xref: /linux/drivers/md/dm-vdo/indexer/radix-sort.h (revision 6e7fd890f1d6ac83805409e9c346240de2705584)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright 2023 Red Hat
4  */
5 
6 #ifndef UDS_RADIX_SORT_H
7 #define UDS_RADIX_SORT_H
8 
9 /*
10  * Radix sort is implemented using an American Flag sort, an unstable, in-place 8-bit radix
11  * exchange sort. This is adapted from the algorithm in the paper by Peter M. McIlroy, Keith
12  * Bostic, and M. Douglas McIlroy, "Engineering Radix Sort".
13  *
14  * http://www.usenix.org/publications/compsystems/1993/win_mcilroy.pdf
15  */
16 
17 struct radix_sorter;
18 
19 int __must_check uds_make_radix_sorter(unsigned int count, struct radix_sorter **sorter);
20 
21 void uds_free_radix_sorter(struct radix_sorter *sorter);
22 
23 int __must_check uds_radix_sort(struct radix_sorter *sorter, const unsigned char *keys[],
24 				unsigned int count, unsigned short length);
25 
26 #endif /* UDS_RADIX_SORT_H */
27