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--

-- Licensed to the Apache Software Foundation (ASF) under one

-- or more contributor license agreements. See the NOTICE file

-- distributed with this work for additional information

-- regarding copyright ownership. The ASF licenses this file

-- to you under the Apache License, Version 2.0 (the

-- "License"); you may not use this file except in compliance

-- with the License. You may obtain a copy of the License at

--

--   http://www.apache.org/licenses/LICENSE-2.0

--

-- Unless required by applicable law or agreed to in writing,

-- software distributed under the License is distributed on an

-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

-- KIND, either express or implied. See the License for the

-- specific language governing permissions and limitations

-- under the License.

--

module Thrift.Transport

  ( Transport(..)

  , TransportExn(..)

  , TransportExnType(..)

  ) where

import Control.Monad ( when )

import Control.Exception ( Exception, throw )

import Data.Typeable ( Typeable )

class Transport a where

    tIsOpen :: a -> IO Bool

    tClose  :: a -> IO ()

    tRead   :: a -> Int -> IO String

    tWrite  :: a -> String ->IO ()

    tFlush  :: a -> IO ()

    tReadAll :: a -> Int -> IO String

    tReadAll a 0 = return []

    tReadAll a len = do

        result <- tRead a len

        let rlen = length result

        when (rlen == 0) (throw $ TransportExn "Cannot read. Remote side has closed." TE_UNKNOWN)

        if len <= rlen

            then return result

            else (result ++) `fmap` (tReadAll a (len - rlen))

data TransportExn = TransportExn String TransportExnType

  deriving ( Show, Typeable )

instance Exception TransportExn

data TransportExnType

    = TE_UNKNOWN

    | TE_NOT_OPEN

    | TE_ALREADY_OPEN

    | TE_TIMED_OUT

    | TE_END_OF_FILE

      deriving ( Eq, Show, Typeable )