{- |
Copyright  : Will Thompson, Iñaki García Etxebarria and Jonas Platte
License    : LGPL-2.1
Maintainer : Iñaki García Etxebarria (garetxe@gmail.com)

Structure used for scatter/gather data output.
You generally pass in an array of #GOutputVectors
and the operation will use all the buffers as if they were
one buffer.
-}

module GI.Gio.Structs.OutputVector
    ( 

-- * Exported types
    OutputVector(..)                        ,
    newZeroOutputVector                     ,
    noOutputVector                          ,


 -- * Properties
-- ** Buffer
    outputVectorReadBuffer                  ,


-- ** Size
    outputVectorReadSize                    ,




    ) where

import Prelude ()
import Data.GI.Base.ShortPrelude

import qualified Data.Text as T
import qualified Data.ByteString.Char8 as B
import qualified Data.Map as Map

import GI.Gio.Types
import GI.Gio.Callbacks

newtype OutputVector = OutputVector (ForeignPtr OutputVector)
-- | Construct a `OutputVector` struct initialized to zero.
newZeroOutputVector :: MonadIO m => m OutputVector
newZeroOutputVector = liftIO $ callocBytes 16 >>= wrapPtr OutputVector

noOutputVector :: Maybe OutputVector
noOutputVector = Nothing

outputVectorReadBuffer :: OutputVector -> IO (Ptr ())
outputVectorReadBuffer s = withManagedPtr s $ \ptr -> do
    val <- peek (ptr `plusPtr` 0) :: IO (Ptr ())
    return val

outputVectorReadSize :: OutputVector -> IO Word64
outputVectorReadSize s = withManagedPtr s $ \ptr -> do
    val <- peek (ptr `plusPtr` 8) :: IO Word64
    return val

type family ResolveOutputVectorMethod (t :: Symbol) (o :: *) :: * where
    ResolveOutputVectorMethod l o = MethodResolutionFailed l o

instance (info ~ ResolveOutputVectorMethod t OutputVector, MethodInfo info OutputVector p) => IsLabelProxy t (OutputVector -> p) where
    fromLabelProxy _ = overloadedMethod (MethodProxy :: MethodProxy info)

#if MIN_VERSION_base(4,9,0)
instance (info ~ ResolveOutputVectorMethod t OutputVector, MethodInfo info OutputVector p) => IsLabel t (OutputVector -> p) where
    fromLabel _ = overloadedMethod (MethodProxy :: MethodProxy info)
#endif