diff options
Diffstat (limited to 'Git/CatFile.hs')
| -rw-r--r-- | Git/CatFile.hs | 130 |
1 files changed, 102 insertions, 28 deletions
diff --git a/Git/CatFile.hs b/Git/CatFile.hs index c63a064..061349f 100644 --- a/Git/CatFile.hs +++ b/Git/CatFile.hs @@ -1,6 +1,6 @@ {- git cat-file interface - - - Copyright 2011, 2013 Joey Hess <id@joeyh.name> + - Copyright 2011-2016 Joey Hess <id@joeyh.name> - - Licensed under the GNU GPL version 3 or higher. -} @@ -13,13 +13,19 @@ module Git.CatFile ( catFile, catFileDetails, catTree, + catCommit, catObject, catObjectDetails, + catObjectMetaData, ) where import System.IO import qualified Data.ByteString as S import qualified Data.ByteString.Lazy as L +import qualified Data.ByteString.Lazy.Char8 as L8 +import qualified Data.Map as M +import Data.String +import Data.Char import Data.Tuple.Utils import Numeric import System.Posix.Types @@ -32,21 +38,28 @@ import Git.Types import Git.FilePath import qualified Utility.CoProcess as CoProcess -data CatFileHandle = CatFileHandle CoProcess.CoProcessHandle Repo +data CatFileHandle = CatFileHandle + { catFileProcess :: CoProcess.CoProcessHandle + , checkFileProcess :: CoProcess.CoProcessHandle + } catFileStart :: Repo -> IO CatFileHandle catFileStart = catFileStart' True catFileStart' :: Bool -> Repo -> IO CatFileHandle -catFileStart' restartable repo = do - coprocess <- CoProcess.rawMode =<< gitCoProcessStart restartable +catFileStart' restartable repo = CatFileHandle + <$> startp "--batch" + <*> startp "--batch-check=%(objectname) %(objecttype) %(objectsize)" + where + startp p = gitCoProcessStart restartable [ Param "cat-file" - , Param "--batch" + , Param p ] repo - return $ CatFileHandle coprocess repo catFileStop :: CatFileHandle -> IO () -catFileStop (CatFileHandle p _) = CoProcess.stop p +catFileStop h = do + CoProcess.stop (catFileProcess h) + CoProcess.stop (checkFileProcess h) {- Reads a file from a specified branch. -} catFile :: CatFileHandle -> Branch -> FilePath -> IO L.ByteString @@ -63,32 +76,52 @@ catObject :: CatFileHandle -> Ref -> IO L.ByteString catObject h object = maybe L.empty fst3 <$> catObjectDetails h object catObjectDetails :: CatFileHandle -> Ref -> IO (Maybe (L.ByteString, Sha, ObjectType)) -catObjectDetails (CatFileHandle hdl _) object = CoProcess.query hdl send receive +catObjectDetails h object = query (catFileProcess h) object $ \from -> do + header <- hGetLine from + case parseResp object header of + Just (ParsedResp sha size objtype) -> do + content <- S.hGet from (fromIntegral size) + eatchar '\n' from + return $ Just (L.fromChunks [content], sha, objtype) + Just DNE -> return Nothing + Nothing -> error $ "unknown response from git cat-file " ++ show (header, object) where - query = fromRef object - send to = hPutStrLn to query - receive from = do - header <- hGetLine from - case words header of - [sha, objtype, size] - | length sha == shaSize -> - case (readObjectType objtype, reads size) of - (Just t, [(bytes, "")]) -> readcontent t bytes from sha - _ -> dne - | otherwise -> dne - _ - | header == fromRef object ++ " missing" -> dne - | otherwise -> error $ "unknown response from git cat-file " ++ show (header, query) - readcontent objtype bytes from sha = do - content <- S.hGet from bytes - eatchar '\n' from - return $ Just (L.fromChunks [content], Ref sha, objtype) - dne = return Nothing eatchar expected from = do c <- hGetChar from when (c /= expected) $ error $ "missing " ++ (show expected) ++ " from git cat-file" +{- Gets the size and type of an object, without reading its content. -} +catObjectMetaData :: CatFileHandle -> Ref -> IO (Maybe (Integer, ObjectType)) +catObjectMetaData h object = query (checkFileProcess h) object $ \from -> do + resp <- hGetLine from + case parseResp object resp of + Just (ParsedResp _ size objtype) -> + return $ Just (size, objtype) + Just DNE -> return Nothing + Nothing -> error $ "unknown response from git cat-file " ++ show (resp, object) + +data ParsedResp = ParsedResp Sha Integer ObjectType | DNE + +query :: CoProcess.CoProcessHandle -> Ref -> (Handle -> IO a) -> IO a +query hdl object receive = CoProcess.query hdl send receive + where + send to = hPutStrLn to (fromRef object) + +parseResp :: Ref -> String -> Maybe ParsedResp +parseResp object l + | " missing" `isSuffixOf` l -- less expensive than full check + && l == fromRef object ++ " missing" = Just DNE + | otherwise = case words l of + [sha, objtype, size] + | length sha == shaSize -> + case (readObjectType objtype, reads size) of + (Just t, [(bytes, "")]) -> + Just $ ParsedResp (Ref sha) bytes t + _ -> Nothing + | otherwise -> Nothing + _ -> Nothing + {- Gets a list of files and directories in a tree. (Not recursive.) -} catTree :: CatFileHandle -> Ref -> IO [(FilePath, FileMode)] catTree h treeref = go <$> catObjectDetails h treeref @@ -104,10 +137,51 @@ catTree h treeref = go <$> catObjectDetails h treeref (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 (== ' ') (decodeBS b) in (file, readmode modestr) readmode = fromMaybe 0 . fmap fst . headMaybe . readOct + +catCommit :: CatFileHandle -> Ref -> IO (Maybe Commit) +catCommit h commitref = go <$> catObjectDetails h commitref + where + go (Just (b, _, CommitObject)) = parseCommit b + go _ = Nothing + +parseCommit :: L.ByteString -> Maybe Commit +parseCommit b = Commit + <$> (extractSha . L8.unpack =<< field "tree") + <*> Just (maybe [] (mapMaybe (extractSha . L8.unpack)) (fields "parent")) + <*> (parsemetadata <$> field "author") + <*> (parsemetadata <$> field "committer") + <*> Just (L8.unpack $ L.intercalate (L.singleton nl) message) + where + field n = headMaybe =<< fields n + fields n = M.lookup (fromString n) fieldmap + fieldmap = M.fromListWith (++) ((map breakfield) header) + breakfield l = + let (k, sp_v) = L.break (== sp) l + in (k, [L.drop 1 sp_v]) + (header, message) = separate L.null ls + ls = L.split nl b + + -- author and committer lines have the form: "name <email> date" + -- The email is always present, even if empty "<>" + parsemetadata l = CommitMetaData + { commitName = whenset $ L.init name_sp + , commitEmail = whenset email + , commitDate = whenset $ L.drop 2 gt_sp_date + } + where + (name_sp, rest) = L.break (== lt) l + (email, gt_sp_date) = L.break (== gt) (L.drop 1 rest) + whenset v + | L.null v = Nothing + | otherwise = Just (L8.unpack v) + + nl = fromIntegral (ord '\n') + sp = fromIntegral (ord ' ') + lt = fromIntegral (ord '<') + gt = fromIntegral (ord '>') |