133 lines
3.7 KiB
Haskell
133 lines
3.7 KiB
Haskell
{- git cat-file interface
|
|
-
|
|
- Copyright 2011, 2013 Joey Hess <joey@kitenet.net>
|
|
-
|
|
- Licensed under the GNU GPL version 3 or higher.
|
|
-}
|
|
|
|
module Git.CatFile (
|
|
CatFileHandle,
|
|
catFileStart,
|
|
catFileStop,
|
|
catFile,
|
|
catTree,
|
|
catObject,
|
|
catObjectDetails,
|
|
) where
|
|
|
|
import System.IO
|
|
import qualified Data.ByteString as S
|
|
import qualified Data.ByteString.Lazy as L
|
|
import Data.Digest.Pure.SHA
|
|
import Data.Char
|
|
import System.Process (std_out, std_err)
|
|
import Numeric
|
|
import System.Posix.Types
|
|
|
|
import Common
|
|
import Git
|
|
import Git.Sha
|
|
import Git.Command
|
|
import Git.Types
|
|
import Git.FilePath
|
|
import qualified Utility.CoProcess as CoProcess
|
|
|
|
data CatFileHandle = CatFileHandle CoProcess.CoProcessHandle Repo
|
|
|
|
catFileStart :: Repo -> IO CatFileHandle
|
|
catFileStart repo = do
|
|
coprocess <- CoProcess.rawMode =<< gitCoProcessStart True
|
|
[ Param "cat-file"
|
|
, Param "--batch"
|
|
] repo
|
|
return $ CatFileHandle coprocess repo
|
|
|
|
catFileStop :: CatFileHandle -> IO ()
|
|
catFileStop (CatFileHandle p _) = CoProcess.stop p
|
|
|
|
{- Reads a file from a specified branch. -}
|
|
catFile :: CatFileHandle -> Branch -> FilePath -> IO L.ByteString
|
|
catFile h branch file = catObject h $ Ref $
|
|
show branch ++ ":" ++ toInternalGitPath file
|
|
|
|
{- Uses a running git cat-file read the content of an object.
|
|
- Objects that do not exist will have "" returned. -}
|
|
catObject :: CatFileHandle -> Ref -> IO L.ByteString
|
|
catObject h object = maybe L.empty fst <$> catObjectDetails h object
|
|
|
|
{- Gets both the content of an object, and its Sha. -}
|
|
catObjectDetails :: CatFileHandle -> Ref -> IO (Maybe (L.ByteString, Sha))
|
|
catObjectDetails (CatFileHandle hdl repo) object = CoProcess.query hdl send receive
|
|
where
|
|
query = show object
|
|
send to = hPutStrLn to query
|
|
receive from = do
|
|
header <- hGetLine from
|
|
case words header of
|
|
[sha, objtype, size]
|
|
| length sha == shaSize &&
|
|
isJust (readObjectType objtype) ->
|
|
case reads size of
|
|
[(bytes, "")] -> readcontent bytes from sha
|
|
_ -> dne
|
|
| otherwise -> dne
|
|
_
|
|
| header == show object ++ " missing" -> dne
|
|
| otherwise ->
|
|
if any isSpace query
|
|
then fallback
|
|
else error $ "unknown response from git cat-file " ++ show (header, object)
|
|
readcontent bytes from sha = do
|
|
content <- S.hGet from bytes
|
|
eatchar '\n' from
|
|
return $ Just (L.fromChunks [content], Ref sha)
|
|
dne = return Nothing
|
|
eatchar expected from = do
|
|
c <- hGetChar from
|
|
when (c /= expected) $
|
|
error $ "missing " ++ (show expected) ++ " from git cat-file"
|
|
|
|
{- Work around a bug in git 1.8.4 rc0 which broke it for filenames
|
|
- containing spaces. http://bugs.debian.org/718517
|
|
- Slow! Also can use a lot of memory, if the object is large. -}
|
|
fallback = do
|
|
let p = gitCreateProcess
|
|
[ Param "cat-file"
|
|
, Param "-p"
|
|
, Param query
|
|
] repo
|
|
(_, Just h, _, pid) <- withNullHandle $ \h ->
|
|
createProcess p
|
|
{ std_out = CreatePipe
|
|
, std_err = UseHandle h
|
|
}
|
|
fileEncoding h
|
|
content <- L.hGetContents h
|
|
let sha = (\s -> length s `seq` s) (showDigest $ sha1 content)
|
|
ok <- checkSuccessProcess pid
|
|
return $ if ok
|
|
then Just (content, Ref sha)
|
|
else Nothing
|
|
|
|
{- Gets a list of files and directories in a tree. (Not recursive.) -}
|
|
catTree :: CatFileHandle -> Ref -> IO [(FilePath, FileMode)]
|
|
catTree h treeref = go <$> catObjectDetails h treeref
|
|
where
|
|
go Nothing = []
|
|
go (Just (b, _)) = parsetree [] b
|
|
|
|
parsetree c b = case L.break (== 0) b of
|
|
(modefile, rest)
|
|
| L.null modefile -> c
|
|
| otherwise -> parsetree
|
|
(parsemodefile modefile:c)
|
|
(dropsha rest)
|
|
|
|
-- these 20 bytes after the NUL hold the file's sha
|
|
-- TODO: convert from raw form to regular sha
|
|
dropsha = L.drop 21
|
|
|
|
parsemodefile b =
|
|
let (modestr, file) = separate (== ' ') (encodeW8 $ L.unpack b)
|
|
in (file, readmode modestr)
|
|
readmode = fst . Prelude.head . readOct
|