index-page-map.h

 1/* SPDX-License-Identifier: GPL-2.0-only */
 2/*
 3 * Copyright 2023 Red Hat
 4 */
 5
 6#ifndef UDS_INDEX_PAGE_MAP_H
 7#define UDS_INDEX_PAGE_MAP_H
 8
 9#include "geometry.h"
10#include "io-factory.h"
11
12/*
13 * The index maintains a page map which records how the chapter delta lists are distributed among
14 * the index pages for each chapter, allowing the volume to be efficient about reading only pages
15 * that it knows it will need.
16 */
17
18struct index_page_map {
19	const struct index_geometry *geometry;
20	u64 last_update;
21	u32 entries_per_chapter;
22	u16 *entries;
23};
24
25int __must_check uds_make_index_page_map(const struct index_geometry *geometry,
26					 struct index_page_map **map_ptr);
27
28void uds_free_index_page_map(struct index_page_map *map);
29
30int __must_check uds_read_index_page_map(struct index_page_map *map,
31					 struct buffered_reader *reader);
32
33int __must_check uds_write_index_page_map(struct index_page_map *map,
34					  struct buffered_writer *writer);
35
36void uds_update_index_page_map(struct index_page_map *map, u64 virtual_chapter_number,
37			       u32 chapter_number, u32 index_page_number,
38			       u32 delta_list_number);
39
40u32 __must_check uds_find_index_page_number(const struct index_page_map *map,
41					    const struct uds_record_name *name,
42					    u32 chapter_number);
43
44void uds_get_list_number_bounds(const struct index_page_map *map, u32 chapter_number,
45				u32 index_page_number, u32 *lowest_list,
46				u32 *highest_list);
47
48u64 uds_compute_index_page_map_save_size(const struct index_geometry *geometry);
49
50#endif /* UDS_INDEX_PAGE_MAP_H */