Network.HTTP.Semantics.Server

http-semantics-0.3.0: HTTP senmatics libarry

Safe Haskell | None
Language | Haskell2010

Network.HTTP.Semantics.Server

Contents

- HTTP server
- Request
  - Accessing request
- Aux
- Response
  - Creating response
  - Generalized streaming interface
  - Accessing response
  - Trailers maker
- Push promise
- Types

Synopsis

- type Server = Request -> Aux -> (Response -> [PushPromise] -> IO ()) -> IO ()
- data Request
- requestMethod :: Request -> Maybe Method
- requestPath :: Request -> Maybe Path
- requestAuthority :: Request -> Maybe Authority
- requestScheme :: Request -> Maybe Scheme
- requestHeaders :: Request -> TokenHeaderTable
- requestBodySize :: Request -> Maybe Int
- getRequestBodyChunk :: Request -> IO ByteString
- getRequestBodyChunk' :: Request -> IO (ByteString, Bool)
- getRequestTrailers :: Request -> IO (Maybe TokenHeaderTable)
- data Aux
- auxTimeHandle :: Aux -> Handle
- auxMySockAddr :: Aux -> SockAddr
- auxPeerSockAddr :: Aux -> SockAddr
- data Response
- responseNoBody :: Status -> ResponseHeaders -> Response
- responseFile :: Status -> ResponseHeaders -> FileSpec -> Response
- responseStreaming :: Status -> ResponseHeaders -> ((Builder -> IO ()) -> IO () -> IO ()) -> Response
- responseBuilder :: Status -> ResponseHeaders -> Builder -> Response
- data OutBodyIface = OutBodyIface {
  - outBodyUnmask :: forall x. IO x -> IO x
  - outBodyPush :: Builder -> IO ()
  - outBodyPushFinal :: Builder -> IO ()
  - outBodyCancel :: Maybe SomeException -> IO ()
  - outBodyFlush :: IO ()
  }
- responseStreamingIface :: Status -> ResponseHeaders -> (OutBodyIface -> IO ()) -> Response
- responseBodySize :: Response -> Maybe Int
- type TrailersMaker = Maybe ByteString -> IO NextTrailersMaker
- data NextTrailersMaker
  - = NextTrailersMaker TrailersMaker
  - | Trailers [Header]
- defaultTrailersMaker :: TrailersMaker
- setResponseTrailersMaker :: Response -> TrailersMaker -> Response
- data PushPromise = PushPromise {
  - promiseRequestPath :: ByteString
  - promiseResponse :: Response
  }
- pushPromise :: ByteString -> Response -> Int -> PushPromise
- type Path = ByteString
- type Authority = String
- type Scheme = ByteString
- data FileSpec = FileSpec FilePath FileOffset ByteCount
- type FileOffset = Int64
- type ByteCount = Int64
- type ReadN = Int -> IO ByteString
- defaultReadN :: Socket -> IORef (Maybe ByteString) -> ReadN
- type PositionRead = FileOffset -> ByteCount -> Buffer -> IO ByteCount
- type PositionReadMaker = FilePath -> IO (PositionRead, Sentinel)
- data Sentinel
  - = Closer (IO ())
  - | Refresher (IO ())
- defaultPositionReadMaker :: PositionReadMaker

# HTTP server

type Server = Request -> Aux -> (Response -> [PushPromise] -> IO ()) -> IO () #

Server type. Server takes a HTTP request, should generate a HTTP response and push promises, then should give them to the sending function. The sending function would throw exceptions so that they can be logged.

The sending function must only be called once.

# Request

data Request #

Request from client.

#### Instances

Instances details

Show Request # |
Instance details Defined in Network.HTTP.Semantics.Server.Internal Methods showsPrec :: Int -> Request -> ShowS # show :: Request -> String # showList :: [Request] -> ShowS #

## Accessing request

requestMethod :: Request -> Maybe Method #

Getting the method from a request.

requestPath :: Request -> Maybe Path #

Getting the path from a request.

requestAuthority :: Request -> Maybe Authority #

Getting the authority from a request.

requestScheme :: Request -> Maybe Scheme #

Getting the scheme from a request.

requestHeaders :: Request -> TokenHeaderTable #

Getting the headers from a request.

requestBodySize :: Request -> Maybe Int #

Getting the body size from a request.

getRequestBodyChunk :: Request -> IO ByteString #

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

getRequestBodyChunk' :: Request -> IO (ByteString, Bool) #

Generalization of `getRequestBodyChunk` which also returns if the `ByteString` is the final one

getRequestTrailers :: Request -> IO (Maybe TokenHeaderTable) #

Reading request trailers. This function must be called after `getRequestBodyChunk` returns an empty.

# Aux

data Aux #

Additional information.

auxTimeHandle :: Aux -> Handle #

Time handle for the worker processing this request and response.

auxMySockAddr :: Aux -> SockAddr #

Local socket address copied from `Config`.

auxPeerSockAddr :: Aux -> SockAddr #

Remove socket address copied from `Config`.

# Response

data Response #

Response from server.

#### Instances

Instances details

Show Response # |
Instance details Defined in Network.HTTP.Semantics.Server.Internal Methods showsPrec :: Int -> Response -> ShowS # show :: Response -> String # showList :: [Response] -> ShowS #

## Creating response

responseNoBody :: Status -> ResponseHeaders -> Response #

Creating response without body.

responseFile :: Status -> ResponseHeaders -> FileSpec -> Response #

Creating response with file.

responseStreaming :: Status -> ResponseHeaders -> ((Builder -> IO ()) -> IO () -> IO ()) -> Response #

Creating response with streaming.

responseBuilder :: Status -> ResponseHeaders -> Builder -> Response #

Creating response with builder.

## Generalized streaming interface

data OutBodyIface #

Constructors

OutBodyIface |
Fields outBodyUnmask :: forall x. IO x -> IO x Unmask exceptions in the thread spawned for the request body This is used in the client: we spawn the new thread for the request body with exceptions masked, and provide the body of `OutBodyStreamingIface` with a callback to unmask them again (typically after installing an exception handler). Unmasking in the server is a no-op, as here the scope of the thread that is spawned for the server is the entire handler, not just the response streaming body. outBodyPush :: Builder -> IO () Push a new chunk In `http2`, there is no direct correspondence between chunks and the resulting `DATA` frames sent: the chunks are collected (written to an internal write buffer) until we can fill a frame. See also `outBodyFlush`. outBodyPushFinal :: Builder -> IO () Push the final chunk Using this function instead of `outBodyPush` can be used to guarantee that the final HTTP2 DATA frame is marked end-of-stream; with `outBodyPush` it may happen that an additional empty DATA frame is used for this purpose. Additionally, after calling this function, `outBodyCancel` will be a no-op. outBodyCancel :: Maybe SomeException -> IO () Cancel the stream Sends a `RST_STREAM` to the peer. If cancelling as the result of an exception, a `Just` should be provided which specifies the exception which will be stored locally as the reason for cancelling the stream; in this case, the error code sent with the `RST_STREAM` will be `INTERNAL_ERROR` (see https://datatracker.ietf.org/doc/html/rfc7540#section-7). If `Nothing` is given, the error code will be `CANCEL`. If there is a partially constructed `DATA` frame at the time of cancellation, this frame is discarded. If this is undesirable, you should call `outBodyFlush` prior to cancelling. outBodyFlush :: IO () Flush This can be used to emit a DATA frame with the data collected so far (using `outBodyPush`), even if that DATA frame has not yet reached the maximum frame size. Calling `outBodyFlush` unnecessarily can therefore result in excessive overhead from frame headers. If no data is available to send, this is a no-op.

responseStreamingIface :: Status -> ResponseHeaders -> (OutBodyIface -> IO ()) -> Response #

Generalization of `responseStreaming`.

## Accessing response

responseBodySize :: Response -> Maybe Int #

Getter for response body size. This value is available for file body.

## 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.

setResponseTrailersMaker :: Response -> TrailersMaker -> Response #

Setting `TrailersMaker` to `Response`.

# Push promise

data PushPromise #

HTTP/2 push promise or sever push. Pseudo REQUEST headers in push promise is automatically generated. Then, a server push is sent according to `promiseResponse`.

Constructors

PushPromise |
Fields promiseRequestPath :: ByteString Accessor for a URL path in a push promise (a virtual request from a server). E.g. "/style/default.css". promiseResponse :: Response Accessor for response actually pushed from a server.

pushPromise :: ByteString -> Response -> Int -> PushPromise #

Creating push promise. The third argument is traditional, not used.

# Types

type Path = ByteString #

Path.

type Authority = String #

Authority.

type Scheme = ByteString #

"http" or "https".

data FileSpec #

File specification.

Constructors

FileSpec FilePath FileOffset ByteCount |

#### Instances

Instances details

Show FileSpec # |
Instance details Defined in Network.HTTP.Semantics.Types Methods showsPrec :: Int -> FileSpec -> ShowS # show :: FileSpec -> String # showList :: [FileSpec] -> ShowS #
Eq FileSpec # |
Instance details Defined in Network.HTTP.Semantics.Types Methods (==) :: FileSpec -> FileSpec -> Bool # (/=) :: FileSpec -> FileSpec -> Bool #

type FileOffset = Int64 #

Offset for file.

type ByteCount = Int64 #

How many bytes to read

type ReadN = Int -> IO ByteString #

Reading n bytes.

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

Naive implementation for readN.

NOTE: This function is intended to be used by a single thread only. (It is probably quite rare anyway to want concurrent reads from the same network socket.)

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`.