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-rw-r--r--src/Erebos/Storage.hs33
1 files changed, 19 insertions, 14 deletions
diff --git a/src/Erebos/Storage.hs b/src/Erebos/Storage.hs
index 034ed04..95ef649 100644
--- a/src/Erebos/Storage.hs
+++ b/src/Erebos/Storage.hs
@@ -117,21 +117,26 @@ storageVersion = "0.1"
openStorage :: FilePath -> IO Storage
openStorage path = modifyIOError annotate $ do
- let versionPath = path </> "erebos-storage"
- doesFileExist versionPath >>= \case
- True -> readFile versionPath >>= \case
- content | (ver:_) <- lines content, ver == storageVersion -> return ()
- | otherwise -> fail "unsupported storage version"
+ let versionFileName = "erebos-storage"
+ let versionPath = path </> versionFileName
+ let writeVersionFile = writeFile versionPath $ storageVersion <> "\n"
+
+ doesDirectoryExist path >>= \case
+ True -> do
+ listDirectory path >>= \case
+ files@(_:_)
+ | versionFileName `elem` files -> do
+ readFile versionPath >>= \case
+ content | (ver:_) <- lines content, ver == storageVersion -> return ()
+ | otherwise -> fail "unsupported storage version"
+
+ | "objects" `notElem` files || "heads" `notElem` files -> do
+ fail "directory is neither empty, nor an existing erebos storage"
+
+ _ -> writeVersionFile
False -> do
- doesDirectoryExist path >>= \case
- True -> do
- listDirectory path >>= \case
- contents@(_:_) | "objects" `notElem` contents || "heads" `notElem` contents
- -> fail "directory is neither empty, nor an existing erebos storage"
- _ -> return ()
- False -> do
- createDirectoryIfMissing True $ path
- writeFile versionPath $ storageVersion <> "\n"
+ createDirectoryIfMissing True $ path
+ writeVersionFile
createDirectoryIfMissing True $ path </> "objects"
createDirectoryIfMissing True $ path </> "heads"