drivers/md/dm-vdo/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
  24 struct int_map;
  25
  26 int __must_check vdo_int_map_create(size_t initial_capacity, struct int_map **map_ptr);
  27
  28 void vdo_int_map_free(struct int_map *map);
  29
  30 size_t vdo_int_map_size(const struct int_map *map);
  31
  32 void *vdo_int_map_get(struct int_map *map, u64 key);
  33
  34 int __must_check vdo_int_map_put(struct int_map *map, u64 key, void *new_value,
  35                                  bool update, void **old_value_ptr);
  36
  37 void *vdo_int_map_remove(struct int_map *map, u64 key);
  38
  39 #endif /* VDO_INT_MAP_H */