Now that we have extracted the `midx_key_to_pack_pos()` function, we can
implement the `midx_pair_to_pack_pos()` function which accepts (pack_id,
offset) tuples and returns an index into the psuedo-pack order.
This will be used in a following commit in order to figure out whether
or not the MIDX chose a given delta's base object from the same pack as
the delta resides in. It will do so by locating the base object's offset
in the pack, and then performing a binary search using the same pack ID
with the base object's offset.
If (and only if) it finds a match (at any position) we can guarantee
that the MIDX selected both halves of the delta/base pair from the same
pack.
Signed-off-by: Taylor Blau <me@xxxxxxxxxxxx>
---
pack-revindex.c | 11 +++++++++++
pack-revindex.h | 3 +++
2 files changed, 14 insertions(+)
diff --git a/pack-revindex.c b/pack-revindex.c
index baa4657ed3..a7624d8be8 100644
--- a/pack-revindex.c
+++ b/pack-revindex.c
@@ -564,3 +564,14 @@ int midx_to_pack_pos(struct multi_pack_index *m, uint32_t at, uint32_t *pos)
return midx_key_to_pack_pos(m, &key, pos);
}
+
+int midx_pair_to_pack_pos(struct multi_pack_index *m, uint32_t pack_int_id,
+ off_t ofs, uint32_t *pos)
+{
+ struct midx_pack_key key = {
+ .pack = pack_int_id,
+ .offset = ofs,
+ .midx = m,
+ };
+ return midx_key_to_pack_pos(m, &key, pos);
+}
diff --git a/pack-revindex.h b/pack-revindex.h
index 6dd47efea1..422c2487ae 100644
--- a/pack-revindex.h
+++ b/pack-revindex.h
@@ -142,4 +142,7 @@ uint32_t pack_pos_to_midx(struct multi_pack_index *m, uint32_t pos);
*/
int midx_to_pack_pos(struct multi_pack_index *midx, uint32_t at, uint32_t *pos);
+int midx_pair_to_pack_pos(struct multi_pack_index *midx, uint32_t pack_id,
+ off_t ofs, uint32_t *pos);
+
#endif
--
2.43.0.102.ga31d690331.dirty
