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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __EROFS_HASHMAP_H
#define __EROFS_HASHMAP_H
#ifdef __cplusplus
extern "C"
{
#endif
/* Copied from https://github.com/git/git.git */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "flex-array.h"
/*
* Generic implementation of hash-based key-value mappings.
* See Documentation/technical/api-hashmap.txt.
*/
/* FNV-1 functions */
unsigned int strhash(const char *str);
unsigned int strihash(const char *str);
unsigned int memhash(const void *buf, size_t len);
unsigned int memihash(const void *buf, size_t len);
static inline unsigned int sha1hash(const unsigned char *sha1)
{
/*
* Equivalent to 'return *(unsigned int *)sha1;', but safe on
* platforms that don't support unaligned reads.
*/
unsigned int hash;
memcpy(&hash, sha1, sizeof(hash));
return hash;
}
/* data structures */
struct hashmap_entry {
struct hashmap_entry *next;
unsigned int hash;
};
typedef int (*hashmap_cmp_fn)(const void *entry, const void *entry_or_key,
const void *keydata);
struct hashmap {
struct hashmap_entry **table;
hashmap_cmp_fn cmpfn;
unsigned int size, tablesize, grow_at, shrink_at;
};
struct hashmap_iter {
struct hashmap *map;
struct hashmap_entry *next;
unsigned int tablepos;
};
/* hashmap functions */
void hashmap_init(struct hashmap *map, hashmap_cmp_fn equals_function,
size_t initial_size);
int hashmap_free(struct hashmap *map);
/* hashmap_entry functions */
static inline void hashmap_entry_init(void *entry, unsigned int hash)
{
struct hashmap_entry *e = entry;
e->hash = hash;
e->next = NULL;
}
void *hashmap_get(const struct hashmap *map, const void *key, const void *keydata);
void *hashmap_get_next(const struct hashmap *map, const void *entry);
void hashmap_add(struct hashmap *map, void *entry);
void *hashmap_remove(struct hashmap *map, const void *key);
static inline void *hashmap_get_from_hash(const struct hashmap *map,
unsigned int hash,
const void *keydata)
{
struct hashmap_entry key;
hashmap_entry_init(&key, hash);
return hashmap_get(map, &key, keydata);
}
/* hashmap_iter functions */
void hashmap_iter_init(struct hashmap *map, struct hashmap_iter *iter);
void *hashmap_iter_next(struct hashmap_iter *iter);
static inline void *hashmap_iter_first(struct hashmap *map,
struct hashmap_iter *iter)
{
hashmap_iter_init(map, iter);
return hashmap_iter_next(iter);
}
/* string interning */
const void *memintern(const void *data, size_t len);
static inline const char *strintern(const char *string)
{
return memintern(string, strlen(string));
}
#ifdef __cplusplus
}
#endif
#endif
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