d-bus-0.1.0: src/DBus/Message.hs
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE UndecidableInstances #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE NoMonomorphismRestriction #-}
{-# LANGUAGE ScopedTypeVariables #-}
module DBus.Message where
import Control.Applicative
import Control.Concurrent.STM
import Control.Monad
import Control.Monad.Reader
import qualified Data.Attoparsec.ByteString.Char8 as AP8
import qualified Data.Binary.Get as B
import Data.Bits
import qualified Data.ByteString as BS
import qualified Data.ByteString.Lazy.Builder as BS
import Data.Char
import qualified Data.Conduit as C
import qualified Data.Map as Map
import Data.Maybe
import Data.Monoid
import Data.Singletons
import Data.Singletons.Decide
import qualified Data.Text as Text
import Data.Word
import System.Mem.Weak
import Control.Monad.Catch (MonadThrow, throwM)
import Data.Singletons.Prelude.List
import DBus.Error
import DBus.Representable
import DBus.TH
import DBus.Types
import DBus.Wire
import DBus.Object
data MessageType = MessageTypeInvalid
| MessageTypeMethodCall
| MessageTypeMethodReturn
| MessageTypeError
| MessageTypeSignal
| MessageTypeOther Word8
deriving (Eq, Show)
instance Representable MessageType where
type RepType MessageType = 'DBusSimpleType TypeByte
toRep MessageTypeInvalid = DBVByte $ 0
toRep MessageTypeMethodCall = DBVByte $ 1
toRep MessageTypeMethodReturn = DBVByte $ 2
toRep MessageTypeError = DBVByte $ 3
toRep MessageTypeSignal = DBVByte $ 4
toRep (MessageTypeOther i) = DBVByte $ fromIntegral i
fromRep (DBVByte 0) = Just $ MessageTypeInvalid
fromRep (DBVByte 1) = Just $ MessageTypeMethodCall
fromRep (DBVByte 2) = Just $ MessageTypeMethodReturn
fromRep (DBVByte 3) = Just $ MessageTypeError
fromRep (DBVByte 4) = Just $ MessageTypeSignal
fromRep (DBVByte i) = Just $ MessageTypeOther $ fromIntegral i
data Flag = NoReplyExpected
| NoAutoStart
deriving (Eq, Show)
newtype Flags = Flags [Flag]
deriving (Show, Eq)
instance Representable Flags where
type RepType Flags = 'DBusSimpleType TypeByte
toRep (Flags xs) = DBVByte $ foldr (.|.) 0 (map toFlag xs)
where
toFlag NoReplyExpected = 0x1
toFlag NoAutoStart = 0x2
fromRep (DBVByte x) = Just . Flags $ fromFlags x
fromFlags x | x .&. 0x1 > 0 = NoReplyExpected : fromFlags (x `xor` 0x1)
| x .&. 0x2 > 0 = NoAutoStart : fromFlags (x `xor` 0x2)
| otherwise = []
instance Representable Signature where
type RepType Signature = 'DBusSimpleType TypeSignature
toRep (Signature ts) = DBVSignature ts
fromRep (DBVSignature ts) = Just $ Signature ts
data HeaderFields = HeaderFields { hFPath :: Maybe ObjectPath
, hFInterface :: Maybe Text.Text
, hFMember :: Maybe Text.Text
, hFErrorName :: Maybe Text.Text
, hFReplySerial :: Maybe Word32
, hFDestination :: Maybe Text.Text
, hFSender :: Maybe Text.Text
, hFMessageSignature :: Maybe Signature
, hFUnixfds :: Maybe Word32
} deriving (Show, Eq)
instance Representable HeaderFields where
type RepType HeaderFields = RepType [HeaderField]
toRep = toRep . toFields
fromRep = fmap fromFields . fromRep
emptyHeaderFields :: HeaderFields
emptyHeaderFields = HeaderFields Nothing Nothing Nothing Nothing Nothing
Nothing Nothing Nothing Nothing
toFields :: HeaderFields -> [HeaderField]
toFields hfs = catMaybes
[ HeaderFieldPath <$> hFPath hfs
, HeaderFieldInterface <$> hFInterface hfs
, HeaderFieldMember <$> hFMember hfs
, HeaderFieldErrorName <$> hFErrorName hfs
, HeaderFieldReplySerial <$> hFReplySerial hfs
, HeaderFieldDestination <$> hFDestination hfs
, HeaderFieldSender <$> hFSender hfs
, HeaderFieldMessageSignature <$> hFMessageSignature hfs
, HeaderFieldUnixFDs <$> hFUnixfds hfs
]
fromFields :: [HeaderField] -> HeaderFields
fromFields fs = foldr fromField emptyHeaderFields fs
where
fromField (HeaderFieldPath x) hf = hf{hFPath = Just x}
fromField (HeaderFieldInterface x) hf = hf{hFInterface = Just x}
fromField (HeaderFieldMember x) hf = hf{hFMember = Just x}
fromField (HeaderFieldErrorName x) hf = hf{hFErrorName = Just x}
fromField (HeaderFieldReplySerial x) hf = hf{hFReplySerial = Just x}
fromField (HeaderFieldDestination x) hf = hf{hFDestination = Just x}
fromField (HeaderFieldSender x) hf = hf{hFSender = Just x}
fromField (HeaderFieldMessageSignature x) hf = hf{hFMessageSignature = Just x}
fromField (HeaderFieldUnixFDs x) hf = hf{hFUnixfds = Just x}
fromFields _ hf = hf
data HeaderField = HeaderFieldInvalid
| HeaderFieldPath ObjectPath
| HeaderFieldInterface Text.Text
| HeaderFieldMember Text.Text
| HeaderFieldErrorName Text.Text
| HeaderFieldReplySerial Word32
| HeaderFieldDestination Text.Text
| HeaderFieldSender Text.Text
| HeaderFieldMessageSignature Signature
| HeaderFieldUnixFDs Word32
deriving (Show, Eq)
makeRepresentable ''HeaderField
instance Representable Endian where
type RepType Endian = 'DBusSimpleType TypeByte
toRep Little = DBVByte $ fromIntegral $ ord 'l'
toRep Big = DBVByte $ fromIntegral $ ord 'b'
fromRep (DBVByte x) = case chr (fromIntegral x) of
'l' -> Just Little
'b' -> Just Big
_ -> Nothing
data MessageHeader =
MessageHeader { endianessFlag :: Endian
, messageType :: MessageType
, flags :: Flags
, version :: Word8
, messageLength :: Word32
, serial :: Word32
, fields :: HeaderFields
} deriving (Show, Eq)
makeRepresentable ''MessageHeader
methodCall :: Word32
-> Text.Text
-> ObjectPath
-> Text.Text
-> Text.Text
-> [SomeDBusValue]
-> [Flag]
-> BS.Builder
methodCall sid dest path interface member args flags =
let hFields = emptyHeaderFields{ hFPath = Just path
, hFInterface = Just interface
, hFMember = Just member
, hFDestination = Just dest
}
header = MessageHeader
{ endianessFlag = Little
, messageType = MessageTypeMethodCall
, flags = Flags flags
, version = 1
, messageLength = 0
, serial = sid
, fields = hFields
}
in serializeMessage header args
mkSignal sid flags sig =
let hFields = emptyHeaderFields { hFPath = Just $ signalPath sig
, hFInterface = Just $ signalInterface sig
, hFMember = Just $ signalMember sig
}
header = MessageHeader
{ endianessFlag = Little
, messageType = MessageTypeSignal
, flags = Flags flags
, version = 1
, messageLength = 0
, serial = sid
, fields = hFields
}
in serializeMessage header (signalBody sig)
methodReturn :: Word32
-> Word32
-> Text.Text
-> SomeDBusArguments
-> BS.Builder
methodReturn sid rsid dest args =
let hFields = emptyHeaderFields{ hFDestination = Just dest
, hFReplySerial = Just rsid
}
header = MessageHeader
{ endianessFlag = Little
, messageType = MessageTypeMethodReturn
, flags = Flags []
, version = 1
, messageLength = 0
, serial = sid
, fields = hFields
}
in serializeMessage header (argsToValues args)
errorMessage :: Word32
-> Maybe Word32
-> Text.Text
-> Text.Text
-> Maybe Text.Text
-> [SomeDBusValue]
-> BS.Builder
errorMessage sid rsid dest name text args =
let hFields = emptyHeaderFields{ hFDestination = Just dest
, hFErrorName = Just name
, hFReplySerial = rsid
}
header = MessageHeader
{ endianessFlag = Little
, messageType = MessageTypeError
, flags = Flags []
, version = 1
, messageLength = 0
, serial = sid
, fields = hFields
}
in serializeMessage header (maybe id (\t -> (DBV (DBVString t) :))
text args)
serializeMessage head args =
let vs = putValues args
sig = Signature $ map (\(DBV v) -> typeOf v) args
header len = head { messageLength = len
, fields = (fields head){hFMessageSignature = Just sig}
}
in runDBusPut Little $ do
l <- sizeOf 0 1 vs
putDBV . toRep $ header (fromIntegral l)
alignPut 8
vs
getMessage = do
mbEndian <- fromRep <$> (B.lookAhead $ runReaderT getDBV Little)
endian <- case mbEndian of
Nothing -> fail "could not read endiannes flag"
Just e -> return e
flip runReaderT endian $ do
mbHeader <- fromRep <$> getDBV
header <- case mbHeader of
Nothing -> fail "Header has wrong type"
Just h -> return h
alignGet 8
args <- case hFMessageSignature $ fields header of
Nothing -> return []
Just (Signature sigs) -> forM sigs $ \t ->
getDBVByType t
return (header, args)
parseMessages :: MonadThrow m =>
C.ConduitM BS.ByteString (MessageHeader, [SomeDBusValue]) m b
parseMessages = forever $ C.yield =<< sinkGet getMessage
sendBS conn bs = do
write <- atomically . takeTMVar $ dBusWriteLock conn
write bs
atomically $ putTMVar (dBusWriteLock conn) write
-- | Asychronously call a method.
--
-- This is the "raw" version of 'callMethod'. It doesn't do argument conversion.
callMethod' :: Text.Text -- ^ Entity to send the message to
-> ObjectPath -- ^ Object
-> Text.Text -- ^ Interface
-> Text.Text -- ^ Member (method) name
-> [SomeDBusValue] -- ^ Arguments
-> [Flag] -- ^ Method call flags
-> DBusConnection -- ^ Connection to send the call over
-> IO (STM (Either [SomeDBusValue] [SomeDBusValue] ))
callMethod' dest path interface member args flags conn = do
serial <- atomically $ dBusCreateSerial conn
ref <- newEmptyTMVarIO
rSlot <- newTVarIO ()
mkWeak rSlot (connectionAliveRef conn) Nothing
addFinalizer rSlot (finalizeSlot serial)
slot <- atomically $ do
modifyTVar (dBusAnswerSlots conn) (Map.insert serial $ putTMVar ref)
return ref
let bs = methodCall serial dest path interface member args flags
sendBS conn bs
return $ readTMVar slot <* readTVar rSlot
where
finalizeSlot s = do
atomically $ modifyTVar (dBusAnswerSlots conn)
(Map.delete s)
-- | Wait for the answer of a method call
getAnswer :: IO (STM b) -> IO b
getAnswer = (atomically =<<)
-- | Synchronously call a method.
--
-- This is the "cooked" version of callMethod\''. It automatically converts
-- arguments and returns values and throws conversion errors as exceptions
--
-- If the returned value's type doesn't match the expected type a
-- 'MethodSignatureMissmatch' is thrown.
--
-- You can pass in and extract multiple arguments and return values with types
-- that are represented by DBus Structs (e.g. tuples). More specifically,
-- multiple arguments/return values are handled in the following way:
--
-- * If the method returns multiple values and the RepType of the expected
-- return value is a struct it tries to match up the arguments with the struct
-- fields
--
-- * If the method returns /a single struct/ and the RepType is a struct it will
-- try to match up those two
--
-- * If the RepType of the expected return value is not a struct it will only
-- match if the method returned exactly one value and those two match up (as per
-- normal)
--
-- This means that if the RepType of the expected return value is a struct it
-- might be matched in two ways: Either by the method returning multiple values
-- or the method returning a single struct. At the moment there is no way to
-- exclude either
callMethod :: ( Representable args
, Representable ret
) =>
Text.Text -- ^ Entity to send the message to
-> ObjectPath -- ^ Object
-> Text.Text -- ^ Interface
-> Text.Text -- ^ Member (method) to call
-> args -- ^ Arguments
-> [Flag] -- ^ Method call flags
-> DBusConnection -- ^ Connection to send the call over
-> IO (Either MethodError ret)
callMethod dest path interface member (arg :: args) flags conn = do
let sng = sing :: Sing (RepType args)
flsng = flattenRepS sng
args' = withSingI flsng $ argsToValues $ SDBA (flattenRep arg)
ret <- getAnswer $ callMethod' dest path interface member args' flags conn
return $ case ret of
Left e -> Left $ MethodErrorMessage e
Right rvs -> case listToSomeArguments rvs of
sr@(SDBA (r :: DBusArguments ats)) ->
maybe (Left $ MethodSignatureMissmatch rvs) Right
$ fix $ \(_ :: Maybe ret) ->
case sing :: Sing (RepType ret) of
STypeStruct ts -> case (r, sing :: Sing ats) of
(ArgsNil, SNil) -> Nothing
(ArgsCons r' ArgsNil, SCons a SNil) ->
case a %~ (sing :: Sing (RepType ret)) of
Proved Refl -> fromRep r'
Disproved _ -> Nothing
_ -> withSingI ts
$ fromRep . DBVStruct =<< maybeArgsToStruct r
STypeUnit -> case r of
ArgsNil -> fromRep DBVUnit
_ -> Nothing
_ -> case (sing :: Sing ats, r) of
(SCons at SNil, ArgsCons r' ArgsNil) ->
case at %~ (sing :: Sing (RepType ret)) of
Proved Refl -> fromRep r'
Disproved _ -> Nothing