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 () Source #

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 Source #

Request from client.

#### Instances

Instances details

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

## Accessing request

requestMethod :: Request -> Maybe Method Source #

Getting the method from a request.

requestPath :: Request -> Maybe Path Source #

Getting the path from a request.

requestAuthority :: Request -> Maybe Authority Source #

Getting the authority from a request.

requestScheme :: Request -> Maybe Scheme Source #

Getting the scheme from a request.

requestHeaders :: Request -> TokenHeaderTable Source #

Getting the headers from a request.

requestBodySize :: Request -> Maybe Int Source #

Getting the body size from a request.

getRequestBodyChunk :: Request -> IO ByteString Source #

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

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

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

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

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

# Aux

data Aux Source #

Additional information.

auxTimeHandle :: Aux -> Handle Source #

Time handle for the worker processing this request and response.

auxMySockAddr :: Aux -> SockAddr Source #

Local socket address copied from `Config`.

auxPeerSockAddr :: Aux -> SockAddr Source #

Remove socket address copied from `Config`.

# Response

data Response Source #

Response from server.

#### Instances

Instances details

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

## Creating response

responseNoBody :: Status -> ResponseHeaders -> Response Source #

Creating response without body.

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

Creating response with file.

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

Creating response with streaming.

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

Creating response with builder.

## Generalized streaming interface

data OutBodyIface Source #

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 Source #

Generalization of `responseStreaming`.

## Accessing response

responseBodySize :: Response -> Maybe Int Source #

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

## Trailers maker

type TrailersMaker = Maybe ByteString -> IO NextTrailersMaker Source #

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 Source #

Either the next trailers maker or final trailers.

Constructors

NextTrailersMaker TrailersMaker |
Trailers [Header] |

defaultTrailersMaker :: TrailersMaker Source #

TrailersMake to create no trailers.

setResponseTrailersMaker :: Response -> TrailersMaker -> Response Source #

Setting `TrailersMaker` to `Response`.

# Push promise

data PushPromise Source #

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 Source #

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

# Types

type Path = ByteString Source #

Path.

type Authority = String Source #

Authority.

type Scheme = ByteString Source #

"http" or "https".

data FileSpec Source #

File specification.

Constructors

FileSpec FilePath FileOffset ByteCount |

#### Instances

Instances details

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

type FileOffset = Int64 Source #

Offset for file.

type ByteCount = Int64 Source #

How many bytes to read

type ReadN = Int -> IO ByteString Source #

Reading n bytes.

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

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 Source #

Position read for files.

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

Making a position read and its closer.

data Sentinel Source #

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 Source #

Position read based on `Handle`.