Network.SocketServer

This module provides an infrastructure to simplify server design.

Written by John Goerzen, [e-mail]

Please note: this module is designed to work with TCP, UDP, and Unix domain sockets, but only TCP sockets have been tested to date.

This module is presently under-documented. For an example of usage, please see the description of Network.FTP.Server.

Generic Options and Types

data InetServerOptions

Options for your server.

Constructors

InetServerOptions

Fields

• listenQueueSize :: Int
• portNumber :: PortNumber
• interface :: HostAddress
• reuse :: Bool
• family :: Family
• sockType :: SocketType
• protoStr :: String

Instances

Eq InetServerOptions

Methods

(==) :: InetServerOptions -> InetServerOptions -> Bool

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

Show InetServerOptions

Methods

showsPrec :: Int -> InetServerOptions -> ShowS

show :: InetServerOptions -> String

showList :: [InetServerOptions] -> ShowS

simpleTCPOptions

Arguments

:: Int

Port Number

-> InetServerOptions

Get Default options. You can always modify it later.

data SocketServer

Constructors

SocketServer

Fields

• optionsSS :: InetServerOptions
• sockSS :: Socket

Instances

Eq SocketServer

Methods

(==) :: SocketServer -> SocketServer -> Bool

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

Show SocketServer

Methods

showsPrec :: Int -> SocketServer -> ShowS

show :: SocketServer -> String

showList :: [SocketServer] -> ShowS

type HandlerT = Socket -> SockAddr -> SockAddr -> IO ()

The main handler type.

The first parameter is the socket itself.

The second is the address of the remote endpoint.

The third is the address of the local endpoint.

TCP server convenient setup

serveTCPforever

Arguments

:: InetServerOptions

Server options

-> HandlerT

Handler function

-> IO ()

Convenience function to completely set up a TCP SocketServer and handle all incoming requests.

This function is literally this:

serveTCPforever options func =
    do sockserv <- setupSocketServer options
       serveForever sockserv func

Lower-Level Processing

setupSocketServer :: InetServerOptions -> IO SocketServer

Takes some options and sets up the SocketServer. I will bind and begin listening, but will not accept any connections itself.

handleOne :: SocketServer -> HandlerT -> IO ()

Handle one incoming request from the given SocketServer.

serveForever :: SocketServer -> HandlerT -> IO ()

Handle all incoming requests from the given SocketServer.

closeSocketServer :: SocketServer -> IO ()

Close the socket server. Does not terminate active handlers, if any.

Combinators

loggingHandler

Arguments

:: String

Name of logger to use

-> Priority

Priority of logged messages

-> HandlerT

Handler to call after logging

-> HandlerT

Resulting handler

Log each incoming connection using the interface in System.Log.Logger.

Log when the incoming connection disconnects.

Also, log any failures that may occur in the child handler.

threadedHandler

Arguments

:: HandlerT

Handler to call in the new thread

-> HandlerT

Resulting handler

Handle each incoming connection in its own thread to make the server multi-tasking.

handleHandler

Arguments

:: (Handle -> SockAddr -> SockAddr -> IO ())

Handler to call

-> HandlerT

Give your handler function a Handle instead of a Socket.

The Handle will be opened with ReadWriteMode (you use one handle for both directions of the Socket). Also, it will be initialized with LineBuffering.

Unlike other handlers, the handle will be closed when the function returns. Therefore, if you are doing threading, you should to it before you call this handler.