git-annex/RemoteDaemon/Core.hs
2014-04-12 16:32:59 -04:00

126 lines
3.4 KiB
Haskell

{- git-remote-daemon core
-
- Copyright 2014 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module RemoteDaemon.Core (runForeground) where
import qualified Annex
import Common
import Types.GitConfig
import RemoteDaemon.Common
import RemoteDaemon.Types
import RemoteDaemon.Transport
import qualified Git
import qualified Git.Types as Git
import qualified Git.CurrentRepo
import Utility.SimpleProtocol
import Config
import Annex.Ssh
import Control.Concurrent.Async
import Control.Concurrent
import Network.URI
import qualified Data.Map as M
runForeground :: IO ()
runForeground = do
(readh, writeh) <- ioHandles
ichan <- newChan :: IO (Chan Consumed)
ochan <- newChan :: IO (Chan Emitted)
let reader = forever $ do
l <- hGetLine readh
case parseMessage l of
Nothing -> error $ "protocol error: " ++ l
Just cmd -> writeChan ichan cmd
let writer = forever $ do
msg <- readChan ochan
hPutStrLn writeh $ unwords $ formatMessage msg
hFlush writeh
let controller = runController ichan ochan
-- If any thread fails, the rest will be killed.
void $ tryIO $
reader `concurrently` writer `concurrently` controller
type RemoteMap = M.Map Git.Repo (IO (), Chan Consumed)
-- Runs the transports, dispatching messages to them, and handling
-- the main control messages.
runController :: Chan Consumed -> Chan Emitted -> IO ()
runController ichan ochan = do
h <- genTransportHandle
m <- genRemoteMap h ochan
startrunning m
go h False m
where
go h paused m = do
cmd <- readChan ichan
case cmd of
RELOAD -> do
liftAnnex h reloadConfig
m' <- genRemoteMap h ochan
let common = M.intersection m m'
let new = M.difference m' m
let old = M.difference m m'
broadcast STOP old
unless paused $
startrunning new
go h paused (M.union common new)
LOSTNET -> do
-- force close all cached ssh connections
-- (done here so that if there are multiple
-- ssh remotes, it's only done once)
liftAnnex h forceSshCleanup
broadcast LOSTNET m
go h True M.empty
PAUSE -> do
broadcast STOP m
go h True M.empty
RESUME -> do
when paused $
startrunning m
go h False m
STOP -> exitSuccess
-- All remaining messages are sent to
-- all Transports.
msg -> do
unless paused $
forM_ chans (`writeChan` msg)
go h paused m
where
chans = map snd (M.elems m)
startrunning m = forM_ (M.elems m) startrunning'
startrunning' (transport, _) = void $ async transport
broadcast msg m = forM_ (M.elems m) send
where
send (_, c) = writeChan c msg
-- Generates a map with a transport for each supported remote in the git repo,
-- except those that have annex.sync = false
genRemoteMap :: TransportHandle -> Chan Emitted -> IO RemoteMap
genRemoteMap h@(TransportHandle g _) ochan =
M.fromList . catMaybes <$> mapM gen (Git.remotes g)
where
gen r = case Git.location r of
Git.Url u -> case M.lookup (uriScheme u) remoteTransports of
Just transport
| remoteAnnexSync (extractRemoteGitConfig r (Git.repoDescribe r)) -> do
ichan <- newChan :: IO (Chan Consumed)
return $ Just
( r
, (transport r (RemoteURI u) h ichan ochan, ichan)
)
_ -> return Nothing
_ -> return Nothing
genTransportHandle :: IO TransportHandle
genTransportHandle = do
annexstate <- newMVar =<< Annex.new =<< Git.CurrentRepo.get
g <- Annex.repo <$> readMVar annexstate
return $ TransportHandle g annexstate