Revert "Fix support for older GHCs"

This reverts commit 21dd1718c0.

hpath.cabal

@@ -41,14 +41,13 @@ library
                    , deepseq
                    , exceptions
                    , hspec
+                   , simple-sendfile >= 0.2.24
+                   , streamly >= 0.7
                    , unix >= 2.5
                    , unix-bytestring
                    , utf8-string
                    , word8
-  if impl(ghc >= 8.2)
+
-    build-depends:     streamly >= 0.7
-  else
-    build-depends:     simple-sendfile >= 0.2.24
 
 test-suite doctests-hpath
   if os(windows)

src/HPath/IO.hs

@@ -154,10 +154,6 @@ import Foreign.C.Error
   , eNOTEMPTY
   , eXDEV
   , getErrno
-#if __GLASGOW_HASKELL__ < 802
-  , eINVAL
-  , eNOSYS
-#endif
   )
 import Foreign.C.Types
   (
@@ -179,18 +175,10 @@ import HPath
 import HPath.Internal
 import HPath.IO.Errors
 import Prelude hiding (appendFile, readFile, writeFile)
-#if __GLASGOW_HASKELL__ >= 802
 import qualified Streamly.FileSystem.Handle as FH
 import qualified Streamly.Internal.FileSystem.Handle as IFH
 import qualified Streamly.Prelude as S
 import qualified System.IO as SIO
-#else
-import System.Linux.Sendfile
-  (
-    sendfileFd
-  , FileRange(..)
-  )
-#endif
 import System.IO.Error
   (
     catchIOError
@@ -503,14 +491,11 @@ recreateSymlink symsource@(MkPath symsourceBS) newsym@(MkPath newsymBS) cm
 --
 -- Notes:
 --
---    - on GHC < 8.2: calls `sendfile` and possibly `read`/`write` as fallback
---    - on GHC >= 8.2: uses streamly for file copying
 --    - may call `getcwd` in Overwrite mode (if destination is a relative path)
 copyFile :: Path b1   -- ^ source file
          -> Path b2   -- ^ destination file
          -> CopyMode
          -> IO ()
-#if __GLASGOW_HASKELL__ >= 802
 copyFile fp@(MkPath from) tp@(MkPath to) cm = do
   throwSameFile fp tp
   bracket (do
@@ -541,78 +526,6 @@ copyFile fp@(MkPath from) tp@(MkPath to) cm = do
                                            streamlyCopy (fH, tH)
   where
     streamlyCopy (fH, tH) = S.fold (FH.writeChunks tH) $ IFH.toChunksWithBufferOf (256*1024) fH
-#else
-copyFile from to cm = do
-  throwSameFile from to
-
-  case cm of
-    Strict -> _copyFile [SPDF.oNofollow]
-                        [SPDF.oNofollow, SPDF.oExcl]
-                        from to
-    Overwrite ->
-      catchIOError (_copyFile [SPDF.oNofollow]
-                              [SPDF.oNofollow, SPDF.oTrunc]
-                              from to) $ \e ->
-        case ioeGetErrorType e of
-          -- if the destination file is not writable, we need to
-          -- figure out if we can still copy by deleting it first
-          PermissionDenied -> do
-            exists   <- doesFileExist to
-            writable <- toAbs to >>= isWritable
-            if (exists && writable)
-              then deleteFile to >> copyFile from to Strict
-              else ioError e
-          _ -> ioError e
-
-
-_copyFile :: [SPDF.Flags]
-          -> [SPDF.Flags]
-          -> Path b1  -- ^ source file
-          -> Path b2  -- ^ destination file
-          -> IO ()
-_copyFile sflags dflags (MkPath fromBS) to@(MkPath toBS)
-  =
-    -- from sendfile(2) manpage:
-    --   Applications  may  wish  to  fall back to read(2)/write(2) in
-    --   the case where sendfile() fails with EINVAL or ENOSYS.
-    catchErrno [eINVAL, eNOSYS]
-               (sendFileCopy fromBS toBS)
-               (void $ readWriteCopy fromBS toBS)
-  where
-    copyWith copyAction source dest =
-      bracket (openFd source SPI.ReadOnly sflags Nothing)
-              SPI.closeFd
-              $ \sfd -> do
-                fileM <- System.Posix.Files.ByteString.fileMode
-                         <$> getFdStatus sfd
-                bracketeer (openFd dest SPI.WriteOnly
-                             dflags $ Just fileM)
-                           SPI.closeFd
-                           (\fd -> SPI.closeFd fd >> deleteFile to)
-                           $ \dfd -> copyAction sfd dfd
-    -- this is low-level stuff utilizing sendfile(2) for speed
-    sendFileCopy :: ByteString -> ByteString -> IO ()
-    sendFileCopy = copyWith
-      (\sfd dfd -> sendfileFd dfd sfd EntireFile $ return ())
-    -- low-level copy operation utilizing read(2)/write(2)
-    -- in case `sendFileCopy` fails/is unsupported
-    readWriteCopy :: ByteString -> ByteString -> IO Int
-    readWriteCopy = copyWith
-      (\sfd dfd -> allocaBytes (fromIntegral bufSize)
-                     $ \buf -> write' sfd dfd buf 0)
-      where
-        bufSize :: CSize
-        bufSize = 8192
-        write' :: Fd -> Fd -> Ptr Word8 -> Int -> IO Int
-        write' sfd dfd buf totalsize = do
-            size <- SPB.fdReadBuf sfd buf bufSize
-            if size == 0
-              then return $ fromIntegral totalsize
-              else do rsize <- SPB.fdWriteBuf dfd buf size
-                      when (rsize /= size) (ioError $ userError
-                                                      "wrong size!")
-                      write' sfd dfd buf (totalsize + fromIntegral size)
-#endif
 
 -- |Copies a regular file, directory or symbolic link. In case of a
 -- symbolic link it is just recreated, even if it points to a directory.