Network.HTTP2.Client

HTTP/2 client library.

Example:

{-# LANGUAGE OverloadedStrings #-}

module Main where

import Control.Concurrent.Async
import qualified Control.Exception as E
import qualified Data.ByteString.Char8 as C8
import Network.HTTP.Types
import Network.Run.TCP (runTCPClient) -- network-run

import Network.HTTP2.Client

serverName :: String
serverName = "127.0.0.1"

main :: IO ()
main = runTCPClient serverName "80" $ runHTTP2Client serverName
  where
    cliconf host = ClientConfig "http" (C8.pack host) 20
    runHTTP2Client host s = E.bracket (allocSimpleConfig s 4096)
                                      freeSimpleConfig
                                      (\conf -> run (cliconf host) conf client)
    client sendRequest = do
        let req0 = requestNoBody methodGet "/" []
            client0 = sendRequest req0 $ \rsp -> do
                print rsp
                getResponseBodyChunk rsp >>= C8.putStrLn
            req1 = requestNoBody methodGet "/foo" []
            client1 = sendRequest req1 $ \rsp -> do
                print rsp
                getResponseBodyChunk rsp >>= C8.putStrLn
        ex <- E.try $ concurrently_ client0 client1
        case ex of
          Left  e  -> print (e :: HTTP2Error)
          Right () -> putStrLn "OK"

Runner

run :: ClientConfig -> Config -> Client a -> IO a

Running HTTP/2 client.

type Scheme = ByteString

"http" or "https".

type Authority = ByteString

Authority.

Runner arguments

data ClientConfig

Client configuration

Constructors

ClientConfig

Fields

• scheme :: Scheme

  https or http

• authority :: Authority

  Server name

• cacheLimit :: Int

  How many pushed responses are contained in the cache

data Config

HTTP/2 configuration.

Constructors

Config

Fields

• confWriteBuffer :: Buffer

  This is used only by frameSender. This MUST be freed after frameSender is terminated.

• confBufferSize :: BufferSize

  The size of the write buffer. We assume that the read buffer is the same size. So, this value is announced via SETTINGS_MAX_FRAME_SIZE to the peer.

• confSendAll :: ByteString -> IO ()
• confReadN :: Int -> IO ByteString
• confPositionReadMaker :: PositionReadMaker
• confTimeoutManager :: Manager

allocSimpleConfig :: Socket -> BufferSize -> IO Config

Making simple configuration whose IO is not efficient. A write buffer is allocated internally.

freeSimpleConfig :: Config -> IO ()

Deallocating the resource of the simple configuration.

HTTP/2 client

type Client a = (Request -> (Response -> IO a) -> IO a) -> IO a

Client type.

Request

data Request

Request from client.

Instances

Show Request

Defined in Network.HTTP2.Client.Types

Methods

showsPrec :: Int -> Request -> ShowS

show :: Request -> String

showList :: [Request] -> ShowS

Creating request

requestNoBody :: Method -> Path -> RequestHeaders -> Request

Creating request without body.

requestFile :: Method -> Path -> RequestHeaders -> FileSpec -> Request

Creating request with file.

requestStreaming :: Method -> Path -> RequestHeaders -> ((Builder -> IO ()) -> IO () -> IO ()) -> Request

Creating request with streaming.

requestBuilder :: Method -> Path -> RequestHeaders -> Builder -> Request

Creating request with builder.

Trailers maker

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

data NextTrailersMaker

Either the next trailers maker or final trailers.

Constructors

NextTrailersMaker TrailersMaker

Trailers [Header]

defaultTrailersMaker :: TrailersMaker

TrailersMake to create no trailers.

setRequestTrailersMaker :: Request -> TrailersMaker -> Request

Setting TrailersMaker to Response.

Response

data Response

Response from server.

Instances

Show Response

Defined in Network.HTTP2.Client.Types

Methods

showsPrec :: Int -> Response -> ShowS

show :: Response -> String

showList :: [Response] -> ShowS

Accessing response

responseStatus :: Response -> Maybe Status

Getting the status of a response.

responseHeaders :: Response -> HeaderTable

Getting the headers from a response.

responseBodySize :: Response -> Maybe Int

Getting the body size from a response.

getResponseBodyChunk :: Response -> IO ByteString

Reading a chunk of the response body. An empty ByteString returned when finished.

getResponseTrailers :: Response -> IO (Maybe HeaderTable)

Reading response trailers. This function must be called after getResponseBodyChunk returns an empty.

Types

type Method = ByteString

HTTP method (flat string type).

type Path = ByteString

Path.

data FileSpec

File specification.

Constructors

FileSpec FilePath FileOffset ByteCount

Instances

Show FileSpec

Defined in Network.HTTP2.Arch.Types

Methods

showsPrec :: Int -> FileSpec -> ShowS

show :: FileSpec -> String

showList :: [FileSpec] -> ShowS

Eq FileSpec

Defined in Network.HTTP2.Arch.Types

Methods

(==) :: FileSpec -> FileSpec -> Bool

(/=) :: FileSpec -> FileSpec -> Bool

type FileOffset = Int64

Offset for file.

type ByteCount = Int64

How many bytes to read

Error

data HTTP2Error

The connection error or the stream error. Stream errors are treated as connection errors since there are no good recovery ways. ErrorCode in connection errors should be the highest stream identifier but in this implementation it identifies the stream that caused this error.

Constructors

ConnectionIsClosed

ConnectionErrorIsReceived ErrorCode StreamId ReasonPhrase

ConnectionErrorIsSent ErrorCode StreamId ReasonPhrase

StreamErrorIsReceived ErrorCode StreamId

StreamErrorIsSent ErrorCode StreamId ReasonPhrase

BadThingHappen SomeException

Instances

Exception HTTP2Error

Defined in Network.HTTP2.Arch.Types

Methods

toException :: HTTP2Error -> SomeException

fromException :: SomeException -> Maybe HTTP2Error

displayException :: HTTP2Error -> String

Show HTTP2Error

Defined in Network.HTTP2.Arch.Types

Methods

showsPrec :: Int -> HTTP2Error -> ShowS

show :: HTTP2Error -> String

showList :: [HTTP2Error] -> ShowS

newtype ErrorCode

The type for raw error code.

Constructors

ErrorCode Word32

Bundled Patterns

pattern NoError :: ErrorCode

The type for error code. See https://www.rfc-editor.org/rfc/rfc9113#ErrorCodes.

pattern ProtocolError :: ErrorCode

pattern InternalError :: ErrorCode

pattern FlowControlError :: ErrorCode

pattern SettingsTimeout :: ErrorCode

pattern StreamClosed :: ErrorCode

pattern FrameSizeError :: ErrorCode

pattern RefusedStream :: ErrorCode

pattern Cancel :: ErrorCode

pattern CompressionError :: ErrorCode

pattern ConnectError :: ErrorCode

pattern EnhanceYourCalm :: ErrorCode

pattern InadequateSecurity :: ErrorCode

pattern HTTP11Required :: ErrorCode

Instances

Read ErrorCode

Defined in Network.HTTP2.Frame.Types

Methods

readsPrec :: Int -> ReadS ErrorCode

readList :: ReadS [ErrorCode]

readPrec :: ReadPrec ErrorCode

readListPrec :: ReadPrec [ErrorCode]

Show ErrorCode

Defined in Network.HTTP2.Frame.Types

Methods

showsPrec :: Int -> ErrorCode -> ShowS

show :: ErrorCode -> String

showList :: [ErrorCode] -> ShowS

Eq ErrorCode

Defined in Network.HTTP2.Frame.Types

Methods

(==) :: ErrorCode -> ErrorCode -> Bool

(/=) :: ErrorCode -> ErrorCode -> Bool

Ord ErrorCode

Defined in Network.HTTP2.Frame.Types

Methods

compare :: ErrorCode -> ErrorCode -> Ordering

(<) :: ErrorCode -> ErrorCode -> Bool

(<=) :: ErrorCode -> ErrorCode -> Bool

(>) :: ErrorCode -> ErrorCode -> Bool

(>=) :: ErrorCode -> ErrorCode -> Bool

max :: ErrorCode -> ErrorCode -> ErrorCode

min :: ErrorCode -> ErrorCode -> ErrorCode

RecvN

defaultReadN :: Socket -> IORef (Maybe ByteString) -> Int -> IO ByteString

Naive implementation for readN.

Position read for files

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

Making a position read and its closer.

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

Position read for files.

data Sentinel

Manipulating a file resource.

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.