catch IO exceptions

1 files changed, 10 insertions, 2 deletions

diff --git a/Storage/LocalFiles.hs b/Storage/LocalFiles.hs
index a9496da..d339774 100644
--- a/Storage/LocalFiles.hs
+++ b/Storage/LocalFiles.hs
@@ -20,6 +20,7 @@ import System.Posix
 import System.FilePath
 import Raaz.Core.Encode
 import Control.DeepSeq
+import Control.Exception
 
 localFiles :: Storage
 localFiles = Storage
@@ -28,7 +29,7 @@ localFiles = Storage
 	}
 
 store :: StorableObjectIdent -> Shard -> IO StoreResult
-store i s = do
+store i s = onError (StoreFailure . show) $ do
 	dir <- shardDir
 	createDirectoryIfMissing True dir
 	fd <- openFd (dir </> shardFile i) WriteOnly (Just 0o666)
@@ -39,7 +40,7 @@ store i s = do
 	return StoreSuccess
 
 retrieve :: ShardNum -> StorableObjectIdent -> IO RetrieveResult
-retrieve n i = do
+retrieve n i = onError (RetrieveFailure . show) $ do
 	dir <- shardDir
 	fd <- openFd (dir </> shardFile i) ReadOnly Nothing defaultFileFlags
 	h <- fdToHandle fd
@@ -47,6 +48,13 @@ retrieve n i = do
 	b `deepseq` hClose h
 	return $ RetrieveSuccess $ Shard n (StorableObject b)
 
+onError :: (IOException -> a) -> IO a -> IO a
+onError f a = do
+	v <- try a
+	return $ case v of
+		Left e -> f e
+		Right r -> r
+
 shardDir :: IO FilePath
 shardDir = do
 	u <- getUserEntryForID =<< getEffectiveUserID