git.iko.soy/streamly
on 364af08 help sign in
streamly/src/Streamly/FileSystem/IOVec.hsc
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1{-# LANGUAGE CPP #-}
2{-# LANGUAGE BangPatterns #-}
3{-# LANGUAGE CApiFFI #-}
4{-# LANGUAGE ScopedTypeVariables #-}
6-- |
7-- Module : Streamly.FileSystem.IOVec
8-- Copyright : (c) 2019 Composewell Technologies
9--
10-- License : BSD3
11-- Maintainer : harendra.kumar@gmail.com
12-- Stability : experimental
13-- Portability : GHC
14--
15-- Low level IO routines interfacing the operating system.
16--
18module Streamly.FileSystem.IOVec
19 ( IOVec(..)
20 , c_writev
21 , c_safe_writev
22 )
23where
25import Data.Word (Word8, Word64)
26import Foreign.C.Types (CInt(..))
27import Foreign.Ptr (Ptr)
28import Foreign.Storable (Storable(..))
29import System.Posix.Types (CSsize(..))
31-------------------------------------------------------------------------------
32-- IOVec
33-------------------------------------------------------------------------------
35#if !defined(mingw32_HOST_OS)
37#include <sys/uio.h>
39data IOVec = IOVec
40 { iovBase :: {-# UNPACK #-} !(Ptr Word8)
41 , iovLen :: {-# UNPACK #-} !Word64
42 } deriving (Eq, Show)
44instance Storable IOVec where
45 sizeOf _ = #{size struct iovec}
46 alignment _ = #{alignment struct iovec}
47 peek ptr = do
48 base <- #{peek struct iovec, iov_base} ptr
49 len :: #{type size_t} <- #{peek struct iovec, iov_len} ptr
50 return $ IOVec base len
51 poke ptr vec = do
52 let base = iovBase vec
53 len :: #{type size_t} = iovLen vec
54 #{poke struct iovec, iov_base} ptr base
55 #{poke struct iovec, iov_len} ptr len
57foreign import capi unsafe "sys/uio.h writev"
58 c_writev :: CInt -> Ptr IOVec -> CInt -> IO CSsize
60foreign import capi safe "sys/uio.h writev"
61 c_safe_writev :: CInt -> Ptr IOVec -> CInt -> IO CSsize
63#else
64c_writev = error "writev not implemented for windows"
65c_safe_writev = error "writev not implemented for windows"
66#endif