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/*
* zdev - Modify and display the persistent configuration of devices
*
* Copyright IBM Corp. 2016, 2017
*
* s390-tools is free software; you can redistribute it and/or modify
* it under the terms of the MIT license. See LICENSE for details.
*/
#ifndef HASH_H
#define HASH_H
#include "lib/util_list.h"
/* A hash is a list of entries. Each entry provides an ID. A hashing function
* maps the ID to an integer bucket number. When adding entries to a hash, the
* entry is stored in a list associated with this bucket number. This approach
* can greatly reduce the effort needed to find an entry in a hash by ID. */
/* Return the ID of an entry. */
typedef const void *(*hash_id_fn_t)(void *);
/* Check if two IDs are identical. */
typedef int (*hash_cmp_fn_t)(const void *, const void *);
/* Return the bucket number for an ID. */
typedef int (*hash_fn_t)(const void *);
/**
* hash - A hash supported list
* @list: Sequential list of entries
* @buckets: Number of hash buckets
* @get_id: Return the ID of an entry
* @cmp_id: Return 0 if two IDs are identical
* @get_hash: Function that returns a hash index for an ID
* @hash: Lists per hash index
*/
struct hash {
struct util_list list;
int buckets;
hash_id_fn_t get_id;
hash_cmp_fn_t cmp_id;
hash_fn_t get_hash;
struct util_list **hash;
};
#define hash_init(hash, buckets, get_id, cmp_id, get_hash, type, member) \
_hash_init((hash), (buckets), (get_id), (cmp_id), (get_hash), \
offsetof(type, member))
#define hash_new(buckets, get_id, cmp_id, get_hash, type, member) \
_hash_new((buckets), (get_id), (cmp_id), (get_hash), \
offsetof(type, member))
void _hash_init(struct hash *hash, int buckets, hash_id_fn_t get_id,
hash_cmp_fn_t cmp_id, hash_fn_t get_hash, unsigned long offset);
struct hash *_hash_new(int buckets, hash_id_fn_t get_id, hash_cmp_fn_t cmp_id,
hash_fn_t get_hash, unsigned long offset);
void hash_clear(struct hash *hash, void (*free_fn)(void *));
void hash_free(struct hash *hash, void (*free_fn)(void *));
void hash_add(struct hash *hash, void *entry);
void hash_remove(struct hash *hash, void *entry);
void *hash_find_by_id(struct hash *hash, const void *id);
void hash_print(struct hash *hash, int ind);
#endif /* HASH_H */
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