Orange Pi5 kernel

// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
 
/*
 * Generic non-thread safe hash map implementation.
 *
 * Copyright (c) 2019 Facebook
 */
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <linux/err.h>
#include "hashmap.h"
 
/* make sure libbpf doesn't use kernel-only integer typedefs */
#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64
 
/* prevent accidental re-addition of reallocarray() */
#pragma GCC poison reallocarray
 
/* start with 4 buckets */
#define HASHMAP_MIN_CAP_BITS 2
 
static void hashmap_add_entry(struct hashmap_entry **pprev,
<------><------><------>      struct hashmap_entry *entry)
{
<------>entry->next = *pprev;
<------>*pprev = entry;
}
 
static void hashmap_del_entry(struct hashmap_entry **pprev,
<------><------><------>      struct hashmap_entry *entry)
{
<------>*pprev = entry->next;
<------>entry->next = NULL;
}
 
void hashmap__init(struct hashmap *map, hashmap_hash_fn hash_fn,
<------><------>   hashmap_equal_fn equal_fn, void *ctx)
{
<------>map->hash_fn = hash_fn;
<------>map->equal_fn = equal_fn;
<------>map->ctx = ctx;
 
<------>map->buckets = NULL;
<------>map->cap = 0;
<------>map->cap_bits = 0;
<------>map->sz = 0;
}
 
struct hashmap *hashmap__new(hashmap_hash_fn hash_fn,
<------><------><------>     hashmap_equal_fn equal_fn,
<------><------><------>     void *ctx)
{
<------>struct hashmap *map = malloc(sizeof(struct hashmap));
 
<------>if (!map)
<------><------>return ERR_PTR(-ENOMEM);
<------>hashmap__init(map, hash_fn, equal_fn, ctx);
<------>return map;
}
 
void hashmap__clear(struct hashmap *map)
{
<------>struct hashmap_entry *cur, *tmp;
<------>size_t bkt;
 
<------>hashmap__for_each_entry_safe(map, cur, tmp, bkt) {
<------><------>free(cur);
<------>}
<------>free(map->buckets);
<------>map->buckets = NULL;
<------>map->cap = map->cap_bits = map->sz = 0;
}
 
void hashmap__free(struct hashmap *map)
{
<------>if (!map)
<------><------>return;
 
<------>hashmap__clear(map);
<------>free(map);
}
 
size_t hashmap__size(const struct hashmap *map)
{
<------>return map->sz;
}
 
size_t hashmap__capacity(const struct hashmap *map)
{
<------>return map->cap;
}
 
static bool hashmap_needs_to_grow(struct hashmap *map)
{
<------>/* grow if empty or more than 75% filled */
<------>return (map->cap == 0) || ((map->sz + 1) * 4 / 3 > map->cap);
}
 
static int hashmap_grow(struct hashmap *map)
{
<------>struct hashmap_entry **new_buckets;
<------>struct hashmap_entry *cur, *tmp;
<------>size_t new_cap_bits, new_cap;
<------>size_t h, bkt;
 
<------>new_cap_bits = map->cap_bits + 1;
<------>if (new_cap_bits < HASHMAP_MIN_CAP_BITS)
<------><------>new_cap_bits = HASHMAP_MIN_CAP_BITS;
 
<------>new_cap = 1UL << new_cap_bits;
<------>new_buckets = calloc(new_cap, sizeof(new_buckets[0]));
<------>if (!new_buckets)
<------><------>return -ENOMEM;
 
<------>hashmap__for_each_entry_safe(map, cur, tmp, bkt) {
<------><------>h = hash_bits(map->hash_fn(cur->key, map->ctx), new_cap_bits);
<------><------>hashmap_add_entry(&new_buckets[h], cur);
<------>}
 
<------>map->cap = new_cap;
<------>map->cap_bits = new_cap_bits;
<------>free(map->buckets);
<------>map->buckets = new_buckets;
 
<------>return 0;
}
 
static bool hashmap_find_entry(const struct hashmap *map,
<------><------><------>       const void *key, size_t hash,
<------><------><------>       struct hashmap_entry ***pprev,
<------><------><------>       struct hashmap_entry **entry)
{
<------>struct hashmap_entry *cur, **prev_ptr;
 
<------>if (!map->buckets)
<------><------>return false;
 
<------>for (prev_ptr = &map->buckets[hash], cur = *prev_ptr;
<------>     cur;
<------>     prev_ptr = &cur->next, cur = cur->next) {
<------><------>if (map->equal_fn(cur->key, key, map->ctx)) {
<------><------><------>if (pprev)
<------><------><------><------>*pprev = prev_ptr;
<------><------><------>*entry = cur;
<------><------><------>return true;
<------><------>}
<------>}
 
<------>return false;
}
 
int hashmap__insert(struct hashmap *map, const void *key, void *value,
<------><------>    enum hashmap_insert_strategy strategy,
<------><------>    const void **old_key, void **old_value)
{
<------>struct hashmap_entry *entry;
<------>size_t h;
<------>int err;
 
<------>if (old_key)
<------><------>*old_key = NULL;
<------>if (old_value)
<------><------>*old_value = NULL;
 
<------>h = hash_bits(map->hash_fn(key, map->ctx), map->cap_bits);
<------>if (strategy != HASHMAP_APPEND &&
<------>    hashmap_find_entry(map, key, h, NULL, &entry)) {
<------><------>if (old_key)
<------><------><------>*old_key = entry->key;
<------><------>if (old_value)
<------><------><------>*old_value = entry->value;
 
<------><------>if (strategy == HASHMAP_SET || strategy == HASHMAP_UPDATE) {
<------><------><------>entry->key = key;
<------><------><------>entry->value = value;
<------><------><------>return 0;
<------><------>} else if (strategy == HASHMAP_ADD) {
<------><------><------>return -EEXIST;
<------><------>}
<------>}
 
<------>if (strategy == HASHMAP_UPDATE)
<------><------>return -ENOENT;
 
<------>if (hashmap_needs_to_grow(map)) {
<------><------>err = hashmap_grow(map);
<------><------>if (err)
<------><------><------>return err;
<------><------>h = hash_bits(map->hash_fn(key, map->ctx), map->cap_bits);
<------>}
 
<------>entry = malloc(sizeof(struct hashmap_entry));
<------>if (!entry)
<------><------>return -ENOMEM;
 
<------>entry->key = key;
<------>entry->value = value;
<------>hashmap_add_entry(&map->buckets[h], entry);
<------>map->sz++;
 
<------>return 0;
}
 
bool hashmap__find(const struct hashmap *map, const void *key, void **value)
{
<------>struct hashmap_entry *entry;
<------>size_t h;
 
<------>h = hash_bits(map->hash_fn(key, map->ctx), map->cap_bits);
<------>if (!hashmap_find_entry(map, key, h, NULL, &entry))
<------><------>return false;
 
<------>if (value)
<------><------>*value = entry->value;
<------>return true;
}
 
bool hashmap__delete(struct hashmap *map, const void *key,
<------><------>     const void **old_key, void **old_value)
{
<------>struct hashmap_entry **pprev, *entry;
<------>size_t h;
 
<------>h = hash_bits(map->hash_fn(key, map->ctx), map->cap_bits);
<------>if (!hashmap_find_entry(map, key, h, &pprev, &entry))
<------><------>return false;
 
<------>if (old_key)
<------><------>*old_key = entry->key;
<------>if (old_value)
<------><------>*old_value = entry->value;
 
<------>hashmap_del_entry(pprev, entry);
<------>free(entry);
<------>map->sz--;
 
<------>return true;
}