{-# LANGUAGE Trustworthy #-} {-# LANGUAGE NoImplicitPrelude , BangPatterns , NondecreasingIndentation , MagicHash #-} {-# OPTIONS_GHC -funbox-strict-fields #-} ----------------------------------------------------------------------------- -- | -- Module : GHC.IO.Encoding.UTF16 -- Copyright : (c) The University of Glasgow, 2009 -- License : see libraries/base/LICENSE -- -- Maintainer : libraries@haskell.org -- Stability : internal -- Portability : non-portable -- -- UTF-16 Codecs for the IO library -- -- Portions Copyright : (c) Tom Harper 2008-2009, -- (c) Bryan O'Sullivan 2009, -- (c) Duncan Coutts 2009 -- ----------------------------------------------------------------------------- module GHC.IO.Encoding.UTF16 ( utf16, mkUTF16, utf16_decode, utf16_encode, utf16be, mkUTF16be, utf16be_decode, utf16be_encode, utf16le, mkUTF16le, utf16le_decode, utf16le_encode, ) where import GHC.Base import GHC.Real import GHC.Num -- import GHC.IO import GHC.IO.Buffer import GHC.IO.Encoding.Failure import GHC.IO.Encoding.Types import GHC.Word import Data.Bits import GHC.IORef -- ----------------------------------------------------------------------------- -- The UTF-16 codec: either UTF16BE or UTF16LE with a BOM utf16 :: TextEncoding utf16 = mkUTF16 ErrorOnCodingFailure -- | @since 4.4.0.0 mkUTF16 :: CodingFailureMode -> TextEncoding mkUTF16 cfm = TextEncoding { textEncodingName = "UTF-16", mkTextDecoder = utf16_DF cfm, mkTextEncoder = utf16_EF cfm } utf16_DF :: CodingFailureMode -> IO (TextDecoder (Maybe DecodeBuffer)) utf16_DF cfm = do seen_bom <- newIORef Nothing return (BufferCodec { encode = utf16_decode seen_bom, recover = recoverDecode cfm, close = return (), getState = readIORef seen_bom, setState = writeIORef seen_bom }) utf16_EF :: CodingFailureMode -> IO (TextEncoder Bool) utf16_EF cfm = do done_bom <- newIORef False return (BufferCodec { encode = utf16_encode done_bom, recover = recoverEncode cfm, close = return (), getState = readIORef done_bom, setState = writeIORef done_bom }) utf16_encode :: IORef Bool -> EncodeBuffer utf16_encode done_bom input output@Buffer{ bufRaw=oraw, bufL=_, bufR=ow, bufSize=os } = do b <- readIORef done_bom if b then utf16_native_encode input output else if os - ow < 2 then return (OutputUnderflow,input,output) else do writeIORef done_bom True writeWord8Buf oraw ow bom1 writeWord8Buf oraw (ow+1) bom2 utf16_native_encode input output{ bufR = ow+2 } utf16_decode :: IORef (Maybe DecodeBuffer) -> DecodeBuffer utf16_decode seen_bom input@Buffer{ bufRaw=iraw, bufL=ir, bufR=iw, bufSize=_ } output = do mb <- readIORef seen_bom case mb of Just decode -> decode input output Nothing -> if iw - ir < 2 then return (InputUnderflow,input,output) else do c0 <- readWord8Buf iraw ir c1 <- readWord8Buf iraw (ir+1) case () of _ | c0 == bomB && c1 == bomL -> do writeIORef seen_bom (Just utf16be_decode) utf16be_decode input{ bufL= ir+2 } output | c0 == bomL && c1 == bomB -> do writeIORef seen_bom (Just utf16le_decode) utf16le_decode input{ bufL= ir+2 } output | otherwise -> do writeIORef seen_bom (Just utf16_native_decode) utf16_native_decode input output bomB, bomL, bom1, bom2 :: Word8 bomB = 0xfe bomL = 0xff -- choose UTF-16BE by default for UTF-16 output utf16_native_decode :: DecodeBuffer utf16_native_decode = utf16be_decode utf16_native_encode :: EncodeBuffer utf16_native_encode = utf16be_encode bom1 = bomB bom2 = bomL -- ----------------------------------------------------------------------------- -- UTF16LE and UTF16BE utf16be :: TextEncoding utf16be = mkUTF16be ErrorOnCodingFailure -- | @since 4.4.0.0 mkUTF16be :: CodingFailureMode -> TextEncoding mkUTF16be cfm = TextEncoding { textEncodingName = "UTF-16BE", mkTextDecoder = utf16be_DF cfm, mkTextEncoder = utf16be_EF cfm } utf16be_DF :: CodingFailureMode -> IO (TextDecoder ()) utf16be_DF cfm = return (BufferCodec { encode = utf16be_decode, recover = recoverDecode cfm, close = return (), getState = return (), setState = const $ return () }) utf16be_EF :: CodingFailureMode -> IO (TextEncoder ()) utf16be_EF cfm = return (BufferCodec { encode = utf16be_encode, recover = recoverEncode cfm, close = return (), getState = return (), setState = const $ return () }) utf16le :: TextEncoding utf16le = mkUTF16le ErrorOnCodingFailure -- | @since 4.4.0.0 mkUTF16le :: CodingFailureMode -> TextEncoding mkUTF16le cfm = TextEncoding { textEncodingName = "UTF16-LE", mkTextDecoder = utf16le_DF cfm, mkTextEncoder = utf16le_EF cfm } utf16le_DF :: CodingFailureMode -> IO (TextDecoder ()) utf16le_DF cfm = return (BufferCodec { encode = utf16le_decode, recover = recoverDecode cfm, close = return (), getState = return (), setState = const $ return () }) utf16le_EF :: CodingFailureMode -> IO (TextEncoder ()) utf16le_EF cfm = return (BufferCodec { encode = utf16le_encode, recover = recoverEncode cfm, close = return (), getState = return (), setState = const $ return () }) utf16be_decode :: DecodeBuffer utf16be_decode input@Buffer{ bufRaw=iraw, bufL=ir0, bufR=iw, bufSize=_ } output@Buffer{ bufRaw=oraw, bufL=_, bufR=ow0, bufSize=os } = let loop !ir !ow | ow >= os = done OutputUnderflow ir ow | ir >= iw = done InputUnderflow ir ow | ir + 1 == iw = done InputUnderflow ir ow | otherwise = do c0 <- readWord8Buf iraw ir c1 <- readWord8Buf iraw (ir+1) let x1 = fromIntegral c0 `shiftL` 8 + fromIntegral c1 if validate1 x1 then do ow' <- writeCharBuf oraw ow (unsafeChr (fromIntegral x1)) loop (ir+2) ow' else if iw - ir < 4 then done InputUnderflow ir ow else do c2 <- readWord8Buf iraw (ir+2) c3 <- readWord8Buf iraw (ir+3) let x2 = fromIntegral c2 `shiftL` 8 + fromIntegral c3 if not (validate2 x1 x2) then invalid else do ow' <- writeCharBuf oraw ow (chr2 x1 x2) loop (ir+4) ow' where invalid = done InvalidSequence ir ow -- lambda-lifted, to avoid thunks being built in the inner-loop: done why !ir !ow = return (why, if ir == iw then input{ bufL=0, bufR=0 } else input{ bufL=ir }, output{ bufR=ow }) in loop ir0 ow0 utf16le_decode :: DecodeBuffer utf16le_decode input@Buffer{ bufRaw=iraw, bufL=ir0, bufR=iw, bufSize=_ } output@Buffer{ bufRaw=oraw, bufL=_, bufR=ow0, bufSize=os } = let loop !ir !ow | ow >= os = done OutputUnderflow ir ow | ir >= iw = done InputUnderflow ir ow | ir + 1 == iw = done InputUnderflow ir ow | otherwise = do c0 <- readWord8Buf iraw ir c1 <- readWord8Buf iraw (ir+1) let x1 = fromIntegral c1 `shiftL` 8 + fromIntegral c0 if validate1 x1 then do ow' <- writeCharBuf oraw ow (unsafeChr (fromIntegral x1)) loop (ir+2) ow' else if iw - ir < 4 then done InputUnderflow ir ow else do c2 <- readWord8Buf iraw (ir+2) c3 <- readWord8Buf iraw (ir+3) let x2 = fromIntegral c3 `shiftL` 8 + fromIntegral c2 if not (validate2 x1 x2) then invalid else do ow' <- writeCharBuf oraw ow (chr2 x1 x2) loop (ir+4) ow' where invalid = done InvalidSequence ir ow -- lambda-lifted, to avoid thunks being built in the inner-loop: done why !ir !ow = return (why, if ir == iw then input{ bufL=0, bufR=0 } else input{ bufL=ir }, output{ bufR=ow }) in loop ir0 ow0 utf16be_encode :: EncodeBuffer utf16be_encode input@Buffer{ bufRaw=iraw, bufL=ir0, bufR=iw, bufSize=_ } output@Buffer{ bufRaw=oraw, bufL=_, bufR=ow0, bufSize=os } = let done why !ir !ow = return (why, if ir == iw then input{ bufL=0, bufR=0 } else input{ bufL=ir }, output{ bufR=ow }) loop !ir !ow | ir >= iw = done InputUnderflow ir ow | os - ow < 2 = done OutputUnderflow ir ow | otherwise = do (c,ir') <- readCharBuf iraw ir case ord c of x | x < 0x10000 -> if isSurrogate c then done InvalidSequence ir ow else do writeWord8Buf oraw ow (fromIntegral (x `shiftR` 8)) writeWord8Buf oraw (ow+1) (fromIntegral x) loop ir' (ow+2) | otherwise -> do if os - ow < 4 then done OutputUnderflow ir ow else do let n1 = x - 0x10000 c1 = fromIntegral (n1 `shiftR` 18 + 0xD8) c2 = fromIntegral (n1 `shiftR` 10) n2 = n1 .&. 0x3FF c3 = fromIntegral (n2 `shiftR` 8 + 0xDC) c4 = fromIntegral n2 -- writeWord8Buf oraw ow c1 writeWord8Buf oraw (ow+1) c2 writeWord8Buf oraw (ow+2) c3 writeWord8Buf oraw (ow+3) c4 loop ir' (ow+4) in loop ir0 ow0 utf16le_encode :: EncodeBuffer utf16le_encode input@Buffer{ bufRaw=iraw, bufL=ir0, bufR=iw, bufSize=_ } output@Buffer{ bufRaw=oraw, bufL=_, bufR=ow0, bufSize=os } = let done why !ir !ow = return (why, if ir == iw then input{ bufL=0, bufR=0 } else input{ bufL=ir }, output{ bufR=ow }) loop !ir !ow | ir >= iw = done InputUnderflow ir ow | os - ow < 2 = done OutputUnderflow ir ow | otherwise = do (c,ir') <- readCharBuf iraw ir case ord c of x | x < 0x10000 -> if isSurrogate c then done InvalidSequence ir ow else do writeWord8Buf oraw ow (fromIntegral x) writeWord8Buf oraw (ow+1) (fromIntegral (x `shiftR` 8)) loop ir' (ow+2) | otherwise -> if os - ow < 4 then done OutputUnderflow ir ow else do let n1 = x - 0x10000 c1 = fromIntegral (n1 `shiftR` 18 + 0xD8) c2 = fromIntegral (n1 `shiftR` 10) n2 = n1 .&. 0x3FF c3 = fromIntegral (n2 `shiftR` 8 + 0xDC) c4 = fromIntegral n2 -- writeWord8Buf oraw ow c2 writeWord8Buf oraw (ow+1) c1 writeWord8Buf oraw (ow+2) c4 writeWord8Buf oraw (ow+3) c3 loop ir' (ow+4) in loop ir0 ow0 chr2 :: Word16 -> Word16 -> Char chr2 (W16# a#) (W16# b#) = C# (chr# (upper# +# lower# +# 0x10000#)) where !x# = word2Int# (word16ToWord# a#) !y# = word2Int# (word16ToWord# b#) !upper# = uncheckedIShiftL# (x# -# 0xD800#) 10# !lower# = y# -# 0xDC00# {-# INLINE chr2 #-} validate1 :: Word16 -> Bool validate1 x1 = (x1 >= 0 && x1 < 0xD800) || x1 > 0xDFFF {-# INLINE validate1 #-} validate2 :: Word16 -> Word16 -> Bool validate2 x1 x2 = x1 >= 0xD800 && x1 <= 0xDBFF && x2 >= 0xDC00 && x2 <= 0xDFFF {-# INLINE validate2 #-}