warp-3.1.12: A fast, light-weight web server for WAI applications.

Safe Haskell | None
Language | Haskell98

Network.Wai.Handler.Warp

Contents

- Run a Warp server
- Run an HTTP/2-aware server
- Settings
  - Setters
  - Getters
  - Exception handler
  - Exception response handler
- Data types
- Utilities
- Internal
  - Low level run functions
  - Connection
  - Buffer
  - Sendfile
  - Version
  - Data types
  - File descriptor cache
  - Date
  - Request and response
  - Time out manager
  - Types
  - Manager
  - Registration
  - Control
  - Exceptions

Description

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

HTTP/1.0, HTTP/1.1 and HTTP/2 are supported. For HTTP/2, Warp supports direct and ALPN (in TLS) but not upgrade.

Note on slowloris timeouts: to prevent slowloris attacks, timeouts are used at various points in request receiving and response sending. One interesting corner case is partial request body consumption; in that case, Warp's timeout handling is still in effect, and the timeout will not be triggered again. Therefore, it is recommended that once you start consuming the request body, you either:

- consume the entire body promptly
- call the `pauseTimeout` function

For more information, see https://github.com/yesodweb/wai/issues/351.

Synopsis

- run :: Port -> Application -> IO ()
- runEnv :: Port -> Application -> IO ()
- runSettings :: Settings -> Application -> IO ()
- runSettingsSocket :: Settings -> Socket -> Application -> IO ()
- runHTTP2 :: Port -> HTTP2Application -> Application -> IO ()
- runHTTP2Env :: Port -> HTTP2Application -> Application -> IO ()
- runHTTP2Settings :: Settings -> HTTP2Application -> Application -> IO ()
- runHTTP2SettingsSocket :: Settings -> Socket -> HTTP2Application -> Application -> IO ()
- data Settings
- defaultSettings :: Settings
- setPort :: Port -> Settings -> Settings
- setHost :: HostPreference -> Settings -> Settings
- setOnException :: (Maybe Request -> SomeException -> IO ()) -> Settings -> Settings
- setOnExceptionResponse :: (SomeException -> Response) -> Settings -> Settings
- setOnOpen :: (SockAddr -> IO Bool) -> Settings -> Settings
- setOnClose :: (SockAddr -> IO ()) -> Settings -> Settings
- setTimeout :: Int -> Settings -> Settings
- setManager :: Manager -> Settings -> Settings
- setFdCacheDuration :: Int -> Settings -> Settings
- setFileInfoCacheDuration :: Int -> Settings -> Settings
- setBeforeMainLoop :: IO () -> Settings -> Settings
- setNoParsePath :: Bool -> Settings -> Settings
- setInstallShutdownHandler :: (IO () -> IO ()) -> Settings -> Settings
- setServerName :: ByteString -> Settings -> Settings
- setMaximumBodyFlush :: Maybe Int -> Settings -> Settings
- setFork :: (((forall a. IO a -> IO a) -> IO ()) -> IO ()) -> Settings -> Settings
- setProxyProtocolNone :: Settings -> Settings
- setProxyProtocolRequired :: Settings -> Settings
- setProxyProtocolOptional :: Settings -> Settings
- setSlowlorisSize :: Int -> Settings -> Settings
- setHTTP2Disabled :: Settings -> Settings
- setLogger :: (Request -> Status -> Maybe Integer -> IO ()) -> Settings -> Settings
- getPort :: Settings -> Port
- getHost :: Settings -> HostPreference
- getOnOpen :: Settings -> SockAddr -> IO Bool
- getOnClose :: Settings -> SockAddr -> IO ()
- getOnException :: Settings -> Maybe Request -> SomeException -> IO ()
- defaultOnException :: Maybe Request -> SomeException -> IO ()
- defaultShouldDisplayException :: SomeException -> Bool
- defaultOnExceptionResponse :: SomeException -> Response
- exceptionResponseForDebug :: SomeException -> Response
- data HostPreference :: *
- type Port = Int
- data InvalidRequest
  - = NotEnoughLines [String]
  - | BadFirstLine String
  - | NonHttp
  - | IncompleteHeaders
  - | ConnectionClosedByPeer
  - | OverLargeHeader
  - | BadProxyHeader String
- pauseTimeout :: Request -> IO ()
- data FileInfo = FileInfo {
  - fileInfoName :: !FilePath
  - fileInfoSize :: !Integer
  - fileInfoTime :: HTTPDate
  - fileInfoDate :: ByteString
  }
- getFileInfo :: Request -> FilePath -> IO FileInfo
- runSettingsConnection :: Settings -> IO (Connection, SockAddr) -> Application -> IO ()
- runSettingsConnectionMaker :: Settings -> IO (IO Connection, SockAddr) -> Application -> IO ()
- runSettingsConnectionMakerSecure :: Settings -> IO (IO (Connection, Transport), SockAddr) -> Application -> IO ()
- data Transport
  - = TCP
  - | TLS {
    - tlsMajorVersion :: Int
    - tlsMinorVersion :: Int
    - tlsNegotiatedProtocol :: Maybe ByteString
    - tlsChiperID :: Word16
    }
- data Connection = Connection {
  - connSendMany :: [ByteString] -> IO ()
  - connSendAll :: ByteString -> IO ()
  - connSendFile :: SendFile
  - connClose :: IO ()
  - connRecv :: Recv
  - connRecvBuf :: RecvBuf
  - connWriteBuffer :: Buffer
  - connBufferSize :: BufSize
  }
- socketConnection :: Socket -> IO Connection
- type Buffer = Ptr Word8
- type BufSize = Int
- bufferSize :: BufSize
- allocateBuffer :: Int -> IO Buffer
- freeBuffer :: Buffer -> IO ()
- data FileId = FileId {
  - fileIdPath :: FilePath
  - fileIdFd :: Maybe Fd
  }
- type SendFile = FileId -> Integer -> Integer -> IO () -> [ByteString] -> IO ()
- sendFile :: Socket -> Buffer -> BufSize -> (ByteString -> IO ()) -> SendFile
- readSendFile :: Buffer -> BufSize -> (ByteString -> IO ()) -> SendFile
- warpVersion :: String
- data InternalInfo = InternalInfo {
  - threadHandle :: Handle
  - timeoutManager :: Manager
  - fdCacher :: Maybe MutableFdCache
  - fileInfo :: FilePath -> IO FileInfo
  - dateCacher :: DateCache
  }
- type HeaderValue = ByteString
- type IndexedHeader = Array Int (Maybe HeaderValue)
- requestMaxIndex :: Int
- withFdCache :: Int -> (Maybe MutableFdCache -> IO a) -> IO a
- getFd :: MutableFdCache -> FilePath -> IO (Fd, Refresh)
- type MutableFdCache = Reaper FdCache (Hash, FdEntry)
- type Refresh = IO ()
- withDateCache :: (DateCache -> IO a) -> IO a
- getDate :: DateCache -> IO GMTDate
- type DateCache = IO GMTDate
- type GMTDate = ByteString
- data Source
- recvRequest :: Settings -> Connection -> InternalInfo -> SockAddr -> Source -> IO (Request, Maybe (IORef Int), IndexedHeader, IO ByteString)
- sendResponse :: Settings -> Connection -> InternalInfo -> Request -> IndexedHeader -> IO ByteString -> Response -> IO Bool
- type Manager = Reaper [Handle] Handle
- type TimeoutAction = IO ()
- data Handle
- initialize :: Int -> IO Manager
- stopManager :: Manager -> IO ()
- killManager :: Manager -> IO ()
- withManager :: Int -> (Manager -> IO a) -> IO a
- register :: Manager -> TimeoutAction -> IO Handle
- registerKillThread :: Manager -> IO Handle
- tickle :: Handle -> IO ()
- cancel :: Handle -> IO ()
- pause :: Handle -> IO ()
- resume :: Handle -> IO ()
- data TimeoutThread = TimeoutThread

# Run a Warp server

All of these automatically serve the same `Application` over HTTP/1, HTTP/1.1, and HTTP/2.

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

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

runEnv :: Port -> Application -> IO () Source

Run an `Application` on the port present in the `PORT` environment variable. Uses the `Port` given when the variable is unset. This calls `runSettings` with `defaultSettings`.

Since 3.0.9

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

Run an `Application` with the given `Settings`. This opens a listen socket on the port defined in `Settings` and calls `runSettingsSocket`.

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

This installs a shutdown handler for the given socket and calls `runSettingsConnection` with the default connection setup action which handles plain (non-cipher) HTTP. When the listen socket in the second argument is closed, all live connections are gracefully shut down.

The supplied socket can be a Unix named socket, which can be used when reverse HTTP proxying into your application.

Note that the `settingsPort` will still be passed to `Application`s via the `serverPort` record.

# Run an HTTP/2-aware server

Each of these takes an HTTP/2-aware application as well as a backup `Application` to be used for HTTP/1.1 and HTTP/1 connections. These are only needed if your application needs access to HTTP/2-specific features such as trailers or pushed streams.

runHTTP2 :: Port -> HTTP2Application -> Application -> IO () Source

Serve an `HTTP2Application` and an `Application` together on the given port.

runHTTP2Env :: Port -> HTTP2Application -> Application -> IO () Source

The HTTP/2-aware form of `runEnv`.

runHTTP2Settings :: Settings -> HTTP2Application -> Application -> IO () Source

The HTTP/2-aware form of `runSettings`.

runHTTP2SettingsSocket :: Settings -> Socket -> HTTP2Application -> Application -> IO () Source

The HTTP/2-aware form of `runSettingsSocket`.

# Settings

data Settings Source

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 the various 'set' functions to modify individual fields. For example:

    setTimeout 20 defaultSettings

defaultSettings :: Settings Source

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

## Setters

setPort :: Port -> Settings -> Settings Source

Port to listen on. Default value: 3000

Since 2.1.0

setHost :: HostPreference -> Settings -> Settings Source

Interface to bind to. Default value: HostIPv4

Since 2.1.0

setOnException :: (Maybe Request -> SomeException -> IO ()) -> Settings -> Settings Source

What to do with exceptions thrown by either the application or server. Default: `defaultOnException`

Since 2.1.0

setOnExceptionResponse :: (SomeException -> Response) -> Settings -> Settings Source

A function to create a `Response` when an exception occurs.

Default: `defaultOnExceptionResponse`

Since 2.1.0

setOnOpen :: (SockAddr -> IO Bool) -> Settings -> Settings Source

What to do when a connection is opened. When `False` is returned, the connection is closed immediately. Otherwise, the connection is going on. Default: always returns `True`.

Since 2.1.0

setOnClose :: (SockAddr -> IO ()) -> Settings -> Settings Source

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

Since 2.1.0

setTimeout :: Int -> Settings -> Settings Source

Timeout value in seconds. Default value: 30

Since 2.1.0

setManager :: Manager -> Settings -> Settings Source

Use an existing timeout manager instead of spawning a new one. If used, `settingsTimeout` is ignored.

Since 2.1.0

setFdCacheDuration :: Int -> Settings -> Settings Source

Cache duration time of file descriptors in seconds. 0 means that the cache mechanism is not used.

The FD cache is an optimization that is useful for servers dealing with static files. However, if files are being modified, it can cause incorrect results in some cases. Therefore, we disable it by default. If you know that your files will be static or you prefer performance to file consistency, it's recommended to turn this on; a reasonable value for those cases is 10. Enabling this cache results in drastic performance improvement for file transfers.

Default value: 0, was previously 10

Since 3.0.13

setFileInfoCacheDuration :: Int -> Settings -> Settings Source

Cache duration time of file information in seconds. 0 means that the cache mechanism is not used.

The file information cache is an optimization that is useful for servers dealing with static files. However, if files are being modified, it can cause incorrect results in some cases. Therefore, we disable it by default. If you know that your files will be static or you prefer performance to file consistency, it's recommended to turn this on; a reasonable value for those cases is 10. Enabling this cache results in drastic performance improvement for file transfers.

Default value: 0

setBeforeMainLoop :: IO () -> Settings -> Settings Source

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 2.1.0

setNoParsePath :: Bool -> Settings -> Settings Source

Perform no parsing on the rawPathInfo.

This is useful for writing HTTP proxies.

Default: False

Since 2.1.0

setInstallShutdownHandler :: (IO () -> IO ()) -> Settings -> Settings Source

A code to install shutdown handler.

For instance, this code should set up a UNIX signal handler. The handler should call the first argument, which close the listen socket, at shutdown.

Default: does not install any code.

Since 3.0.1

setServerName :: ByteString -> Settings -> Settings Source

Default server name if application does not set one.

Since 3.0.2

setMaximumBodyFlush :: Maybe Int -> Settings -> Settings Source

The maximum number of bytes to flush from an unconsumed request body.

By default, Warp does not flush the request body so that, if a large body is present, the connection is simply terminated instead of wasting time and bandwidth on transmitting it. However, some clients do not deal with that situation well. You can either change this setting to `Nothing` to flush the entire body in all cases, or in your application ensure that you always consume the entire request body.

Default: 8192 bytes.

Since 3.0.3

setFork :: (((forall a. IO a -> IO a) -> IO ()) -> IO ()) -> Settings -> Settings Source

Code to fork a new thread to accept a connection.

This may be useful if you need OS bound threads, or if you wish to develop an alternative threading model.

Default: void . forkIOWithUnmask

Since 3.0.4

setProxyProtocolNone :: Settings -> Settings Source

Do not use the PROXY protocol.

Since 3.0.5

setProxyProtocolRequired :: Settings -> Settings Source

Require PROXY header.

This is for cases where a "dumb" TCP/SSL proxy is being used, which cannot add an `X-Forwarded-For` HTTP header field but has enabled support for the PROXY protocol.

See http://www.haproxy.org/download/1.5/doc/proxy-protocol.txt and http://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/TerminologyandKeyConcepts.html#proxy-protocol.

Only the human-readable header format (version 1) is supported. The binary header format (version 2) is not supported.

Since 3.0.5

setProxyProtocolOptional :: Settings -> Settings Source

Use the PROXY header if it exists, but also accept connections without the header. See `setProxyProtocolRequired`.

WARNING: This is contrary to the PROXY protocol specification and using it can indicate a security problem with your architecture if the web server is directly accessable to the public, since it would allow easy IP address spoofing. However, it can be useful in some cases, such as if a load balancer health check uses regular HTTP without the PROXY header, but proxied connections do include the PROXY header.

Since 3.0.5

setSlowlorisSize :: Int -> Settings -> Settings Source

Size in bytes read to prevent Slowloris protection. Default value: 2048

Since 3.1.2

setHTTP2Disabled :: Settings -> Settings Source

Disable HTTP2.

Since 3.1.7

setLogger :: (Request -> Status -> Maybe Integer -> IO ()) -> Settings -> Settings Source

Setting a log function.

Since 3.X.X

## Getters

getPort :: Settings -> Port Source

Get the listening port.

Since 2.1.1

getHost :: Settings -> HostPreference Source

Get the interface to bind to.

Since 2.1.1

getOnOpen :: Settings -> SockAddr -> IO Bool Source

Get the action on opening connection.

getOnClose :: Settings -> SockAddr -> IO () Source

Get the action on closeing connection.

getOnException :: Settings -> Maybe Request -> SomeException -> IO () Source

Get the exception handler.

## Exception handler

defaultOnException :: Maybe Request -> SomeException -> IO () Source

Printing an exception to standard error if `defaultShouldDisplayException` returns `True`.

Since: 3.1.0

defaultShouldDisplayException :: SomeException -> Bool Source

Apply the logic provided by `defaultOnException` to determine if an exception should be shown or not. The goal is to hide exceptions which occur under the normal course of the web server running.

Since 2.1.3

## Exception response handler

defaultOnExceptionResponse :: SomeException -> Response Source

Sending 400 for bad requests. Sending 500 for internal server errors.

Since: 3.1.0

exceptionResponseForDebug :: SomeException -> Response Source

Exception handler for the debugging purpose. 500, text/plain, a showed exception.

Since: 2.0.3.2

# 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`

Any other values is treated as a hostname. As an example, to bind to the IPv4 local host only, use "127.0.0.1".

Instances

Eq HostPreference |
Ord HostPreference |
Read HostPreference |
Show HostPreference |
IsString HostPreference |

type Port = Int Source

TCP port number.

data InvalidRequest Source

Error types for bad `Request`.

Constructors

NotEnoughLines [String] |
BadFirstLine String |
NonHttp |
IncompleteHeaders |
ConnectionClosedByPeer |
OverLargeHeader |
BadProxyHeader String |

Instances

Eq InvalidRequest Source |
Show InvalidRequest Source |
Exception InvalidRequest Source |

# Utilities

pauseTimeout :: Request -> IO () Source

Explicitly pause the slowloris timeout.

This is useful for cases where you partially consume a request body. For more information, see https://github.com/yesodweb/wai/issues/351

Since 3.0.10

data FileInfo Source

File information.

Constructors

FileInfo |

Fields

fileInfoName :: !FilePath
fileInfoSize :: !Integer
fileInfoTime :: HTTPDate

  Modification time

fileInfoDate :: ByteString

  Modification time in the GMT format

Instances

Eq FileInfo Source |
Show FileInfo Source |

getFileInfo :: Request -> FilePath -> IO FileInfo Source

Getting file information of the target file.

This function first uses a stat(2) or similar system call to obtain information of the target file, then registers it into the internal cache. From the next time, the information is obtained from the cache. This reduces the overhead to call the system call. The internal cache is refreshed every duration specified by `setFileInfoCacheDuration`.

This function throws an `IO` exception if the information is not available. For instance, the target file does not exist. If this function is used an a Request generated by a WAI backend besides Warp, it also throws an `IO` exception.

Since 3.1.10

# Internal

The following APIs will be removed in Warp 3.2.0. Please use ones exported from Network.Wai.Handler.Warp.Internal.

## Low level run functions

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

The connection setup action would be expensive. A good example is initialization of TLS. So, this converts the connection setup action to the connection maker which will be executed after forking a new worker thread. Then this calls `runSettingsConnectionMaker` with the connection maker. This allows the expensive computations to be performed in a separate worker thread instead of the main server loop.

Since 1.3.5

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

This modifies the connection maker so that it returns `TCP` for `Transport` (i.e. plain HTTP) then calls `runSettingsConnectionMakerSecure`.

runSettingsConnectionMakerSecure :: Settings -> IO (IO (Connection, Transport), SockAddr) -> Application -> IO () Source

The core run function which takes `Settings`, a connection maker and `Application`. The connection maker can return a connection of either plain HTTP or HTTP over TLS.

Since 2.1.4

data Transport Source

What kind of transport is used for this connection?

Constructors

TCP | Plain channel: TCP
TLS | Encrypted channel: TLS or SSL

Fields

tlsMajorVersion :: Int
tlsMinorVersion :: Int
tlsNegotiatedProtocol :: Maybe ByteString

  The result of Application Layer Protocol Negociation in RFC 7301

tlsChiperID :: Word16

## Connection

data Connection Source

Data type to manipulate IO actions for connections. This is used to abstract IO actions for plain HTTP and HTTP over TLS.

Constructors

Connection |

Fields

connSendMany :: [ByteString] -> IO ()

  This is not used at this moment.

connSendAll :: ByteString -> IO ()

  The sending function.

connSendFile :: SendFile

  The sending function for files in HTTP/1.1.

connClose :: IO ()

  The connection closing function.

connRecv :: Recv

  The connection receiving function. This returns "" for EOF.

connRecvBuf :: RecvBuf

  The connection receiving function. This tries to fill the buffer. This returns when the buffer is filled or reaches EOF.

connWriteBuffer :: Buffer

  The write buffer.

connBufferSize :: BufSize

  The size of the write buffer.

socketConnection :: Socket -> IO Connection Source

Creating `Connection` for plain HTTP based on a given socket.

## Buffer

type Buffer = Ptr Word8 Source

Type for buffer

type BufSize = Int Source

Type for buffer size

bufferSize :: BufSize Source

The default size of the write buffer: 16384 (2^14 = 1024 * 16). This is the maximum size of TLS record. This is also the maximum size of HTTP/2 frame payload (excluding frame header).

allocateBuffer :: Int -> IO Buffer Source

Allocating a buffer with malloc().

freeBuffer :: Buffer -> IO () Source

Releasing a buffer with free().

## Sendfile

data FileId Source

Data type to abstract file identifiers. On Unix, a file descriptor would be specified to make use of the file descriptor cache.

Since: 3.1.0

Constructors

FileId |

Fields

fileIdPath :: FilePath
fileIdFd :: Maybe Fd

type SendFile = FileId -> Integer -> Integer -> IO () -> [ByteString] -> IO () Source

fileid, offset, length, hook action, HTTP headers

Since: 3.1.0

sendFile :: Socket -> Buffer -> BufSize -> (ByteString -> IO ()) -> SendFile Source

Function to send a file based on sendfile() for Linux/Mac/FreeBSD. This makes use of the file descriptor cache. For other OSes, this is identical to `readSendFile`.

Since: 3.1.0

readSendFile :: Buffer -> BufSize -> (ByteString -> IO ()) -> SendFile Source

Function to send a file based on pread()/send() for Unix. This makes use of the file descriptor cache. For Windows, this is emulated by `Handle`.

Since: 3.1.0

## Version

warpVersion :: String Source

The version of Warp.

## Data types

data InternalInfo Source

Internal information.

Constructors

InternalInfo |

Fields

threadHandle :: Handle
timeoutManager :: Manager
fdCacher :: Maybe MutableFdCache
fileInfo :: FilePath -> IO FileInfo
dateCacher :: DateCache

type HeaderValue = ByteString Source

The type for header value used with `HeaderName`.

type IndexedHeader = Array Int (Maybe HeaderValue) Source

Array for a set of HTTP headers.

requestMaxIndex :: Int Source

The size for `IndexedHeader` for HTTP Request. From 0 to this corresponds to "Content-Length", "Transfer-Encoding", "Expect", "Connection", "Range", "Host", "If-Modified-Since", "If-Unmodified-Since" and "If-Range".

## File descriptor cache

withFdCache :: Int -> (Maybe MutableFdCache -> IO a) -> IO a Source

Creating `MutableFdCache` and executing the action in the second argument. The first argument is a cache duration in second.

getFd :: MutableFdCache -> FilePath -> IO (Fd, Refresh) Source

Getting `Fd` and `Refresh` from the mutable Fd cacher.

type MutableFdCache = Reaper FdCache (Hash, FdEntry) Source

Mutable Fd cacher.

type Refresh = IO () Source

An action to activate a Fd cache entry.

## Date

withDateCache :: (DateCache -> IO a) -> IO a Source

Creating `DateCache` and executing the action.

getDate :: DateCache -> IO GMTDate Source

Getting current `GMTDate` based on `DateCache`.

type DateCache = IO GMTDate Source

The type of the cache of the Date header value.

type GMTDate = ByteString Source

The type of the Date header value.

## Request and response

data Source Source

Type for input streaming.

recvRequest Source

Arguments

:: Settings |
-> Connection |
-> InternalInfo |
-> SockAddr | Peer's address.
-> Source | Where HTTP request comes from.
-> IO (Request, Maybe (IORef Int), IndexedHeader, IO ByteString) | `Request` passed to `Application`, how many bytes remain to be consumed, if known `IndexedHeader` of HTTP request for internal use, Body producing action used for flushing the request body

Receiving a HTTP request from `Connection` and parsing its header to create `Request`.

sendResponse Source

Arguments

:: Settings |
-> Connection |
-> InternalInfo |
-> Request | HTTP request.
-> IndexedHeader | Indexed header of HTTP request.
-> IO ByteString | source from client, for raw response
-> Response | HTTP response including status code and response header.
-> IO Bool | Returing True if the connection is persistent.

Sending a HTTP response to `Connection` according to `Response`.

Applications/middlewares MUST provide a proper `ResponseHeaders`. so that inconsistency does not happen. No header is deleted by this function.

Especially, Applications/middlewares MUST provide a proper Content-Type. They MUST NOT provide Content-Length, Content-Range, and Transfer-Encoding because they are inserted, when necessary, regardless they already exist. This function does not insert Content-Encoding. It's middleware's responsibility.

The Date and Server header is added if not exist in HTTP response header.

There are three basic APIs to create `Response`:

`responseBuilder` :: `Status` -> `ResponseHeaders` -> `Builder` -> `Response`
  HTTP response body is created from `Builder`. Transfer-Encoding: chunked is used in HTTP/1.1.
`responseStream` :: `Status` -> `ResponseHeaders` -> `StreamingBody` -> `Response`
  HTTP response body is created from `Builder`. Transfer-Encoding: chunked is used in HTTP/1.1.
`responseRaw` :: (`IO` `ByteString` -> (`ByteString` -> `IO` ()) -> `IO` ()) -> `Response` -> `Response`
  No header is added and no Transfer-Encoding: is applied.
`responseFile` :: `Status` -> `ResponseHeaders` -> `FilePath` -> `Maybe` `FilePart` -> `Response`
  HTTP response body is sent (by sendfile(), if possible) for GET method. HTTP response body is not sent by HEAD method. Content-Length and Content-Range are automatically added into the HTTP response header if necessary. If Content-Length and Content-Range exist in the HTTP response header, they would cause inconsistency. "Accept-Ranges: bytes" is also inserted.

Applications are categorized into simple and sophisticated. Sophisticated applications should specify `Just` to `Maybe` `FilePart`. They should treat the conditional request by themselves. A proper `Status` (200 or 206) must be provided.

Simple applications should specify `Nothing` to `Maybe` `FilePart`. The size of the specified file is obtained by disk access or from the file infor cache. If-Modified-Since, If-Unmodified-Since, If-Range and Range are processed. Since a proper status is chosen, `Status` is ignored. Last-Modified is inserted.

## Time out manager

## Types

type Manager = Reaper [Handle] Handle Source

A timeout manager

type TimeoutAction = IO () Source

An action to be performed on timeout.

data Handle Source

A handle used by `Manager`

## Manager

initialize :: Int -> IO Manager Source

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

stopManager :: Manager -> IO () Source

Stopping timeout manager with onTimeout fired.

killManager :: Manager -> IO () Source

Killing timeout manager immediately without firing onTimeout.

withManager Source

Arguments

:: Int | timeout in microseconds
-> (Manager -> IO a) |
-> IO a |

Call the inner function with a timeout manager.

## Registration

register :: Manager -> TimeoutAction -> IO Handle Source

Registering a timeout action.

registerKillThread :: Manager -> IO Handle Source

Registering a timeout action of killing this thread.

## Control

tickle :: Handle -> IO () Source

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

cancel :: Handle -> IO () Source

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

pause :: Handle -> IO () Source

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

resume :: Handle -> IO () Source

Setting the paused state to active. This is an alias to `tickle`.

## Exceptions

data TimeoutThread Source

Constructors

TimeoutThread |

Instances

Show TimeoutThread Source |
Exception TimeoutThread Source |