From 94cd775a6c52a99caeb1278c3d8044ee109e2d3e Mon Sep 17 00:00:00 2001 From: Taylor Blau Date: Fri, 20 May 2022 19:17:35 -0400 Subject: pack-mtimes: support reading .mtimes files To store the individual mtimes of objects in a cruft pack, introduce a new `.mtimes` format that can optionally accompany a single pack in the repository. The format is defined in Documentation/technical/pack-format.txt, and stores a 4-byte network order timestamp for each object in name (index) order. This patch prepares for cruft packs by defining the `.mtimes` format, and introducing a basic API that callers can use to read out individual mtimes. Signed-off-by: Taylor Blau Signed-off-by: Junio C Hamano --- Documentation/technical/pack-format.txt | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'Documentation/technical') diff --git a/Documentation/technical/pack-format.txt b/Documentation/technical/pack-format.txt index 6d3efb7d16..b520aa9c45 100644 --- a/Documentation/technical/pack-format.txt +++ b/Documentation/technical/pack-format.txt @@ -294,6 +294,25 @@ Pack file entry: <+ All 4-byte numbers are in network order. +== pack-*.mtimes files have the format: + +All 4-byte numbers are in network byte order. + + - A 4-byte magic number '0x4d544d45' ('MTME'). + + - A 4-byte version identifier (= 1). + + - A 4-byte hash function identifier (= 1 for SHA-1, 2 for SHA-256). + + - A table of 4-byte unsigned integers. The ith value is the + modification time (mtime) of the ith object in the corresponding + pack by lexicographic (index) order. The mtimes count standard + epoch seconds. + + - A trailer, containing a checksum of the corresponding packfile, + and a checksum of all of the above (each having length according + to the specified hash function). + == multi-pack-index (MIDX) files have the following format: The multi-pack-index files refer to multiple pack-files and loose objects. -- cgit v1.3