diff options
Diffstat (limited to 'Utility/FileSystemEncoding.hs')
| -rw-r--r-- | Utility/FileSystemEncoding.hs | 43 |
1 files changed, 41 insertions, 2 deletions
diff --git a/Utility/FileSystemEncoding.hs b/Utility/FileSystemEncoding.hs index ac105e73d..690942cba 100644 --- a/Utility/FileSystemEncoding.hs +++ b/Utility/FileSystemEncoding.hs @@ -1,14 +1,17 @@ {- GHC File system encoding handling. - - - Copyright 2012-2013 Joey Hess <joey@kitenet.net> + - Copyright 2012-2014 Joey Hess <joey@kitenet.net> - - Licensed under the GNU GPL version 3 or higher. -} +{-# LANGUAGE CPP #-} + module Utility.FileSystemEncoding ( fileEncoding, withFilePath, md5FilePath, + decodeBS, decodeW8, encodeW8, truncateFilePath, @@ -22,13 +25,24 @@ import System.IO.Unsafe import qualified Data.Hash.MD5 as MD5 import Data.Word import Data.Bits.Utils +import qualified Data.ByteString.Lazy as L +#ifdef mingw32_HOST_OS +import qualified Data.ByteString.Lazy.UTF8 as L8 +#endif {- Sets a Handle to use the filesystem encoding. This causes data - written or read from it to be encoded/decoded the same - as ghc 7.4 does to filenames etc. This special encoding - - allows "arbitrary undecodable bytes to be round-tripped through it". -} + - allows "arbitrary undecodable bytes to be round-tripped through it". + -} fileEncoding :: Handle -> IO () +#ifndef mingw32_HOST_OS fileEncoding h = hSetEncoding h =<< Encoding.getFileSystemEncoding +#else +{- The file system encoding does not work well on Windows, + - and Windows only has utf FilePaths anyway. -} +fileEncoding h = hSetEncoding h Encoding.utf8 +#endif {- Marshal a Haskell FilePath into a NUL terminated C string using temporary - storage. The FilePath is encoded using the filesystem encoding, @@ -60,6 +74,16 @@ _encodeFilePath fp = unsafePerformIO $ do md5FilePath :: FilePath -> MD5.Str md5FilePath = MD5.Str . _encodeFilePath +{- Decodes a ByteString into a FilePath, applying the filesystem encoding. -} +decodeBS :: L.ByteString -> FilePath +#ifndef mingw32_HOST_OS +decodeBS = encodeW8 . L.unpack +#else +{- On Windows, we assume that the ByteString is utf-8, since Windows + - only uses unicode for filenames. -} +decodeBS = L8.toString +#endif + {- Converts a [Word8] to a FilePath, encoding using the filesystem encoding. - - w82c produces a String, which may contain Chars that are invalid @@ -84,6 +108,7 @@ decodeW8 = s2w8 . _encodeFilePath - cost of efficiency when running on a large FilePath. -} truncateFilePath :: Int -> FilePath -> FilePath +#ifndef mingw32_HOST_OS truncateFilePath n = go . reverse where go f = @@ -91,3 +116,17 @@ truncateFilePath n = go . reverse in if length bytes <= n then reverse f else go (drop 1 f) +#else +{- On Windows, count the number of bytes used by each utf8 character. -} +truncateFilePath n = reverse . go [] n . L8.fromString + where + go coll cnt bs + | cnt <= 0 = coll + | otherwise = case L8.decode bs of + Just (c, x) | c /= L8.replacement_char -> + let x' = fromIntegral x + in if cnt - x' < 0 + then coll + else go (c:coll) (cnt - x') (L8.drop 1 bs) + _ -> coll +#endif |