Orange Pi5 kernel

/* 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 */