git-annex/Git/HashObject.hs
Joey Hess 53905490df
convert Git.HashObject to use ByteStrings
Both lazy and strict, because sometimes it's more efficient to build a
small strict bytestring, and other times better to lazily stream.
2019-01-03 13:21:01 -04:00

72 lines
2 KiB
Haskell

{- git hash-object interface
-
- Copyright 2011-2019 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
module Git.HashObject where
import Common
import Git
import Git.Sha
import Git.Command
import Git.Types
import qualified Utility.CoProcess as CoProcess
import Utility.Tmp
import qualified Data.ByteString as S
import qualified Data.ByteString.Lazy as L
type HashObjectHandle = CoProcess.CoProcessHandle
hashObjectStart :: Repo -> IO HashObjectHandle
hashObjectStart = gitCoProcessStart True
[ Param "hash-object"
, Param "-w"
, Param "--stdin-paths"
, Param "--no-filters"
]
hashObjectStop :: HashObjectHandle -> IO ()
hashObjectStop = CoProcess.stop
{- Injects a file into git, returning the Sha of the object. -}
hashFile :: HashObjectHandle -> FilePath -> IO Sha
hashFile h file = CoProcess.query h send receive
where
send to = hPutStrLn to =<< absPath file
receive from = getSha "hash-object" $ hGetLine from
class HashableBlob t where
hashableBlobToHandle :: Handle -> t -> IO ()
instance HashableBlob L.ByteString where
hashableBlobToHandle = L.hPut
instance HashableBlob S.ByteString where
hashableBlobToHandle = S.hPut
{- Injects a blob into git. Unfortunately, the current git-hash-object
- interface does not allow batch hashing without using temp files. -}
hashBlob :: HashableBlob b => HashObjectHandle -> b -> IO Sha
hashBlob h b = withTmpFile "hash" $ \tmp tmph -> do
hashableBlobToHandle tmph b
hClose tmph
hashFile h tmp
{- Injects some content into git, returning its Sha.
-
- Avoids using a tmp file, but runs a new hash-object command each
- time called. -}
hashObject :: ObjectType -> String -> Repo -> IO Sha
hashObject objtype content = hashObject' objtype (flip hPutStr content)
hashObject' :: ObjectType -> (Handle -> IO ()) -> Repo -> IO Sha
hashObject' objtype writer repo = getSha subcmd $
pipeWriteRead (map Param params) (Just writer) repo
where
subcmd = "hash-object"
params = [subcmd, "-t", show objtype, "-w", "--stdin", "--no-filters"]