git-commit-vandalism/pack-bitmap.h
Jeff King 30cdc33fba pack-bitmap: save "have" bitmap from walk
When we do a bitmap walk, we save the result, which
represents (WANTs & ~HAVEs); i.e., every object we care
about visiting in our walk. However, we throw away the
haves bitmap, which can sometimes be useful, too. Save it
and provide an access function so code which has performed a
walk can query it.

A few notes on the accessor interface:

 - the bitmap code calls these "haves" because it grew out
   of the want/have negotiation for fetches. But really,
   these are simply the objects that would be flagged
   UNINTERESTING in a regular traversal. Let's use that
   more universal nomenclature for the external module
   interface. We may want to change the internal naming
   inside the bitmap code, but that's outside the scope of
   this patch.

 - it still uses a bare "sha1" rather than "oid". That's
   true of all of the bitmap code. And in this particular
   instance, our caller in pack-objects is dealing with the
   bare sha1 that comes from a packed REF_DELTA (we're
   pointing directly to the mmap'd pack on disk). That's
   something we'll have to deal with as we transition to a
   new hash, but we can wait and see how the caller ends up
   being fixed and adjust this interface accordingly.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-21 12:33:39 -07:00

78 lines
2.3 KiB
C

#ifndef PACK_BITMAP_H
#define PACK_BITMAP_H
#include "ewah/ewok.h"
#include "khash.h"
#include "pack-objects.h"
struct commit;
struct rev_info;
struct bitmap_disk_header {
char magic[4];
uint16_t version;
uint16_t options;
uint32_t entry_count;
unsigned char checksum[20];
};
static const char BITMAP_IDX_SIGNATURE[] = {'B', 'I', 'T', 'M'};
#define NEEDS_BITMAP (1u<<22)
enum pack_bitmap_opts {
BITMAP_OPT_FULL_DAG = 1,
BITMAP_OPT_HASH_CACHE = 4,
};
enum pack_bitmap_flags {
BITMAP_FLAG_REUSE = 0x1
};
typedef int (*show_reachable_fn)(
const struct object_id *oid,
enum object_type type,
int flags,
uint32_t hash,
struct packed_git *found_pack,
off_t found_offset);
struct bitmap_index;
struct bitmap_index *prepare_bitmap_git(void);
void count_bitmap_commit_list(struct bitmap_index *, uint32_t *commits,
uint32_t *trees, uint32_t *blobs, uint32_t *tags);
void traverse_bitmap_commit_list(struct bitmap_index *,
show_reachable_fn show_reachable);
void test_bitmap_walk(struct rev_info *revs);
struct bitmap_index *prepare_bitmap_walk(struct rev_info *revs);
int reuse_partial_packfile_from_bitmap(struct bitmap_index *,
struct packed_git **packfile,
uint32_t *entries, off_t *up_to);
int rebuild_existing_bitmaps(struct bitmap_index *, struct packing_data *mapping,
khash_sha1 *reused_bitmaps, int show_progress);
void free_bitmap_index(struct bitmap_index *);
/*
* After a traversal has been performed on the bitmap_index, this can be
* queried to see if a particular object was reachable from any of the
* objects flagged as UNINTERESTING.
*/
int bitmap_has_sha1_in_uninteresting(struct bitmap_index *, const unsigned char *sha1);
void bitmap_writer_show_progress(int show);
void bitmap_writer_set_checksum(unsigned char *sha1);
void bitmap_writer_build_type_index(struct packing_data *to_pack,
struct pack_idx_entry **index,
uint32_t index_nr);
void bitmap_writer_reuse_bitmaps(struct packing_data *to_pack);
void bitmap_writer_select_commits(struct commit **indexed_commits,
unsigned int indexed_commits_nr, int max_bitmaps);
void bitmap_writer_build(struct packing_data *to_pack);
void bitmap_writer_finish(struct pack_idx_entry **index,
uint32_t index_nr,
const char *filename,
uint16_t options);
#endif