midx: teach nth_bitmapped_pack() about incremental MIDXs

In a similar fashion as in previous commits, teach the function
`nth_bitmapped_pack()` about incremental MIDXs by translating the given
`pack_int_id` from the concatenated lexical order to a MIDX-local
lexical position.

When accessing the containing MIDX's array of packs, use the local pack
ID. Likewise, when reading the 'BTMP' chunk, use the MIDX-local offset
when accessing the data within that chunk.

(Note that the both the call to prepare_midx_pack() and the assignment
of bp->pack_int_id both care about the global pack_int_id, so avoid
shadowing the given 'pack_int_id' parameter).

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Taylor Blau
2024-08-06 11:37:27 -04:00
committed by Junio C Hamano
parent 26afb5afa1
commit 60750e1eb9

8
midx.c
View File

@ -311,17 +311,19 @@ int prepare_midx_pack(struct repository *r, struct multi_pack_index *m,
int nth_bitmapped_pack(struct repository *r, struct multi_pack_index *m, int nth_bitmapped_pack(struct repository *r, struct multi_pack_index *m,
struct bitmapped_pack *bp, uint32_t pack_int_id) struct bitmapped_pack *bp, uint32_t pack_int_id)
{ {
uint32_t local_pack_int_id = midx_for_pack(&m, pack_int_id);
if (!m->chunk_bitmapped_packs) if (!m->chunk_bitmapped_packs)
return error(_("MIDX does not contain the BTMP chunk")); return error(_("MIDX does not contain the BTMP chunk"));
if (prepare_midx_pack(r, m, pack_int_id)) if (prepare_midx_pack(r, m, pack_int_id))
return error(_("could not load bitmapped pack %"PRIu32), pack_int_id); return error(_("could not load bitmapped pack %"PRIu32), pack_int_id);
bp->p = m->packs[pack_int_id]; bp->p = m->packs[local_pack_int_id];
bp->bitmap_pos = get_be32((char *)m->chunk_bitmapped_packs + bp->bitmap_pos = get_be32((char *)m->chunk_bitmapped_packs +
MIDX_CHUNK_BITMAPPED_PACKS_WIDTH * pack_int_id); MIDX_CHUNK_BITMAPPED_PACKS_WIDTH * local_pack_int_id);
bp->bitmap_nr = get_be32((char *)m->chunk_bitmapped_packs + bp->bitmap_nr = get_be32((char *)m->chunk_bitmapped_packs +
MIDX_CHUNK_BITMAPPED_PACKS_WIDTH * pack_int_id + MIDX_CHUNK_BITMAPPED_PACKS_WIDTH * local_pack_int_id +
sizeof(uint32_t)); sizeof(uint32_t));
bp->pack_int_id = pack_int_id; bp->pack_int_id = pack_int_id;