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src.rivoreo.one / systemd-stable / v241-stable / . / src / basic / hashmap.c
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/* SPDX-License-Identifier: LGPL-2.1+ */
#include <errno.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "alloc-util.h"
#include "fileio.h"
#include "hashmap.h"
#include "macro.h"
#include "mempool.h"
#include "missing.h"
#include "process-util.h"
#include "random-util.h"
#include "set.h"
#include "siphash24.h"
#include "string-util.h"
#include "strv.h"
#include "util.h"
#if ENABLE_DEBUG_HASHMAP
#include <pthread.h>
#include "list.h"
#endif
/*
* Implementation of hashmaps.
* Addressing: open
* - uses less RAM compared to closed addressing (chaining), because
* our entries are small (especially in Sets, which tend to contain
* the majority of entries in systemd).
* Collision resolution: Robin Hood
* - tends to equalize displacement of entries from their optimal buckets.
* Probe sequence: linear
* - though theoretically worse than random probing/uniform hashing/double
* hashing, it is good for cache locality.
*
* References:
* Celis, P. 1986. Robin Hood Hashing.
* Ph.D. Dissertation. University of Waterloo, Waterloo, Ont., Canada, Canada.
* https://cs.uwaterloo.ca/research/tr/1986/CS-86-14.pdf
* - The results are derived for random probing. Suggests deletion with
* tombstones and two mean-centered search methods. None of that works
* well for linear probing.
*
* Janson, S. 2005. Individual displacements for linear probing hashing with different insertion policies.
* ACM Trans. Algorithms 1, 2 (October 2005), 177-213.
* DOI=10.1145/1103963.1103964 http://doi.acm.org/10.1145/1103963.1103964
* http://www.math.uu.se/~svante/papers/sj157.pdf
* - Applies to Robin Hood with linear probing. Contains remarks on
* the unsuitability of mean-centered search with linear probing.
*
* Viola, A. 2005. Exact distribution of individual displacements in linear probing hashing.
* ACM Trans. Algorithms 1, 2 (October 2005), 214-242.
* DOI=10.1145/1103963.1103965 http://doi.acm.org/10.1145/1103963.1103965
* - Similar to Janson. Note that Viola writes about C_{m,n} (number of probes
* in a successful search), and Janson writes about displacement. C = d + 1.
*
* Goossaert, E. 2013. Robin Hood hashing: backward shift deletion.
* http://codecapsule.com/2013/11/17/robin-hood-hashing-backward-shift-deletion/
* - Explanation of backward shift deletion with pictures.
*
* Khuong, P. 2013. The Other Robin Hood Hashing.
* http://www.pvk.ca/Blog/2013/11/26/the-other-robin-hood-hashing/
* - Short summary of random vs. linear probing, and tombstones vs. backward shift.
*/
/*
* XXX Ideas for improvement:
* For unordered hashmaps, randomize iteration order, similarly to Perl:
* http://blog.booking.com/hardening-perls-hash-function.html
*/
/* INV_KEEP_FREE = 1 / (1 - max_load_factor)
* e.g. 1 / (1 - 0.8) = 5 ... keep one fifth of the buckets free. */
#define INV_KEEP_FREE 5U
/* Fields common to entries of all hashmap/set types */
struct hashmap_base_entry {
const void *key;
};
/* Entry types for specific hashmap/set types
* hashmap_base_entry must be at the beginning of each entry struct. */
struct plain_hashmap_entry {
struct hashmap_base_entry b;
void *value;
};
struct ordered_hashmap_entry {
struct plain_hashmap_entry p;
unsigned iterate_next, iterate_previous;
};
struct set_entry {
struct hashmap_base_entry b;
};
/* In several functions it is advantageous to have the hash table extended
* virtually by a couple of additional buckets. We reserve special index values
* for these "swap" buckets. */
#define _IDX_SWAP_BEGIN (UINT_MAX - 3)
#define IDX_PUT (_IDX_SWAP_BEGIN + 0)
#define IDX_TMP (_IDX_SWAP_BEGIN + 1)
#define _IDX_SWAP_END (_IDX_SWAP_BEGIN + 2)
#define IDX_FIRST (UINT_MAX - 1) /* special index for freshly initialized iterators */
#define IDX_NIL UINT_MAX /* special index value meaning "none" or "end" */
assert_cc(IDX_FIRST == _IDX_SWAP_END);
assert_cc(IDX_FIRST == _IDX_ITERATOR_FIRST);
/* Storage space for the "swap" buckets.
* All entry types can fit into a ordered_hashmap_entry. */
struct swap_entries {
struct ordered_hashmap_entry e[_IDX_SWAP_END - _IDX_SWAP_BEGIN];
};
/* Distance from Initial Bucket */
typedef uint8_t dib_raw_t;
#define DIB_RAW_OVERFLOW ((dib_raw_t)0xfdU) /* indicates DIB value is greater than representable */
#define DIB_RAW_REHASH ((dib_raw_t)0xfeU) /* entry yet to be rehashed during in-place resize */
#define DIB_RAW_FREE ((dib_raw_t)0xffU) /* a free bucket */
#define DIB_RAW_INIT ((char)DIB_RAW_FREE) /* a byte to memset a DIB store with when initializing */
#define DIB_FREE UINT_MAX
#if ENABLE_DEBUG_HASHMAP
struct hashmap_debug_info {
LIST_FIELDS(struct hashmap_debug_info, debug_list);
unsigned max_entries; /* high watermark of n_entries */
/* who allocated this hashmap */
int line;
const char *file;
const char *func;
/* fields to detect modification while iterating */
unsigned put_count; /* counts puts into the hashmap */
unsigned rem_count; /* counts removals from hashmap */
unsigned last_rem_idx; /* remembers last removal index */
};
/* Tracks all existing hashmaps. Get at it from gdb. See sd_dump_hashmaps.py */
static LIST_HEAD(struct hashmap_debug_info, hashmap_debug_list);
static pthread_mutex_t hashmap_debug_list_mutex = PTHREAD_MUTEX_INITIALIZER;
#define HASHMAP_DEBUG_FIELDS struct hashmap_debug_info debug;
#else /* !ENABLE_DEBUG_HASHMAP */
#define HASHMAP_DEBUG_FIELDS
#endif /* ENABLE_DEBUG_HASHMAP */
enum HashmapType {
HASHMAP_TYPE_PLAIN,
HASHMAP_TYPE_ORDERED,
HASHMAP_TYPE_SET,
_HASHMAP_TYPE_MAX
};
struct _packed_ indirect_storage {
void *storage; /* where buckets and DIBs are stored */
uint8_t hash_key[HASH_KEY_SIZE]; /* hash key; changes during resize */
unsigned n_entries; /* number of stored entries */
unsigned n_buckets; /* number of buckets */
unsigned idx_lowest_entry; /* Index below which all buckets are free.
Makes "while(hashmap_steal_first())" loops
O(n) instead of O(n^2) for unordered hashmaps. */
uint8_t _pad[3]; /* padding for the whole HashmapBase */
/* The bitfields in HashmapBase complete the alignment of the whole thing. */
};
struct direct_storage {
/* This gives us 39 bytes on 64bit, or 35 bytes on 32bit.
* That's room for 4 set_entries + 4 DIB bytes + 3 unused bytes on 64bit,
* or 7 set_entries + 7 DIB bytes + 0 unused bytes on 32bit. */
uint8_t storage[sizeof(struct indirect_storage)];
};
#define DIRECT_BUCKETS(entry_t) \
(sizeof(struct direct_storage) / (sizeof(entry_t) + sizeof(dib_raw_t)))
/* We should be able to store at least one entry directly. */
assert_cc(DIRECT_BUCKETS(struct ordered_hashmap_entry) >= 1);
/* We have 3 bits for n_direct_entries. */
assert_cc(DIRECT_BUCKETS(struct set_entry) < (1 << 3));
/* Hashmaps with directly stored entries all use this shared hash key.
* It's no big deal if the key is guessed, because there can be only
* a handful of directly stored entries in a hashmap. When a hashmap
* outgrows direct storage, it gets its own key for indirect storage. */
static uint8_t shared_hash_key[HASH_KEY_SIZE];
static bool shared_hash_key_initialized;
/* Fields that all hashmap/set types must have */
struct HashmapBase {
const struct hash_ops *hash_ops; /* hash and compare ops to use */
union _packed_ {
struct indirect_storage indirect; /* if has_indirect */
struct direct_storage direct; /* if !has_indirect */
};
enum HashmapType type:2; /* HASHMAP_TYPE_* */
bool has_indirect:1; /* whether indirect storage is used */
unsigned n_direct_entries:3; /* Number of entries in direct storage.
* Only valid if !has_indirect. */
bool from_pool:1; /* whether was allocated from mempool */
bool dirty:1; /* whether dirtied since last iterated_cache_get() */
bool cached:1; /* whether this hashmap is being cached */
HASHMAP_DEBUG_FIELDS /* optional hashmap_debug_info */
};
/* Specific hash types
* HashmapBase must be at the beginning of each hashmap struct. */
struct Hashmap {
struct HashmapBase b;
};
struct OrderedHashmap {
struct HashmapBase b;
unsigned iterate_list_head, iterate_list_tail;
};
struct Set {
struct HashmapBase b;
};
typedef struct CacheMem {
const void **ptr;
size_t n_populated, n_allocated;
bool active:1;
} CacheMem;
struct IteratedCache {
HashmapBase *hashmap;
CacheMem keys, values;
};
DEFINE_MEMPOOL(hashmap_pool, Hashmap, 8);
DEFINE_MEMPOOL(ordered_hashmap_pool, OrderedHashmap, 8);
/* No need for a separate Set pool */
assert_cc(sizeof(Hashmap) == sizeof(Set));
struct hashmap_type_info {
size_t head_size;
size_t entry_size;
struct mempool *mempool;
unsigned n_direct_buckets;
};
static const struct hashmap_type_info hashmap_type_info[_HASHMAP_TYPE_MAX] = {
[HASHMAP_TYPE_PLAIN] = {
.head_size = sizeof(Hashmap),
.entry_size = sizeof(struct plain_hashmap_entry),
.mempool = &hashmap_pool,
.n_direct_buckets = DIRECT_BUCKETS(struct plain_hashmap_entry),
},
[HASHMAP_TYPE_ORDERED] = {
.head_size = sizeof(OrderedHashmap),
.entry_size = sizeof(struct ordered_hashmap_entry),
.mempool = &ordered_hashmap_pool,
.n_direct_buckets = DIRECT_BUCKETS(struct ordered_hashmap_entry),
},
[HASHMAP_TYPE_SET] = {
.head_size = sizeof(Set),
.entry_size = sizeof(struct set_entry),
.mempool = &hashmap_pool,
.n_direct_buckets = DIRECT_BUCKETS(struct set_entry),
},
};
#if VALGRIND
_destructor_ static void cleanup_pools(void) {
_cleanup_free_ char *t = NULL;
int r;
/* Be nice to valgrind */
/* The pool is only allocated by the main thread, but the memory can
* be passed to other threads. Let's clean up if we are the main thread
* and no other threads are live. */
/* We build our own is_main_thread() here, which doesn't use C11
* TLS based caching of the result. That's because valgrind apparently
* doesn't like malloc() (which C11 TLS internally uses) to be called
* from a GCC destructors. */
if (getpid() != gettid())
return;
r = get_proc_field("/proc/self/status", "Threads", WHITESPACE, &t);
if (r < 0 || !streq(t, "1"))
return;
mempool_drop(&hashmap_pool);
mempool_drop(&ordered_hashmap_pool);
}
#endif
static unsigned n_buckets(HashmapBase *h) {
return h->has_indirect ? h->indirect.n_buckets
: hashmap_type_info[h->type].n_direct_buckets;
}
static unsigned n_entries(HashmapBase *h) {
return h->has_indirect ? h->indirect.n_entries
: h->n_direct_entries;
}
static void n_entries_inc(HashmapBase *h) {
if (h->has_indirect)
h->indirect.n_entries++;
else
h->n_direct_entries++;
}
static void n_entries_dec(HashmapBase *h) {
if (h->has_indirect)
h->indirect.n_entries--;
else
h->n_direct_entries--;
}
static void *storage_ptr(HashmapBase *h) {
return h->has_indirect ? h->indirect.storage
: h->direct.storage;
}
static uint8_t *hash_key(HashmapBase *h) {
return h->has_indirect ? h->indirect.hash_key
: shared_hash_key;
}
static unsigned base_bucket_hash(HashmapBase *h, const void *p) {
struct siphash state;
uint64_t hash;
siphash24_init(&state, hash_key(h));
h->hash_ops->hash(p, &state);
hash = siphash24_finalize(&state);
return (unsigned) (hash % n_buckets(h));
}
#define bucket_hash(h, p) base_bucket_hash(HASHMAP_BASE(h), p)
static void base_set_dirty(HashmapBase *h) {
h->dirty = true;
}
#define hashmap_set_dirty(h) base_set_dirty(HASHMAP_BASE(h))
static void get_hash_key(uint8_t hash_key[HASH_KEY_SIZE], bool reuse_is_ok) {
static uint8_t current[HASH_KEY_SIZE];
static bool current_initialized = false;
/* Returns a hash function key to use. In order to keep things
* fast we will not generate a new key each time we allocate a
* new hash table. Instead, we'll just reuse the most recently
* generated one, except if we never generated one or when we
* are rehashing an entire hash table because we reached a
* fill level */
if (!current_initialized || !reuse_is_ok) {
random_bytes(current, sizeof(current));
current_initialized = true;
}
memcpy(hash_key, current, sizeof(current));
}
static struct hashmap_base_entry *bucket_at(HashmapBase *h, unsigned idx) {
return (struct hashmap_base_entry*)
((uint8_t*) storage_ptr(h) + idx * hashmap_type_info[h->type].entry_size);
}
static struct plain_hashmap_entry *plain_bucket_at(Hashmap *h, unsigned idx) {
return (struct plain_hashmap_entry*) bucket_at(HASHMAP_BASE(h), idx);
}
static struct ordered_hashmap_entry *ordered_bucket_at(OrderedHashmap *h, unsigned idx) {
return (struct ordered_hashmap_entry*) bucket_at(HASHMAP_BASE(h), idx);
}
static struct set_entry *set_bucket_at(Set *h, unsigned idx) {
return (struct set_entry*) bucket_at(HASHMAP_BASE(h), idx);
}
static struct ordered_hashmap_entry *bucket_at_swap(struct swap_entries *swap, unsigned idx) {
return &swap->e[idx - _IDX_SWAP_BEGIN];
}
/* Returns a pointer to the bucket at index idx.
* Understands real indexes and swap indexes, hence "_virtual". */
static struct hashmap_base_entry *bucket_at_virtual(HashmapBase *h, struct swap_entries *swap,
unsigned idx) {
if (idx < _IDX_SWAP_BEGIN)
return bucket_at(h, idx);
if (idx < _IDX_SWAP_END)
return &bucket_at_swap(swap, idx)->p.b;
assert_not_reached("Invalid index");
}
static dib_raw_t *dib_raw_ptr(HashmapBase *h) {
return (dib_raw_t*)
((uint8_t*) storage_ptr(h) + hashmap_type_info[h->type].entry_size * n_buckets(h));
}
static unsigned bucket_distance(HashmapBase *h, unsigned idx, unsigned from) {
return idx >= from ? idx - from
: n_buckets(h) + idx - from;
}
static unsigned bucket_calculate_dib(HashmapBase *h, unsigned idx, dib_raw_t raw_dib) {
unsigned initial_bucket;
if (raw_dib == DIB_RAW_FREE)
return DIB_FREE;
if (_likely_(raw_dib < DIB_RAW_OVERFLOW))
return raw_dib;
/*
* Having an overflow DIB value is very unlikely. The hash function
* would have to be bad. For example, in a table of size 2^24 filled
* to load factor 0.9 the maximum observed DIB is only about 60.
* In theory (assuming I used Maxima correctly), for an infinite size
* hash table with load factor 0.8 the probability of a given entry
* having DIB > 40 is 1.9e-8.
* This returns the correct DIB value by recomputing the hash value in
* the unlikely case. XXX Hitting this case could be a hint to rehash.
*/
initial_bucket = bucket_hash(h, bucket_at(h, idx)->key);
return bucket_distance(h, idx, initial_bucket);
}
static void bucket_set_dib(HashmapBase *h, unsigned idx, unsigned dib) {
dib_raw_ptr(h)[idx] = dib != DIB_FREE ? MIN(dib, DIB_RAW_OVERFLOW) : DIB_RAW_FREE;
}
static unsigned skip_free_buckets(HashmapBase *h, unsigned idx) {
dib_raw_t *dibs;
dibs = dib_raw_ptr(h);
for ( ; idx < n_buckets(h); idx++)
if (dibs[idx] != DIB_RAW_FREE)
return idx;
return IDX_NIL;
}
static void bucket_mark_free(HashmapBase *h, unsigned idx) {
memzero(bucket_at(h, idx), hashmap_type_info[h->type].entry_size);
bucket_set_dib(h, idx, DIB_FREE);
}
static void bucket_move_entry(HashmapBase *h, struct swap_entries *swap,
unsigned from, unsigned to) {
struct hashmap_base_entry *e_from, *e_to;
assert(from != to);
e_from = bucket_at_virtual(h, swap, from);
e_to = bucket_at_virtual(h, swap, to);
memcpy(e_to, e_from, hashmap_type_info[h->type].entry_size);
if (h->type == HASHMAP_TYPE_ORDERED) {
OrderedHashmap *lh = (OrderedHashmap*) h;
struct ordered_hashmap_entry *le, *le_to;
le_to = (struct ordered_hashmap_entry*) e_to;
if (le_to->iterate_next != IDX_NIL) {
le = (struct ordered_hashmap_entry*)
bucket_at_virtual(h, swap, le_to->iterate_next);
le->iterate_previous = to;
}
if (le_to->iterate_previous != IDX_NIL) {
le = (struct ordered_hashmap_entry*)
bucket_at_virtual(h, swap, le_to->iterate_previous);
le->iterate_next = to;
}
if (lh->iterate_list_head == from)
lh->iterate_list_head = to;
if (lh->iterate_list_tail == from)
lh->iterate_list_tail = to;
}
}
static unsigned next_idx(HashmapBase *h, unsigned idx) {
return (idx + 1U) % n_buckets(h);
}
static unsigned prev_idx(HashmapBase *h, unsigned idx) {
return (n_buckets(h) + idx - 1U) % n_buckets(h);
}
static void *entry_value(HashmapBase *h, struct hashmap_base_entry *e) {
switch (h->type) {
case HASHMAP_TYPE_PLAIN:
case HASHMAP_TYPE_ORDERED:
return ((struct plain_hashmap_entry*)e)->value;
case HASHMAP_TYPE_SET:
return (void*) e->key;
default:
assert_not_reached("Unknown hashmap type");
}
}
static void base_remove_entry(HashmapBase *h, unsigned idx) {
unsigned left, right, prev, dib;
dib_raw_t raw_dib, *dibs;
dibs = dib_raw_ptr(h);
assert(dibs[idx] != DIB_RAW_FREE);
#if ENABLE_DEBUG_HASHMAP
h->debug.rem_count++;
h->debug.last_rem_idx = idx;
#endif
left = idx;
/* Find the stop bucket ("right"). It is either free or has DIB == 0. */
for (right = next_idx(h, left); ; right = next_idx(h, right)) {
raw_dib = dibs[right];
if (IN_SET(raw_dib, 0, DIB_RAW_FREE))
break;
/* The buckets are not supposed to be all occupied and with DIB > 0.
* That would mean we could make everyone better off by shifting them
* backward. This scenario is impossible. */
assert(left != right);
}
if (h->type == HASHMAP_TYPE_ORDERED) {
OrderedHashmap *lh = (OrderedHashmap*) h;
struct ordered_hashmap_entry *le = ordered_bucket_at(lh, idx);
if (le->iterate_next != IDX_NIL)
ordered_bucket_at(lh, le->iterate_next)->iterate_previous = le->iterate_previous;
else
lh->iterate_list_tail = le->iterate_previous;
if (le->iterate_previous != IDX_NIL)
ordered_bucket_at(lh, le->iterate_previous)->iterate_next = le->iterate_next;
else
lh->iterate_list_head = le->iterate_next;
}
/* Now shift all buckets in the interval (left, right) one step backwards */
for (prev = left, left = next_idx(h, left); left != right;
prev = left, left = next_idx(h, left)) {
dib = bucket_calculate_dib(h, left, dibs[left]);
assert(dib != 0);
bucket_move_entry(h, NULL, left, prev);
bucket_set_dib(h, prev, dib - 1);
}
bucket_mark_free(h, prev);
n_entries_dec(h);
base_set_dirty(h);
}
#define remove_entry(h, idx) base_remove_entry(HASHMAP_BASE(h), idx)
static unsigned hashmap_iterate_in_insertion_order(OrderedHashmap *h, Iterator *i) {
struct ordered_hashmap_entry *e;
unsigned idx;
assert(h);
assert(i);
if (i->idx == IDX_NIL)
goto at_end;
if (i->idx == IDX_FIRST && h->iterate_list_head == IDX_NIL)
goto at_end;
if (i->idx == IDX_FIRST) {
idx = h->iterate_list_head;
e = ordered_bucket_at(h, idx);
} else {
idx = i->idx;
e = ordered_bucket_at(h, idx);
/*
* We allow removing the current entry while iterating, but removal may cause
* a backward shift. The next entry may thus move one bucket to the left.
* To detect when it happens, we remember the key pointer of the entry we were
* going to iterate next. If it does not match, there was a backward shift.
*/
if (e->p.b.key != i->next_key) {
idx = prev_idx(HASHMAP_BASE(h), idx);
e = ordered_bucket_at(h, idx);
}
assert(e->p.b.key == i->next_key);
}
#if ENABLE_DEBUG_HASHMAP
i->prev_idx = idx;
#endif
if (e->iterate_next != IDX_NIL) {
struct ordered_hashmap_entry *n;
i->idx = e->iterate_next;
n = ordered_bucket_at(h, i->idx);
i->next_key = n->p.b.key;
} else
i->idx = IDX_NIL;
return idx;
at_end:
i->idx = IDX_NIL;
return IDX_NIL;
}
static unsigned hashmap_iterate_in_internal_order(HashmapBase *h, Iterator *i) {
unsigned idx;
assert(h);
assert(i);
if (i->idx == IDX_NIL)
goto at_end;
if (i->idx == IDX_FIRST) {
/* fast forward to the first occupied bucket */
if (h->has_indirect) {
i->idx = skip_free_buckets(h, h->indirect.idx_lowest_entry);
h->indirect.idx_lowest_entry = i->idx;
} else
i->idx = skip_free_buckets(h, 0);
if (i->idx == IDX_NIL)
goto at_end;
} else {
struct hashmap_base_entry *e;
assert(i->idx > 0);
e = bucket_at(h, i->idx);
/*
* We allow removing the current entry while iterating, but removal may cause
* a backward shift. The next entry may thus move one bucket to the left.
* To detect when it happens, we remember the key pointer of the entry we were
* going to iterate next. If it does not match, there was a backward shift.
*/
if (e->key != i->next_key)
e = bucket_at(h, --i->idx);
assert(e->key == i->next_key);
}
idx = i->idx;
#if ENABLE_DEBUG_HASHMAP
i->prev_idx = idx;
#endif
i->idx = skip_free_buckets(h, i->idx + 1);
if (i->idx != IDX_NIL)
i->next_key = bucket_at(h, i->idx)->key;
else
i->idx = IDX_NIL;
return idx;
at_end:
i->idx = IDX_NIL;
return IDX_NIL;
}
static unsigned hashmap_iterate_entry(HashmapBase *h, Iterator *i) {
if (!h) {
i->idx = IDX_NIL;
return IDX_NIL;
}
#if ENABLE_DEBUG_HASHMAP
if (i->idx == IDX_FIRST) {
i->put_count = h->debug.put_count;
i->rem_count = h->debug.rem_count;
} else {
/* While iterating, must not add any new entries */
assert(i->put_count == h->debug.put_count);
/* ... or remove entries other than the current one */
assert(i->rem_count == h->debug.rem_count ||
(i->rem_count == h->debug.rem_count - 1 &&
i->prev_idx == h->debug.last_rem_idx));
/* Reset our removals counter */
i->rem_count = h->debug.rem_count;
}
#endif
return h->type == HASHMAP_TYPE_ORDERED ? hashmap_iterate_in_insertion_order((OrderedHashmap*) h, i)
: hashmap_iterate_in_internal_order(h, i);
}
bool internal_hashmap_iterate(HashmapBase *h, Iterator *i, void **value, const void **key) {
struct hashmap_base_entry *e;
void *data;
unsigned idx;
idx = hashmap_iterate_entry(h, i);
if (idx == IDX_NIL) {
if (value)
*value = NULL;
if (key)
*key = NULL;
return false;
}
e = bucket_at(h, idx);
data = entry_value(h, e);
if (value)
*value = data;
if (key)
*key = e->key;
return true;
}
bool set_iterate(Set *s, Iterator *i, void **value) {
return internal_hashmap_iterate(HASHMAP_BASE(s), i, value, NULL);
}
#define HASHMAP_FOREACH_IDX(idx, h, i) \
for ((i) = ITERATOR_FIRST, (idx) = hashmap_iterate_entry((h), &(i)); \
(idx != IDX_NIL); \
(idx) = hashmap_iterate_entry((h), &(i)))
IteratedCache *internal_hashmap_iterated_cache_new(HashmapBase *h) {
IteratedCache *cache;
assert(h);
assert(!h->cached);
if (h->cached)
return NULL;
cache = new0(IteratedCache, 1);
if (!cache)
return NULL;
cache->hashmap = h;
h->cached = true;
return cache;
}
static void reset_direct_storage(HashmapBase *h) {
const struct hashmap_type_info *hi = &hashmap_type_info[h->type];
void *p;
assert(!h->has_indirect);
p = mempset(h->direct.storage, 0, hi->entry_size * hi->n_direct_buckets);
memset(p, DIB_RAW_INIT, sizeof(dib_raw_t) * hi->n_direct_buckets);
}
static struct HashmapBase *hashmap_base_new(const struct hash_ops *hash_ops, enum HashmapType type HASHMAP_DEBUG_PARAMS) {
HashmapBase *h;
const struct hashmap_type_info *hi = &hashmap_type_info[type];
bool up;
up = mempool_enabled();
h = up ? mempool_alloc0_tile(hi->mempool) : malloc0(hi->head_size);
if (!h)
return NULL;
h->type = type;
h->from_pool = up;
h->hash_ops = hash_ops ?: &trivial_hash_ops;
if (type == HASHMAP_TYPE_ORDERED) {
OrderedHashmap *lh = (OrderedHashmap*)h;
lh->iterate_list_head = lh->iterate_list_tail = IDX_NIL;
}
reset_direct_storage(h);
if (!shared_hash_key_initialized) {
random_bytes(shared_hash_key, sizeof(shared_hash_key));
shared_hash_key_initialized= true;
}
#if ENABLE_DEBUG_HASHMAP
h->debug.func = func;
h->debug.file = file;
h->debug.line = line;
assert_se(pthread_mutex_lock(&hashmap_debug_list_mutex) == 0);
LIST_PREPEND(debug_list, hashmap_debug_list, &h->debug);
assert_se(pthread_mutex_unlock(&hashmap_debug_list_mutex) == 0);
#endif
return h;
}
Hashmap *internal_hashmap_new(const struct hash_ops *hash_ops HASHMAP_DEBUG_PARAMS) {
return (Hashmap*) hashmap_base_new(hash_ops, HASHMAP_TYPE_PLAIN HASHMAP_DEBUG_PASS_ARGS);
}
OrderedHashmap *internal_ordered_hashmap_new(const struct hash_ops *hash_ops HASHMAP_DEBUG_PARAMS) {
return (OrderedHashmap*) hashmap_base_new(hash_ops, HASHMAP_TYPE_ORDERED HASHMAP_DEBUG_PASS_ARGS);
}
Set *internal_set_new(const struct hash_ops *hash_ops HASHMAP_DEBUG_PARAMS) {
return (Set*) hashmap_base_new(hash_ops, HASHMAP_TYPE_SET HASHMAP_DEBUG_PASS_ARGS);
}
static int hashmap_base_ensure_allocated(HashmapBase **h, const struct hash_ops *hash_ops,
enum HashmapType type HASHMAP_DEBUG_PARAMS) {
HashmapBase *q;
assert(h);
if (*h)
return 0;
q = hashmap_base_new(hash_ops, type HASHMAP_DEBUG_PASS_ARGS);
if (!q)
return -ENOMEM;
*h = q;
return 0;
}
int internal_hashmap_ensure_allocated(Hashmap **h, const struct hash_ops *hash_ops HASHMAP_DEBUG_PARAMS) {
return hashmap_base_ensure_allocated((HashmapBase**)h, hash_ops, HASHMAP_TYPE_PLAIN HASHMAP_DEBUG_PASS_ARGS);
}
int internal_ordered_hashmap_ensure_allocated(OrderedHashmap **h, const struct hash_ops *hash_ops HASHMAP_DEBUG_PARAMS) {
return hashmap_base_ensure_allocated((HashmapBase**)h, hash_ops, HASHMAP_TYPE_ORDERED HASHMAP_DEBUG_PASS_ARGS);
}
int internal_set_ensure_allocated(Set **s, const struct hash_ops *hash_ops HASHMAP_DEBUG_PARAMS) {
return hashmap_base_ensure_allocated((HashmapBase**)s, hash_ops, HASHMAP_TYPE_SET HASHMAP_DEBUG_PASS_ARGS);
}
static void hashmap_free_no_clear(HashmapBase *h) {
assert(!h->has_indirect);
assert(h->n_direct_entries == 0);
#if ENABLE_DEBUG_HASHMAP
assert_se(pthread_mutex_lock(&hashmap_debug_list_mutex) == 0);
LIST_REMOVE(debug_list, hashmap_debug_list, &h->debug);
assert_se(pthread_mutex_unlock(&hashmap_debug_list_mutex) == 0);
#endif
if (h->from_pool) {
/* Ensure that the object didn't get migrated between threads. */
assert_se(is_main_thread());
mempool_free_tile(hashmap_type_info[h->type].mempool, h);
} else
free(h);
}
HashmapBase *internal_hashmap_free(HashmapBase *h, free_func_t default_free_key, free_func_t default_free_value) {
if (h) {
internal_hashmap_clear(h, default_free_key, default_free_value);
hashmap_free_no_clear(h);
}
return NULL;
}
void internal_hashmap_clear(HashmapBase *h, free_func_t default_free_key, free_func_t default_free_value) {
free_func_t free_key, free_value;
if (!h)
return;
free_key = h->hash_ops->free_key ?: default_free_key;
free_value = h->hash_ops->free_value ?: default_free_value;
if (free_key || free_value) {
/* If destructor calls are defined, let's destroy things defensively: let's take the item out of the
* hash table, and only then call the destructor functions. If these destructors then try to unregister
* themselves from our hash table a second time, the entry is already gone. */
while (internal_hashmap_size(h) > 0) {
void *k = NULL;
void *v;
v = internal_hashmap_first_key_and_value(h, true, &k);
if (free_key)
free_key(k);
if (free_value)
free_value(v);
}
}
if (h->has_indirect) {
free(h->indirect.storage);
h->has_indirect = false;
}
h->n_direct_entries = 0;
reset_direct_storage(h);
if (h->type == HASHMAP_TYPE_ORDERED) {
OrderedHashmap *lh = (OrderedHashmap*) h;
lh->iterate_list_head = lh->iterate_list_tail = IDX_NIL;
}
base_set_dirty(h);
}
static int resize_buckets(HashmapBase *h, unsigned entries_add);
/*
* Finds an empty bucket to put an entry into, starting the scan at 'idx'.
* Performs Robin Hood swaps as it goes. The entry to put must be placed
* by the caller into swap slot IDX_PUT.
* If used for in-place resizing, may leave a displaced entry in swap slot
* IDX_PUT. Caller must rehash it next.
* Returns: true if it left a displaced entry to rehash next in IDX_PUT,
* false otherwise.
*/
static bool hashmap_put_robin_hood(HashmapBase *h, unsigned idx,
struct swap_entries *swap) {
dib_raw_t raw_dib, *dibs;
unsigned dib, distance;
#if ENABLE_DEBUG_HASHMAP
h->debug.put_count++;
#endif
dibs = dib_raw_ptr(h);
for (distance = 0; ; distance++) {
raw_dib = dibs[idx];
if (IN_SET(raw_dib, DIB_RAW_FREE, DIB_RAW_REHASH)) {
if (raw_dib == DIB_RAW_REHASH)
bucket_move_entry(h, swap, idx, IDX_TMP);
if (h->has_indirect && h->indirect.idx_lowest_entry > idx)
h->indirect.idx_lowest_entry = idx;
bucket_set_dib(h, idx, distance);
bucket_move_entry(h, swap, IDX_PUT, idx);
if (raw_dib == DIB_RAW_REHASH) {
bucket_move_entry(h, swap, IDX_TMP, IDX_PUT);
return true;
}
return false;
}
dib = bucket_calculate_dib(h, idx, raw_dib);
if (dib < distance) {
/* Found a wealthier entry. Go Robin Hood! */
bucket_set_dib(h, idx, distance);
/* swap the entries */
bucket_move_entry(h, swap, idx, IDX_TMP);
bucket_move_entry(h, swap, IDX_PUT, idx);
bucket_move_entry(h, swap, IDX_TMP, IDX_PUT);
distance = dib;
}
idx = next_idx(h, idx);
}
}
/*
* Puts an entry into a hashmap, boldly - no check whether key already exists.
* The caller must place the entry (only its key and value, not link indexes)
* in swap slot IDX_PUT.
* Caller must ensure: the key does not exist yet in the hashmap.
* that resize is not needed if !may_resize.
* Returns: 1 if entry was put successfully.
* -ENOMEM if may_resize==true and resize failed with -ENOMEM.
* Cannot return -ENOMEM if !may_resize.
*/
static int hashmap_base_put_boldly(HashmapBase *h, unsigned idx,
struct swap_entries *swap, bool may_resize) {
struct ordered_hashmap_entry *new_entry;
int r;
assert(idx < n_buckets(h));
new_entry = bucket_at_swap(swap, IDX_PUT);
if (may_resize) {
r = resize_buckets(h, 1);
if (r < 0)
return r;
if (r > 0)
idx = bucket_hash(h, new_entry->p.b.key);
}
assert(n_entries(h) < n_buckets(h));
if (h->type == HASHMAP_TYPE_ORDERED) {
OrderedHashmap *lh = (OrderedHashmap*) h;
new_entry->iterate_next = IDX_NIL;
new_entry->iterate_previous = lh->iterate_list_tail;
if (lh->iterate_list_tail != IDX_NIL) {
struct ordered_hashmap_entry *old_tail;
old_tail = ordered_bucket_at(lh, lh->iterate_list_tail);
assert(old_tail->iterate_next == IDX_NIL);
old_tail->iterate_next = IDX_PUT;
}
lh->iterate_list_tail = IDX_PUT;
if (lh->iterate_list_head == IDX_NIL)
lh->iterate_list_head = IDX_PUT;
}
assert_se(hashmap_put_robin_hood(h, idx, swap) == false);
n_entries_inc(h);
#if ENABLE_DEBUG_HASHMAP
h->debug.max_entries = MAX(h->debug.max_entries, n_entries(h));
#endif
base_set_dirty(h);
return 1;
}
#define hashmap_put_boldly(h, idx, swap, may_resize) \
hashmap_base_put_boldly(HASHMAP_BASE(h), idx, swap, may_resize)
/*
* Returns 0 if resize is not needed.
* 1 if successfully resized.
* -ENOMEM on allocation failure.
*/
static int resize_buckets(HashmapBase *h, unsigned entries_add) {
struct swap_entries swap;
void *new_storage;
dib_raw_t *old_dibs, *new_dibs;
const struct hashmap_type_info *hi;
unsigned idx, optimal_idx;
unsigned old_n_buckets, new_n_buckets, n_rehashed, new_n_entries;
uint8_t new_shift;
bool rehash_next;
assert(h);
hi = &hashmap_type_info[h->type];
new_n_entries = n_entries(h) + entries_add;
/* overflow? */
if (_unlikely_(new_n_entries < entries_add))
return -ENOMEM;
/* For direct storage we allow 100% load, because it's tiny. */
if (!h->has_indirect && new_n_entries <= hi->n_direct_buckets)
return 0;
/*
* Load factor = n/m = 1 - (1/INV_KEEP_FREE).
* From it follows: m = n + n/(INV_KEEP_FREE - 1)
*/
new_n_buckets = new_n_entries + new_n_entries / (INV_KEEP_FREE - 1);
/* overflow? */
if (_unlikely_(new_n_buckets < new_n_entries))
return -ENOMEM;
if (_unlikely_(new_n_buckets > UINT_MAX / (hi->entry_size + sizeof(dib_raw_t))))
return -ENOMEM;
old_n_buckets = n_buckets(h);
if (_likely_(new_n_buckets <= old_n_buckets))
return 0;
new_shift = log2u_round_up(MAX(
new_n_buckets * (hi->entry_size + sizeof(dib_raw_t)),
2 * sizeof(struct direct_storage)));
/* Realloc storage (buckets and DIB array). */
new_storage = realloc(h->has_indirect ? h->indirect.storage : NULL,
1U << new_shift);
if (!new_storage)
return -ENOMEM;
/* Must upgrade direct to indirect storage. */
if (!h->has_indirect) {
memcpy(new_storage, h->direct.storage,
old_n_buckets * (hi->entry_size + sizeof(dib_raw_t)));
h->indirect.n_entries = h->n_direct_entries;
h->indirect.idx_lowest_entry = 0;
h->n_direct_entries = 0;
}
/* Get a new hash key. If we've just upgraded to indirect storage,
* allow reusing a previously generated key. It's still a different key
* from the shared one that we used for direct storage. */
get_hash_key(h->indirect.hash_key, !h->has_indirect);
h->has_indirect = true;
h->indirect.storage = new_storage;
h->indirect.n_buckets = (1U << new_shift) /
(hi->entry_size + sizeof(dib_raw_t));
old_dibs = (dib_raw_t*)((uint8_t*) new_storage + hi->entry_size * old_n_buckets);
new_dibs = dib_raw_ptr(h);
/*
* Move the DIB array to the new place, replacing valid DIB values with
* DIB_RAW_REHASH to indicate all of the used buckets need rehashing.
* Note: Overlap is not possible, because we have at least doubled the
* number of buckets and dib_raw_t is smaller than any entry type.
*/
for (idx = 0; idx < old_n_buckets; idx++) {
assert(old_dibs[idx] != DIB_RAW_REHASH);
new_dibs[idx] = old_dibs[idx] == DIB_RAW_FREE ? DIB_RAW_FREE
: DIB_RAW_REHASH;
}
/* Zero the area of newly added entries (including the old DIB area) */
memzero(bucket_at(h, old_n_buckets),
(n_buckets(h) - old_n_buckets) * hi->entry_size);
/* The upper half of the new DIB array needs initialization */
memset(&new_dibs[old_n_buckets], DIB_RAW_INIT,
(n_buckets(h) - old_n_buckets) * sizeof(dib_raw_t));
/* Rehash entries that need it */
n_rehashed = 0;
for (idx = 0; idx < old_n_buckets; idx++) {
if (new_dibs[idx] != DIB_RAW_REHASH)
continue;
optimal_idx = bucket_hash(h, bucket_at(h, idx)->key);
/*
* Not much to do if by luck the entry hashes to its current
* location. Just set its DIB.
*/
if (optimal_idx == idx) {
new_dibs[idx] = 0;
n_rehashed++;
continue;
}
new_dibs[idx] = DIB_RAW_FREE;
bucket_move_entry(h, &swap, idx, IDX_PUT);
/* bucket_move_entry does not clear the source */
memzero(bucket_at(h, idx), hi->entry_size);
do {
/*
* Find the new bucket for the current entry. This may make
* another entry homeless and load it into IDX_PUT.
*/
rehash_next = hashmap_put_robin_hood(h, optimal_idx, &swap);
n_rehashed++;
/* Did the current entry displace another one? */
if (rehash_next)
optimal_idx = bucket_hash(h, bucket_at_swap(&swap, IDX_PUT)->p.b.key);
} while (rehash_next);
}
assert(n_rehashed == n_entries(h));
return 1;
}
/*
* Finds an entry with a matching key
* Returns: index of the found entry, or IDX_NIL if not found.
*/
static unsigned base_bucket_scan(HashmapBase *h, unsigned idx, const void *key) {
struct hashmap_base_entry *e;
unsigned dib, distance;
dib_raw_t *dibs = dib_raw_ptr(h);
assert(idx < n_buckets(h));
for (distance = 0; ; distance++) {
if (dibs[idx] == DIB_RAW_FREE)
return IDX_NIL;
dib = bucket_calculate_dib(h, idx, dibs[idx]);
if (dib < distance)
return IDX_NIL;
if (dib == distance) {
e = bucket_at(h, idx);
if (h->hash_ops->compare(e->key, key) == 0)
return idx;
}
idx = next_idx(h, idx);
}
}
#define bucket_scan(h, idx, key) base_bucket_scan(HASHMAP_BASE(h), idx, key)
int hashmap_put(Hashmap *h, const void *key, void *value) {
struct swap_entries swap;
struct plain_hashmap_entry *e;
unsigned hash, idx;
assert(h);
hash = bucket_hash(h, key);
idx = bucket_scan(h, hash, key);
if (idx != IDX_NIL) {
e = plain_bucket_at(h, idx);
if (e->value == value)
return 0;
return -EEXIST;
}
e = &bucket_at_swap(&swap, IDX_PUT)->p;
e->b.key = key;
e->value = value;
return hashmap_put_boldly(h, hash, &swap, true);
}
int set_put(Set *s, const void *key) {
struct swap_entries swap;
struct hashmap_base_entry *e;
unsigned hash, idx;
assert(s);
hash = bucket_hash(s, key);
idx = bucket_scan(s, hash, key);
if (idx != IDX_NIL)
return 0;
e = &bucket_at_swap(&swap, IDX_PUT)->p.b;
e->key = key;
return hashmap_put_boldly(s, hash, &swap, true);
}
int hashmap_replace(Hashmap *h, const void *key, void *value) {
struct swap_entries swap;
struct plain_hashmap_entry *e;
unsigned hash, idx;
assert(h);
hash = bucket_hash(h, key);
idx = bucket_scan(h, hash, key);
if (idx != IDX_NIL) {
e = plain_bucket_at(h, idx);
#if ENABLE_DEBUG_HASHMAP
/* Although the key is equal, the key pointer may have changed,
* and this would break our assumption for iterating. So count
* this operation as incompatible with iteration. */
if (e->b.key != key) {
h->b.debug.put_count++;
h->b.debug.rem_count++;
h->b.debug.last_rem_idx = idx;
}
#endif
e->b.key = key;
e->value = value;
hashmap_set_dirty(h);
return 0;
}
e = &bucket_at_swap(&swap, IDX_PUT)->p;
e->b.key = key;
e->value = value;
return hashmap_put_boldly(h, hash, &swap, true);
}
int hashmap_update(Hashmap *h, const void *key, void *value) {
struct plain_hashmap_entry *e;
unsigned hash, idx;
assert(h);
hash = bucket_hash(h, key);
idx = bucket_scan(h, hash, key);
if (idx == IDX_NIL)
return -ENOENT;
e = plain_bucket_at(h, idx);
e->value = value;
hashmap_set_dirty(h);
return 0;
}
void *internal_hashmap_get(HashmapBase *h, const void *key) {
struct hashmap_base_entry *e;
unsigned hash, idx;
if (!h)
return NULL;
hash = bucket_hash(h, key);
idx = bucket_scan(h, hash, key);
if (idx == IDX_NIL)
return NULL;
e = bucket_at(h, idx);
return entry_value(h, e);
}
void *hashmap_get2(Hashmap *h, const void *key, void **key2) {
struct plain_hashmap_entry *e;
unsigned hash, idx;
if (!h)
return NULL;
hash = bucket_hash(h, key);
idx = bucket_scan(h, hash, key);
if (idx == IDX_NIL)
return NULL;
e = plain_bucket_at(h, idx);
if (key2)
*key2 = (void*) e->b.key;
return e->value;
}
bool internal_hashmap_contains(HashmapBase *h, const void *key) {
unsigned hash;
if (!h)
return false;
hash = bucket_hash(h, key);
return bucket_scan(h, hash, key) != IDX_NIL;
}
void *internal_hashmap_remove(HashmapBase *h, const void *key) {
struct hashmap_base_entry *e;
unsigned hash, idx;
void *data;
if (!h)
return NULL;
hash = bucket_hash(h, key);
idx = bucket_scan(h, hash, key);
if (idx == IDX_NIL)
return NULL;
e = bucket_at(h, idx);
data = entry_value(h, e);
remove_entry(h, idx);
return data;
}
void *hashmap_remove2(Hashmap *h, const void *key, void **rkey) {
struct plain_hashmap_entry *e;
unsigned hash, idx;
void *data;
if (!h) {
if (rkey)
*rkey = NULL;
return NULL;
}
hash = bucket_hash(h, key);
idx = bucket_scan(h, hash, key);
if (idx == IDX_NIL) {
if (rkey)
*rkey = NULL;
return NULL;
}
e = plain_bucket_at(h, idx);
data = e->value;
if (rkey)
*rkey = (void*) e->b.key;
remove_entry(h, idx);
return data;
}
int hashmap_remove_and_put(Hashmap *h, const void *old_key, const void *new_key, void *value) {
struct swap_entries swap;
struct plain_hashmap_entry *e;
unsigned old_hash, new_hash, idx;
if (!h)
return -ENOENT;
old_hash = bucket_hash(h, old_key);
idx = bucket_scan(h, old_hash, old_key);
if (idx == IDX_NIL)
return -ENOENT;
new_hash = bucket_hash(h, new_key);
if (bucket_scan(h, new_hash, new_key) != IDX_NIL)
return -EEXIST;
remove_entry(h, idx);
e = &bucket_at_swap(&swap, IDX_PUT)->p;
e->b.key = new_key;
e->value = value;
assert_se(hashmap_put_boldly(h, new_hash, &swap, false) == 1);
return 0;
}
int set_remove_and_put(Set *s, const void *old_key, const void *new_key) {
struct swap_entries swap;
struct hashmap_base_entry *e;
unsigned old_hash, new_hash, idx;
if (!s)
return -ENOENT;
old_hash = bucket_hash(s, old_key);
idx = bucket_scan(s, old_hash, old_key);
if (idx == IDX_NIL)
return -ENOENT;
new_hash = bucket_hash(s, new_key);
if (bucket_scan(s, new_hash, new_key) != IDX_NIL)
return -EEXIST;
remove_entry(s, idx);
e = &bucket_at_swap(&swap, IDX_PUT)->p.b;
e->key = new_key;
assert_se(hashmap_put_boldly(s, new_hash, &swap, false) == 1);
return 0;
}
int hashmap_remove_and_replace(Hashmap *h, const void *old_key, const void *new_key, void *value) {
struct swap_entries swap;
struct plain_hashmap_entry *e;
unsigned old_hash, new_hash, idx_old, idx_new;
if (!h)
return -ENOENT;
old_hash = bucket_hash(h, old_key);
idx_old = bucket_scan(h, old_hash, old_key);
if (idx_old == IDX_NIL)
return -ENOENT;
old_key = bucket_at(HASHMAP_BASE(h), idx_old)->key;
new_hash = bucket_hash(h, new_key);
idx_new = bucket_scan(h, new_hash, new_key);
if (idx_new != IDX_NIL)
if (idx_old != idx_new) {
remove_entry(h, idx_new);
/* Compensate for a possible backward shift. */
if (old_key != bucket_at(HASHMAP_BASE(h), idx_old)->key)
idx_old = prev_idx(HASHMAP_BASE(h), idx_old);
assert(old_key == bucket_at(HASHMAP_BASE(h), idx_old)->key);
}
remove_entry(h, idx_old);
e = &bucket_at_swap(&swap, IDX_PUT)->p;
e->b.key = new_key;
e->value = value;
assert_se(hashmap_put_boldly(h, new_hash, &swap, false) == 1);
return 0;
}
void *internal_hashmap_remove_value(HashmapBase *h, const void *key, void *value) {
struct hashmap_base_entry *e;
unsigned hash, idx;
if (!h)
return NULL;
hash = bucket_hash(h, key);
idx = bucket_scan(h, hash, key);
if (idx == IDX_NIL)
return NULL;
e = bucket_at(h, idx);
if (entry_value(h, e) != value)
return NULL;
remove_entry(h, idx);
return value;
}
static unsigned find_first_entry(HashmapBase *h) {
Iterator i = ITERATOR_FIRST;
if (!h || !n_entries(h))
return IDX_NIL;
return hashmap_iterate_entry(h, &i);
}
void *internal_hashmap_first_key_and_value(HashmapBase *h, bool remove, void **ret_key) {
struct hashmap_base_entry *e;
void *key, *data;
unsigned idx;
idx = find_first_entry(h);
if (idx == IDX_NIL) {
if (ret_key)
*ret_key = NULL;
return NULL;
}
e = bucket_at(h, idx);
key = (void*) e->key;
data = entry_value(h, e);
if (remove)
remove_entry(h, idx);
if (ret_key)
*ret_key = key;
return data;
}
unsigned internal_hashmap_size(HashmapBase *h) {
if (!h)
return 0;
return n_entries(h);
}
unsigned internal_hashmap_buckets(HashmapBase *h) {
if (!h)
return 0;
return n_buckets(h);
}
int internal_hashmap_merge(Hashmap *h, Hashmap *other) {
Iterator i;
unsigned idx;
assert(h);
HASHMAP_FOREACH_IDX(idx, HASHMAP_BASE(other), i) {
struct plain_hashmap_entry *pe = plain_bucket_at(other, idx);
int r;
r = hashmap_put(h, pe->b.key, pe->value);
if (r < 0 && r != -EEXIST)
return r;
}
return 0;
}
int set_merge(Set *s, Set *other) {
Iterator i;
unsigned idx;
assert(s);
HASHMAP_FOREACH_IDX(idx, HASHMAP_BASE(other), i) {
struct set_entry *se = set_bucket_at(other, idx);
int r;
r = set_put(s, se->b.key);
if (r < 0)
return r;
}
return 0;
}
int internal_hashmap_reserve(HashmapBase *h, unsigned entries_add) {
int r;
assert(h);
r = resize_buckets(h, entries_add);
if (r < 0)
return r;
return 0;
}
/*
* The same as hashmap_merge(), but every new item from other is moved to h.
* Keys already in h are skipped and stay in other.
* Returns: 0 on success.
* -ENOMEM on alloc failure, in which case no move has been done.
*/
int internal_hashmap_move(HashmapBase *h, HashmapBase *other) {
struct swap_entries swap;
struct hashmap_base_entry *e, *n;
Iterator i;
unsigned idx;
int r;
assert(h);
if (!other)
return 0;
assert(other->type == h->type);
/*
* This reserves buckets for the worst case, where none of other's
* entries are yet present in h. This is preferable to risking
* an allocation failure in the middle of the moving and having to
* rollback or return a partial result.
*/
r = resize_buckets(h, n_entries(other));
if (r < 0)
return r;
HASHMAP_FOREACH_IDX(idx, other, i) {
unsigned h_hash;
e = bucket_at(other, idx);
h_hash = bucket_hash(h, e->key);
if (bucket_scan(h, h_hash, e->key) != IDX_NIL)
continue;
n = &bucket_at_swap(&swap, IDX_PUT)->p.b;
n->key = e->key;
if (h->type != HASHMAP_TYPE_SET)
((struct plain_hashmap_entry*) n)->value =
((struct plain_hashmap_entry*) e)->value;
assert_se(hashmap_put_boldly(h, h_hash, &swap, false) == 1);
remove_entry(other, idx);
}
return 0;
}
int internal_hashmap_move_one(HashmapBase *h, HashmapBase *other, const void *key) {
struct swap_entries swap;
unsigned h_hash, other_hash, idx;
struct hashmap_base_entry *e, *n;
int r;
assert(h);
h_hash = bucket_hash(h, key);
if (bucket_scan(h, h_hash, key) != IDX_NIL)
return -EEXIST;
if (!other)
return -ENOENT;
assert(other->type == h->type);
other_hash = bucket_hash(other, key);
idx = bucket_scan(other, other_hash, key);
if (idx == IDX_NIL)
return -ENOENT;
e = bucket_at(other, idx);
n = &bucket_at_swap(&swap, IDX_PUT)->p.b;
n->key = e->key;
if (h->type != HASHMAP_TYPE_SET)
((struct plain_hashmap_entry*) n)->value =
((struct plain_hashmap_entry*) e)->value;
r = hashmap_put_boldly(h, h_hash, &swap, true);
if (r < 0)
return r;
remove_entry(other, idx);
return 0;
}
HashmapBase *internal_hashmap_copy(HashmapBase *h) {
HashmapBase *copy;
int r;
assert(h);
copy = hashmap_base_new(h->hash_ops, h->type HASHMAP_DEBUG_SRC_ARGS);
if (!copy)
return NULL;
switch (h->type) {
case HASHMAP_TYPE_PLAIN:
case HASHMAP_TYPE_ORDERED:
r = hashmap_merge((Hashmap*)copy, (Hashmap*)h);
break;
case HASHMAP_TYPE_SET:
r = set_merge((Set*)copy, (Set*)h);
break;
default:
assert_not_reached("Unknown hashmap type");
}
if (r < 0) {
internal_hashmap_free(copy, false, false);
return NULL;
}
return copy;
}
char **internal_hashmap_get_strv(HashmapBase *h) {
char **sv;
Iterator i;
unsigned idx, n;
sv = new(char*, n_entries(h)+1);
if (!sv)
return NULL;
n = 0;
HASHMAP_FOREACH_IDX(idx, h, i)
sv[n++] = entry_value(h, bucket_at(h, idx));
sv[n] = NULL;
return sv;
}
void *ordered_hashmap_next(OrderedHashmap *h, const void *key) {
struct ordered_hashmap_entry *e;
unsigned hash, idx;
if (!h)
return NULL;
hash = bucket_hash(h, key);
idx = bucket_scan(h, hash, key);
if (idx == IDX_NIL)
return NULL;
e = ordered_bucket_at(h, idx);
if (e->iterate_next == IDX_NIL)
return NULL;
return ordered_bucket_at(h, e->iterate_next)->p.value;
}
int set_consume(Set *s, void *value) {
int r;
assert(s);
assert(value);
r = set_put(s, value);
if (r <= 0)
free(value);
return r;
}
int set_put_strdup(Set *s, const char *p) {
char *c;
assert(s);
assert(p);
if (set_contains(s, (char*) p))
return 0;
c = strdup(p);
if (!c)
return -ENOMEM;
return set_consume(s, c);
}
int set_put_strdupv(Set *s, char **l) {
int n = 0, r;
char **i;
assert(s);
STRV_FOREACH(i, l) {
r = set_put_strdup(s, *i);
if (r < 0)
return r;
n += r;
}
return n;
}
int set_put_strsplit(Set *s, const char *v, const char *separators, ExtractFlags flags) {
const char *p = v;
int r;
assert(s);
assert(v);
for (;;) {
char *word;
r = extract_first_word(&p, &word, separators, flags);
if (r <= 0)
return r;
r = set_consume(s, word);
if (r < 0)
return r;
}
}
/* expand the cachemem if needed, return true if newly (re)activated. */
static int cachemem_maintain(CacheMem *mem, unsigned size) {
assert(mem);
if (!GREEDY_REALLOC(mem->ptr, mem->n_allocated, size)) {
if (size > 0)
return -ENOMEM;
}
if (!mem->active) {
mem->active = true;
return true;
}
return false;
}
int iterated_cache_get(IteratedCache *cache, const void ***res_keys, const void ***res_values, unsigned *res_n_entries) {
bool sync_keys = false, sync_values = false;
unsigned size;
int r;
assert(cache);
assert(cache->hashmap);
size = n_entries(cache->hashmap);
if (res_keys) {
r = cachemem_maintain(&cache->keys, size);
if (r < 0)
return r;
sync_keys = r;
} else
cache->keys.active = false;
if (res_values) {
r = cachemem_maintain(&cache->values, size);
if (r < 0)
return r;
sync_values = r;
} else
cache->values.active = false;
if (cache->hashmap->dirty) {
if (cache->keys.active)
sync_keys = true;
if (cache->values.active)
sync_values = true;
cache->hashmap->dirty = false;
}
if (sync_keys || sync_values) {
unsigned i, idx;
Iterator iter;
i = 0;
HASHMAP_FOREACH_IDX(idx, cache->hashmap, iter) {
struct hashmap_base_entry *e;
e = bucket_at(cache->hashmap, idx);
if (sync_keys)
cache->keys.ptr[i] = e->key;
if (sync_values)
cache->values.ptr[i] = entry_value(cache->hashmap, e);
i++;
}
}
if (res_keys)
*res_keys = cache->keys.ptr;
if (res_values)
*res_values = cache->values.ptr;
if (res_n_entries)
*res_n_entries = size;
return 0;
}
IteratedCache *iterated_cache_free(IteratedCache *cache) {
if (cache) {
free(cache->keys.ptr);
free(cache->values.ptr);
free(cache);
}
return NULL;
}