#include "inline.hs"

-- |
-- Module      : Streamly.Internal.FileSystem.Handle
-- Copyright   : (c) 2018 Composewell Technologies
--
-- License     : BSD3
-- Maintainer  : streamly@composewell.com
-- Stability   : experimental
-- Portability : GHC

module Streamly.Internal.FileSystem.Handle
    (
    -- ** Read from Handle
      read
    -- , readUtf8
    -- , readLines
    -- , readFrames
    , readWithBufferOf

    , toBytes
    , toBytesWithBufferOf

    -- -- * Array Read
    -- , readArrayUpto
    -- , readArrayOf
    , readChunks
    , readChunksWithBufferOf

    , toChunksWithBufferOf
    , toChunks

    -- ** Write to Handle
    -- Byte stream write (Folds)
    , write
    , write2
    -- , writeUtf8
    -- , writeUtf8ByLines
    -- , writeByFrames
    -- , writeLines
    , writeWithBufferOf

    -- Byte stream write (Streams)
    , putBytes
    , putBytesWithBufferOf

    -- -- * Array Write
    , writeArray
    , writeChunks
    , writeChunksWithBufferOf

    -- -- * Array stream Write
    , putChunksWithBufferOf
    , putChunks

    -- -- * Random Access (Seek)
    -- -- | Unlike the streaming APIs listed above, these APIs apply to devices or
    -- files that have random access or seek capability.  This type of devices
    -- include disks, files, memory devices and exclude terminals, pipes,
    -- sockets and fifos.
    --
    -- XXX need to decide whether to use readFromStepN style or readFromThenTo
    -- style. The latter is consistent with list enumeration. The former may be
    -- more unambiguous and it is easier and clearer to specify 0 elements.
    --
    -- We can also generate the request pattern using a funciton.
    --
    -- , readIndex
    -- , readFrom -- read from a given position to the end of file
    -- , readFromRev -- read from a given position the beginning of file
    -- , readTo   -- read from beginning up to the given position
    -- , readToRev -- read from end to the given position in file
    -- , readFromTo
    -- , readFromThenTo

    -- , readChunksFrom
    -- , readChunksFromTo
    -- , readChunksFromToWithBufferOf
    -- , readChunksFromThenToWithBufferOf

    -- , writeIndex
    -- , writeFrom -- start writing at the given position
    -- , writeFromRev
    -- , writeTo   -- write from beginning up to the given position
    -- , writeToRev
    -- , writeFromTo
    -- , writeFromThenTo
    --
    -- , writeChunksFrom
    -- , writeChunksFromTo
    -- , writeChunksFromToWithBufferOf
    -- , writeChunksFromThenToWithBufferOf
    )
where

import Control.Monad.IO.Class (MonadIO(..))
import Data.Word (Word8)
import Foreign.ForeignPtr.Unsafe (unsafeForeignPtrToPtr)
import Foreign.ForeignPtr (withForeignPtr)
import Foreign.Ptr (minusPtr, plusPtr)
import Foreign.Storable (Storable(..))
import GHC.ForeignPtr (mallocPlainForeignPtrBytes)
import System.IO (Handle, hGetBufSome, hPutBuf)
import Prelude hiding (read)

import Streamly.Internal.BaseCompat
import Streamly.Data.Fold (Fold)
import Streamly.Internal.Data.Fold.Type (Fold2(..))
import Streamly.Internal.Data.Unfold.Type (Unfold(..))
import Streamly.Internal.Data.Array.Foreign.Type
       (Array(..), writeNUnsafe, defaultChunkSize , unsafeFreezeWithShrink)
import Streamly.Internal.Data.Array.Foreign.Mut.Type (mutableArray)
import Streamly.Internal.Data.Stream.Serial (SerialT)
import Streamly.Internal.Data.Stream.StreamK.Type (IsStream, mkStream)
import Streamly.Internal.Data.Array.Stream.Foreign (lpackArraysChunksOf)
-- import Streamly.String (encodeUtf8, decodeUtf8, foldLines)

import qualified Streamly.Data.Fold as FL
import qualified Streamly.Internal.Data.Fold.Type as FL
import qualified Streamly.Internal.Data.Unfold as UF
import qualified Streamly.Internal.Data.Array.Stream.Foreign as AS
import qualified Streamly.Internal.Data.Stream.IsStream as S
import qualified Streamly.Data.Array.Foreign as A
import qualified Streamly.Internal.Data.Stream.StreamD.Type as D

-------------------------------------------------------------------------------
-- References
-------------------------------------------------------------------------------
--
-- The following references may be useful to build an understanding about the
-- file API design:
--
-- http://www.linux-mag.com/id/308/ for blocking/non-blocking IO on linux.
-- https://lwn.net/Articles/612483/ Non-blocking buffered file read operations
-- https://en.wikipedia.org/wiki/C_file_input/output for C APIs.
-- https://docs.oracle.com/javase/tutorial/essential/io/file.html for Java API.
-- https://www.w3.org/TR/FileAPI/ for http file API.

-------------------------------------------------------------------------------
-- Array IO (Input)
-------------------------------------------------------------------------------

-- | Read a 'ByteArray' from a file handle. If no data is available on the
-- handle it blocks until some data becomes available. If data is available
-- then it immediately returns that data without blocking. It reads a maximum
-- of up to the size requested.
{-# INLINABLE readArrayUpto #-}
readArrayUpto :: Int -> Handle -> IO (Array Word8)
readArrayUpto :: Int -> Handle -> IO (Array Word8)
readArrayUpto Int
size Handle
h = do
    ForeignPtr Word8
ptr <- Int -> IO (ForeignPtr Word8)
forall a. Int -> IO (ForeignPtr a)
mallocPlainForeignPtrBytes Int
size
    -- ptr <- mallocPlainForeignPtrAlignedBytes size (alignment (undefined :: Word8))
    ForeignPtr Word8
-> (Ptr Word8 -> IO (Array Word8)) -> IO (Array Word8)
forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
withForeignPtr ForeignPtr Word8
ptr ((Ptr Word8 -> IO (Array Word8)) -> IO (Array Word8))
-> (Ptr Word8 -> IO (Array Word8)) -> IO (Array Word8)
forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p -> do
        Int
n <- Handle -> Ptr Word8 -> Int -> IO Int
forall a. Handle -> Ptr a -> Int -> IO Int
hGetBufSome Handle
h Ptr Word8
p Int
size
        -- XXX shrink only if the diff is significant
        Array Word8 -> IO (Array Word8)
forall (m :: * -> *) a. Monad m => a -> m a
return (Array Word8 -> IO (Array Word8))
-> Array Word8 -> IO (Array Word8)
forall a b. (a -> b) -> a -> b
$
            Array Word8 -> Array Word8
forall a. Storable a => Array a -> Array a
unsafeFreezeWithShrink (Array Word8 -> Array Word8) -> Array Word8 -> Array Word8
forall a b. (a -> b) -> a -> b
$
            ForeignPtr Word8 -> Ptr Word8 -> Ptr Word8 -> Array Word8
forall a. ForeignPtr a -> Ptr a -> Ptr a -> Array a
mutableArray ForeignPtr Word8
ptr (Ptr Word8
p Ptr Word8 -> Int -> Ptr Word8
forall a b. Ptr a -> Int -> Ptr b
`plusPtr` Int
n) (Ptr Word8
p Ptr Word8 -> Int -> Ptr Word8
forall a b. Ptr a -> Int -> Ptr b
`plusPtr` Int
size)

-------------------------------------------------------------------------------
-- Stream of Arrays IO
-------------------------------------------------------------------------------

-- | @toChunksWithBufferOf size h@ reads a stream of arrays from file handle @h@.
-- The maximum size of a single array is specified by @size@. The actual size
-- read may be less than or equal to @size@.
{-# INLINABLE _toChunksWithBufferOf #-}
_toChunksWithBufferOf :: (IsStream t, MonadIO m)
    => Int -> Handle -> t m (Array Word8)
_toChunksWithBufferOf :: Int -> Handle -> t m (Array Word8)
_toChunksWithBufferOf Int
size Handle
h = t m (Array Word8)
go
  where
    -- XXX use cons/nil instead
    go :: t m (Array Word8)
go = (forall r.
 State Stream m (Array Word8)
 -> (Array Word8 -> t m (Array Word8) -> m r)
 -> (Array Word8 -> m r)
 -> m r
 -> m r)
-> t m (Array Word8)
forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
IsStream t =>
(forall r.
 State Stream m a
 -> (a -> t m a -> m r) -> (a -> m r) -> m r -> m r)
-> t m a
mkStream ((forall r.
  State Stream m (Array Word8)
  -> (Array Word8 -> t m (Array Word8) -> m r)
  -> (Array Word8 -> m r)
  -> m r
  -> m r)
 -> t m (Array Word8))
-> (forall r.
    State Stream m (Array Word8)
    -> (Array Word8 -> t m (Array Word8) -> m r)
    -> (Array Word8 -> m r)
    -> m r
    -> m r)
-> t m (Array Word8)
forall a b. (a -> b) -> a -> b
$ \State Stream m (Array Word8)
_ Array Word8 -> t m (Array Word8) -> m r
yld Array Word8 -> m r
_ m r
stp -> do
        Array Word8
arr <- IO (Array Word8) -> m (Array Word8)
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO (Array Word8) -> m (Array Word8))
-> IO (Array Word8) -> m (Array Word8)
forall a b. (a -> b) -> a -> b
$ Int -> Handle -> IO (Array Word8)
readArrayUpto Int
size Handle
h
        if Array Word8 -> Int
forall a. Storable a => Array a -> Int
A.length Array Word8
arr Int -> Int -> Bool
forall a. Eq a => a -> a -> Bool
== Int
0
        then m r
stp
        else Array Word8 -> t m (Array Word8) -> m r
yld Array Word8
arr t m (Array Word8)
go

-- | @toChunksWithBufferOf size handle@ reads a stream of arrays from the file
-- handle @handle@.  The maximum size of a single array is limited to @size@.
-- The actual size read may be less than or equal to @size@.
--
-- @since 0.7.0
{-# INLINE_NORMAL toChunksWithBufferOf #-}
toChunksWithBufferOf :: (IsStream t, MonadIO m) => Int -> Handle -> t m (Array Word8)
toChunksWithBufferOf :: Int -> Handle -> t m (Array Word8)
toChunksWithBufferOf Int
size Handle
h = Stream m (Array Word8) -> t m (Array Word8)
forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(IsStream t, Monad m) =>
Stream m a -> t m a
D.fromStreamD ((State Stream m (Array Word8) -> () -> m (Step () (Array Word8)))
-> () -> Stream m (Array Word8)
forall (m :: * -> *) a s.
(State Stream m a -> s -> m (Step s a)) -> s -> Stream m a
D.Stream State Stream m (Array Word8) -> () -> m (Step () (Array Word8))
forall (m :: * -> *) p p.
MonadIO m =>
p -> p -> m (Step () (Array Word8))
step ())
  where
    {-# INLINE_LATE step #-}
    step :: p -> p -> m (Step () (Array Word8))
step p
_ p
_ = do
        Array Word8
arr <- IO (Array Word8) -> m (Array Word8)
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO (Array Word8) -> m (Array Word8))
-> IO (Array Word8) -> m (Array Word8)
forall a b. (a -> b) -> a -> b
$ Int -> Handle -> IO (Array Word8)
readArrayUpto Int
size Handle
h
        Step () (Array Word8) -> m (Step () (Array Word8))
forall (m :: * -> *) a. Monad m => a -> m a
return (Step () (Array Word8) -> m (Step () (Array Word8)))
-> Step () (Array Word8) -> m (Step () (Array Word8))
forall a b. (a -> b) -> a -> b
$
            case Array Word8 -> Int
forall a. Storable a => Array a -> Int
A.length Array Word8
arr of
                Int
0 -> Step () (Array Word8)
forall s a. Step s a
D.Stop
                Int
_ -> Array Word8 -> () -> Step () (Array Word8)
forall s a. a -> s -> Step s a
D.Yield Array Word8
arr ()

-- | Unfold the tuple @(bufsize, handle)@ into a stream of 'Word8' arrays.
-- Read requests to the IO device are performed using a buffer of size
-- @bufsize@.  The size of an array in the resulting stream is always less than
-- or equal to @bufsize@.
--
-- @since 0.7.0
{-# INLINE_NORMAL readChunksWithBufferOf #-}
readChunksWithBufferOf :: MonadIO m => Unfold m (Int, Handle) (Array Word8)
readChunksWithBufferOf :: Unfold m (Int, Handle) (Array Word8)
readChunksWithBufferOf = ((Int, Handle) -> m (Step (Int, Handle) (Array Word8)))
-> ((Int, Handle) -> m (Int, Handle))
-> Unfold m (Int, Handle) (Array Word8)
forall (m :: * -> *) a b s.
(s -> m (Step s b)) -> (a -> m s) -> Unfold m a b
Unfold (Int, Handle) -> m (Step (Int, Handle) (Array Word8))
forall (m :: * -> *).
MonadIO m =>
(Int, Handle) -> m (Step (Int, Handle) (Array Word8))
step (Int, Handle) -> m (Int, Handle)
forall (m :: * -> *) a. Monad m => a -> m a
return
    where
    {-# INLINE_LATE step #-}
    step :: (Int, Handle) -> m (Step (Int, Handle) (Array Word8))
step (Int
size, Handle
h) = do
        Array Word8
arr <- IO (Array Word8) -> m (Array Word8)
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO (Array Word8) -> m (Array Word8))
-> IO (Array Word8) -> m (Array Word8)
forall a b. (a -> b) -> a -> b
$ Int -> Handle -> IO (Array Word8)
readArrayUpto Int
size Handle
h
        Step (Int, Handle) (Array Word8)
-> m (Step (Int, Handle) (Array Word8))
forall (m :: * -> *) a. Monad m => a -> m a
return (Step (Int, Handle) (Array Word8)
 -> m (Step (Int, Handle) (Array Word8)))
-> Step (Int, Handle) (Array Word8)
-> m (Step (Int, Handle) (Array Word8))
forall a b. (a -> b) -> a -> b
$
            case Array Word8 -> Int
forall a. Storable a => Array a -> Int
A.length Array Word8
arr of
                Int
0 -> Step (Int, Handle) (Array Word8)
forall s a. Step s a
D.Stop
                Int
_ -> Array Word8 -> (Int, Handle) -> Step (Int, Handle) (Array Word8)
forall s a. a -> s -> Step s a
D.Yield Array Word8
arr (Int
size, Handle
h)

-- XXX read 'Array a' instead of Word8
--
-- | @toChunks handle@ reads a stream of arrays from the specified file
-- handle.  The maximum size of a single array is limited to
-- @defaultChunkSize@. The actual size read may be less than or equal to
-- @defaultChunkSize@.
--
-- > toChunks = toChunksWithBufferOf defaultChunkSize
--
-- @since 0.7.0
{-# INLINE toChunks #-}
toChunks :: (IsStream t, MonadIO m) => Handle -> t m (Array Word8)
toChunks :: Handle -> t m (Array Word8)
toChunks = Int -> Handle -> t m (Array Word8)
forall (t :: (* -> *) -> * -> *) (m :: * -> *).
(IsStream t, MonadIO m) =>
Int -> Handle -> t m (Array Word8)
toChunksWithBufferOf Int
defaultChunkSize

-- | Unfolds a handle into a stream of 'Word8' arrays. Requests to the IO
-- device are performed using a buffer of size
-- 'Streamly.Internal.Data.Array.Foreign.Type.defaultChunkSize'. The
-- size of arrays in the resulting stream are therefore less than or equal to
-- 'Streamly.Internal.Data.Array.Foreign.Type.defaultChunkSize'.
--
-- @since 0.7.0
{-# INLINE readChunks #-}
readChunks :: MonadIO m => Unfold m Handle (Array Word8)
readChunks :: Unfold m Handle (Array Word8)
readChunks = Int
-> Unfold m (Int, Handle) (Array Word8)
-> Unfold m Handle (Array Word8)
forall a (m :: * -> *) b c. a -> Unfold m (a, b) c -> Unfold m b c
UF.supplyFirst Int
defaultChunkSize Unfold m (Int, Handle) (Array Word8)
forall (m :: * -> *).
MonadIO m =>
Unfold m (Int, Handle) (Array Word8)
readChunksWithBufferOf

-------------------------------------------------------------------------------
-- Read File to Stream
-------------------------------------------------------------------------------

-- TODO for concurrent streams implement readahead IO. We can send multiple
-- read requests at the same time. For serial case we can use async IO. We can
-- also control the read throughput in mbps or IOPS.

-- | Unfolds the tuple @(bufsize, handle)@ into a byte stream, read requests
-- to the IO device are performed using buffers of @bufsize@.
--
-- @since 0.7.0
{-# INLINE readWithBufferOf #-}
readWithBufferOf :: MonadIO m => Unfold m (Int, Handle) Word8
readWithBufferOf :: Unfold m (Int, Handle) Word8
readWithBufferOf = Unfold m (Int, Handle) (Array Word8)
-> Unfold m (Array Word8) Word8 -> Unfold m (Int, Handle) Word8
forall (m :: * -> *) a b c.
Monad m =>
Unfold m a b -> Unfold m b c -> Unfold m a c
UF.many Unfold m (Int, Handle) (Array Word8)
forall (m :: * -> *).
MonadIO m =>
Unfold m (Int, Handle) (Array Word8)
readChunksWithBufferOf Unfold m (Array Word8) Word8
forall (m :: * -> *) a.
(Monad m, Storable a) =>
Unfold m (Array a) a
A.read

-- | @toBytesWithBufferOf bufsize handle@ reads a byte stream from a file
-- handle, reads are performed in chunks of up to @bufsize@.
--
-- /Pre-release/
{-# INLINE toBytesWithBufferOf #-}
toBytesWithBufferOf :: (IsStream t, MonadIO m) => Int -> Handle -> t m Word8
toBytesWithBufferOf :: Int -> Handle -> t m Word8
toBytesWithBufferOf Int
chunkSize Handle
h = t m (Array Word8) -> t m Word8
forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(IsStream t, MonadIO m, Storable a) =>
t m (Array a) -> t m a
AS.concat (t m (Array Word8) -> t m Word8) -> t m (Array Word8) -> t m Word8
forall a b. (a -> b) -> a -> b
$ Int -> Handle -> t m (Array Word8)
forall (t :: (* -> *) -> * -> *) (m :: * -> *).
(IsStream t, MonadIO m) =>
Int -> Handle -> t m (Array Word8)
toChunksWithBufferOf Int
chunkSize Handle
h

-- TODO
-- Generate a stream of elements of the given type from a file 'Handle'.
-- read :: (IsStream t, MonadIO m, Storable a) => Handle -> t m a
--
-- | Unfolds a file handle into a byte stream. IO requests to the device are
-- performed in sizes of
-- 'Streamly.Internal.Data.Array.Foreign.Type.defaultChunkSize'.
--
-- @since 0.7.0
{-# INLINE read #-}
read :: MonadIO m => Unfold m Handle Word8
read :: Unfold m Handle Word8
read = Int -> Unfold m (Int, Handle) Word8 -> Unfold m Handle Word8
forall a (m :: * -> *) b c. a -> Unfold m (a, b) c -> Unfold m b c
UF.supplyFirst Int
defaultChunkSize Unfold m (Int, Handle) Word8
forall (m :: * -> *). MonadIO m => Unfold m (Int, Handle) Word8
readWithBufferOf

-- | Generate a byte stream from a file 'Handle'.
--
-- /Pre-release/
{-# INLINE toBytes #-}
toBytes :: (IsStream t, MonadIO m) => Handle -> t m Word8
toBytes :: Handle -> t m Word8
toBytes = t m (Array Word8) -> t m Word8
forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(IsStream t, MonadIO m, Storable a) =>
t m (Array a) -> t m a
AS.concat (t m (Array Word8) -> t m Word8)
-> (Handle -> t m (Array Word8)) -> Handle -> t m Word8
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Handle -> t m (Array Word8)
forall (t :: (* -> *) -> * -> *) (m :: * -> *).
(IsStream t, MonadIO m) =>
Handle -> t m (Array Word8)
toChunks

-------------------------------------------------------------------------------
-- Writing
-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
-- Array IO (output)
-------------------------------------------------------------------------------

-- | Write an 'Array' to a file handle.
--
-- @since 0.7.0
{-# INLINABLE writeArray #-}
writeArray :: Storable a => Handle -> Array a -> IO ()
writeArray :: Handle -> Array a -> IO ()
writeArray Handle
_ Array a
arr | Array a -> Int
forall a. Storable a => Array a -> Int
A.length Array a
arr Int -> Int -> Bool
forall a. Eq a => a -> a -> Bool
== Int
0 = () -> IO ()
forall (m :: * -> *) a. Monad m => a -> m a
return ()
writeArray Handle
h Array{Ptr a
ForeignPtr a
aEnd :: forall a. Array a -> Ptr a
aStart :: forall a. Array a -> ForeignPtr a
aEnd :: Ptr a
aStart :: ForeignPtr a
..} = ForeignPtr a -> (Ptr a -> IO ()) -> IO ()
forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
unsafeWithForeignPtr ForeignPtr a
aStart ((Ptr a -> IO ()) -> IO ()) -> (Ptr a -> IO ()) -> IO ()
forall a b. (a -> b) -> a -> b
$ \Ptr a
p -> Handle -> Ptr a -> Int -> IO ()
forall a. Handle -> Ptr a -> Int -> IO ()
hPutBuf Handle
h Ptr a
p Int
aLen
    where
    aLen :: Int
aLen =
        let p :: Ptr a
p = ForeignPtr a -> Ptr a
forall a. ForeignPtr a -> Ptr a
unsafeForeignPtrToPtr ForeignPtr a
aStart
        in Ptr a
aEnd Ptr a -> Ptr a -> Int
forall a b. Ptr a -> Ptr b -> Int
`minusPtr` Ptr a
p

-------------------------------------------------------------------------------
-- Stream of Arrays IO
-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
-- Writing
-------------------------------------------------------------------------------

-- XXX use an unfold to fromObjects or fromUnfold so that we can put any object
-- | Write a stream of arrays to a handle.
--
-- @since 0.7.0
{-# INLINE putChunks #-}
putChunks :: (MonadIO m, Storable a)
    => Handle -> SerialT m (Array a) -> m ()
putChunks :: Handle -> SerialT m (Array a) -> m ()
putChunks Handle
h = (Array a -> m ()) -> SerialT m (Array a) -> m ()
forall (m :: * -> *) a b.
Monad m =>
(a -> m b) -> SerialT m a -> m ()
S.mapM_ (IO () -> m ()
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO () -> m ()) -> (Array a -> IO ()) -> Array a -> m ()
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Handle -> Array a -> IO ()
forall a. Storable a => Handle -> Array a -> IO ()
writeArray Handle
h)

-- | @putChunksWithBufferOf bufsize handle stream@ writes a stream of arrays
-- to @handle@ after coalescing the adjacent arrays in chunks of @bufsize@.
-- The chunk size is only a maximum and the actual writes could be smaller as
-- we do not split the arrays to fit exactly to the specified size.
--
-- @since 0.7.0
{-# INLINE putChunksWithBufferOf #-}
putChunksWithBufferOf :: (MonadIO m, Storable a)
    => Int -> Handle -> SerialT m (Array a) -> m ()
putChunksWithBufferOf :: Int -> Handle -> SerialT m (Array a) -> m ()
putChunksWithBufferOf Int
n Handle
h SerialT m (Array a)
xs = Handle -> SerialT m (Array a) -> m ()
forall (m :: * -> *) a.
(MonadIO m, Storable a) =>
Handle -> SerialT m (Array a) -> m ()
putChunks Handle
h (SerialT m (Array a) -> m ()) -> SerialT m (Array a) -> m ()
forall a b. (a -> b) -> a -> b
$ Int -> SerialT m (Array a) -> SerialT m (Array a)
forall (m :: * -> *) a.
(MonadIO m, Storable a) =>
Int -> SerialT m (Array a) -> SerialT m (Array a)
AS.compact Int
n SerialT m (Array a)
xs

-- | @putBytesWithBufferOf bufsize handle stream@ writes @stream@ to @handle@
-- in chunks of @bufsize@.  A write is performed to the IO device as soon as we
-- collect the required input size.
--
-- @since 0.7.0
{-# INLINE putBytesWithBufferOf #-}
putBytesWithBufferOf :: MonadIO m => Int -> Handle -> SerialT m Word8 -> m ()
putBytesWithBufferOf :: Int -> Handle -> SerialT m Word8 -> m ()
putBytesWithBufferOf Int
n Handle
h SerialT m Word8
m = Handle -> SerialT m (Array Word8) -> m ()
forall (m :: * -> *) a.
(MonadIO m, Storable a) =>
Handle -> SerialT m (Array a) -> m ()
putChunks Handle
h (SerialT m (Array Word8) -> m ())
-> SerialT m (Array Word8) -> m ()
forall a b. (a -> b) -> a -> b
$ Int -> SerialT m Word8 -> SerialT m (Array Word8)
forall (t :: (* -> *) -> * -> *) (m :: * -> *) a.
(IsStream t, MonadIO m, Storable a) =>
Int -> t m a -> t m (Array a)
S.arraysOf Int
n SerialT m Word8
m
-- putBytesWithBufferOf n h m = putChunks h $ AS.arraysOf n m

-- > write = 'writeWithBufferOf' A.defaultChunkSize
--
-- | Write a byte stream to a file handle. Accumulates the input in chunks of
-- up to 'Streamly.Internal.Data.Array.Foreign.Type.defaultChunkSize' before writing.
--
-- NOTE: This may perform better than the 'write' fold, you can try this if you
-- need some extra perf boost.
--
-- @since 0.7.0
{-# INLINE putBytes #-}
putBytes :: MonadIO m => Handle -> SerialT m Word8 -> m ()
putBytes :: Handle -> SerialT m Word8 -> m ()
putBytes = Int -> Handle -> SerialT m Word8 -> m ()
forall (m :: * -> *).
MonadIO m =>
Int -> Handle -> SerialT m Word8 -> m ()
putBytesWithBufferOf Int
defaultChunkSize

-- | Write a stream of arrays to a handle. Each array in the stream is written
-- to the device as a separate IO request.
--
-- @since 0.7.0
{-# INLINE writeChunks #-}
writeChunks :: (MonadIO m, Storable a) => Handle -> Fold m (Array a) ()
writeChunks :: Handle -> Fold m (Array a) ()
writeChunks Handle
h = (Array a -> m ()) -> Fold m (Array a) ()
forall (m :: * -> *) a b. Monad m => (a -> m b) -> Fold m a ()
FL.drainBy (IO () -> m ()
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO () -> m ()) -> (Array a -> IO ()) -> Array a -> m ()
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Handle -> Array a -> IO ()
forall a. Storable a => Handle -> Array a -> IO ()
writeArray Handle
h)

{-# INLINE writeChunks2 #-}
writeChunks2 :: (MonadIO m, Storable a) => Fold2 m Handle (Array a) ()
writeChunks2 :: Fold2 m Handle (Array a) ()
writeChunks2 = (Handle -> Array a -> m Handle)
-> (Handle -> m Handle)
-> (Handle -> m ())
-> Fold2 m Handle (Array a) ()
forall (m :: * -> *) c a b s.
(s -> a -> m s) -> (c -> m s) -> (s -> m b) -> Fold2 m c a b
Fold2 (\Handle
h Array a
arr -> IO Handle -> m Handle
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO Handle -> m Handle) -> IO Handle -> m Handle
forall a b. (a -> b) -> a -> b
$ Handle -> Array a -> IO ()
forall a. Storable a => Handle -> Array a -> IO ()
writeArray Handle
h Array a
arr IO () -> IO Handle -> IO Handle
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> Handle -> IO Handle
forall (m :: * -> *) a. Monad m => a -> m a
return Handle
h) Handle -> m Handle
forall (m :: * -> *) a. Monad m => a -> m a
return (\Handle
_ -> () -> m ()
forall (m :: * -> *) a. Monad m => a -> m a
return ())

-- | @writeChunksWithBufferOf bufsize handle@ writes a stream of arrays
-- to @handle@ after coalescing the adjacent arrays in chunks of @bufsize@.
-- We never split an array, if a single array is bigger than the specified size
-- it emitted as it is. Multiple arrays are coalesed as long as the total size
-- remains below the specified size.
--
-- @since 0.7.0
{-# INLINE writeChunksWithBufferOf #-}
writeChunksWithBufferOf :: (MonadIO m, Storable a)
    => Int -> Handle -> Fold m (Array a) ()
writeChunksWithBufferOf :: Int -> Handle -> Fold m (Array a) ()
writeChunksWithBufferOf Int
n Handle
h = Int -> Fold m (Array a) () -> Fold m (Array a) ()
forall (m :: * -> *) a.
(MonadIO m, Storable a) =>
Int -> Fold m (Array a) () -> Fold m (Array a) ()
lpackArraysChunksOf Int
n (Handle -> Fold m (Array a) ()
forall (m :: * -> *) a.
(MonadIO m, Storable a) =>
Handle -> Fold m (Array a) ()
writeChunks Handle
h)

-- GHC buffer size dEFAULT_FD_BUFFER_SIZE=8192 bytes.
--
-- XXX test this
-- Note that if you use a chunk size less than 8K (GHC's default buffer
-- size) then you are advised to use 'NOBuffering' mode on the 'Handle' in case you
-- do not want buffering to occur at GHC level as well. Same thing applies to
-- writes as well.

-- | @writeWithBufferOf reqSize handle@ writes the input stream to @handle@.
-- Bytes in the input stream are collected into a buffer until we have a chunk
-- of @reqSize@ and then written to the IO device.
--
-- @since 0.7.0
{-# INLINE writeWithBufferOf #-}
writeWithBufferOf :: MonadIO m => Int -> Handle -> Fold m Word8 ()
writeWithBufferOf :: Int -> Handle -> Fold m Word8 ()
writeWithBufferOf Int
n Handle
h = Int
-> Fold m Word8 (Array Word8)
-> Fold m (Array Word8) ()
-> Fold m Word8 ()
forall (m :: * -> *) a b c.
Monad m =>
Int -> Fold m a b -> Fold m b c -> Fold m a c
FL.chunksOf Int
n (Int -> Fold m Word8 (Array Word8)
forall (m :: * -> *) a.
(MonadIO m, Storable a) =>
Int -> Fold m a (Array a)
writeNUnsafe Int
n) (Handle -> Fold m (Array Word8) ()
forall (m :: * -> *) a.
(MonadIO m, Storable a) =>
Handle -> Fold m (Array a) ()
writeChunks Handle
h)

{-# INLINE writeWithBufferOf2 #-}
writeWithBufferOf2 :: MonadIO m => Int -> Fold2 m Handle Word8 ()
writeWithBufferOf2 :: Int -> Fold2 m Handle Word8 ()
writeWithBufferOf2 Int
n = Int
-> Fold m Word8 (Array Word8)
-> Fold2 m Handle (Array Word8) ()
-> Fold2 m Handle Word8 ()
forall (m :: * -> *) a b x c.
Monad m =>
Int -> Fold m a b -> Fold2 m x b c -> Fold2 m x a c
FL.chunksOf2 Int
n (Int -> Fold m Word8 (Array Word8)
forall (m :: * -> *) a.
(MonadIO m, Storable a) =>
Int -> Fold m a (Array a)
writeNUnsafe Int
n) Fold2 m Handle (Array Word8) ()
forall (m :: * -> *) a.
(MonadIO m, Storable a) =>
Fold2 m Handle (Array a) ()
writeChunks2

-- > write = 'writeWithBufferOf' A.defaultChunkSize
--
-- | Write a byte stream to a file handle. Accumulates the input in chunks of
-- up to 'Streamly.Internal.Data.Array.Foreign.Type.defaultChunkSize' before writing
-- to the IO device.
--
-- @since 0.7.0
{-# INLINE write #-}
write :: MonadIO m => Handle -> Fold m Word8 ()
write :: Handle -> Fold m Word8 ()
write = Int -> Handle -> Fold m Word8 ()
forall (m :: * -> *). MonadIO m => Int -> Handle -> Fold m Word8 ()
writeWithBufferOf Int
defaultChunkSize

{-# INLINE write2 #-}
write2 :: MonadIO m => Fold2 m Handle Word8 ()
write2 :: Fold2 m Handle Word8 ()
write2 = Int -> Fold2 m Handle Word8 ()
forall (m :: * -> *). MonadIO m => Int -> Fold2 m Handle Word8 ()
writeWithBufferOf2 Int
defaultChunkSize

{-
{-# INLINE write #-}
write :: (MonadIO m, Storable a) => Handle -> SerialT m a -> m ()
write = toHandleWith A.defaultChunkSize
-}

-- XXX mmap a file into an array. This could be useful for in-place operations
-- on a file. For example, we can quicksort the contents of a file by mmapping
-- it.

-------------------------------------------------------------------------------
-- IO with encoding/decoding Unicode characters
-------------------------------------------------------------------------------

{-
-- |
-- > readUtf8 = decodeUtf8 . read
--
-- Read a UTF8 encoded stream of unicode characters from a file handle.
--
-- @since 0.7.0
{-# INLINE readUtf8 #-}
readUtf8 :: (IsStream t, MonadIO m) => Handle -> t m Char
readUtf8 = decodeUtf8 . read

-- |
-- > writeUtf8 h s = write h $ encodeUtf8 s
--
-- Encode a stream of unicode characters to UTF8 and write it to the given file
-- handle. Default block buffering applies to the writes.
--
-- @since 0.7.0
{-# INLINE writeUtf8 #-}
writeUtf8 :: MonadIO m => Handle -> SerialT m Char -> m ()
writeUtf8 h s = write h $ encodeUtf8 s

-- | Write a stream of unicode characters after encoding to UTF-8 in chunks
-- separated by a linefeed character @'\n'@. If the size of the buffer exceeds
-- @defaultChunkSize@ and a linefeed is not yet found, the buffer is written
-- anyway.  This is similar to writing to a 'Handle' with the 'LineBuffering'
-- option.
--
-- @since 0.7.0
{-# INLINE writeUtf8ByLines #-}
writeUtf8ByLines :: (IsStream t, MonadIO m) => Handle -> t m Char -> m ()
writeUtf8ByLines = undefined

-- | Read UTF-8 lines from a file handle and apply the specified fold to each
-- line. This is similar to reading a 'Handle' with the 'LineBuffering' option.
--
-- @since 0.7.0
{-# INLINE readLines #-}
readLines :: (IsStream t, MonadIO m) => Handle -> Fold m Char b -> t m b
readLines h f = foldLines (readUtf8 h) f

-------------------------------------------------------------------------------
-- Framing on a sequence
-------------------------------------------------------------------------------

-- | Read a stream from a file handle and split it into frames delimited by
-- the specified sequence of elements. The supplied fold is applied on each
-- frame.
--
-- @since 0.7.0
{-# INLINE readFrames #-}
readFrames :: (IsStream t, MonadIO m, Storable a)
    => Array a -> Handle -> Fold m a b -> t m b
readFrames = undefined -- foldFrames . read

-- | Write a stream to the given file handle buffering up to frames separated
-- by the given sequence or up to a maximum of @defaultChunkSize@.
--
-- @since 0.7.0
{-# INLINE writeByFrames #-}
writeByFrames :: (IsStream t, MonadIO m, Storable a)
    => Array a -> Handle -> t m a -> m ()
writeByFrames = undefined

-------------------------------------------------------------------------------
-- Framing by time
-------------------------------------------------------------------------------

-- | Write collecting the input in sessions of n seconds or if chunkSize
-- gets exceeded.
{-# INLINE writeByChunksOrSessionsOf #-}
writeByChunksOrSessionsOf :: MonadIO m
    => Int -> Double -> Handle -> SerialT m Word8 -> m ()
writeByChunksOrSessionsOf chunkSize sessionSize h m = undefined

-- | Write collecting the input in sessions of n seconds or if defaultChunkSize
-- gets exceeded.
{-# INLINE writeBySessionsOf #-}
writeBySessionsOf :: MonadIO m => Double -> Handle -> SerialT m Word8 -> m ()
writeBySessionsOf n = writeByChunksOrSessionsOf defaultChunkSize n

-------------------------------------------------------------------------------
-- Random Access IO (Seek)
-------------------------------------------------------------------------------

-- XXX handles could be shared, so we may not want to use the handle state at
-- all for these APIs. we can use pread and pwrite instead. On windows we will
-- need to use readFile/writeFile with an offset argument.

-------------------------------------------------------------------------------

-- | Read the element at the given index treating the file as an array.
--
-- @since 0.7.0
{-# INLINE readIndex #-}
readIndex :: Storable a => Handle -> Int -> Maybe a
readIndex arr i = undefined

-- NOTE: To represent a range to read we have chosen (start, size) instead of
-- (start, end). This helps in removing the ambiguity of whether "end" is
-- included in the range or not.
--
-- We could avoid specifying the range to be read and instead use "take size"
-- on the stream, but it may end up reading more and then consume it partially.

-- | @readSliceWith chunkSize handle pos len@ reads up to @len@ bytes
-- from @handle@ starting at the offset @pos@ from the beginning of the file.
--
-- Reads are performed in chunks of size @chunkSize@.  For block devices, to
-- avoid reading partial blocks @chunkSize@ must align with the block size of
-- the underlying device. If the underlying block size is unknown, it is a good
-- idea to keep it a multiple 4KiB. This API ensures that the start of each
-- chunk is aligned with @chunkSize@ from second chunk onwards.
--
{-# INLINE readSliceWith #-}
readSliceWith :: (IsStream t, MonadIO m, Storable a)
    => Int -> Handle -> Int -> Int -> t m a
readSliceWith chunkSize h pos len = undefined

-- | @readSlice h i count@ streams a slice from the file handle @h@ starting
-- at index @i@ and reading up to @count@ elements in the forward direction
-- ending at the index @i + count - 1@.
--
-- @since 0.7.0
{-# INLINE readSlice #-}
readSlice :: (IsStream t, MonadIO m, Storable a)
    => Handle -> Int -> Int -> t m a
readSlice = readSliceWith A.defaultChunkSize

-- | @readSliceRev h i count@ streams a slice from the file handle @h@ starting
-- at index @i@ and reading up to @count@ elements in the reverse direction
-- ending at the index @i - count + 1@.
--
-- @since 0.7.0
{-# INLINE readSliceRev #-}
readSliceRev :: (IsStream t, MonadIO m, Storable a)
    => Handle -> Int -> Int -> t m a
readSliceRev h i count = undefined

-- | Write the given element at the given index in the file.
--
-- @since 0.7.0
{-# INLINE writeIndex #-}
writeIndex :: (MonadIO m, Storable a) => Handle -> Int -> a -> m ()
writeIndex h i a = undefined

-- | @writeSlice h i count stream@ writes a stream to the file handle @h@
-- starting at index @i@ and writing up to @count@ elements in the forward
-- direction ending at the index @i + count - 1@.
--
-- @since 0.7.0
{-# INLINE writeSlice #-}
writeSlice :: (IsStream t, Monad m, Storable a)
    => Handle -> Int -> Int -> t m a -> m ()
writeSlice h i len s = undefined

-- | @writeSliceRev h i count stream@ writes a stream to the file handle @h@
-- starting at index @i@ and writing up to @count@ elements in the reverse
-- direction ending at the index @i - count + 1@.
--
-- @since 0.7.0
{-# INLINE writeSliceRev #-}
writeSliceRev :: (IsStream t, Monad m, Storable a)
    => Handle -> Int -> Int -> t m a -> m ()
writeSliceRev arr i len s = undefined
-}