DIRECT_BUCKETS(entry_t) \
184 (sizeof(struct direct_storage) / (sizeof(entry_t) + sizeof(dib_raw_t)))
186 /* We should be able to store at least one entry directly. */
187 assert_cc(DIRECT_BUCKETS(struct ordered_hashmap_entry
) >= 1);
189 /* We have 3 bits for n_direct_entries. */
190 assert_cc(DIRECT_BUCKETS(struct set_entry
) < (1 << 3));
192 /* Hashmaps with directly stored entries all use this shared hash key.
193 * It's no big deal if the key is guessed, because there can be only
194 * a handful of directly stored entries in a hashmap. When a hashmap
195 * outgrows direct storage, it gets its own key for indirect storage. */
196 static uint8_t shared_hash_key
[HASH_KEY_SIZE
];
197 static bool shared_hash_key_initialized
;
199 /* Fields that all hashmap/set types must have */
201 const struct hash_ops
*hash_ops
; /* hash and compare ops to use */
204 struct indirect_storage indirect
; /* if has_indirect */
205 struct direct_storage direct
; /* if !has_indirect */
208 enum HashmapType type
:2; /* HASHMAP_TYPE_* */
209 bool has_indirect
:1; /* whether indirect storage is used */
210 unsigned n_direct_entries
:3; /* Number of entries in direct storage.
211 * Only valid if !has_indirect. */
212 bool from_pool
:1; /* whether was allocated from mempool */
213 bool dirty
:1; /* whether dirtied since last iterated_cache_get() */
214 bool cached
:1; /* whether this hashmap is being cached */
215 HASHMAP_DEBUG_FIELDS
/* optional hashmap_debug_info */
218 /* Specific hash types
219 * HashmapBase must be at the beginning of each hashmap struct. */
222 struct HashmapBase b
;
225 struct OrderedHashmap
{
226 struct HashmapBase b
;
227 unsigned iterate_list_head
, iterate_list_tail
;
231 struct HashmapBase b
;
234 typedef struct CacheMem
{
236 size_t n_populated
, n_allocated
;
240 struct IteratedCache
{
241 HashmapBase
*hashmap
;
242 CacheMem keys
, values
;
245 DEFINE_MEMPOOL(hashmap_pool
, Hashmap
, 8);
246 DEFINE_MEMPOOL(ordered_hashmap_pool
, OrderedHashmap
, 8);
247 /* No need for a separate Set pool */
248 assert_cc(sizeof(Hashmap
) == sizeof(Set
));
250 struct hashmap_type_info
{
253 struct mempool
*mempool
;
254 unsigned n_direct_buckets
;
257 static const struct hashmap_type_info hashmap_type_info
[_HASHMAP_TYPE_MAX
] = {
258 [HASHMAP_TYPE_PLAIN
] = {
259 .head_size
= sizeof(Hashmap
),
260 .entry_size
= sizeof(struct plain_hashmap_entry
),
261 .mempool
= &hashmap_pool
,
262 .n_direct_buckets
= DIRECT_BUCKETS(struct plain_hashmap_entry
),
264 [HASHMAP_TYPE_ORDERED
] = {
265 .head_size
= sizeof(OrderedHashmap
),
266 .entry_size
= sizeof(struct ordered_hashmap_entry
),
267 .mempool
= &ordered_hashmap_pool
,
268 .n_direct_buckets
= DIRECT_BUCKETS(struct ordered_hashmap_entry
),
270 [HASHMAP_TYPE_SET
] = {
271 .head_size
= sizeof(Set
),
272 .entry_size
= sizeof(struct set_entry
),
273 .mempool
= &hashmap_pool
,
274 .n_direct_buckets
= DIRECT_BUCKETS(struct set_entry
),
279 __attribute__((destructor
)) static void cleanup_pools(void) {
280 _cleanup_free_
char *t
= NULL
;
283 /* Be nice to valgrind */
285 /* The pool is only allocated by the main thread, but the memory can
286 * be passed to other threads. Let's clean up if we are the main thread
287 * and no other threads are live. */
288 if (!is_main_thread())
291 r
= get_proc_field("/proc/self/status", "Threads", WHITESPACE
, &t
);
292 if (r
< 0 || !streq(t
, "1"))
295 mempool_drop(&hashmap_pool
);
296 mempool_drop(&ordered_hashmap_pool
);
300 static unsigned n_buckets(HashmapBase
*h
) {
301 return h
->has_indirect
? h
->indirect
.n_buckets
302 : hashmap_type_info
[h
->type
].n_direct_buckets
;
305 static unsigned n_entries(HashmapBase
*h
) {
306 return h
->has_indirect
? h
->indirect
.n_entries
307 : h
->n_direct_entries
;
310 static void n_entries_inc(HashmapBase
*h
) {
312 h
->indirect
.n_entries
++;
314 h
->n_direct_entries
++;
317 static void n_entries_dec(HashmapBase
*h
) {
319 h
->indirect
.n_entries
--;
321 h
->n_direct_entries
--;
324 static void *storage_ptr(HashmapBase
*h
) {
325 return h
->has_indirect
? h
->indirect
.storage
329 static uint8_t *hash_key(HashmapBase
*h
) {
330 return h
->has_indirect
? h
->indirect
.hash_key
334 static unsigned base_bucket_hash(HashmapBase
*h
, const void *p
) {
335 struct siphash state
;
338 siphash24_init(&state
, hash_key(h
));
340 h
->hash_ops
->hash(p
, &state
);
342 hash
= siphash24_finalize(&state
);
344 return (unsigned) (hash
% n_buckets(h
));
346 #define bucket_hash(h, p) base_bucket_hash(HASHMAP_BASE(h), p)
348 static inline void base_set_dirty(HashmapBase
*h
) {
351 #define hashmap_set_dirty(h) base_set_dirty(HASHMAP_BASE(h))
353 static void get_hash_key(uint8_t hash_key
[HASH_KEY_SIZE
], bool reuse_is_ok
) {
354 static uint8_t current
[HASH_KEY_SIZE
];
355 static bool current_initialized
= false;
357 /* Returns a hash function key to use. In order to keep things
358 * fast we will not generate a new key each time we allocate a
359 * new hash table. Instead, we'll just reuse the most recently
360 * generated one, except if we never generated one or when we
361 * are rehashing an entire hash table because we reached a
364 if (!current_initialized
|| !reuse_is_ok
) {
365 random_bytes(current
, sizeof(current
));
366 current_initialized
= true;
369 memcpy(hash_key
, current
, sizeof(current
));
372 static struct hashmap_base_entry
*bucket_at(HashmapBase
*h
, unsigned idx
) {
373 return (struct hashmap_base_entry
*)
374 ((uint8_t*) storage_ptr(h
) + idx
* hashmap_type_info
[h
->type
].entry_size
);
377 static struct plain_hashmap_entry
*plain_bucket_at(Hashmap
*h
, unsigned idx
) {
378 return (struct plain_hashmap_entry
*) bucket_at(HASHMAP_BASE(h
), idx
);
381 static struct ordered_hashmap_entry
*ordered_bucket_at(OrderedHashmap
*h
, unsigned idx
) {
382 return (struct ordered_hashmap_entry
*) bucket_at(HASHMAP_BASE(h
), idx
);
385 static struct set_entry
*set_bucket_at(Set
*h
, unsigned idx
) {
386 return (struct set_entry
*) bucket_at(HASHMAP_BASE(h
), idx
);
389 static struct ordered_hashmap_entry
*bucket_at_swap(struct swap_entries
*swap
, unsigned idx
) {
390 return &swap
->e
[idx
- _IDX_SWAP_BEGIN
];
393 /* Returns a pointer to the bucket at index idx.
394 * Understands real indexes and swap indexes, hence "_virtual". */
395 static struct hashmap_base_entry
*bucket_at_virtual(HashmapBase
*h
, struct swap_entries
*swap
,
397 if (idx
< _IDX_SWAP_BEGIN
)
398 return bucket_at(h
, idx
);
400 if (idx
< _IDX_SWAP_END
)
401 return &bucket_at_swap(swap
, idx
)->p
.b
;
403 assert_not_reached("Invalid index");
406 static dib_raw_t
*dib_raw_ptr(HashmapBase
*h
) {
408 ((uint8_t*) storage_ptr(h
) + hashmap_type_info
[h
->type
].entry_size
* n_buckets(h
));
411 static unsigned bucket_distance(HashmapBase
*h
, unsigned idx
, unsigned from
) {
412 return idx
>= from
? idx
- from
413 : n_buckets(h
) + idx
- from
;
416 static unsigned bucket_calculate_dib(HashmapBase
*h
, unsigned idx
, dib_raw_t raw_dib
) {
417 unsigned initial_bucket
;
419 if (raw_dib
== DIB_RAW_FREE
)
422 if (_likely_(raw_dib
< DIB_RAW_OVERFLOW
))
426 * Having an overflow DIB value is very unlikely. The hash function
427 * would have to be bad. For example, in a table of size 2^24 filled
428 * to load factor 0.9 the maximum observed DIB is only about 60.
429 * In theory (assuming I used Maxima correctly), for an infinite size
430 * hash table with load factor 0.8 the probability of a given entry
431 * having DIB > 40 is 1.9e-8.
432 * This returns the correct DIB value by recomputing the hash value in
433 * the unlikely case. XXX Hitting this case could be a hint to rehash.
435 initial_bucket
= bucket_hash(h
, bucket_at(h
, idx
)->key
);
436 return bucket_distance(h
, idx
, initial_bucket
);
439 static void bucket_set_dib(HashmapBase
*h
, unsigned idx
, unsigned dib
) {
440 dib_raw_ptr(h
)[idx
] = dib
!= DIB_FREE
? MIN(dib
, DIB_RAW_OVERFLOW
) : DIB_RAW_FREE
;
443 static unsigned skip_free_buckets(HashmapBase
*h
, unsigned idx
) {
446 dibs
= dib_raw_ptr(h
);
448 for ( ; idx
< n_buckets(h
); idx
++)
449 if (dibs
[idx
] != DIB_RAW_FREE
)
455 static void bucket_mark_free(HashmapBase
*h
, unsigned idx
) {
456 memzero(bucket_at(h
, idx
), hashmap_type_info
[h
->type
].entry_size
);
457 bucket_set_dib(h
, idx
, DIB_FREE
);
460 static void bucket_move_entry(HashmapBase
*h
, struct swap_entries
*swap
,
461 unsigned from
, unsigned to
) {
462 struct hashmap_base_entry
*e_from
, *e_to
;
466 e_from
= bucket_at_virtual(h
, swap
, from
);
467 e_to
= bucket_at_virtual(h
, swap
, to
);
469 memcpy(e_to
, e_from
, hashmap_type_info
[h
->type
].entry_size
);
471 if (h
->type
== HASHMAP_TYPE_ORDERED
) {
472 OrderedHashmap
*lh
= (OrderedHashmap
*) h
;
473 struct ordered_hashmap_entry
*le
, *le_to
;
475 le_to
= (struct ordered_hashmap_entry
*) e_to
;
477 if (le_to
->iterate_next
!= IDX_NIL
) {
478 le
= (struct ordered_hashmap_entry
*)
479 bucket_at_virtual(h
, swap
, le_to
->iterate_next
);
480 le
->iterate_previous
= to
;
483 if (le_to
->iterate_previous
!= IDX_NIL
) {
484 le
= (struct ordered_hashmap_entry
*)
485 bucket_at_virtual(h
, swap
, le_to
->iterate_previous
);
486 le
->iterate_next
= to
;
489 if (lh
->iterate_list_head
== from
)
490 lh
->iterate_list_head
= to
;
491 if (lh
->iterate_list_tail
== from
)
492 lh
->iterate_list_tail
= to
;
496 static unsigned next_idx(HashmapBase
*h
, unsigned idx
) {
497 return (idx
+ 1U) % n_buckets(h
);
500 static unsigned prev_idx(HashmapBase
*h
, unsigned idx
) {
501 return (n_buckets(h
) + idx
- 1U) % n_buckets(h
);
504 static void *entry_value(HashmapBase
*h
, struct hashmap_base_entry
*e
) {
507 case HASHMAP_TYPE_PLAIN
:
508 case HASHMAP_TYPE_ORDERED
:
509 return ((struct plain_hashmap_entry
*)e
)->value
;
511 case HASHMAP_TYPE_SET
:
512 return (void*) e
->key
;
515 assert_not_reached("Unknown hashmap type");
519 static void base_remove_entry(HashmapBase
*h
, unsigned idx
) {
520 unsigned left
, right
, prev
, dib
;
521 dib_raw_t raw_dib
, *dibs
;
523 dibs
= dib_raw_ptr(h
);
524 assert(dibs
[idx
] != DIB_RAW_FREE
);
526 #if ENABLE_DEBUG_HASHMAP
527 h
->debug
.rem_count
++;
528 h
->debug
.last_rem_idx
= idx
;
532 /* Find the stop bucket ("right"). It is either free or has DIB == 0. */
533 for (right
= next_idx(h
, left
); ; right
= next_idx(h
, right
)) {
534 raw_dib
= dibs
[right
];
535 if (IN_SET(raw_dib
, 0, DIB_RAW_FREE
))
538 /* The buckets are not supposed to be all occupied and with DIB > 0.
539 * That would mean we could make everyone better off by shifting them
540 * backward. This scenario is impossible. */
541 assert(left
!= right
);
544 if (h
->type
== HASHMAP_TYPE_ORDERED
) {
545 OrderedHashmap
*lh
= (OrderedHashmap
*) h
;
546 struct ordered_hashmap_entry
*le
= ordered_bucket_at(lh
, idx
);
548 if (le
->iterate_next
!= IDX_NIL
)
549 ordered_bucket_at(lh
, le
->iterate_next
)->iterate_previous
= le
->iterate_previous
;
551 lh
->iterate_list_tail
= le
->iterate_previous
;
553 if (le
->iterate_previous
!= IDX_NIL
)
554 ordered_bucket_at(lh
, le
->iterate_previous
)->iterate_next
= le
->iterate_next
;
556 lh
->iterate_list_head
= le
->iterate_next
;
559 /* Now shift all buckets in the interval (left, right) one step backwards */
560 for (prev
= left
, left
= next_idx(h
, left
); left
!= right
;
561 prev
= left
, left
= next_idx(h
, left
)) {
562 dib
= bucket_calculate_dib(h
, left
, dibs
[left
]);
564 bucket_move_entry(h
, NULL
, left
, prev
);
565 bucket_set_dib(h
, prev
, dib
- 1);
568 bucket_mark_free(h
, prev
);
572 #define remove_entry(h, idx) base_remove_entry(HASHMAP_BASE(h), idx)
574 static unsigned hashmap_iterate_in_insertion_order(OrderedHashmap
*h
, Iterator
*i
) {
575 struct ordered_hashmap_entry
*e
;
581 if (i
->idx
== IDX_NIL
)
584 if (i
->idx
== IDX_FIRST
&& h
->iterate_list_head
== IDX_NIL
)
587 if (i
->idx
== IDX_FIRST
) {
588 idx
= h
->iterate_list_head
;
589 e
= ordered_bucket_at(h
, idx
);
592 e
= ordered_bucket_at(h
, idx
);
594 * We allow removing the current entry while iterating, but removal may cause
595 * a backward shift. The next entry may thus move one bucket to the left.
596 * To detect when it happens, we remember the key pointer of the entry we were
597 * going to iterate next. If it does not match, there was a backward shift.
599 if (e
->p
.b
.key
!= i
->next_key
) {
600 idx
= prev_idx(HASHMAP_BASE(h
), idx
);
601 e
= ordered_bucket_at(h
, idx
);
603 assert(e
->p
.b
.key
== i
->next_key
);
606 #if ENABLE_DEBUG_HASHMAP
610 if (e
->iterate_next
!= IDX_NIL
) {
611 struct ordered_hashmap_entry
*n
;
612 i
->idx
= e
->iterate_next
;
613 n
= ordered_bucket_at(h
, i
->idx
);
614 i
->next_key
= n
->p
.b
.key
;
625 static unsigned hashmap_iterate_in_internal_order(HashmapBase
*h
, Iterator
*i
) {
631 if (i
->idx
== IDX_NIL
)
634 if (i
->idx
== IDX_FIRST
) {
635 /* fast forward to the first occupied bucket */
636 if (h
->has_indirect
) {
637 i
->idx
= skip_free_buckets(h
, h
->indirect
.idx_lowest_entry
);
638 h
->indirect
.idx_lowest_entry
= i
->idx
;
640 i
->idx
= skip_free_buckets(h
, 0);
642 if (i
->idx
== IDX_NIL
)
645 struct hashmap_base_entry
*e
;
649 e
= bucket_at(h
, i
->idx
);
651 * We allow removing the current entry while iterating, but removal may cause
652 * a backward shift. The next entry may thus move one bucket to the left.
653 * To detect when it happens, we remember the key pointer of the entry we were
654 * going to iterate next. If it does not match, there was a backward shift.
656 if (e
->key
!= i
->next_key
)
657 e
= bucket_at(h
, --i
->idx
);
659 assert(e
->key
== i
->next_key
);
663 #if ENABLE_DEBUG_HASHMAP
667 i
->idx
= skip_free_buckets(h
, i
->idx
+ 1);
668 if (i
->idx
!= IDX_NIL
)
669 i
->next_key
= bucket_at(h
, i
->idx
)->key
;
680 static unsigned hashmap_iterate_entry(HashmapBase
*h
, Iterator
*i
) {
686 #if ENABLE_DEBUG_HASHMAP
687 if (i
->idx
== IDX_FIRST
) {
688 i
->put_count
= h
->debug
.put_count
;
689 i
->rem_count
= h
->debug
.rem_count
;
691 /* While iterating, must not add any new entries */
692 assert(i
->put_count
== h
->debug
.put_count
);
693 /* ... or remove entries other than the current one */
694 assert(i
->rem_count
== h
->debug
.rem_count
||
695 (i
->rem_count
== h
->debug
.rem_count
- 1 &&
696 i
->prev_idx
== h
->debug
.last_rem_idx
));
697 /* Reset our removals counter */
698 i
->rem_count
= h
->debug
.rem_count
;
702 return h
->type
== HASHMAP_TYPE_ORDERED
? hashmap_iterate_in_insertion_order((OrderedHashmap
*) h
, i
)
703 : hashmap_iterate_in_internal_order(h
, i
);
706 bool internal_hashmap_iterate(HashmapBase
*h
, Iterator
*i
, void **value
, const void **key
) {
707 struct hashmap_base_entry
*e
;
711 idx
= hashmap_iterate_entry(h
, i
);
712 if (idx
== IDX_NIL
) {
721 e
= bucket_at(h
, idx
);
722 data
= entry_value(h
, e
);
731 bool set_iterate(Set
*s
, Iterator
*i
, void **value
) {
732 return internal_hashmap_iterate(HASHMAP_BASE(s
), i
, value
, NULL
);
735 #define HASHMAP_FOREACH_IDX(idx, h, i) \
736 for ((i) = ITERATOR_FIRST, (idx) = hashmap_iterate_entry((h), &(i)); \
738 (idx) = hashmap_iterate_entry((h), &(i)))
740 IteratedCache
*internal_hashmap_iterated_cache_new(HashmapBase
*h
) {
741 IteratedCache
*cache
;
749 cache
= new0(IteratedCache
, 1);
759 static void reset_direct_storage(HashmapBase
*h
) {
760 const struct hashmap_type_info
*hi
= &hashmap_type_info
[h
->type
];
763 assert(!h
->has_indirect
);
765 p
= mempset(h
->direct
.storage
, 0, hi
->entry_size
* hi
->n_direct_buckets
);
766 memset(p
, DIB_RAW_INIT
, sizeof(dib_raw_t
) * hi
->n_direct_buckets
);
769 static struct HashmapBase
*hashmap_base_new(const struct hash_ops
*hash_ops
, enum HashmapType type HASHMAP_DEBUG_PARAMS
) {
771 const struct hashmap_type_info
*hi
= &hashmap_type_info
[type
];
774 up
= mempool_enabled();
776 h
= up
? mempool_alloc0_tile(hi
->mempool
) : malloc0(hi
->head_size
);
782 h
->hash_ops
= hash_ops
? hash_ops
: &trivial_hash_ops
;
784 if (type
== HASHMAP_TYPE_ORDERED
) {
785 OrderedHashmap
*lh
= (OrderedHashmap
*)h
;
786 lh
->iterate_list_head
= lh
->iterate_list_tail
= IDX_NIL
;
789 reset_direct_storage(h
);
791 if (!shared_hash_key_initialized
) {
792 random_bytes(shared_hash_key
, sizeof(shared_hash_key
));
793 shared_hash_key_initialized
= true;
796 #if ENABLE_DEBUG_HASHMAP
797 h
->debug
.func
= func
;
798 h
->debug
.file
= file
;
799 h
->debug
.line
= line
;
800 assert_se(pthread_mutex_lock(&hashmap_debug_list_mutex
) == 0);
801 LIST_PREPEND(debug_list
, hashmap_debug_list
, &h
->debug
);
802 assert_se(pthread_mutex_unlock(&hashmap_debug_list_mutex
) == 0);
808 Hashmap
*internal_hashmap_new(const struct hash_ops
*hash_ops HASHMAP_DEBUG_PARAMS
) {
809 return (Hashmap
*) hashmap_base_new(hash_ops
, HASHMAP_TYPE_PLAIN HASHMAP_DEBUG_PASS_ARGS
);
812 OrderedHashmap
*internal_ordered_hashmap_new(const struct hash_ops
*hash_ops HASHMAP_DEBUG_PARAMS
) {
813 return (OrderedHashmap
*) hashmap_base_new(hash_ops
, HASHMAP_TYPE_ORDERED HASHMAP_DEBUG_PASS_ARGS
);
816 Set
*internal_set_new(const struct hash_ops
*hash_ops HASHMAP_DEBUG_PARAMS
) {
817 return (Set
*) hashmap_base_new(hash_ops
, HASHMAP_TYPE_SET HASHMAP_DEBUG_PASS_ARGS
);
820 static int hashmap_base_ensure_allocated(HashmapBase
**h
, const struct hash_ops
*hash_ops
,
821 enum HashmapType type HASHMAP_DEBUG_PARAMS
) {
829 q
= hashmap_base_new(hash_ops
, type HASHMAP_DEBUG_PASS_ARGS
);
837 int internal_hashmap_ensure_allocated(Hashmap
**h
, const struct hash_ops
*hash_ops HASHMAP_DEBUG_PARAMS
) {
838 return hashmap_base_ensure_allocated((HashmapBase
**)h
, hash_ops
, HASHMAP_TYPE_PLAIN HASHMAP_DEBUG_PASS_ARGS
);
841 int internal_ordered_hashmap_ensure_allocated(OrderedHashmap
**h
, const struct hash_ops
*hash_ops HASHMAP_DEBUG_PARAMS
) {
842 return hashmap_base_ensure_allocated((HashmapBase
**)h
, hash_ops
, HASHMAP_TYPE_ORDERED HASHMAP_DEBUG_PASS_ARGS
);
845 int internal_set_ensure_allocated(Set
**s
, const struct hash_ops
*hash_ops HASHMAP_DEBUG_PARAMS
) {
846 return hashmap_base_ensure_allocated((HashmapBase
**)s
, hash_ops
, HASHMAP_TYPE_SET HASHMAP_DEBUG_PASS_ARGS
);
849 static void hashmap_free_no_clear(HashmapBase
*h
) {
850 assert(!h
->has_indirect
);
851 assert(h
->n_direct_entries
== 0);
853 #if ENABLE_DEBUG_HASHMAP
854 assert_se(pthread_mutex_lock(&hashmap_debug_list_mutex
) == 0);
855 LIST_REMOVE(debug_list
, hashmap_debug_list
, &h
->debug
);
856 assert_se(pthread_mutex_unlock(&hashmap_debug_list_mutex
) == 0);
860 /* Ensure that the object didn't get migrated between threads. */
861 assert_se(is_main_thread());
862 mempool_free_tile(hashmap_type_info
[h
->type
].mempool
, h
);
867 HashmapBase
*internal_hashmap_free(HashmapBase
*h
, free_func_t default_free_key
, free_func_t default_free_value
) {
869 internal_hashmap_clear(h
, default_free_key
, default_free_value
);
870 hashmap_free_no_clear(h
);
876 void internal_hashmap_clear(HashmapBase
*h
, free_func_t default_free_key
, free_func_t default_free_value
) {
877 free_func_t free_key
, free_value
;
881 free_key
= h
->hash_ops
->free_key
?: default_free_key
;
882 free_value
= h
->hash_ops
->free_value
?: default_free_value
;
884 if (free_key
|| free_value
) {
887 for (idx
= skip_free_buckets(h
, 0); idx
!= IDX_NIL
;
888 idx
= skip_free_buckets(h
, idx
+ 1)) {
889 struct hashmap_base_entry
*e
= bucket_at(h
, idx
);
892 free_key((void *) e
->key
);
895 free_value(entry_value(h
, e
));
899 if (h
->has_indirect
) {
900 free(h
->indirect
.storage
);
901 h
->has_indirect
= false;
904 h
->n_direct_entries
= 0;
905 reset_direct_storage(h
);
907 if (h
->type
== HASHMAP_TYPE_ORDERED
) {
908 OrderedHashmap
*lh
= (OrderedHashmap
*) h
;
909 lh
->iterate_list_head
= lh
->iterate_list_tail
= IDX_NIL
;
915 static int resize_buckets(HashmapBase
*h
, unsigned entries_add
);
918 * Finds an empty bucket to put an entry into, starting the scan at 'idx'.
919 * Performs Robin Hood swaps as it goes. The entry to put must be placed
920 * by the caller into swap slot IDX_PUT.
921 * If used for in-place resizing, may leave a displaced entry in swap slot
922 * IDX_PUT. Caller must rehash it next.
923 * Returns: true if it left a displaced entry to rehash next in IDX_PUT,
926 static bool hashmap_put_robin_hood(HashmapBase
*h
, unsigned idx
,
927 struct swap_entries
*swap
) {
928 dib_raw_t raw_dib
, *dibs
;
929 unsigned dib
, distance
;
931 #if ENABLE_DEBUG_HASHMAP
932 h
->debug
.put_count
++;
935 dibs
= dib_raw_ptr(h
);
937 for (distance
= 0; ; distance
++) {
939 if (IN_SET(raw_dib
, DIB_RAW_FREE
, DIB_RAW_REHASH
)) {
940 if (raw_dib
== DIB_RAW_REHASH
)
941 bucket_move_entry(h
, swap
, idx
, IDX_TMP
);
943 if (h
->has_indirect
&& h
->indirect
.idx_lowest_entry
> idx
)
944 h
->indirect
.idx_lowest_entry
= idx
;
946 bucket_set_dib(h
, idx
, distance
);
947 bucket_move_entry(h
, swap
, IDX_PUT
, idx
);
948 if (raw_dib
== DIB_RAW_REHASH
) {
949 bucket_move_entry(h
, swap
, IDX_TMP
, IDX_PUT
);
956 dib
= bucket_calculate_dib(h
, idx
, raw_dib
);
958 if (dib
< distance
) {
959 /* Found a wealthier entry. Go Robin Hood! */
960 bucket_set_dib(h
, idx
, distance
);
962 /* swap the entries */
963 bucket_move_entry(h
, swap
, idx
, IDX_TMP
);
964 bucket_move_entry(h
, swap
, IDX_PUT
, idx
);
965 bucket_move_entry(h
, swap
, IDX_TMP
, IDX_PUT
);
970 idx
= next_idx(h
, idx
);
975 * Puts an entry into a hashmap, boldly - no check whether key already exists.
976 * The caller must place the entry (only its key and value, not link indexes)
977 * in swap slot IDX_PUT.
978 * Caller must ensure: the key does not exist yet in the hashmap.
979 * that resize is not needed if !may_resize.
980 * Returns: 1 if entry was put successfully.
981 * -ENOMEM if may_resize==true and resize failed with -ENOMEM.
982 * Cannot return -ENOMEM if !may_resize.
984 static int hashmap_base_put_boldly(HashmapBase
*h
, unsigned idx
,
985 struct swap_entries
*swap
, bool may_resize
) {
986 struct ordered_hashmap_entry
*new_entry
;
989 assert(idx
< n_buckets(h
));
991 new_entry
= bucket_at_swap(swap
, IDX_PUT
);
994 r
= resize_buckets(h
, 1);
998 idx
= bucket_hash(h
, new_entry
->p
.b
.key
);
1000 assert(n_entries(h
) < n_buckets(h
));
1002 if (h
->type
== HASHMAP_TYPE_ORDERED
) {
1003 OrderedHashmap
*lh
= (OrderedHashmap
*) h
;
1005 new_entry
->iterate_next
= IDX_NIL
;
1006 new_entry
->iterate_previous
= lh
->iterate_list_tail
;
1008 if (lh
->iterate_list_tail
!= IDX_NIL
) {
1009 struct ordered_hashmap_entry
*old_tail
;
1011 old_tail
= ordered_bucket_at(lh
, lh
->iterate_list_tail
);
1012 assert(old_tail
->iterate_next
== IDX_NIL
);
1013 old_tail
->iterate_next
= IDX_PUT
;
1016 lh
->iterate_list_tail
= IDX_PUT
;
1017 if (lh
->iterate_list_head
== IDX_NIL
)
1018 lh
->iterate_list_head
= IDX_PUT
;
1021 assert_se(hashmap_put_robin_hood(h
, idx
, swap
) == false);
1024 #if ENABLE_DEBUG_HASHMAP
1025 h
->debug
.max_entries
= MAX(h
->debug
.max_entries
, n_entries(h
));
1032 #define hashmap_put_boldly(h, idx, swap, may_resize) \
1033 hashmap_base_put_boldly(HASHMAP_BASE(h), idx, swap, may_resize)
1036 * Returns 0 if resize is not needed.
1037 * 1 if successfully resized.
1038 * -ENOMEM on allocation failure.
1040 static int resize_buckets(HashmapBase
*h
, unsigned entries_add
) {
1041 struct swap_entries swap
;
1043 dib_raw_t
*old_dibs
, *new_dibs
;
1044 const struct hashmap_type_info
*hi
;
1045 unsigned idx
, optimal_idx
;
1046 unsigned old_n_buckets
, new_n_buckets
, n_rehashed
, new_n_entries
;
1052 hi
= &hashmap_type_info
[h
->type
];
1053 new_n_entries
= n_entries(h
) + entries_add
;
1056 if (_unlikely_(new_n_entries
< entries_add
))
1059 /* For direct storage we allow 100% load, because it's tiny. */
1060 if (!h
->has_indirect
&& new_n_entries
<= hi
->n_direct_buckets
)
1064 * Load factor = n/m = 1 - (1/INV_KEEP_FREE).
1065 * From it follows: m = n + n/(INV_KEEP_FREE - 1)
1067 new_n_buckets
= new_n_entries
+ new_n_entries
/ (INV_KEEP_FREE
- 1);
1069 if (_unlikely_(new_n_buckets
< new_n_entries
))
1072 if (_unlikely_(new_n_buckets
> UINT_MAX
/ (hi
->entry_size
+ sizeof(dib_raw_t
))))
1075 old_n_buckets
= n_buckets(h
);
1077 if (_likely_(new_n_buckets
<= old_n_buckets
))
1080 new_shift
= log2u_round_up(MAX(
1081 new_n_buckets
* (hi
->entry_size
+ sizeof(dib_raw_t
)),
1082 2 * sizeof(struct direct_storage
)));
1084 /* Realloc storage (buckets and DIB array). */
1085 new_storage
= realloc(h
->has_indirect
? h
->indirect
.storage
: NULL
,
1090 /* Must upgrade direct to indirect storage. */
1091 if (!h
->has_indirect
) {
1092 memcpy(new_storage
, h
->direct
.storage
,
1093 old_n_buckets
* (hi
->entry_size
+ sizeof(dib_raw_t
)));
1094 h
->indirect
.n_entries
= h
->n_direct_entries
;
1095 h
->indirect
.idx_lowest_entry
= 0;
1096 h
->n_direct_entries
= 0;
1099 /* Get a new hash key. If we've just upgraded to indirect storage,
1100 * allow reusing a previously generated key. It's still a different key
1101 * from the shared one that we used for direct storage. */
1102 get_hash_key(h
->indirect
.hash_key
, !h
->has_indirect
);
1104 h
->has_indirect
= true;
1105 h
->indirect
.storage
= new_storage
;
1106 h
->indirect
.n_buckets
= (1U << new_shift
) /
1107 (hi
->entry_size
+ sizeof(dib_raw_t
));
1109 old_dibs
= (dib_raw_t
*)((uint8_t*) new_storage
+ hi
->entry_size
* old_n_buckets
);
1110 new_dibs
= dib_raw_ptr(h
);
1113 * Move the DIB array to the new place, replacing valid DIB values with
1114 * DIB_RAW_REHASH to indicate all of the used buckets need rehashing.
1115 * Note: Overlap is not possible, because we have at least doubled the
1116 * number of buckets and dib_raw_t is smaller than any entry type.
1118 for (idx
= 0; idx
< old_n_buckets
; idx
++) {
1119 assert(old_dibs
[idx
] != DIB_RAW_REHASH
);
1120 new_dibs
[idx
] = old_dibs
[idx
] == DIB_RAW_FREE
? DIB_RAW_FREE
1124 /* Zero the area of newly added entries (including the old DIB area) */
1125 memzero(bucket_at(h
, old_n_buckets
),
1126 (n_buckets(h
) - old_n_buckets
) * hi
->entry_size
);
1128 /* The upper half of the new DIB array needs initialization */
1129 memset(&new_dibs
[old_n_buckets
], DIB_RAW_INIT
,
1130 (n_buckets(h
) - old_n_buckets
) * sizeof(dib_raw_t
));
1132 /* Rehash entries that need it */
1134 for (idx
= 0; idx
< old_n_buckets
; idx
++) {
1135 if (new_dibs
[idx
] != DIB_RAW_REHASH
)
1138 optimal_idx
= bucket_hash(h
, bucket_at(h
, idx
)->key
);
1141 * Not much to do if by luck the entry hashes to its current
1142 * location. Just set its DIB.
1144 if (optimal_idx
== idx
) {
1150 new_dibs
[idx
] = DIB_RAW_FREE
;
1151 bucket_move_entry(h
, &swap
, idx
, IDX_PUT
);
1152 /* bucket_move_entry does not clear the source */
1153 memzero(bucket_at(h
, idx
), hi
->entry_size
);
1157 * Find the new bucket for the current entry. This may make
1158 * another entry homeless and load it into IDX_PUT.
1160 rehash_next
= hashmap_put_robin_hood(h
, optimal_idx
, &swap
);
1163 /* Did the current entry displace another one? */
1165 optimal_idx
= bucket_hash(h
, bucket_at_swap(&swap
, IDX_PUT
)->p
.b
.key
);
1166 } while (rehash_next
);
1169 assert(n_rehashed
== n_entries(h
));
1175 * Finds an entry with a matching key
1176 * Returns: index of the found entry, or IDX_NIL if not found.
1178 static unsigned base_bucket_scan(HashmapBase
*h
, unsigned idx
, const void *key
) {
1179 struct hashmap_base_entry
*e
;
1180 unsigned dib
, distance
;
1181 dib_raw_t
*dibs
= dib_raw_ptr(h
);
1183 assert(idx
< n_buckets(h
));
1185 for (distance
= 0; ; distance
++) {
1186 if (dibs
[idx
] == DIB_RAW_FREE
)
1189 dib
= bucket_calculate_dib(h
, idx
, dibs
[idx
]);
1193 if (dib
== distance
) {
1194 e
= bucket_at(h
, idx
);
1195 if (h
->hash_ops
->compare(e
->key
, key
) == 0)
1199 idx
= next_idx(h
, idx
);
1202 #define bucket_scan(h, idx, key) base_bucket_scan(HASHMAP_BASE(h), idx, key)
1204 int hashmap_put(Hashmap
*h
, const void *key
, void *value
) {
1205 struct swap_entries swap
;
1206 struct plain_hashmap_entry
*e
;
1211 hash
= bucket_hash(h
, key
);
1212 idx
= bucket_scan(h
, hash
, key
);
1213 if (idx
!= IDX_NIL
) {
1214 e
= plain_bucket_at(h
, idx
);
1215 if (e
->value
== value
)
1220 e
= &bucket_at_swap(&swap
, IDX_PUT
)->p
;
1223 return hashmap_put_boldly(h
, hash
, &swap
, true);
1226 int set_put(Set
*s
, const void *key
) {
1227 struct swap_entries swap
;
1228 struct hashmap_base_entry
*e
;
1233 hash
= bucket_hash(s
, key
);
1234 idx
= bucket_scan(s
, hash
, key
);
1238 e
= &bucket_at_swap(&swap
, IDX_PUT
)->p
.b
;
1240 return hashmap_put_boldly(s
, hash
, &swap
, true);
1243 int hashmap_replace(Hashmap
*h
, const void *key
, void *value
) {
1244 struct swap_entries swap
;
1245 struct plain_hashmap_entry
*e
;
1250 hash
= bucket_hash(h
, key
);
1251 idx
= bucket_scan(h
, hash
, key
);
1252 if (idx
!= IDX_NIL
) {
1253 e
= plain_bucket_at(h
, idx
);
1254 #if ENABLE_DEBUG_HASHMAP
1255 /* Although the key is equal, the key pointer may have changed,
1256 * and this would break our assumption for iterating. So count
1257 * this operation as incompatible with iteration. */
1258 if (e
->b
.key
!= key
) {
1259 h
->b
.debug
.put_count
++;
1260 h
->b
.debug
.rem_count
++;
1261 h
->b
.debug
.last_rem_idx
= idx
;
1266 hashmap_set_dirty(h
);
1271 e
= &bucket_at_swap(&swap
, IDX_PUT
)->p
;
1274 return hashmap_put_boldly(h
, hash
, &swap
, true);
1277 int hashmap_update(Hashmap
*h
, const void *key
, void *value
) {
1278 struct plain_hashmap_entry
*e
;
1283 hash
= bucket_hash(h
, key
);
1284 idx
= bucket_scan(h
, hash
, key
);
1288 e
= plain_bucket_at(h
, idx
);
1290 hashmap_set_dirty(h
);
1295 void *internal_hashmap_get(HashmapBase
*h
, const void *key
) {
1296 struct hashmap_base_entry
*e
;
1302 hash
= bucket_hash(h
, key
);
1303 idx
= bucket_scan(h
, hash
, key
);
1307 e
= bucket_at(h
, idx
);
1308 return entry_value(h
, e
);
1311 void *hashmap_get2(Hashmap
*h
, const void *key
, void **key2
) {
1312 struct plain_hashmap_entry
*e
;
1318 hash
= bucket_hash(h
, key
);
1319 idx
= bucket_scan(h
, hash
, key
);
1323 e
= plain_bucket_at(h
, idx
);
1325 *key2
= (void*) e
->b
.key
;
1330 bool internal_hashmap_contains(HashmapBase
*h
, const void *key
) {
1336 hash
= bucket_hash(h
, key
);
1337 return bucket_scan(h
, hash
, key
) != IDX_NIL
;
1340 void *internal_hashmap_remove(HashmapBase
*h
, const void *key
) {
1341 struct hashmap_base_entry
*e
;
1348 hash
= bucket_hash(h
, key
);
1349 idx
= bucket_scan(h
, hash
, key
);
1353 e
= bucket_at(h
, idx
);
1354 data
= entry_value(h
, e
);
1355 remove_entry(h
, idx
);
1360 void *hashmap_remove2(Hashmap
*h
, const void *key
, void **rkey
) {
1361 struct plain_hashmap_entry
*e
;
1371 hash
= bucket_hash(h
, key
);
1372 idx
= bucket_scan(h
, hash
, key
);
1373 if (idx
== IDX_NIL
) {
1379 e
= plain_bucket_at(h
, idx
);
1382 *rkey
= (void*) e
->b
.key
;
1384 remove_entry(h
, idx
);
1389 int hashmap_remove_and_put(Hashmap
*h
, const void *old_key
, const void *new_key
, void *value
) {
1390 struct swap_entries swap
;
1391 struct plain_hashmap_entry
*e
;
1392 unsigned old_hash
, new_hash
, idx
;
1397 old_hash
= bucket_hash(h
, old_key
);
1398 idx
= bucket_scan(h
, old_hash
, old_key
);
1402 new_hash
= bucket_hash(h
, new_key
);
1403 if (bucket_scan(h
, new_hash
, new_key
) != IDX_NIL
)
1406 remove_entry(h
, idx
);
1408 e
= &bucket_at_swap(&swap
, IDX_PUT
)->p
;
1411 assert_se(hashmap_put_boldly(h
, new_hash
, &swap
, false) == 1);
1416 int set_remove_and_put(Set
*s
, const void *old_key
, const void *new_key
) {
1417 struct swap_entries swap
;
1418 struct hashmap_base_entry
*e
;
1419 unsigned old_hash
, new_hash
, idx
;
1424 old_hash
= bucket_hash(s
, old_key
);
1425 idx
= bucket_scan(s
, old_hash
, old_key
);
1429 new_hash
= bucket_hash(s
, new_key
);
1430 if (bucket_scan(s
, new_hash
, new_key
) != IDX_NIL
)
1433 remove_entry(s
, idx
);
1435 e
= &bucket_at_swap(&swap
, IDX_PUT
)->p
.b
;
1437 assert_se(hashmap_put_boldly(s
, new_hash
, &swap
, false) == 1);
1442 int hashmap_remove_and_replace(Hashmap
*h
, const void *old_key
, const void *new_key
, void *value
) {
1443 struct swap_entries swap
;
1444 struct plain_hashmap_entry
*e
;
1445 unsigned old_hash
, new_hash
, idx_old
, idx_new
;
1450 old_hash
= bucket_hash(h
, old_key
);
1451 idx_old
= bucket_scan(h
, old_hash
, old_key
);
1452 if (idx_old
== IDX_NIL
)
1455 old_key
= bucket_at(HASHMAP_BASE(h
), idx_old
)->key
;
1457 new_hash
= bucket_hash(h
, new_key
);
1458 idx_new
= bucket_scan(h
, new_hash
, new_key
);
1459 if (idx_new
!= IDX_NIL
)
1460 if (idx_old
!= idx_new
) {
1461 remove_entry(h
, idx_new
);
1462 /* Compensate for a possible backward shift. */
1463 if (old_key
!= bucket_at(HASHMAP_BASE(h
), idx_old
)->key
)
1464 idx_old
= prev_idx(HASHMAP_BASE(h
), idx_old
);
1465 assert(old_key
== bucket_at(HASHMAP_BASE(h
), idx_old
)->key
);
1468 remove_entry(h
, idx_old
);
1470 e
= &bucket_at_swap(&swap
, IDX_PUT
)->p
;
1473 assert_se(hashmap_put_boldly(h
, new_hash
, &swap
, false) == 1);
1478 void *hashmap_remove_value(Hashmap
*h
, const void *key
, void *value
) {
1479 struct plain_hashmap_entry
*e
;
1485 hash
= bucket_hash(h
, key
);
1486 idx
= bucket_scan(h
, hash
, key
);
1490 e
= plain_bucket_at(h
, idx
);
1491 if (e
->value
!= value
)
1494 remove_entry(h
, idx
);
1499 static unsigned find_first_entry(HashmapBase
*h
) {
1500 Iterator i
= ITERATOR_FIRST
;
1502 if (!h
|| !n_entries(h
))
1505 return hashmap_iterate_entry(h
, &i
);
1508 void *internal_hashmap_first_key_and_value(HashmapBase
*h
, bool remove
, void **ret_key
) {
1509 struct hashmap_base_entry
*e
;
1513 idx
= find_first_entry(h
);
1517 e
= bucket_at(h
, idx
);
1518 key
= (void*) e
->key
;
1519 data
= entry_value(h
, e
);
1522 remove_entry(h
, idx
);
1530 unsigned internal_hashmap_size(HashmapBase
*h
) {
1535 return n_entries(h
);
1538 unsigned internal_hashmap_buckets(HashmapBase
*h
) {
1543 return n_buckets(h
);
1546 int internal_hashmap_merge(Hashmap
*h
, Hashmap
*other
) {
1552 HASHMAP_FOREACH_IDX(idx
, HASHMAP_BASE(other
), i
) {
1553 struct plain_hashmap_entry
*pe
= plain_bucket_at(other
, idx
);
1556 r
= hashmap_put(h
, pe
->b
.key
, pe
->value
);
1557 if (r
< 0 && r
!= -EEXIST
)
1564 int set_merge(Set
*s
, Set
*other
) {
1570 HASHMAP_FOREACH_IDX(idx
, HASHMAP_BASE(other
), i
) {
1571 struct set_entry
*se
= set_bucket_at(other
, idx
);
1574 r
= set_put(s
, se
->b
.key
);
1582 int internal_hashmap_reserve(HashmapBase
*h
, unsigned entries_add
) {
1587 r
= resize_buckets(h
, entries_add
);
1595 * The same as hashmap_merge(), but every new item from other is moved to h.
1596 * Keys already in h are skipped and stay in other.
1597 * Returns: 0 on success.
1598 * -ENOMEM on alloc failure, in which case no move has been done.
1600 int internal_hashmap_move(HashmapBase
*h
, HashmapBase
*other
) {
1601 struct swap_entries swap
;
1602 struct hashmap_base_entry
*e
, *n
;
1612 assert(other
->type
== h
->type
);
1615 * This reserves buckets for the worst case, where none of other's
1616 * entries are yet present in h. This is preferable to risking
1617 * an allocation failure in the middle of the moving and having to
1618 * rollback or return a partial result.
1620 r
= resize_buckets(h
, n_entries(other
));
1624 HASHMAP_FOREACH_IDX(idx
, other
, i
) {
1627 e
= bucket_at(other
, idx
);
1628 h_hash
= bucket_hash(h
, e
->key
);
1629 if (bucket_scan(h
, h_hash
, e
->key
) != IDX_NIL
)
1632 n
= &bucket_at_swap(&swap
, IDX_PUT
)->p
.b
;
1634 if (h
->type
!= HASHMAP_TYPE_SET
)
1635 ((struct plain_hashmap_entry
*) n
)->value
=
1636 ((struct plain_hashmap_entry
*) e
)->value
;
1637 assert_se(hashmap_put_boldly(h
, h_hash
, &swap
, false) == 1);
1639 remove_entry(other
, idx
);
1645 int internal_hashmap_move_one(HashmapBase
*h
, HashmapBase
*other
, const void *key
) {
1646 struct swap_entries swap
;
1647 unsigned h_hash
, other_hash
, idx
;
1648 struct hashmap_base_entry
*e
, *n
;
1653 h_hash
= bucket_hash(h
, key
);
1654 if (bucket_scan(h
, h_hash
, key
) != IDX_NIL
)
1660 assert(other
->type
== h
->type
);
1662 other_hash
= bucket_hash(other
, key
);
1663 idx
= bucket_scan(other
, other_hash
, key
);
1667 e
= bucket_at(other
, idx
);
1669 n
= &bucket_at_swap(&swap
, IDX_PUT
)->p
.b
;
1671 if (h
->type
!= HASHMAP_TYPE_SET
)
1672 ((struct plain_hashmap_entry
*) n
)->value
=
1673 ((struct plain_hashmap_entry
*) e
)->value
;
1674 r
= hashmap_put_boldly(h
, h_hash
, &swap
, true);
1678 remove_entry(other
, idx
);
1682 HashmapBase
*internal_hashmap_copy(HashmapBase
*h
) {
1688 copy
= hashmap_base_new(h
->hash_ops
, h
->type HASHMAP_DEBUG_SRC_ARGS
);
1693 case HASHMAP_TYPE_PLAIN
:
1694 case HASHMAP_TYPE_ORDERED
:
1695 r
= hashmap_merge((Hashmap
*)copy
, (Hashmap
*)h
);
1697 case HASHMAP_TYPE_SET
:
1698 r
= set_merge((Set
*)copy
, (Set
*)h
);
1701 assert_not_reached("Unknown hashmap type");
1705 internal_hashmap_free(copy
, false, false);
1712 char **internal_hashmap_get_strv(HashmapBase
*h
) {
1717 sv
= new(char*, n_entries(h
)+1);
1722 HASHMAP_FOREACH_IDX(idx
, h
, i
)
1723 sv
[n
++] = entry_value(h
, bucket_at(h
, idx
));
1729 void *ordered_hashmap_next(OrderedHashmap
*h
, const void *key
) {
1730 struct ordered_hashmap_entry
*e
;
1736 hash
= bucket_hash(h
, key
);
1737 idx
= bucket_scan(h
, hash
, key
);
1741 e
= ordered_bucket_at(h
, idx
);
1742 if (e
->iterate_next
== IDX_NIL
)
1744 return ordered_bucket_at(h
, e
->iterate_next
)->p
.value
;
1747 int set_consume(Set
*s
, void *value
) {
1753 r
= set_put(s
, value
);
1760 int set_put_strdup(Set
*s
, const char *p
) {
1766 if (set_contains(s
, (char*) p
))
1773 return set_consume(s
, c
);
1776 int set_put_strdupv(Set
*s
, char **l
) {
1782 STRV_FOREACH(i
, l
) {
1783 r
= set_put_strdup(s
, *i
);
1793 int set_put_strsplit(Set
*s
, const char *v
, const char *separators
, ExtractFlags flags
) {
1803 r
= extract_first_word(&p
, &word
, separators
, flags
);
1807 r
= set_consume(s
, word
);
1813 /* expand the cachemem if needed, return true if newly (re)activated. */
1814 static int cachemem_maintain(CacheMem
*mem
, unsigned size
) {
1817 if (!GREEDY_REALLOC(mem
->ptr
, mem
->n_allocated
, size
)) {
1830 int iterated_cache_get(IteratedCache
*cache
, const void ***res_keys
, const void ***res_values
, unsigned *res_n_entries
) {
1831 bool sync_keys
= false, sync_values
= false;
1836 assert(cache
->hashmap
);
1838 size
= n_entries(cache
->hashmap
);
1841 r
= cachemem_maintain(&cache
->keys
, size
);
1847 cache
->keys
.active
= false;
1850 r
= cachemem_maintain(&cache
->values
, size
);
1856 cache
->values
.active
= false;
1858 if (cache
->hashmap
->dirty
) {
1859 if (cache
->keys
.active
)
1861 if (cache
->values
.active
)
1864 cache
->hashmap
->dirty
= false;
1867 if (sync_keys
|| sync_values
) {
1872 HASHMAP_FOREACH_IDX(idx
, cache
->hashmap
, iter
) {
1873 struct hashmap_base_entry
*e
;
1875 e
= bucket_at(cache
->hashmap
, idx
);
1878 cache
->keys
.ptr
[i
] = e
->key
;
1880 cache
->values
.ptr
[i
] = entry_value(cache
->hashmap
, e
);
1886 *res_keys
= cache
->keys
.ptr
;
1888 *res_values
= cache
->values
.ptr
;
1890 *res_n_entries
= size
;
1895 IteratedCache
*iterated_cache_free(IteratedCache
*cache
) {
1897 free(cache
->keys
.ptr
);
1898 free(cache
->values
.ptr
);