averello/git-mirror
1
0
Fork 0
mirror of https://github.com/git/git.git synced 2025-12-12 20:36:24 +01:00
Code Issues Packages Projects Releases Wiki Activity

pack-revindex: prepare for incremental MIDX bitmaps

Browse Source 
Prepare the reverse index machinery to handle object lookups in an
incremental MIDX bitmap. These changes are broken out across a few
functions:

  - load_midx_revindex() learns to use the appropriate MIDX filename
    depending on whether the given 'struct multi_pack_index *' is
    incremental or not.

  - pack_pos_to_midx() and midx_to_pack_pos() now both take in a global
    object position in the MIDX pseudo-pack order, and find the
    earliest containing MIDX (similar to midx.c::midx_for_object().

  - midx_pack_order_cmp() adjusts its call to pack_pos_to_midx() by the
    number of objects in the base (since 'vb - midx->revindx_data' is
    relative to the containing MIDX, and pack_pos_to_midx() expects a
    global position).

    Likewise, this function adjusts its output by adding
    m->num_objects_in_base to return a global position out through the
    `*pos` pointer.

Together, these changes are sufficient to use the multi-pack index's
reverse index format for incremental multi-pack reachability bitmaps.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Taylor Blau
2025-03-20 13:56:31 -04:00
committed by Junio C Hamano
parent 4887bdd4c7
commit 8331c17b79
2 changed files with 56 additions and 21 deletions
Download Patch File Download Diff File Expand all files Collapse all files

34
pack-revindex.c
View File

@@ -383,8 +383,14 @@ int load_midx_revindex(struct multi_pack_index *m)
trace2_data_string("load_midx_revindex", the_repository,
"source", "rev");
get_midx_filename_ext(m->repo->hash_algo, &revindex_name, m->object_dir,
get_midx_checksum(m), MIDX_EXT_REV);
if (m->has_chain)
get_split_midx_filename_ext(m->repo->hash_algo, &revindex_name,
m->object_dir, get_midx_checksum(m),
MIDX_EXT_REV);
else
get_midx_filename_ext(m->repo->hash_algo, &revindex_name,
m->object_dir, get_midx_checksum(m),
MIDX_EXT_REV);
ret = load_revindex_from_disk(revindex_name.buf,
m->num_objects,
@@ -471,11 +477,15 @@ off_t pack_pos_to_offset(struct packed_git *p, uint32_t pos)
uint32_t pack_pos_to_midx(struct multi_pack_index *m, uint32_t pos)
{
while (m && pos < m->num_objects_in_base)
m = m->base_midx;
if (!m)
BUG("NULL multi-pack-index for object position: %"PRIu32, pos);
if (!m->revindex_data)
BUG("pack_pos_to_midx: reverse index not yet loaded");
if (m->num_objects <= pos)
if (m->num_objects + m->num_objects_in_base <= pos)
BUG("pack_pos_to_midx: out-of-bounds object at %"PRIu32, pos);
return get_be32(m->revindex_data + pos);
return get_be32(m->revindex_data + pos - m->num_objects_in_base);
}
struct midx_pack_key {
@@ -491,7 +501,8 @@ static int midx_pack_order_cmp(const void *va, const void *vb)
const struct midx_pack_key *key = va;
struct multi_pack_index *midx = key->midx;
uint32_t versus = pack_pos_to_midx(midx, (uint32_t*)vb - (const uint32_t *)midx->revindex_data);
size_t pos = (uint32_t *)vb - (const uint32_t *)midx->revindex_data;
uint32_t versus = pack_pos_to_midx(midx, pos + midx->num_objects_in_base);
uint32_t versus_pack = nth_midxed_pack_int_id(midx, versus);
off_t versus_offset;
@@ -529,9 +540,9 @@ static int midx_key_to_pack_pos(struct multi_pack_index *m,
{
uint32_t *found;
if (key->pack >= m->num_packs)
if (key->pack >= m->num_packs + m->num_packs_in_base)
BUG("MIDX pack lookup out of bounds (%"PRIu32" >= %"PRIu32")",
key->pack, m->num_packs);
key->pack, m->num_packs + m->num_packs_in_base);
/*
* The preferred pack sorts first, so determine its identifier by
* looking at the first object in pseudo-pack order.
@@ -551,7 +562,8 @@ static int midx_key_to_pack_pos(struct multi_pack_index *m,
if (!found)
return -1;
*pos = found - m->revindex_data;
*pos = (found - m->revindex_data) + m->num_objects_in_base;
return 0;
}
@@ -559,9 +571,13 @@ int midx_to_pack_pos(struct multi_pack_index *m, uint32_t at, uint32_t *pos)
{
struct midx_pack_key key;
while (m && at < m->num_objects_in_base)
m = m->base_midx;
if (!m)
BUG("NULL multi-pack-index for object position: %"PRIu32, at);
if (!m->revindex_data)
BUG("midx_to_pack_pos: reverse index not yet loaded");
if (m->num_objects <= at)
if (m->num_objects + m->num_objects_in_base <= at)
BUG("midx_to_pack_pos: out-of-bounds object at %"PRIu32, at);
key.pack = nth_midxed_pack_int_id(m, at);