41 lines
1.1 KiB
Haskell
41 lines
1.1 KiB
Haskell
{- Encoding a git sha as a Key
|
|
-
|
|
- Copyright 2017-2025 Joey Hess <id@joeyh.name>
|
|
-
|
|
- Licensed under the GNU AGPL version 3 or higher.
|
|
-}
|
|
|
|
{-# LANGUAGE OverloadedStrings #-}
|
|
|
|
module Annex.GitShaKey where
|
|
|
|
import Types
|
|
import Types.Key
|
|
import qualified Git
|
|
|
|
import Data.Maybe
|
|
import qualified Data.ByteString.Short as S (fromShort, toShort)
|
|
|
|
-- Encodes a git sha as a Key. This is used to represent a non-annexed
|
|
-- file. For example, when storing a git sha on a special remote.
|
|
--
|
|
-- This is not the same as a SHA1 key, because the mapping needs to be
|
|
-- bijective, also because git may not always use SHA1, and because git
|
|
-- takes a SHA1 of the file size + content, while git-annex SHA1 keys
|
|
-- only checksum the content.
|
|
gitShaKey :: Git.Sha -> Key
|
|
gitShaKey (Git.Ref s) = mkKey $ \kd -> kd
|
|
{ keyName = S.toShort s
|
|
, keyVariety = OtherKey "GIT"
|
|
}
|
|
|
|
-- Reverse of gitShaKey
|
|
keyGitSha :: Key -> Maybe Git.Sha
|
|
keyGitSha k
|
|
| fromKey keyVariety k == OtherKey "GIT" =
|
|
Just (Git.Ref (S.fromShort (fromKey keyName k)))
|
|
| otherwise = Nothing
|
|
|
|
-- Is a key storing a git sha, and not used for an annexed file?
|
|
isGitShaKey :: Key -> Bool
|
|
isGitShaKey = isJust . keyGitSha
|