git-annex/Assistant/Threads/NetWatcher.hs
Joey Hess 8a796cfa64 improve syncing support for special remotes
Avoid trying to git push/pull to special remotes, but still do transfer
scans of them, after git pull from any other remotes, so we know about
any values that have been placed on them.
2012-09-04 15:56:37 -04:00

131 lines
3.9 KiB
Haskell

{- git-annex assistant network connection watcher, using dbus
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE OverloadedStrings #-}
module Assistant.Threads.NetWatcher where
import Assistant.Common
import Assistant.ThreadedMonad
import Assistant.DaemonStatus
import Assistant.ScanRemotes
import Assistant.Sync
import qualified Git
import Utility.ThreadScheduler
import Remote.List
import qualified Types.Remote as Remote
import qualified Control.Exception as E
import Control.Concurrent
#if WITH_DBUS
import Utility.DBus
import DBus.Client
import DBus
import Data.Word (Word32)
#else
#warning Building without dbus support; will poll for network connection changes
#endif
thisThread :: ThreadName
thisThread = "NetWatcher"
netWatcherThread :: ThreadState -> DaemonStatusHandle -> ScanRemoteMap -> IO ()
netWatcherThread st dstatus scanremotes = do
#if WITH_DBUS
void $ forkIO $ dbusThread st dstatus scanremotes
#endif
{- This is a fallback for when dbus cannot be used to detect
- network connection changes, but it also ensures that
- any networked remotes that may have not been routable for a
- while (despite the local network staying up), are synced with
- periodically. -}
runEvery (Seconds 3600) $
handleConnection st dstatus scanremotes
#if WITH_DBUS
dbusThread :: ThreadState -> DaemonStatusHandle -> ScanRemoteMap -> IO ()
dbusThread st dstatus scanremotes = E.catch (go =<< connectSystem) onerr
where
go client = ifM (checkNetMonitor client)
( do
listenNMConnections client handle
listenWicdConnections client handle
, do
runThreadState st $
warning "No known network monitor available through dbus; falling back to polling"
)
onerr :: E.SomeException -> IO ()
onerr e = runThreadState st $
warning $ "Failed to use dbus; falling back to polling (" ++ show e ++ ")"
handle = do
debug thisThread ["detected network connection"]
handleConnection st dstatus scanremotes
{- Examine the list of services connected to dbus, to see if there
- are any we can use to monitor network connections. -}
checkNetMonitor :: Client -> IO Bool
checkNetMonitor client = do
running <- filter (`elem` [networkmanager, wicd])
<$> listServiceNames client
case running of
[] -> return False
(service:_) -> do
debug thisThread [ "Using running DBUS service"
, service
, "to monitor network connection events."
]
return True
where
networkmanager = "org.freedesktop.NetworkManager"
wicd = "org.wicd.daemon"
{- Listens for new NetworkManager connections. -}
listenNMConnections :: Client -> IO () -> IO ()
listenNMConnections client callback =
listen client matcher $ \event ->
when (Just True == anyM activeconnection (signalBody event)) $
callback
where
matcher = matchAny
{ matchInterface = Just "org.freedesktop.NetworkManager.Connection.Active"
, matchMember = Just "PropertiesChanged"
}
nm_connection_activated = toVariant (2 :: Word32)
nm_state_key = toVariant ("State" :: String)
activeconnection v = do
m <- fromVariant v
vstate <- lookup nm_state_key $ dictionaryItems m
state <- fromVariant vstate
return $ state == nm_connection_activated
{- Listens for new Wicd connections. -}
listenWicdConnections :: Client -> IO () -> IO ()
listenWicdConnections client callback =
listen client matcher $ \event ->
when (any (== wicd_success) (signalBody event)) $
callback
where
matcher = matchAny
{ matchInterface = Just "org.wicd.daemon"
, matchMember = Just "ConnectResultsSent"
}
wicd_success = toVariant ("success" :: String)
#endif
handleConnection :: ThreadState -> DaemonStatusHandle -> ScanRemoteMap -> IO ()
handleConnection st dstatus scanremotes =
reconnectRemotes thisThread st dstatus scanremotes
=<< networkRemotes st
{- Finds network remotes. -}
networkRemotes :: ThreadState -> IO [Remote]
networkRemotes st = runThreadState st $
filter (isNothing . Remote.localpath) <$> remoteList