int-map.h

 1/* SPDX-License-Identifier: GPL-2.0-only */
 2/*
 3 * Copyright 2023 Red Hat
 4 */
 5
 6#ifndef VDO_INT_MAP_H
 7#define VDO_INT_MAP_H
 8
 9#include <linux/compiler.h>
10#include <linux/types.h>
11
12/**
13 * DOC: int_map
14 *
15 * An int_map associates pointers (void *) with integer keys (u64). NULL pointer values are
16 * not supported.
17 *
18 * The map is implemented as hash table, which should provide constant-time insert, query, and
19 * remove operations, although the insert may occasionally grow the table, which is linear in the
20 * number of entries in the map. The table will grow as needed to hold new entries, but will not
21 * shrink as entries are removed.
22 */
23
24struct int_map;
25
26int __must_check vdo_int_map_create(size_t initial_capacity, struct int_map **map_ptr);
27
28void vdo_int_map_free(struct int_map *map);
29
30size_t vdo_int_map_size(const struct int_map *map);
31
32void *vdo_int_map_get(struct int_map *map, u64 key);
33
34int __must_check vdo_int_map_put(struct int_map *map, u64 key, void *new_value,
35				 bool update, void **old_value_ptr);
36
37void *vdo_int_map_remove(struct int_map *map, u64 key);
38
39#endif /* VDO_INT_MAP_H */