avoid closing pipe before all the shas are read from it

Could have just used hGetContentsStrict here, but that would require
storing all the shas in memory. Since this is called at the end of a
git-annex run, it may have created a *lot* of shas, so I avoid that memory
use and stream them out like before.

1 files changed, 8 insertions, 6 deletions

diff --git a/Git/HashObject.hs b/Git/HashObject.hs
index f28d865b1..99b96afcb 100644
--- a/Git/HashObject.hs
+++ b/Git/HashObject.hs
@@ -10,16 +10,15 @@ module Git.HashObject where
 import Common
 import Git
 
-{- Injects a set of files into git, returning the shas of the objects. -}
-hashFiles :: [FilePath] -> Repo -> IO [Sha]
+{- Injects a set of files into git, returning the shas of the objects
+ - and an IO action to call ones the the shas have been used. -}
+hashFiles :: [FilePath] -> Repo -> IO ([Sha], IO ())
 hashFiles paths repo = do
 	(pid, fromh, toh) <- hPipeBoth "git" $ toCommand $ git_hash_object repo
 	_ <- forkProcess (feeder toh)
 	hClose toh
-	shas <- map Git.Ref . lines <$> hGetContents fromh
-	hClose fromh
-	forceSuccess pid
-	return shas
+	shas <- map Git.Ref . lines <$> hGetContentsStrict fromh
+	return (shas, ender fromh pid)
 	where
 		git_hash_object = Git.gitCommandLine
 			[Param "hash-object", Param "-w", Param "--stdin-paths"]
@@ -27,3 +26,6 @@ hashFiles paths repo = do
 			hPutStr toh $ unlines paths
 			hClose toh
 			exitSuccess
+		ender fromh pid = do
+			hClose fromh
+			forceSuccess pid