Network.HTTP.Semantics.IO

Reading n bytes

type ReadN = Int -> IO ByteString

Reading n bytes.

defaultReadN :: Socket -> IORef (Maybe ByteString) -> ReadN

Naive implementation for readN.

Position read

type PositionRead = FileOffset -> ByteCount -> Buffer -> IO ByteCount

Position read for files.

type PositionReadMaker = FilePath -> IO (PositionRead, Sentinel)

Making a position read and its closer.

data Sentinel

Constructors

Closer (IO ())

Closing a file resource. Its refresher is automatiaclly generated by the internal timer.

Refresher (IO ())

Refreshing a file resource while reading. Closing the file must be done by its own timer or something.

defaultPositionReadMaker :: PositionReadMaker

Position read based on Handle.

Filling a buffer

data Next

Constructors

Next BytesFilled Bool (Maybe DynaNext)

type DynaNext = Buffer -> BufferSize -> Int -> IO Next

type BytesFilled = Int

data StreamingChunk

Constructors

StreamingFinished (IO ())

StreamingFlush

StreamingBuilder Builder

fillBuilderBodyGetNext :: Builder -> DynaNext

fillFileBodyGetNext :: PositionRead -> FileOffset -> ByteCount -> IO () -> DynaNext

fillStreamBodyGetNext :: IO (Maybe StreamingChunk) -> DynaNext

type TrailersMaker = Maybe ByteString -> IO NextTrailersMaker

Trailers maker. A chunks of the response body is passed with Just. The maker should update internal state with the ByteString and return the next trailers maker. When response body reaches its end, Nothing is passed and the maker should generate trailers. An example:

{-# LANGUAGE BangPatterns #-}
import Data.ByteString (ByteString)
import qualified Data.ByteString.Char8 as C8
import Crypto.Hash (Context, SHA1) -- cryptonite
import qualified Crypto.Hash as CH

-- Strictness is important for Context.
trailersMaker :: Context SHA1 -> Maybe ByteString -> IO NextTrailersMaker
trailersMaker ctx Nothing = return $ Trailers [("X-SHA1", sha1)]
  where
    !sha1 = C8.pack $ show $ CH.hashFinalize ctx
trailersMaker ctx (Just bs) = return $ NextTrailersMaker $ trailersMaker ctx'
  where
    !ctx' = CH.hashUpdate ctx bs

Usage example:

let h2rsp = responseFile ...
    maker = trailersMaker (CH.hashInit :: Context SHA1)
    h2rsp' = setResponseTrailersMaker h2rsp maker

defaultTrailersMaker :: TrailersMaker

TrailersMake to create no trailers.

data NextTrailersMaker

Either the next trailers maker or final trailers.

Constructors

NextTrailersMaker TrailersMaker

Trailers [Header]

runTrailersMaker :: TrailersMaker -> Buffer -> Int -> IO NextTrailersMaker

Running trailers-maker.

bufferIO buf siz $ \bs -> tlrmkr (Just bs)