Copyright	Lukas Braun 2014-2016
License	GPL-3
Maintainer	koomi+mqtt@hackerspace-bamberg.de
Safe Haskell	None
Language	Haskell2010

Network.MQTT.Internal

Contents

User interaction
Main loop
Misc

Description

MQTT Internals.

Use with care and expected changes.

Synopsis

User interaction

data Config Source #

The various options when establishing a connection. See below for available accessors.

Constructors

Config

Fields

cHost :: HostName
Hostname of the broker.
cPort :: PortNumber
Port of the broker.
cClean :: Bool
Should the server forget subscriptions and other state on disconnects?
cWill :: Maybe Will
Optional Will message.
cUsername :: Maybe Text
Optional username used for authentication.
cPassword :: Maybe Text
Optional password used for authentication.
cKeepAlive :: Maybe Word16
Time (in seconds) after which a PingReq is sent to the broker if no regular message was sent. Nothing means no limit.
cClientID :: Text
Client ID used by the server to identify clients.
cLogDebug :: String -> IO ()
Function for debug-level logging.
cResendTimeout :: Int
Time in seconds after which messages that have not been but should be acknowledged are retransmitted.
cPublished :: TChan (Message PUBLISH)
The channel received Publish messages are written to.
cCommands :: Commands
The channel used by publish, subscribe, etc.
cInputBufferSize :: Int
Maximum number of bytes read from the network at once.

data Terminated Source #

Reasons for why the connection was terminated.

Constructors

ParseFailed [String] String	at the context in `[String]` with the given message.
ConnectFailed ConnectError
UserRequested	`disconnect` was called

Instances

Show Terminated Source #
Methods showsPrec :: Int -> Terminated -> ShowS # show :: Terminated -> String # showList :: [Terminated] -> ShowS #

data Command Source #

Commands from the user for the mainLoop.

Constructors

CmdDisconnect
CmdSend SomeMessage
CmdAwait AwaitMessage
CmdStopWaiting AwaitMessage

newtype Commands Source #

The communication channel used by publish, subscribe, etc.

Constructors

Cmds
Fields getCmds :: TChan Command

mkCommands :: IO Commands Source #

Create a new Commands channel.

There should be one channel per MQTT connection. It might be reused by subsequent connections, but never by multiple connections concurrently.

send :: SingI t => Config -> Message t -> IO () Source #

Tell the mainLoop to send the given Message.

await :: SingI t => Config -> MVar (Message t) -> Maybe MsgID -> IO AwaitMessage Source #

Tell the MQTT instance to place the next Message of correct MsgType and MsgID (if present) into the MVar.

data AwaitMessage where Source #

Constructors

AwaitMessage :: SingI t => MVar (Message t) -> Maybe MsgID -> AwaitMessage

Instances

Eq AwaitMessage Source #
Methods (==) :: AwaitMessage -> AwaitMessage -> Bool # (/=) :: AwaitMessage -> AwaitMessage -> Bool #

stopWaiting :: Config -> AwaitMessage -> IO () Source #

Stop waiting for the described Message.

sendAwait :: (SingI t, SingI r) => Config -> Message t -> SMsgType r -> IO (Message r) Source #

Execute the common pattern of sending a message and awaiting a response in a safe, non-racy way. The message message is retransmitted if no response has been received after cResendTimeout seconds, with exponential backoff for further retransmissions

An incoming message is considered a response if it is of the requested type and the MsgIDs match (if present).

writeCmd :: Config -> Command -> IO () Source #

Main loop

mainLoop :: Config -> Handle -> WaitTerminate -> SendSignal -> IO Terminated Source #

type WaitTerminate = STM () Source #

type SendSignal = MVar () Source #

data MqttState Source #

Internal state for the main loop

Constructors

MqttState
Fields msParseCC :: ParseCC Current parser continuation msUnconsumed :: ByteString Not yet parsed input msWaiting :: [AwaitMessage] Messages we're waiting for

type ParseCC = ByteString -> IResult ByteString SomeMessage Source #

data Input Source #

Input for the main loop

Constructors

InMsg SomeMessage
InErr Terminated
InCmd Command

waitForInput :: Config -> Handle -> StateT MqttState IO Input Source #

parseBytes :: Monad m => ByteString -> StateT MqttState m (Maybe Input) Source #

Parse the given ByteString and update the current MqttState.

Returns Nothing if more input is needed.

handleMessage :: Config -> WaitTerminate -> SomeMessage -> StateT MqttState IO () Source #

publishHandler :: Config -> Message PUBLISH -> IO () Source #

Misc

secToMicro :: Int -> Int Source #