1 files changed, 76 insertions, 0 deletions
diff --git a/Git/HashObject.hs b/Git/HashObject.hs
new file mode 100644
index 0000000..3787c9c
--- /dev/null
+++ b/Git/HashObject.hs
@@ -0,0 +1,76 @@
+{- git hash-object interface
+ -
+ - Copyright 2011-2019 Joey Hess <id@joeyh.name>
+ -
+ - Licensed under the GNU AGPL 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
+import Data.ByteString.Builder
+
+type HashObjectHandle = CoProcess.CoProcessHandle
+
+hashObjectStart :: Bool -> Repo -> IO HashObjectHandle
+hashObjectStart writeobject = gitCoProcessStart True $ catMaybes
+	[ Just (Param "hash-object")
+	, if writeobject then Just (Param "-w") else Nothing
+	, Just (Param "--stdin-paths")
+	, Just (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
+
+instance HashableBlob Builder where
+	hashableBlobToHandle = hPutBuilder
+
+{- 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", decodeBS (fmtObjectType objtype), "-w", "--stdin", "--no-filters"]