module ByteStringUtils (
unsafeWithInternals,
gzReadFilePS,
mmapFilePS,
gzWriteFilePS,
gzWriteFilePSs,
isGZFile,
gzDecompress,
ifHeadThenTail,
dropSpace,
breakSpace,
linesPS,
unlinesPS,
hashPS,
breakFirstPS,
breakLastPS,
substrPS,
readIntPS,
is_funky,
fromHex2PS,
fromPS2Hex,
betweenLinesPS,
break_after_nth_newline,
break_before_nth_newline,
intercalate
) where
import Prelude hiding ( catch )
import qualified Data.ByteString as B
import qualified Data.ByteString.Char8 as BC
import qualified Data.ByteString.Internal as BI
import Data.ByteString (intercalate, uncons)
import Data.ByteString.Internal (fromForeignPtr)
#if defined (HAVE_MMAP)
import Control.Exception ( catch )
#endif
import System.IO
import System.IO.Unsafe ( unsafePerformIO )
import Foreign.Storable ( peekElemOff, peek )
import Foreign.Marshal.Array ( advancePtr )
import Foreign.C.Types ( CInt )
import Data.Bits ( rotateL )
import Data.Char ( ord, isSpace )
import Data.Word ( Word8 )
import Data.Int ( Int32 )
import Control.Monad ( when )
import Foreign.Ptr ( plusPtr, Ptr )
import Foreign.ForeignPtr ( withForeignPtr )
#ifdef DEBUG_PS
import Foreign.ForeignPtr ( addForeignPtrFinalizer )
import Foreign.Ptr ( FunPtr )
#endif
import qualified Data.ByteString.Lazy as BL
import qualified Codec.Compression.GZip as GZ
import qualified Codec.Compression.Zlib.Internal as ZI
import Darcs.Global ( addCRCWarning )
#ifdef HAVE_MMAP
import System.IO.MMap( mmapFileByteString )
import System.Mem( performGC )
import System.Posix.Files( fileSize, getSymbolicLinkStatus )
#endif
unsafeWithInternals :: B.ByteString -> (Ptr Word8 -> Int -> IO a) -> IO a
unsafeWithInternals ps f
= case BI.toForeignPtr ps of
(fp,s,l) -> withForeignPtr fp $ \p -> f (p `plusPtr` s) l
readIntPS :: B.ByteString -> Maybe (Int, B.ByteString)
readIntPS = BC.readInt . BC.dropWhile isSpace
ifHeadThenTail :: Word8 -> B.ByteString -> Maybe B.ByteString
ifHeadThenTail c s = case uncons s of
Just (w, t) | w == c -> Just t
_ -> Nothing
isSpaceWord8 :: Word8 -> Bool
isSpaceWord8 w =
w == 0x20 ||
w == 0x09 ||
w == 0x0A ||
w == 0x0D
firstnonspace :: Ptr Word8 -> Int -> Int -> IO Int
firstnonspace !ptr !n !m
| n >= m = return n
| otherwise = do w <- peekElemOff ptr n
if isSpaceWord8 w then firstnonspace ptr (n+1) m else return n
firstspace :: Ptr Word8 -> Int -> Int -> IO Int
firstspace !ptr !n !m
| n >= m = return n
| otherwise = do w <- peekElemOff ptr n
if (not . isSpaceWord8) w then firstspace ptr (n+1) m else return n
dropSpace :: B.ByteString -> B.ByteString
dropSpace (BI.PS x s l) = BI.inlinePerformIO $ withForeignPtr x $ \p -> do
i <- firstnonspace (p `plusPtr` s) 0 l
return $! if i == l then B.empty else BI.PS x (s+i) (li)
breakSpace :: B.ByteString -> (B.ByteString,B.ByteString)
breakSpace (BI.PS x s l) = BI.inlinePerformIO $ withForeignPtr x $ \p -> do
i <- firstspace (p `plusPtr` s) 0 l
return $! case () of {_
| i == 0 -> (B.empty, BI.PS x s l)
| i == l -> (BI.PS x s l, B.empty)
| otherwise -> (BI.PS x s i, BI.PS x (s+i) (li))
}
is_funky :: B.ByteString -> Bool
is_funky ps = case BI.toForeignPtr ps of
(x,s,l) ->
unsafePerformIO $ withForeignPtr x $ \p->
(/=0) `fmap` has_funky_char (p `plusPtr` s) (fromIntegral l)
foreign import ccall unsafe "fpstring.h has_funky_char" has_funky_char
:: Ptr Word8 -> CInt -> IO CInt
hashPS :: B.ByteString -> Int32
hashPS ps =
case BI.toForeignPtr ps of
(x,s,l) ->
unsafePerformIO $ withForeignPtr x $ \p->
do hash (p `plusPtr` s) l
hash :: Ptr Word8 -> Int -> IO Int32
hash ptr len = f (0 :: Int32) ptr len
where f h _ 0 = return h
f h p n = do x <- peek p
let !h' = (fromIntegral x) + (rotateL h 8)
f h' (p `advancePtr` 1) (n1)
substrPS :: B.ByteString -> B.ByteString -> Maybe Int
substrPS tok str
| B.null tok = Just 0
| B.length tok > B.length str = Nothing
| otherwise = do n <- BC.elemIndex (BC.head tok) str
let ttok = B.tail tok
reststr = B.drop (n+1) str
if ttok == B.take (B.length ttok) reststr
then Just n
else ((n+1)+) `fmap` substrPS tok reststr
breakFirstPS :: Char -> B.ByteString -> Maybe (B.ByteString,B.ByteString)
breakFirstPS c p = case BC.elemIndex c p of
Nothing -> Nothing
Just n -> Just (B.take n p, B.drop (n+1) p)
breakLastPS :: Char -> B.ByteString -> Maybe (B.ByteString,B.ByteString)
breakLastPS c p = case BC.elemIndexEnd c p of
Nothing -> Nothing
Just n -> Just (B.take n p, B.drop (n+1) p)
linesPS :: B.ByteString -> [B.ByteString]
linesPS ps
| B.null ps = [B.empty]
| otherwise = BC.split '\n' ps
unlinesPS :: [B.ByteString] -> B.ByteString
unlinesPS [] = BC.empty
unlinesPS x = BC.init $ BC.unlines x
gzDecompress :: Maybe Int -> BL.ByteString -> ([B.ByteString], Bool)
gzDecompress mbufsize =
toListWarn . ZI.decompressWithErrors ZI.gzipFormat decompressParams
where
decompressParams = case mbufsize of
Just bufsize -> GZ.defaultDecompressParams { GZ.decompressBufferSize = bufsize }
Nothing -> GZ.defaultDecompressParams
toListWarn :: ZI.DecompressStream -> ([B.ByteString], Bool)
toListWarn = foldDecompressStream (\x ~(xs, b) -> (x:xs, b)) ([], False) handleBad
foldDecompressStream :: (B.ByteString -> a -> a) -> a
-> (ZI.DecompressError -> String -> a)
-> ZI.DecompressStream -> a
foldDecompressStream chunk end err = fold
where
fold ZI.StreamEnd = end
fold (ZI.StreamChunk bs stream) = chunk bs (fold stream)
fold (ZI.StreamError code msg) = err code msg
handleBad ZI.DataError "incorrect data check" = ([], True)
handleBad _ msg = error msg
isGZFile :: FilePath -> IO (Maybe Int)
isGZFile f = do
h <- openBinaryFile f ReadMode
header <- B.hGet h 2
if header /= BC.pack "\31\139"
then do hClose h
return Nothing
else do hSeek h SeekFromEnd (4)
len <- hGetLittleEndInt h
hClose h
return (Just len)
gzReadFilePS :: FilePath -> IO B.ByteString
gzReadFilePS f = do
mlen <- isGZFile f
case mlen of
Nothing -> mmapFilePS f
Just len ->
do
let doDecompress buf = let (res, bad) = gzDecompress (Just len) buf
in do when bad $ addCRCWarning f
return res
compressed <- (BL.fromChunks . return) `fmap` mmapFilePS f
B.concat `fmap` doDecompress compressed
hGetLittleEndInt :: Handle -> IO Int
hGetLittleEndInt h = do
b1 <- ord `fmap` hGetChar h
b2 <- ord `fmap` hGetChar h
b3 <- ord `fmap` hGetChar h
b4 <- ord `fmap` hGetChar h
return $ b1 + 256*b2 + 65536*b3 + 16777216*b4
gzWriteFilePS :: FilePath -> B.ByteString -> IO ()
gzWriteFilePS f ps = gzWriteFilePSs f [ps]
gzWriteFilePSs :: FilePath -> [B.ByteString] -> IO ()
gzWriteFilePSs f pss =
BL.writeFile f $ GZ.compress $ BL.fromChunks pss
mmapFilePS :: FilePath -> IO B.ByteString
#ifdef HAVE_MMAP
mmapFilePS f = do
x <- mmapFileByteString f Nothing
`catch` (\_ -> do
size <- fileSize `fmap` getSymbolicLinkStatus f
if size == 0
then return B.empty
else performGC >> mmapFileByteString f Nothing)
return x
#else
mmapFilePS = B.readFile
#endif
foreign import ccall unsafe "static fpstring.h conv_to_hex" conv_to_hex
:: Ptr Word8 -> Ptr Word8 -> CInt -> IO ()
fromPS2Hex :: B.ByteString -> B.ByteString
fromPS2Hex ps = case BI.toForeignPtr ps of
(x,s,l) ->
BI.unsafeCreate (2*l) $ \p -> withForeignPtr x $ \f ->
conv_to_hex p (f `plusPtr` s) $ fromIntegral l
foreign import ccall unsafe "static fpstring.h conv_from_hex" conv_from_hex
:: Ptr Word8 -> Ptr Word8 -> CInt -> IO ()
fromHex2PS :: B.ByteString -> B.ByteString
fromHex2PS ps = case BI.toForeignPtr ps of
(x,s,l) ->
BI.unsafeCreate (l `div` 2) $ \p -> withForeignPtr x $ \f ->
conv_from_hex p (f `plusPtr` s) (fromIntegral $ l `div` 2)
betweenLinesPS :: B.ByteString -> B.ByteString -> B.ByteString
-> Maybe (B.ByteString)
betweenLinesPS start end ps
= case break (start ==) (linesPS ps) of
(_, _:rest@(bs1:_)) ->
case BI.toForeignPtr bs1 of
(ps1,s1,_) ->
case break (end ==) rest of
(_, bs2:_) -> case BI.toForeignPtr bs2 of (_,s2,_) -> Just $ fromForeignPtr ps1 s1 (s2 s1)
_ -> Nothing
_ -> Nothing
break_after_nth_newline :: Int -> B.ByteString
-> Maybe (B.ByteString, B.ByteString)
break_after_nth_newline 0 the_ps | B.null the_ps = Just (B.empty, B.empty)
break_after_nth_newline n the_ps =
case BI.toForeignPtr the_ps of
(fp,the_s,l) ->
unsafePerformIO $ withForeignPtr fp $ \p ->
do let findit 0 s | s == end = return $ Just (the_ps, B.empty)
findit _ s | s == end = return Nothing
findit 0 s = let left_l = s the_s
in return $ Just (fromForeignPtr fp the_s left_l,
fromForeignPtr fp s (l left_l))
findit i s = do w <- peekElemOff p s
if w == nl then findit (i1) (s+1)
else findit i (s+1)
nl = BI.c2w '\n'
end = the_s + l
findit n the_s
break_before_nth_newline :: Int -> B.ByteString -> (B.ByteString, B.ByteString)
break_before_nth_newline 0 the_ps
| B.null the_ps = (B.empty, B.empty)
break_before_nth_newline n the_ps =
case BI.toForeignPtr the_ps of
(fp,the_s,l) ->
unsafePerformIO $ withForeignPtr fp $ \p ->
do let findit _ s | s == end = return (the_ps, B.empty)
findit i s = do w <- peekElemOff p s
if w == nl
then if i == 0
then let left_l = s the_s
in return (fromForeignPtr fp the_s left_l,
fromForeignPtr fp s (l left_l))
else findit (i1) (s+1)
else findit i (s+1)
nl = BI.c2w '\n'
end = the_s + l
findit n the_s