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-rw-r--r--Documentation/technical/multi-pack-index.txt1
-rw-r--r--Documentation/technical/pack-format.txt13
2 files changed, 8 insertions, 6 deletions
diff --git a/Documentation/technical/multi-pack-index.txt b/Documentation/technical/multi-pack-index.txt
index b39c69da8c..f2221d2b44 100644
--- a/Documentation/technical/multi-pack-index.txt
+++ b/Documentation/technical/multi-pack-index.txt
@@ -24,6 +24,7 @@ and their offsets into multiple packfiles. It contains:
** An offset within the jth packfile for the object.
* If large offsets are required, we use another list of large
offsets similar to version 2 pack-indexes.
+- An optional list of objects in pseudo-pack order (used with MIDX bitmaps).
Thus, we can provide O(log N) lookup time for any number
of packfiles.
diff --git a/Documentation/technical/pack-format.txt b/Documentation/technical/pack-format.txt
index 8d2f42f29e..6d3efb7d16 100644
--- a/Documentation/technical/pack-format.txt
+++ b/Documentation/technical/pack-format.txt
@@ -376,6 +376,11 @@ CHUNK DATA:
[Optional] Object Large Offsets (ID: {'L', 'O', 'F', 'F'})
8-byte offsets into large packfiles.
+ [Optional] Bitmap pack order (ID: {'R', 'I', 'D', 'X'})
+ A list of MIDX positions (one per object in the MIDX, num_objects in
+ total, each a 4-byte unsigned integer in network byte order), sorted
+ according to their relative bitmap/pseudo-pack positions.
+
TRAILER:
Index checksum of the above contents.
@@ -456,9 +461,5 @@ In short, a MIDX's pseudo-pack is the de-duplicated concatenation of
objects in packs stored by the MIDX, laid out in pack order, and the
packs arranged in MIDX order (with the preferred pack coming first).
-Finally, note that the MIDX's reverse index is not stored as a chunk in
-the multi-pack-index itself. This is done because the reverse index
-includes the checksum of the pack or MIDX to which it belongs, which
-makes it impossible to write in the MIDX. To avoid races when rewriting
-the MIDX, a MIDX reverse index includes the MIDX's checksum in its
-filename (e.g., `multi-pack-index-xyz.rev`).
+The MIDX's reverse index is stored in the optional 'RIDX' chunk within
+the MIDX itself.