mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
195 lines
5.8 KiB
195 lines
5.8 KiB
/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ |
|
|
|
/* |
|
* Generic non-thread safe hash map implementation. |
|
* |
|
* Copyright (c) 2019 Facebook |
|
*/ |
|
#ifndef __LIBBPF_HASHMAP_H |
|
#define __LIBBPF_HASHMAP_H |
|
|
|
#include <stdbool.h> |
|
#include <stddef.h> |
|
#include <limits.h> |
|
|
|
static inline size_t hash_bits(size_t h, int bits) |
|
{ |
|
/* shuffle bits and return requested number of upper bits */ |
|
if (bits == 0) |
|
return 0; |
|
|
|
#if (__SIZEOF_SIZE_T__ == __SIZEOF_LONG_LONG__) |
|
/* LP64 case */ |
|
return (h * 11400714819323198485llu) >> (__SIZEOF_LONG_LONG__ * 8 - bits); |
|
#elif (__SIZEOF_SIZE_T__ <= __SIZEOF_LONG__) |
|
return (h * 2654435769lu) >> (__SIZEOF_LONG__ * 8 - bits); |
|
#else |
|
# error "Unsupported size_t size" |
|
#endif |
|
} |
|
|
|
/* generic C-string hashing function */ |
|
static inline size_t str_hash(const char *s) |
|
{ |
|
size_t h = 0; |
|
|
|
while (*s) { |
|
h = h * 31 + *s; |
|
s++; |
|
} |
|
return h; |
|
} |
|
|
|
typedef size_t (*hashmap_hash_fn)(const void *key, void *ctx); |
|
typedef bool (*hashmap_equal_fn)(const void *key1, const void *key2, void *ctx); |
|
|
|
struct hashmap_entry { |
|
const void *key; |
|
void *value; |
|
struct hashmap_entry *next; |
|
}; |
|
|
|
struct hashmap { |
|
hashmap_hash_fn hash_fn; |
|
hashmap_equal_fn equal_fn; |
|
void *ctx; |
|
|
|
struct hashmap_entry **buckets; |
|
size_t cap; |
|
size_t cap_bits; |
|
size_t sz; |
|
}; |
|
|
|
#define HASHMAP_INIT(hash_fn, equal_fn, ctx) { \ |
|
.hash_fn = (hash_fn), \ |
|
.equal_fn = (equal_fn), \ |
|
.ctx = (ctx), \ |
|
.buckets = NULL, \ |
|
.cap = 0, \ |
|
.cap_bits = 0, \ |
|
.sz = 0, \ |
|
} |
|
|
|
void hashmap__init(struct hashmap *map, hashmap_hash_fn hash_fn, |
|
hashmap_equal_fn equal_fn, void *ctx); |
|
struct hashmap *hashmap__new(hashmap_hash_fn hash_fn, |
|
hashmap_equal_fn equal_fn, |
|
void *ctx); |
|
void hashmap__clear(struct hashmap *map); |
|
void hashmap__free(struct hashmap *map); |
|
|
|
size_t hashmap__size(const struct hashmap *map); |
|
size_t hashmap__capacity(const struct hashmap *map); |
|
|
|
/* |
|
* Hashmap insertion strategy: |
|
* - HASHMAP_ADD - only add key/value if key doesn't exist yet; |
|
* - HASHMAP_SET - add key/value pair if key doesn't exist yet; otherwise, |
|
* update value; |
|
* - HASHMAP_UPDATE - update value, if key already exists; otherwise, do |
|
* nothing and return -ENOENT; |
|
* - HASHMAP_APPEND - always add key/value pair, even if key already exists. |
|
* This turns hashmap into a multimap by allowing multiple values to be |
|
* associated with the same key. Most useful read API for such hashmap is |
|
* hashmap__for_each_key_entry() iteration. If hashmap__find() is still |
|
* used, it will return last inserted key/value entry (first in a bucket |
|
* chain). |
|
*/ |
|
enum hashmap_insert_strategy { |
|
HASHMAP_ADD, |
|
HASHMAP_SET, |
|
HASHMAP_UPDATE, |
|
HASHMAP_APPEND, |
|
}; |
|
|
|
/* |
|
* hashmap__insert() adds key/value entry w/ various semantics, depending on |
|
* provided strategy value. If a given key/value pair replaced already |
|
* existing key/value pair, both old key and old value will be returned |
|
* through old_key and old_value to allow calling code do proper memory |
|
* management. |
|
*/ |
|
int hashmap__insert(struct hashmap *map, const void *key, void *value, |
|
enum hashmap_insert_strategy strategy, |
|
const void **old_key, void **old_value); |
|
|
|
static inline int hashmap__add(struct hashmap *map, |
|
const void *key, void *value) |
|
{ |
|
return hashmap__insert(map, key, value, HASHMAP_ADD, NULL, NULL); |
|
} |
|
|
|
static inline int hashmap__set(struct hashmap *map, |
|
const void *key, void *value, |
|
const void **old_key, void **old_value) |
|
{ |
|
return hashmap__insert(map, key, value, HASHMAP_SET, |
|
old_key, old_value); |
|
} |
|
|
|
static inline int hashmap__update(struct hashmap *map, |
|
const void *key, void *value, |
|
const void **old_key, void **old_value) |
|
{ |
|
return hashmap__insert(map, key, value, HASHMAP_UPDATE, |
|
old_key, old_value); |
|
} |
|
|
|
static inline int hashmap__append(struct hashmap *map, |
|
const void *key, void *value) |
|
{ |
|
return hashmap__insert(map, key, value, HASHMAP_APPEND, NULL, NULL); |
|
} |
|
|
|
bool hashmap__delete(struct hashmap *map, const void *key, |
|
const void **old_key, void **old_value); |
|
|
|
bool hashmap__find(const struct hashmap *map, const void *key, void **value); |
|
|
|
/* |
|
* hashmap__for_each_entry - iterate over all entries in hashmap |
|
* @map: hashmap to iterate |
|
* @cur: struct hashmap_entry * used as a loop cursor |
|
* @bkt: integer used as a bucket loop cursor |
|
*/ |
|
#define hashmap__for_each_entry(map, cur, bkt) \ |
|
for (bkt = 0; bkt < map->cap; bkt++) \ |
|
for (cur = map->buckets[bkt]; cur; cur = cur->next) |
|
|
|
/* |
|
* hashmap__for_each_entry_safe - iterate over all entries in hashmap, safe |
|
* against removals |
|
* @map: hashmap to iterate |
|
* @cur: struct hashmap_entry * used as a loop cursor |
|
* @tmp: struct hashmap_entry * used as a temporary next cursor storage |
|
* @bkt: integer used as a bucket loop cursor |
|
*/ |
|
#define hashmap__for_each_entry_safe(map, cur, tmp, bkt) \ |
|
for (bkt = 0; bkt < map->cap; bkt++) \ |
|
for (cur = map->buckets[bkt]; \ |
|
cur && ({tmp = cur->next; true; }); \ |
|
cur = tmp) |
|
|
|
/* |
|
* hashmap__for_each_key_entry - iterate over entries associated with given key |
|
* @map: hashmap to iterate |
|
* @cur: struct hashmap_entry * used as a loop cursor |
|
* @key: key to iterate entries for |
|
*/ |
|
#define hashmap__for_each_key_entry(map, cur, _key) \ |
|
for (cur = map->buckets \ |
|
? map->buckets[hash_bits(map->hash_fn((_key), map->ctx), map->cap_bits)] \ |
|
: NULL; \ |
|
cur; \ |
|
cur = cur->next) \ |
|
if (map->equal_fn(cur->key, (_key), map->ctx)) |
|
|
|
#define hashmap__for_each_key_entry_safe(map, cur, tmp, _key) \ |
|
for (cur = map->buckets \ |
|
? map->buckets[hash_bits(map->hash_fn((_key), map->ctx), map->cap_bits)] \ |
|
: NULL; \ |
|
cur && ({ tmp = cur->next; true; }); \ |
|
cur = tmp) \ |
|
if (map->equal_fn(cur->key, (_key), map->ctx)) |
|
|
|
#endif /* __LIBBPF_HASHMAP_H */
|
|
|