diff --git a/COPYING b/COPYING new file mode 100644 --- /dev/null +++ b/COPYING @@ -0,0 +1,674 @@ + GNU GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU General Public License is a free, copyleft license for +software and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. By contrast, +the GNU General Public License is intended to guarantee your freedom to +share and change all versions of a program--to make sure it remains free +software for all its users. We, the Free Software Foundation, use the +GNU General Public License for most of our software; it applies also to +any other work released this way by its authors. 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If not, see . + +Also add information on how to contact you by electronic and paper mail. + + If the program does terminal interaction, make it output a short +notice like this when it starts in an interactive mode: + + Copyright (C) + This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type `show c' for details. + +The hypothetical commands `show w' and `show c' should show the appropriate +parts of the General Public License. Of course, your program's commands +might be different; for a GUI interface, you would use an "about box". + + You should also get your employer (if you work as a programmer) or school, +if any, to sign a "copyright disclaimer" for the program, if necessary. +For more information on this, and how to apply and follow the GNU GPL, see +. + + The GNU General Public License does not permit incorporating your program +into proprietary programs. If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +. diff --git a/Setup.lhs b/Setup.lhs new file mode 100644 --- /dev/null +++ b/Setup.lhs @@ -0,0 +1,3 @@ +#!/usr/bin/env runhaskell +> import Distribution.Simple +> main = defaultMain diff --git a/erlang.cabal b/erlang.cabal new file mode 100644 --- /dev/null +++ b/erlang.cabal @@ -0,0 +1,37 @@ +name: erlang +version: 0.1 +stability: alpha +description: + Speaks the Erlang network protocol and impersonates an Erlang node + on the network. Fully capable of bi-directional communication with + Erlang. Erlang types are, as far as reasonable, mapped to Haskell + types. Messages to Erlang are just function calls in Haskell, and + messages from Erlang are delivered to MVars. +license: GPL +license-file: COPYING +author: Eric Sessoms +maintainer: nubgames@gmail.com +homepage: http://github.com/esessoms/haskell-interface +category: Foreign +synopsis: FFI interface to Erlang. +cabal-version: >= 1.2 +build-type: Simple + +library + build-depends: base, + binary >= 0.4.4, + bytestring, + directory, + filepath, + nano-md5 >= 0.1.2, + network >= 2.2.0.1, + random >= 1.0.0.1 + exposed-modules: Foreign.Erlang + other-modules: Foreign.Erlang.Network, + Foreign.Erlang.OTP, + Foreign.Erlang.OTP.GenServer, + Foreign.Erlang.OTP.Mnesia, + Foreign.Erlang.Processes, + Foreign.Erlang.Types, + Foreign.Erlang.Utilities + hs-source-dirs: src diff --git a/src/Foreign/Erlang.lhs b/src/Foreign/Erlang.lhs new file mode 100644 --- /dev/null +++ b/src/Foreign/Erlang.lhs @@ -0,0 +1,36 @@ +> ----------------------------------------------------------------------------- +> -- | +> -- Module : Foreign.Erlang +> -- Copyright : Eric Sessoms +> -- License : GPL3 (see COPYING) +> -- +> -- Maintainer : Eric Sessoms +> -- Stability : alpha +> -- Portability : portable +> -- +> -- Speaks the Erlang network protocol and impersonates an Erlang node +> -- on the network. Fully capable of bi-directional communication with +> -- Erlang. Erlang types are, as far as reasonable, mapped to Haskell +> -- types. Messages to Erlang are just function calls in Haskell, and +> -- messages from Erlang are delivered to MVars. +> -- +> ----------------------------------------------------------------------------- + +> module Foreign.Erlang ( +> module Foreign.Erlang.Network +> , module Foreign.Erlang.OTP +> , module Foreign.Erlang.Processes +> , module Foreign.Erlang.Types +> , module Foreign.Erlang.Utilities +> ) where + +> import Foreign.Erlang.Network hiding (toNetwork) +> import Foreign.Erlang.OTP +> import Foreign.Erlang.Processes +> import Foreign.Erlang.Utilities +> +> import Foreign.Erlang.Types hiding ( +> getA, getC, getErl, getN, geta, getn +> , putA, putC, putErl, putN, puta, putn +> , tag +> ) diff --git a/src/Foreign/Erlang/Network.lhs b/src/Foreign/Erlang/Network.lhs new file mode 100644 --- /dev/null +++ b/src/Foreign/Erlang/Network.lhs @@ -0,0 +1,213 @@ +> module Foreign.Erlang.Network ( +> -- * Low-level communication with the Erlang Port-Mapper Daemon. +> epmdGetNames +> , epmdGetPort +> , epmdGetPortR4 +> +> , ErlRecv +> , ErlSend +> , erlConnect +> , toNetwork +> ) where + +> import Control.Exception (assert, bracketOnError) +> import Control.Monad (liftM) +> import Data.Binary (decode, encode) +> import Data.Binary.Get +> import Data.Binary.Put +> import Data.Bits ((.|.)) +> import Data.Char (chr, ord) +> import Data.Digest.OpenSSL.MD5 (md5sum) +> import Data.List (unfoldr) +> import Data.Word +> import Foreign.Erlang.Types +> import Network (PortID(..), connectTo, withSocketsDo) +> import Network.Socket (PortNumber(..)) +> import Numeric (readHex) +> import System.Directory (getHomeDirectory) +> import System.FilePath (()) +> import System.IO +> import System.IO.Unsafe (unsafePerformIO) +> import System.Random (randomIO) +> import qualified Data.ByteString.Char8 as C +> import qualified Data.ByteString.Lazy.Char8 as B + +> erlangVersion = 5 +> erlangProtocolVersion = 131 +> passThrough = 'p' + +> flagPublished = 0x01 +> flagAtomCache = 0x02 +> flagExtendedReferences = 0x04 +> flagDistMonitor = 0x08 +> flagFunTags = 0x10 +> flagDistMonitorName = 0x20 +> flagHiddenAtomCache = 0x40 +> flagNewFunTags = 0x80 +> flagExtendedPidsPorts = 0x100 + +> getUserCookie = do +> home <- getHomeDirectory +> readFile $ home ".erlang.cookie" + +> toNetwork :: Int -> Integer -> [Word8] +> toNetwork b n = reverse . take b $ unfoldr toNetwork' n ++ repeat 0 +> where +> toNetwork' 0 = Nothing +> toNetwork' n = let (b, a) = n `divMod` 256 in Just (fromIntegral a, b) + +> ntohs n = let (b, a) = n `divMod` 256 in 256*a + b + +> erlDigest :: String -> Word32 -> [Word8] +> erlDigest cookie challenge = let +> [(n, _)] = readHex . md5sum . C.pack $ cookie ++ show challenge +> in toNetwork 16 n + +> packn, packN :: B.ByteString -> Put +> packn msg = putn (fromIntegral . B.length $ msg) >> putLazyByteString msg +> packN msg = putN (fromIntegral . B.length $ msg) >> putLazyByteString msg + +> sendMessage :: (B.ByteString -> Put) -> (B.ByteString -> IO ()) -> B.ByteString -> IO () +> sendMessage pack out = out . runPut . pack + +> recvMessage :: Int -> (Int -> IO B.ByteString) -> IO B.ByteString +> recvMessage hdrlen inf = (liftM (unpack hdrlen) $ inf hdrlen) >>= inf +> where +> unpack 2 = runGet getn +> unpack 4 = runGet getN + +> type ErlSend = (Maybe ErlType, Maybe ErlType) -> IO () +> type ErlRecv = IO (Maybe ErlType, Maybe ErlType) + +> erlSend :: (B.ByteString -> IO ()) -> ErlSend +> erlSend send (Nothing, _) = send B.empty +> erlSend send (Just ctl, msg) = send . runPut $ do +> tag passThrough +> putMsg ctl +> maybe (return ()) putMsg msg +> where +> putMsg msg = do +> putC erlangProtocolVersion +> putErl msg + +> erlRecv :: IO B.ByteString -> ErlRecv +> erlRecv recv = do +> bytes <- recv +> return . flip runGet bytes $ do +> empty <- isEmpty +> if empty +> then return (Nothing, Nothing) +> else do +> pt <- getC +> assert (chr pt == passThrough) $ return () +> ctl <- getMsg +> empty <- isEmpty +> if empty +> then return (Just ctl, Nothing) +> else case ctl of +> ErlTuple (ErlInt n:_) | n `elem` [2, 6] -> do +> msg <- getMsg +> return (Just ctl, Just msg) +> _ -> return (Just ctl, Nothing) +> where +> getMsg = do +> ver <- getC +> assert (ver == erlangProtocolVersion) $ getErl + +> erlConnect :: String -> String -> IO (ErlSend, ErlRecv) +> erlConnect self node = withSocketsDo $ do +> port <- epmdGetPort node +> let port' = PortNumber (PortNum . fromIntegral . ntohs $ port) +> bracketOnError +> (connectTo epmdHost port' >>= \h -> hSetBuffering h NoBuffering >> return h) +> hClose $ \h -> do +> let out = sendMessage packn (B.hPut h) +> let inf = recvMessage 2 (B.hGet h) +> handshake out inf self +> let out' = sendMessage packN (\s -> B.hPut h s >> hFlush h) +> let inf' = recvMessage 4 (B.hGet h) +> return (erlSend out', erlRecv inf') + +> handshake :: (B.ByteString -> IO ()) -> IO B.ByteString -> String -> IO () +> handshake out inf self = do +> cookie <- getUserCookie +> sendName +> recvStatus +> challenge <- recvChallenge +> let reply = erlDigest cookie challenge +> challenge' <- liftM fromIntegral (randomIO :: IO Int) +> challengeReply reply challenge' +> recvChallengeAck cookie challenge' + +> where +> sendName = out . runPut $ do +> tag 'n' +> putn erlangVersion +> putN $ flagExtendedReferences .|. flagExtendedPidsPorts +> putA self + +> recvStatus = do +> msg <- inf +> assert ("sok" == B.unpack msg) $ return () + +> recvChallenge = do +> msg <- inf +> return . flip runGet msg $ do +> tag <- getC +> version <- getn +> flags <- getN +> challenge <- getWord32be +> return challenge + +> challengeReply reply challenge = out . runPut $ do +> tag 'r' +> putWord32be challenge +> puta reply + +> recvChallengeAck cookie challenge = do +> let digest = erlDigest cookie challenge +> msg <- inf +> let reply = take 16 . drop 1 . map (fromIntegral . ord) . B.unpack $ msg +> assert (digest == reply) $ return () + +> epmdHost = "127.0.0.1" +> epmdPort = Service "epmd" + +> withEpmd = withSocketsDo . bracketOnError +> (connectTo epmdHost epmdPort >>= \h -> hSetBuffering h NoBuffering >> return h) +> hClose + +> epmdSend :: String -> IO B.ByteString +> epmdSend msg = withEpmd $ \hdl -> do +> let out = runPut $ putn (length msg) >> putA msg +> B.hPut hdl out +> hFlush hdl +> B.hGetContents hdl + +> -- | Return the names and addresses of all registered Erlang nodes. +> epmdGetNames :: IO [String] +> epmdGetNames = do +> reply <- epmdSend "n" +> let txt = runGet (getN >> liftM B.unpack getRemainingLazyByteString) reply +> return . lines $ txt + +> -- | Return the port address of a named Erlang node. +> epmdGetPort :: String -> IO Int +> epmdGetPort name = do +> reply <- epmdSend $ 'p' : name +> return $ runGet getn reply + +> -- | Returns (port, nodeType, protocol, vsnMax, vsnMin, name, extra) +> epmdGetPortR4 :: String -> IO (Int, Int, Int, Int, Int, String, String) +> epmdGetPortR4 name = do +> reply <- epmdSend $ 'z' : name +> return $ flip runGet reply $ do +> getn +> port <- getn +> nodeType <- getC +> protocol <- getC +> vsnMax <- getn +> vsnMin <- getn +> name <- getn >>= getA +> extra <- liftM B.unpack getRemainingLazyByteString +> return (port, nodeType, protocol, vsnMax, vsnMin, name, extra) diff --git a/src/Foreign/Erlang/OTP.lhs b/src/Foreign/Erlang/OTP.lhs new file mode 100644 --- /dev/null +++ b/src/Foreign/Erlang/OTP.lhs @@ -0,0 +1,7 @@ +> module Foreign.Erlang.OTP ( +> module Foreign.Erlang.OTP.GenServer +> , module Foreign.Erlang.OTP.Mnesia +> ) where + +> import Foreign.Erlang.OTP.GenServer +> import Foreign.Erlang.OTP.Mnesia diff --git a/src/Foreign/Erlang/OTP/GenServer.lhs b/src/Foreign/Erlang/OTP/GenServer.lhs new file mode 100644 --- /dev/null +++ b/src/Foreign/Erlang/OTP/GenServer.lhs @@ -0,0 +1,35 @@ +> module Foreign.Erlang.OTP.GenServer ( +> -- * High-level communication. +> genCall +> , genCast +> , rpcCall +> , rpcCast +> ) where + +> import Foreign.Erlang.Types (Erlang, ErlType(..)) +> import Foreign.Erlang.Processes + +> -- | gen_server:cast(Pid, Msg) + +> genCast :: Erlang a => MBox -> Node -> Pid -> a -> IO () +> genCast mbox node pid msg = mboxSend mbox node pid (ErlAtom "$gen_cast", msg) + +> -- | gen_server:call(Pid, Msg) + +> genCall :: Erlang a => MBox -> Node -> Pid -> a -> IO ErlType +> genCall mbox node pid msg = do +> ref <- mboxRef mbox +> mboxSend mbox node pid (ErlAtom "$gen_call", (mboxSelf mbox, ref), msg) +> mboxRecv' mbox ref + +> -- | rpc:cast(Node, Module, Function, Arguments) + +> rpcCast :: MBox -> Node -> String -> String -> [ErlType] -> IO () +> rpcCast mbox node m f as = genCast mbox node (Right "rex") $ +> (ErlAtom "cast", ErlAtom m, ErlAtom f, as, mboxSelf mbox) + +> -- | rpc:call(Node, Module, Function, Arguments) + +> rpcCall :: MBox -> Node -> String -> String -> [ErlType] -> IO ErlType +> rpcCall mbox node m f as = genCall mbox node (Right "rex") $ +> (ErlAtom "call", ErlAtom m, ErlAtom f, as, mboxSelf mbox) diff --git a/src/Foreign/Erlang/OTP/Mnesia.lhs b/src/Foreign/Erlang/OTP/Mnesia.lhs new file mode 100644 --- /dev/null +++ b/src/Foreign/Erlang/OTP/Mnesia.lhs @@ -0,0 +1,46 @@ +> module Foreign.Erlang.OTP.Mnesia ( +> -- * Mnesia database methods. +> backup +> , dirtyAllKeys +> , dirtyFirst +> , dirtyNext +> , dirtyLast +> , dirtyPrev +> , dirtyMatchObject +> , dirtyRead +> , dirtySelect +> ) where + +> import Foreign.Erlang.OTP.GenServer (rpcCall) +> import Foreign.Erlang.Processes (MBox, Node) +> import Foreign.Erlang.Types (ErlType(..)) + +> mnesia :: MBox -> Node -> String -> [ErlType] -> IO ErlType +> mnesia mbox node f as = rpcCall mbox node "mnesia" f as + +> backup :: MBox -> String -> String -> IO ErlType +> backup mbox node path = mnesia mbox node "backup" [ErlString path] + +> dirtyAllKeys :: MBox -> String -> String -> IO ErlType +> dirtyAllKeys mbox node tab = mnesia mbox node "dirty_all_keys" [ErlAtom tab] + +> dirtyFirst :: MBox -> String -> String -> IO ErlType +> dirtyFirst mbox node tab = mnesia mbox node "dirty_first" [ErlAtom tab] + +> dirtyNext :: MBox -> String -> String -> ErlType -> IO ErlType +> dirtyNext mbox node tab key = mnesia mbox node "dirty_next" [ErlAtom tab, key] + +> dirtyLast :: MBox -> String -> String -> IO ErlType +> dirtyLast mbox node tab = mnesia mbox node "dirty_last" [ErlAtom tab] + +> dirtyPrev :: MBox -> String -> String -> ErlType -> IO ErlType +> dirtyPrev mbox node tab key = mnesia mbox node "dirty_pref" [ErlAtom tab, key] + +> dirtyMatchObject :: MBox -> String -> ErlType -> IO ErlType +> dirtyMatchObject mbox node pat = mnesia mbox node "dirty_match_object" [pat] + +> dirtyRead :: MBox -> String -> String -> ErlType -> IO ErlType +> dirtyRead mbox node tab key = mnesia mbox node "dirty_read" [ErlAtom tab, key] + +> dirtySelect :: MBox -> String -> String -> ErlType -> IO ErlType +> dirtySelect mbox node tab spec = mnesia mbox node "dirty_select" [spec] diff --git a/src/Foreign/Erlang/Processes.lhs b/src/Foreign/Erlang/Processes.lhs new file mode 100644 --- /dev/null +++ b/src/Foreign/Erlang/Processes.lhs @@ -0,0 +1,198 @@ +> module Foreign.Erlang.Processes ( +> -- * Low-level communication. +> -- ** Represents a Haskell node (program). +> Self +> , createSelf +> -- ** Represents a Haskell process (thread). +> , MBox +> , createMBox +> , mboxRef +> , mboxSelf +> -- ** Represents Erlang nodes and processes. +> , Node +> , Pid +> -- ** Communication to/from Erlang. +> , mboxRecv +> , mboxRecv' +> , mboxSend +> ) where + +> import Control.Concurrent (forkIO) +> import Control.Concurrent.MVar +> import Data.Maybe (fromJust) +> import Foreign.Erlang.Network +> import Foreign.Erlang.Types + +> -- | The name of an Erlang node on the network. +> type Node = String + +> data ErlMessage = ErlRegister (ErlType -> IO ()) +> | ErlGenRef ErlType +> | ErlSend String ErlType ErlType +> | ErlRegSend ErlType String String ErlType +> | ErlLink ErlType String ErlType +> | ErlUnlink ErlType String ErlType +> | ErlExit ErlType String ErlType ErlType +> | ErlExit2 ErlType String ErlType ErlType +> | ErlDispatch ErlType ErlType +> | ErlStop +> deriving Show + +> instance Show (a -> b) where +> show _ = "" + +> -- | Represents a Haskell node. There should be one of these per process. +> data Self = Self { send :: ErlMessage -> IO () } + +> genPid nodename id = ErlPid (ErlAtom nodename) id 0 1 +> genRef nodename id = ErlNewRef (ErlAtom nodename) 1 . toNetwork 4 . fromIntegral $ id + +> -- | Instantiate a Haskell node. This initializes the FFI. +> createSelf :: String -> IO Self +> createSelf nodename = do +> inbox <- newEmptyMVar +> forkIO $ self nodename inbox +> return . Self $ putMVar inbox + +> self :: String -> MVar ErlMessage -> IO () +> self nodename inbox = loop 1 [] [] +> where +> loop id mboxes nodes = do +> msg <- takeMVar inbox +> case msg of +> ErlRegister mbox -> do +> let pid = genPid nodename id +> mbox pid +> loop (id+1) ((pid, mbox) : mboxes) nodes +> ErlGenRef pid -> do +> let ref = genRef nodename id +> maybe (return ()) ($ ref) $ lookup pid mboxes +> loop (id+1) mboxes nodes +> ErlSend node pid msg -> do +> let ctl = toErlang (ErlInt 2, ErlAtom "", pid) +> (mnode, nodes') <- findNode node nodes +> case mnode of +> Just n -> n (Just ctl, Just msg) +> Nothing -> return () +> loop id mboxes nodes' +> ErlRegSend from node pid msg -> do +> let ctl = toErlang (ErlInt 6, from, ErlAtom "", ErlAtom pid) +> (mnode, nodes') <- findNode node nodes +> case mnode of +> Just n -> n (Just ctl, Just msg) +> Nothing -> return () +> loop id mboxes nodes' +> ErlLink from to pid -> do +> let ctl = toErlang (ErlInt 1, from, pid) +> (node, nodes') <- findNode to nodes +> fromJust node (Just ctl, Nothing) +> loop id mboxes nodes' +> ErlUnlink from to pid -> do +> let ctl = toErlang (ErlInt 4, from, pid) +> (node, nodes') <- findNode to nodes +> fromJust node (Just ctl, Nothing) +> loop id mboxes nodes' +> ErlExit from to pid reason -> do +> let ctl = toErlang (ErlInt 3, from, to, reason) +> (node, nodes') <- findNode to nodes +> fromJust node (Just ctl, Nothing) +> loop id mboxes nodes' +> ErlExit2 from to pid reason -> do +> let ctl = toErlang (ErlInt 8, from, to, reason) +> (node, nodes') <- findNode to nodes +> fromJust node (Just ctl, Nothing) +> loop id mboxes nodes' +> ErlDispatch ctl msg -> do +> case ctl of +> ErlTuple [ErlInt 2, _, pid] -> +> maybe (return ()) ($ msg) $ lookup pid mboxes +> _ -> return () +> loop id mboxes nodes +> ErlStop -> return () + +> findNode to nodes = +> case lookup to nodes of +> Just node -> return (Just node, nodes) +> Nothing -> do +> (send, recv) <- erlConnect nodename to +> mvar <- newEmptyMVar +> forkIO $ nodeSend mvar send +> forkIO $ nodeRecv mvar recv inbox +> let node = putMVar mvar +> return (Just node, ((to, node) : nodes)) + +A `nodeSend` thread is responsible for communication to an Erlang +process. It receives messages in an `MVar` and forwards them across +the network. + +> nodeSend mvar send = loop +> where +> loop = takeMVar mvar >>= send >> loop + +A `nodeRecv` thread is responsible for communication from an Erlang +process. It receives messages from the network and dispatches them as +appropriate. + +> nodeRecv mvar recv outbox = loop +> where +> loop = do +> (mctl, mmsg) <- recv +> case mctl of +> -- Nothing is a keepalive. All we want to do is echo it. +> Nothing -> putMVar mvar (Nothing, Nothing) +> -- A real message goes to self to be dispatched. +> Just ctl -> putMVar outbox $ ErlDispatch ctl (fromJust mmsg) +> loop + +> -- | Haskell threads don't natively have Erlang process IDs. Instead, we +> -- use a mailbox abstraction that we can assign PIDs to for communication +> -- with Erlang. + +> data MBox = MBox ErlType (MVar ErlType) Self + +> -- | Represents a foreign (Erlang) process. A process can be identified +> -- either by its low-level ID (Left pid) or by its registered name (Right name). + +> type Pid = Either ErlType String + +> -- | Return the PID of the given mailbox. + +> mboxSelf :: MBox -> ErlType +> mboxSelf (MBox pid _ _) = pid + +> -- | Return a new unique object reference. + +> mboxRef :: MBox -> IO ErlType +> mboxRef mbox@(MBox pid _ self) = send self (ErlGenRef pid) >> mboxRecv mbox + +Send an arbitrary message to the specified node and process. + +> -- | {Node, Pid} ! Msg. +> mboxSend :: Erlang a => MBox -> Node -> Pid -> a -> IO () +> mboxSend (MBox _ _ self) node (Left pid) msg = send self $ ErlSend node pid (toErlang msg) +> mboxSend (MBox from _ self) node (Right pid) msg = send self $ ErlRegSend from node pid (toErlang msg) + +> -- | Receive the next message addressed to this mailbox. + +> mboxRecv :: MBox -> IO ErlType +> mboxRecv (MBox _ inbox _) = takeMVar inbox + +> -- | Receive a reply message. That is, looks for the next message +> -- identified by the given reference. + +> mboxRecv' :: MBox -> ErlType -> IO ErlType +> mboxRecv' mbox ref = do +> msg <- mboxRecv mbox +> case msg of +> ErlTuple [ref', result] | ref' == ref -> return result +> _ -> mboxRecv' mbox ref + +> -- | Create a new process on the Haskell side. Usually corresponds +> -- to a thread but doesn't need to. + +> createMBox :: Self -> IO MBox +> createMBox self = do +> inbox <- newEmptyMVar +> send self $ ErlRegister (putMVar inbox) +> pid <- takeMVar inbox +> return $ MBox pid inbox self diff --git a/src/Foreign/Erlang/Types.lhs b/src/Foreign/Erlang/Types.lhs new file mode 100644 --- /dev/null +++ b/src/Foreign/Erlang/Types.lhs @@ -0,0 +1,199 @@ +> {-# LANGUAGE OverlappingInstances #-} +> {-# OPTIONS -XFlexibleInstances -XTypeSynonymInstances #-} + +> module Foreign.Erlang.Types ( +> -- * Native Erlang data types. +> -- ** Haskell representation. +> ErlType(..) +> -- ** Conversion between native Haskell types and ErlType. +> , Erlang +> , fromErlang +> , toErlang +> -- ** Easy type-safe access to tuple members. +> , nth +> +> -- ** Internal packing functions. +> , getA, getC, getErl, getN, geta, getn +> , putA, putC, putErl, putN, puta, putn +> , tag +> ) where + +> import Control.Exception (assert) +> import Control.Monad (forM, liftM) +> import Data.Binary +> import Data.Binary.Get +> import Data.Binary.Put +> import Data.Char (chr, ord) +> import qualified Data.ByteString as B +> import qualified Data.ByteString.Char8 as C + +> nth :: Erlang a => Int -> ErlType -> a +> nth i (ErlTuple lst) = fromErlang $ lst !! i + +> data ErlType = ErlNull +> | ErlInt Int +> | ErlBigInt Integer +> | ErlString String +> | ErlAtom String +> | ErlBinary [Word8] +> | ErlList [ErlType] +> | ErlTuple [ErlType] +> | ErlPid ErlType Int Int Int -- node id serial creation +> | ErlPort ErlType Int Int -- node id creation +> | ErlRef ErlType Int Int -- node id creation +> | ErlNewRef ErlType Int [Word8] -- node creation id +> deriving (Eq, Show) + +> class Erlang a where +> toErlang :: a -> ErlType +> fromErlang :: ErlType -> a + +> instance Erlang ErlType where +> toErlang = id +> fromErlang = id + +> instance Erlang Int where +> toErlang x = ErlInt x +> fromErlang (ErlInt x) = x +> fromErlang (ErlBigInt x) = fromIntegral x + +> instance Erlang Integer where +> toErlang x = ErlBigInt x +> fromErlang (ErlInt x) = fromIntegral x +> fromErlang (ErlBigInt x) = x + +> instance Erlang String where +> toErlang x = ErlString x +> fromErlang ErlNull = "" +> fromErlang (ErlString x) = x +> fromErlang (ErlAtom x) = x +> fromErlang (ErlList xs) = map (chr . fromErlang) xs +> fromErlang x = error $ "can't convert to string: " ++ show x + +> instance Erlang Bool where +> toErlang True = ErlAtom "true" +> toErlang False = ErlAtom "false" +> fromErlang (ErlAtom "true") = True +> fromErlang (ErlAtom "false") = False + +> instance Erlang [ErlType] where +> toErlang [] = ErlNull +> toErlang xs = ErlList xs +> fromErlang ErlNull = [] +> fromErlang (ErlList xs) = xs + +> instance Erlang a => Erlang [a] where +> toErlang [] = ErlNull +> toErlang xs = ErlList . map toErlang $ xs +> fromErlang ErlNull = [] +> fromErlang (ErlList xs) = map fromErlang xs + +> instance (Erlang a, Erlang b) => Erlang (a, b) where +> toErlang (x, y) = ErlTuple [toErlang x, toErlang y] +> fromErlang (ErlTuple [x, y]) = (fromErlang x, fromErlang y) + +> instance (Erlang a, Erlang b, Erlang c) => Erlang (a, b, c) where +> toErlang (x, y, z) = ErlTuple [toErlang x, toErlang y, toErlang z] +> fromErlang (ErlTuple [x, y, z]) = (fromErlang x, fromErlang y, fromErlang z) + +> instance (Erlang a, Erlang b, Erlang c, Erlang d) => Erlang (a, b, c, d) where +> toErlang (x, y, z, w) = ErlTuple [toErlang x, toErlang y, toErlang z, toErlang w] +> fromErlang (ErlTuple [x, y, z, w]) = (fromErlang x, fromErlang y, fromErlang z, fromErlang w) + +> instance (Erlang a, Erlang b, Erlang c, Erlang d, Erlang e) => Erlang (a, b, c, d, e) where +> toErlang (x, y, z, w, a) = ErlTuple [toErlang x, toErlang y, toErlang z, toErlang w, toErlang a] +> fromErlang (ErlTuple [x, y, z, w, a]) = (fromErlang x, fromErlang y, fromErlang z, fromErlang w, fromErlang a) + +> instance Binary ErlType where +> put = putErl +> get = getErl + +> putErl (ErlInt val) +> | 0 <= val && val < 256 = tag 'a' >> putC val +> | otherwise = tag 'b' >> putN val +> putErl (ErlAtom val) = tag 'd' >> putn (length val) >> putA val +> putErl (ErlTuple val) +> | len < 256 = tag 'h' >> putC len >> mapM_ putErl val +> | otherwise = tag 'i' >> putN len >> mapM_ putErl val +> where +> len = length val +> putErl ErlNull = tag 'j' +> putErl (ErlString val) = tag 'k' >> putn (length val) >> putA val +> putErl (ErlList val) = tag 'l' >> putN (length val) >> mapM_ putErl val >> putErl ErlNull +> putErl (ErlBinary val) = tag 'm' >> putN (length val) >> puta val +> putErl (ErlRef node id creation) = do +> tag 'e' +> putErl node +> putN id +> putC creation +> putErl (ErlPort node id creation) = do +> tag 'f' +> putErl node +> putN id +> putC creation +> putErl (ErlPid node id serial creation) = do +> tag 'g' +> putErl node +> putN id +> putN serial +> putC creation +> putErl (ErlNewRef node creation id) = do +> tag 'r' +> putn $ length id `div` 4 +> putErl node +> putC creation +> mapM_ putWord8 id + +> getErl = do +> tag <- liftM chr getC +> case tag of +> 'a' -> liftM ErlInt getC +> 'b' -> liftM ErlInt getN +> 'd' -> getn >>= liftM ErlAtom . getA +> 'e' -> do +> node <- getErl +> id <- getN +> creation <- getC +> return $ ErlRef node id creation +> 'f' -> do +> node <- getErl +> id <- getN +> creation <- getC +> return $ ErlPort node id creation +> 'g' -> do +> node <- getErl +> id <- getN +> serial <- getN +> creation <- getC +> return $ ErlPid node id serial creation +> 'h' -> getC >>= \len -> liftM ErlTuple $ forM [1..len] (const getErl) +> 'i' -> getN >>= \len -> liftM ErlTuple $ forM [1..len] (const getErl) +> 'j' -> return ErlNull +> 'k' -> getn >>= liftM ErlString . getA +> 'l' -> do +> len <- getN +> list <- liftM ErlList $ forM [1..len] (const getErl) +> null <- getErl +> assert (null == ErlNull) $ return list +> 'm' -> getN >>= liftM ErlBinary . geta +> 'r' -> do +> len <- getn +> node <- getErl +> creation <- getC +> id <- forM [1..4*len] (const getWord8) +> return $ ErlNewRef node creation id +> x -> error [x] + +> tag = putC . ord + +> putC = putWord8 . fromIntegral +> putn = putWord16be . fromIntegral +> putN = putWord32be . fromIntegral +> puta = putByteString . B.pack +> putA = putByteString . C.pack + +> getC = liftM fromIntegral getWord8 +> getn = liftM fromIntegral getWord16be +> getN = liftM fromIntegral getWord32be +> geta = liftM B.unpack . getByteString +> getA = liftM C.unpack . getByteString diff --git a/src/Foreign/Erlang/Utilities.lhs b/src/Foreign/Erlang/Utilities.lhs new file mode 100644 --- /dev/null +++ b/src/Foreign/Erlang/Utilities.lhs @@ -0,0 +1,24 @@ +> module Foreign.Erlang.Utilities ( +> -- * Miscellaneous utilities. +> erlangTimeToSeconds +> , secondsToErlangTime +> ) where + +> import Foreign.Erlang.Types (ErlType(..)) + +Erlang's native time format is a tuple: {MegaSeconds, Seconds, +MicroSeconds}. Luckily though, Erlang uses the same epoch, so no +further conversion is necessary. + +> -- | Convert a tuple (from erlang:now()) to seconds from Jan 1, 1970. + +> erlangTimeToSeconds :: Integral a => ErlType -> a +> erlangTimeToSeconds (ErlTuple [ErlInt ms, ErlInt s, _]) = +> fromIntegral $ 1000000*ms + s + +> -- | Convert seconds to an Erlang tuple representing time. + +> secondsToErlangTime :: Integral a => a -> ErlType +> secondsToErlangTime sec = ErlTuple [ErlInt ms, ErlInt s, ErlInt 0] +> where +> (ms, s) = fromIntegral sec `divMod` 1000000