module Data.Conduit.Binary
( sourceFile
, sourceFileRange
, sinkFile
, conduitFile
, isolate
) where
import qualified Data.ByteString as S
import Data.Conduit
import Control.Exception (assert)
import Control.Monad.IO.Class (liftIO)
import qualified System.IO as IO
import Control.Monad.Trans.Resource (withIO, release, newRef, readRef, writeRef)
#if CABAL_OS_WINDOWS
import qualified System.Win32File as F
#elif NO_HANDLES
import qualified System.PosixFile as F
#endif
sourceFile :: ResourceIO m
=> FilePath
-> Source m S.ByteString
sourceFile fp = sourceIO
#if CABAL_OS_WINDOWS || NO_HANDLES
(F.openRead fp)
F.close
(liftIO . F.read)
#else
(IO.openFile fp IO.ReadMode)
IO.hClose
(\handle -> do
bs <- liftIO $ S.hGetSome handle 4096
if S.null bs
then return Closed
else return $ Open bs)
#endif
sourceFileRange :: ResourceIO m
=> FilePath
-> Maybe Integer
-> Maybe Integer
-> Source m S.ByteString
sourceFileRange fp offset count = Source $ do
(key, handle) <- withIO (IO.openFile fp IO.ReadMode) IO.hClose
case offset of
Nothing -> return ()
Just off -> liftIO $ IO.hSeek handle IO.AbsoluteSeek off
pull <-
case count of
Nothing -> return $ pullUnlimited handle key
Just c -> do
ic <- newRef c
return $ pullLimited ic handle key
return PreparedSource
{ sourcePull = pull
, sourceClose = release key
}
where
pullUnlimited handle key = do
bs <- liftIO $ S.hGetSome handle 4096
if S.null bs
then do
release key
return Closed
else return $ Open bs
pullLimited ic handle key = do
c <- fmap fromInteger $ readRef ic
bs <- liftIO $ S.hGetSome handle (min c 4096)
let c' = c S.length bs
assert (c' >= 0) $
if S.null bs
then do
release key
return Closed
else do
writeRef ic $ toInteger c'
return $ Open bs
sinkFile :: ResourceIO m
=> FilePath
-> Sink S.ByteString m ()
sinkFile fp = sinkIO
(IO.openFile fp IO.WriteMode)
IO.hClose
(\handle bs -> liftIO (S.hPut handle bs) >> return Processing)
(const $ return ())
conduitFile :: ResourceIO m
=> FilePath
-> Conduit S.ByteString m S.ByteString
conduitFile fp = conduitIO
(IO.openFile fp IO.WriteMode)
IO.hClose
(\handle bs -> do
liftIO $ S.hPut handle bs
return $ Producing [bs])
(const $ return [])
isolate :: Resource m
=> Int
-> Conduit S.ByteString m S.ByteString
isolate count0 = conduitState
count0
push
close
where
push 0 bs = return (0, Finished (Just bs) [])
push count bs = do
let (a, b) = S.splitAt count bs
let count' = count S.length a
return (count',
if count' == 0
then Finished (if S.null b then Nothing else Just b) (if S.null a then [] else [a])
else assert (S.null b) $ Producing [a])
close _ = return []