Network.Wai.Handler.Warp

A fast, light-weight HTTP server handler for WAI.

Run a Warp server

run :: Port -> Application -> IO ()

Run an Application on the given port. This calls runSettings with defaultSettings.

runSettings :: Settings -> Application -> IO ()

Run a Warp server with the given settings.

runSettingsSocket :: Settings -> Socket -> Application -> IO ()

Same as runSettings, but uses a user-supplied socket instead of opening one. This allows the user to provide, for example, Unix named socket, which can be used when reverse HTTP proxying into your application.

Note that the settingsPort will still be passed to Applications via the serverPort record.

Settings

data Settings

Various Warp server settings. This is purposely kept as an abstract data type so that new settings can be added without breaking backwards compatibility. In order to create a Settings value, use defaultSettings and record syntax to modify individual records. For example:

defaultSettings { settingsTimeout = 20 }

defaultSettings :: Settings

The default settings for the Warp server. See the individual settings for the default value.

settingsPort :: Settings -> Int

Port to listen on. Default value: 3000

settingsHost :: Settings -> HostPreference

Default value: HostIPv4

settingsOnException :: Settings -> SomeException -> IO ()

What to do with exceptions thrown by either the application or server. Default: ignore server-generated exceptions (see InvalidRequest) and print application-generated applications to stderr.

settingsOnOpen :: Settings -> IO ()

What to do when a connection is open. Default: do nothing.

settingsOnClose :: Settings -> IO ()

What to do when a connection is close. Default: do nothing.

settingsTimeout :: Settings -> Int

Timeout value in seconds. Default value: 30

settingsIntercept :: Settings -> Request -> Maybe (Source (ResourceT IO) ByteString -> Connection -> ResourceT IO ())

settingsManager :: Settings -> Maybe Manager

Use an existing timeout manager instead of spawning a new one. If used, settingsTimeout is ignored. Default is Nothing

settingsFdCacheDuration :: Settings -> Int

Cache duratoin time of file descriptors in seconds. 0 means that the cache mechanism is not used. Default value: 10

settingsResourceTPerRequest :: Settings -> Bool

If True, each request/response pair will run in a separate ResourceT. This provides more intuitive behavior for dynamic code, but can hinder performance in high-throughput cases. File servers can safely set to False for increased performance. Default is True.

settingsBeforeMainLoop :: Settings -> IO ()

Code to run after the listening socket is ready but before entering the main event loop. Useful for signaling to tests that they can start running, or to drop permissions after binding to a restricted port.

Default: do nothing.

Since 1.3.6

settingsServerName :: Settings -> ByteString

Server name to be sent in the Server header.

Default: Warp/version

Since 1.3.8

Data types

data HostPreference :: *

Which host to bind.

Note: The IsString instance recognizes the following special values:

• * means HostAny
• *4 means HostIPv4
• !4 means HostIPv4Only
• *6 means HostIPv6
• !6 means HostIPv6Only

Constructors

HostAny

HostIPv4

HostIPv4Only

HostIPv6

HostIPv6Only

Host String

Instances

Eq HostPreference

Ord HostPreference

Read HostPreference

Show HostPreference

IsString HostPreference

Connection

data Connection

In order to provide slowloris protection, Warp provides timeout handlers. We follow these rules:

• A timeout is created when a connection is opened.
• When all request headers are read, the timeout is tickled.
• Every time at least 2048 bytes of the request body are read, the timeout is tickled.
• The timeout is paused while executing user code. This will apply to both the application itself, and a ResponseSource response. The timeout is resumed as soon as we return from user code.
• Every time data is successfully sent to the client, the timeout is tickled.

Constructors

Connection

Fields

connSendMany :: [ByteString] -> IO ()

connSendAll :: ByteString -> IO ()

connSendFile :: FilePath -> Integer -> Integer -> IO () -> [ByteString] -> Cleaner -> IO ()

offset, length

connClose :: IO ()

connRecv :: IO ByteString

runSettingsConnection :: Settings -> IO (Connection, SockAddr) -> Application -> IO ()

runSettingsConnectionMaker :: Settings -> IO (IO Connection, SockAddr) -> Application -> IO ()

Allows you to provide a function which will return a Connection. In cases where creating the Connection can be expensive, this allows the expensive computations to be performed in a separate thread instead of the main server loop.

Since 1.3.5

Datatypes

type Port = Int

TCP port number

data InvalidRequest

Constructors

NotEnoughLines [String]

BadFirstLine String

NonHttp

IncompleteHeaders

ConnectionClosedByPeer

OverLargeHeader

Instances

Eq InvalidRequest

Show InvalidRequest

Exception InvalidRequest

Typeable * InvalidRequest

Internal

Time out manager

data Manager

A timeout manager

data Handle

A handle used by Manager

type TimeoutAction = IO ()

An action to be performed on timeout.

initialize :: Int -> IO Manager

Creating timeout manager which works every N micro seconds where N is the first argument.

withManager

Arguments

:: Int

timeout in microseconds

-> (Manager -> IO a)

-> IO a

Call the inner function with a timeout manager.

register :: Manager -> TimeoutAction -> IO Handle

Registering a timeout action.

registerKillThread :: Manager -> IO Handle

Registering a timeout action of killing this thread.

tickle :: Handle -> IO ()

Setting the state to active. Manager turns active to inactive repeatedly.

cancel :: Handle -> IO ()

Setting the state to canceled. Manager eventually removes this without timeout action.

resume :: Handle -> IO ()

Setting the state to active. This is an alias to ticle.

pause :: Handle -> IO ()

Setting the state to paused. Manager does not change the value.

Cleaner

data Cleaner

A type used to clean up file descriptor caches.

dummyCleaner :: Cleaner

A dummy Cleaner, intended for applications making use of the low-level request parsing and rendering functions.

Since 1.3.4

Request and response

parseRequest :: Connection -> Port -> SockAddr -> Source (ResourceT IO) ByteString -> ResourceT IO (Request, IO (ResumableSource (ResourceT IO) ByteString))

sendResponse :: Settings -> Cleaner -> Request -> Connection -> Response -> ResourceT IO Bool

socketConnection :: Socket -> Connection

Default action value for Connection

Version

warpVersion :: String