{-# LINE 1 "src/Streamly/FileSystem/IOVec.hsc" #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE CApiFFI #-}
{-# LANGUAGE ScopedTypeVariables #-}

-- |
-- Module      : Streamly.FileSystem.IOVec
-- Copyright   : (c) 2019 Composewell Technologies
--
-- License     : BSD3
-- Maintainer  : streamly@composewell.com
-- Stability   : experimental
-- Portability : GHC
--
-- Low level IO routines interfacing the operating system.
--

module Streamly.FileSystem.IOVec
    ( IOVec(..)
    , c_writev
    , c_safe_writev
    )
where

import Data.Word (Word8, Word64)
import Foreign.C.Types (CInt(..))
import Foreign.Ptr (Ptr)
import System.Posix.Types (CSsize(..))

{-# LINE 30 "src/Streamly/FileSystem/IOVec.hsc" #-}
import Foreign.Storable (Storable(..))

{-# LINE 32 "src/Streamly/FileSystem/IOVec.hsc" #-}

-------------------------------------------------------------------------------
-- IOVec
-------------------------------------------------------------------------------

data IOVec = IOVec
  { iovBase :: {-# UNPACK #-} !(Ptr Word8)
  , iovLen  :: {-# UNPACK #-} !Word64
  } deriving (Eq, Show)


{-# LINE 43 "src/Streamly/FileSystem/IOVec.hsc" #-}




{-# LINE 49 "src/Streamly/FileSystem/IOVec.hsc" #-}

instance Storable IOVec where
  sizeOf _ = (16)
{-# LINE 52 "src/Streamly/FileSystem/IOVec.hsc" #-}
  alignment _ = 8
{-# LINE 53 "src/Streamly/FileSystem/IOVec.hsc" #-}
  peek ptr = do
      base <- (\hsc_ptr -> peekByteOff hsc_ptr 0) ptr
{-# LINE 55 "src/Streamly/FileSystem/IOVec.hsc" #-}
      len  :: Word64 <- (\hsc_ptr -> peekByteOff hsc_ptr 8)  ptr
{-# LINE 56 "src/Streamly/FileSystem/IOVec.hsc" #-}
      return $ IOVec base len
  poke ptr vec = do
      let base = iovBase vec
          len  :: Word64 = iovLen  vec
{-# LINE 60 "src/Streamly/FileSystem/IOVec.hsc" #-}
      (\hsc_ptr -> pokeByteOff hsc_ptr 0) ptr base
{-# LINE 61 "src/Streamly/FileSystem/IOVec.hsc" #-}
      (\hsc_ptr -> pokeByteOff hsc_ptr 8)  ptr len
{-# LINE 62 "src/Streamly/FileSystem/IOVec.hsc" #-}

{-# LINE 63 "src/Streamly/FileSystem/IOVec.hsc" #-}

-- capi calling convention does not work without -fobject-code option with GHCi
-- so using this in DEVBUILD only for now.
--

{-# LINE 75 "src/Streamly/FileSystem/IOVec.hsc" #-}
c_writev :: CInt -> Ptr IOVec -> CInt -> IO CSsize
c_writev = error "writev not implemented"

c_safe_writev :: CInt -> Ptr IOVec -> CInt -> IO CSsize
c_safe_writev = error "writev not implemented"

{-# LINE 81 "src/Streamly/FileSystem/IOVec.hsc" #-}