lib/hs/src/Thrift/Transport/Handle.hs

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-- Licensed to the Apache Software Foundation (ASF) under one
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-- to you under the Apache License, Version 2.0 (the
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--   http://www.apache.org/licenses/LICENSE-2.0
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module Thrift.Transport.Handle
    ( module Thrift.Transport
    , HandleSource(..)
    ) where

import Control.Exception ( throw )
import Control.Monad ( replicateM )

import Network

import System.IO
import System.IO.Error ( isEOFError )

import Thrift.Transport


instance Transport Handle where
    tIsOpen = hIsOpen
    tClose h    = hClose h
    tRead  h n  = replicateM n (hGetChar h) `catch` handleEOF
    tWrite h s  = mapM_ (hPutChar h) s
    tFlush = hFlush


-- | Type class for all types that can open a Handle. This class is used to
-- replace tOpen in the Transport type class.
class HandleSource s where
    hOpen :: s -> IO Handle

instance HandleSource FilePath where
    hOpen s = openFile s ReadWriteMode

instance HandleSource (HostName, PortID) where
    hOpen = uncurry connectTo


handleEOF e = if isEOFError e
    then return []
    else throw $ TransportExn "TChannelTransport: Could not read" TE_UNKNOWN