git/midx.h
Taylor Blau defba632c1 midx: replace get_midx_rev_filename() with a generic helper
Commit f894081dea (pack-revindex: read multi-pack reverse indexes,
2021-03-30) introduced the `get_midx_rev_filename()` helper (later
modified by commit 60980aed78 (midx.c: write MIDX filenames to
strbuf, 2021-10-26)).

This function returns the location of the classic ".rev" files we used
to write for MIDXs (prior to 95e8383bac (midx.c: make changing the
preferred pack safe, 2022-01-25)), which is always of the form:

    $GIT_DIR/objects/pack/multi-pack-index-$HASH.rev

Replace this function with a generic helper that populates a strbuf with
the above form, replacing the ".rev" extension with a caller-provided
argument.

This will allow us to remove a similarly-defined function in the
pack-bitmap code (used to determine the location of a MIDX .bitmap file)
by reimplementing it in terms of `get_midx_filename_ext()`.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-30 13:43:52 -07:00

124 lines
4.3 KiB
C

#ifndef MIDX_H
#define MIDX_H
#include "string-list.h"
struct object_id;
struct pack_entry;
struct repository;
struct bitmapped_pack;
#define MIDX_SIGNATURE 0x4d494458 /* "MIDX" */
#define MIDX_VERSION 1
#define MIDX_BYTE_FILE_VERSION 4
#define MIDX_BYTE_HASH_VERSION 5
#define MIDX_BYTE_NUM_CHUNKS 6
#define MIDX_BYTE_NUM_PACKS 8
#define MIDX_HEADER_SIZE 12
#define MIDX_CHUNK_ALIGNMENT 4
#define MIDX_CHUNKID_PACKNAMES 0x504e414d /* "PNAM" */
#define MIDX_CHUNKID_BITMAPPEDPACKS 0x42544d50 /* "BTMP" */
#define MIDX_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */
#define MIDX_CHUNKID_OIDLOOKUP 0x4f49444c /* "OIDL" */
#define MIDX_CHUNKID_OBJECTOFFSETS 0x4f4f4646 /* "OOFF" */
#define MIDX_CHUNKID_LARGEOFFSETS 0x4c4f4646 /* "LOFF" */
#define MIDX_CHUNKID_REVINDEX 0x52494458 /* "RIDX" */
#define MIDX_CHUNK_OFFSET_WIDTH (2 * sizeof(uint32_t))
#define MIDX_LARGE_OFFSET_NEEDED 0x80000000
#define GIT_TEST_MULTI_PACK_INDEX "GIT_TEST_MULTI_PACK_INDEX"
#define GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP \
"GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP"
struct multi_pack_index {
struct multi_pack_index *next;
const unsigned char *data;
size_t data_len;
const uint32_t *revindex_data;
const uint32_t *revindex_map;
size_t revindex_len;
uint32_t signature;
unsigned char version;
unsigned char hash_len;
unsigned char num_chunks;
uint32_t num_packs;
uint32_t num_objects;
int preferred_pack_idx;
int local;
const unsigned char *chunk_pack_names;
size_t chunk_pack_names_len;
const uint32_t *chunk_bitmapped_packs;
size_t chunk_bitmapped_packs_len;
const uint32_t *chunk_oid_fanout;
const unsigned char *chunk_oid_lookup;
const unsigned char *chunk_object_offsets;
const unsigned char *chunk_large_offsets;
size_t chunk_large_offsets_len;
const unsigned char *chunk_revindex;
size_t chunk_revindex_len;
const char **pack_names;
struct packed_git **packs;
char object_dir[FLEX_ARRAY];
};
#define MIDX_PROGRESS (1 << 0)
#define MIDX_WRITE_REV_INDEX (1 << 1)
#define MIDX_WRITE_BITMAP (1 << 2)
#define MIDX_WRITE_BITMAP_HASH_CACHE (1 << 3)
#define MIDX_WRITE_BITMAP_LOOKUP_TABLE (1 << 4)
#define MIDX_EXT_REV "rev"
#define MIDX_EXT_BITMAP "bitmap"
const unsigned char *get_midx_checksum(struct multi_pack_index *m);
void get_midx_filename(struct strbuf *out, const char *object_dir);
void get_midx_filename_ext(struct strbuf *out, const char *object_dir,
const unsigned char *hash, const char *ext);
struct multi_pack_index *load_multi_pack_index(const char *object_dir, int local);
int prepare_midx_pack(struct repository *r, struct multi_pack_index *m, uint32_t pack_int_id);
int nth_bitmapped_pack(struct repository *r, struct multi_pack_index *m,
struct bitmapped_pack *bp, uint32_t pack_int_id);
int bsearch_midx(const struct object_id *oid, struct multi_pack_index *m, uint32_t *result);
off_t nth_midxed_offset(struct multi_pack_index *m, uint32_t pos);
uint32_t nth_midxed_pack_int_id(struct multi_pack_index *m, uint32_t pos);
struct object_id *nth_midxed_object_oid(struct object_id *oid,
struct multi_pack_index *m,
uint32_t n);
int fill_midx_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e, struct multi_pack_index *m);
int midx_contains_pack(struct multi_pack_index *m,
const char *idx_or_pack_name);
int midx_locate_pack(struct multi_pack_index *m, const char *idx_or_pack_name,
uint32_t *pos);
int midx_preferred_pack(struct multi_pack_index *m, uint32_t *pack_int_id);
int prepare_multi_pack_index_one(struct repository *r, const char *object_dir, int local);
/*
* Variant of write_midx_file which writes a MIDX containing only the packs
* specified in packs_to_include.
*/
int write_midx_file(const char *object_dir,
const char *preferred_pack_name,
const char *refs_snapshot,
unsigned flags);
int write_midx_file_only(const char *object_dir,
struct string_list *packs_to_include,
const char *preferred_pack_name,
const char *refs_snapshot,
unsigned flags);
void clear_midx_file(struct repository *r);
int verify_midx_file(struct repository *r, const char *object_dir, unsigned flags);
int expire_midx_packs(struct repository *r, const char *object_dir, unsigned flags);
int midx_repack(struct repository *r, const char *object_dir, size_t batch_size, unsigned flags);
void close_midx(struct multi_pack_index *m);
#endif