module Game.LambdaHack.Utils.File
( encodeEOF, strictDecodeEOF, tryCreateDir, tryCopyDataFiles
) where
import qualified Codec.Compression.Zlib as Z
import Control.Monad
import Data.Binary
import qualified Data.ByteString.Lazy as LBS
import System.Directory
import System.FilePath
import System.IO
encodeData :: Binary a => FilePath -> a -> IO ()
encodeData f = LBS.writeFile f . Z.compress . encode
encodeEOF :: Binary a => FilePath -> a -> IO ()
encodeEOF f a = encodeData f (a, "OK" :: String)
strictReadSerialized :: FilePath -> IO LBS.ByteString
strictReadSerialized f =
withBinaryFile f ReadMode $ \ h -> do
c <- LBS.hGetContents h
let d = Z.decompress c
LBS.length d `seq` return d
strictDecodeData :: Binary a => FilePath -> IO a
strictDecodeData = fmap decode . strictReadSerialized
strictDecodeEOF :: Binary a => FilePath -> IO a
strictDecodeEOF f = do
(a, n) <- strictDecodeData f
if n == ("OK" :: String)
then return a
else error $ "Fatal error: corrupted file " ++ f
tryCreateDir :: FilePath -> IO ()
tryCreateDir dir = do
dirExists <- doesDirectoryExist dir
unless dirExists $ createDirectory dir
tryCopyDataFiles :: FilePath
-> (FilePath -> IO FilePath)
-> [(FilePath, FilePath)]
-> IO ()
tryCopyDataFiles configAppDataDir pathsDataFile files =
let cpFile (fin, fout) = do
pathsDataIn <- pathsDataFile $ takeFileName fin
bIn <- doesFileExist pathsDataIn
let pathsDataOut = configAppDataDir </> fout
bOut <- doesFileExist pathsDataOut
when (not bOut && bIn) $ copyFile pathsDataIn pathsDataOut
in mapM_ cpFile files