diff mbox series

[05/19] midx: teach `nth_midxed_object_oid()` about incremental MIDXs

Message ID a10772585d5fa9dcfd6f5bf5ec6fa81154181144.1717715060.git.me@ttaylorr.com (mailing list archive)
State New, archived
Headers show
Series midx: incremental multi-pack indexes, part one | expand

Commit Message

Taylor Blau June 6, 2024, 11:04 p.m. UTC 
The function `nth_midxed_object_oid()` returns the object ID for a given
object position in the MIDX lexicographic order.

Teach this function to instead operate over the concatenated
lexicographic order defined in an earlier step so that it is able to be
used with incremental MIDXs.

To do this, we need to both (a) adjust the bounds check for the given
'n', as well as record the MIDX-local position after chasing the
`->base_midx` pointer to find the MIDX which contains that object.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
 midx.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/midx.c b/midx.c
index 7fa3a1a7f8..cfab7f8113 100644
--- a/midx.c
+++ b/midx.c
@@ -335,9 +335,11 @@  struct object_id *nth_midxed_object_oid(struct object_id *oid,
 					struct multi_pack_index *m,
 					uint32_t n)
 {
-	if (n >= m->num_objects)
+	if (n >= m->num_objects + m->num_objects_in_base)
 		return NULL;
 
+	n = midx_for_object(&m, n);
+
 	oidread(oid, m->chunk_oid_lookup + st_mult(m->hash_len, n));
 	return oid;
 }