diff options
Diffstat (limited to 'Documentation/technical/multi-pack-index.txt')
| -rw-r--r-- | Documentation/technical/multi-pack-index.txt | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/Documentation/technical/multi-pack-index.txt b/Documentation/technical/multi-pack-index.txt index e8e377a59f..86f40f2490 100644 --- a/Documentation/technical/multi-pack-index.txt +++ b/Documentation/technical/multi-pack-index.txt @@ -36,15 +36,18 @@ Design Details directory of an alternate. It refers only to packfiles in that same directory. -- The core.multiPackIndex config setting must be on to consume MIDX files. +- The core.multiPackIndex config setting must be on (which is the + default) to consume MIDX files. Setting it to `false` prevents + Git from reading a MIDX file, even if one exists. - The file format includes parameters for the object ID hash function, so a future change of hash algorithm does not require a change in format. - The MIDX keeps only one record per object ID. If an object appears - in multiple packfiles, then the MIDX selects the copy in the most- - recently modified packfile. + in multiple packfiles, then the MIDX selects the copy in the + preferred packfile, otherwise selecting from the most-recently + modified packfile. - If there exist packfiles in the pack directory not registered in the MIDX, then those packfiles are loaded into the `packed_git` @@ -70,14 +73,10 @@ Future Work still reducing the number of binary searches required for object lookups. -- The reachability bitmap is currently paired directly with a single - packfile, using the pack-order as the object order to hopefully - compress the bitmaps well using run-length encoding. This could be - extended to pair a reachability bitmap with a multi-pack-index. If - the multi-pack-index is extended to store a "stable object order" +- If the multi-pack-index is extended to store a "stable object order" (a function Order(hash) = integer that is constant for a given hash, - even as the multi-pack-index is updated) then a reachability bitmap - could point to a multi-pack-index and be updated independently. + even as the multi-pack-index is updated) then MIDX bitmaps could be + updated independently of the MIDX. - Packfiles can be marked as "special" using empty files that share the initial name but replace ".pack" with ".keep" or ".promisor". |