git-annex/Utility/DBus.hs
Joey Hess e213ef310f git-annex (5.20140717) unstable; urgency=high
* Fix minor FD leak in journal code. Closes: #754608
  * direct: Fix handling of case where a work tree subdirectory cannot
    be written to due to permissions.
  * migrate: Avoid re-checksumming when migrating from hashE to hash backend.
  * uninit: Avoid failing final removal in some direct mode repositories
    due to file modes.
  * S3: Deal with AWS ACL configurations that do not allow creating or
    checking the location of a bucket, but only reading and writing content to
    it.
  * resolvemerge: New plumbing command that runs the automatic merge conflict
    resolver.
  * Deal with change in git 2.0 that made indirect mode merge conflict
    resolution leave behind old files.
  * sync: Fix git sync with local git remotes even when they don't have an
    annex.uuid set. (The assistant already did so.)
  * Set gcrypt-publish-participants when setting up a gcrypt repository,
    to avoid unncessary passphrase prompts.
    This is a security/usability tradeoff. To avoid exposing the gpg key
    ids who can decrypt the repository, users can unset
    gcrypt-publish-participants.
  * Install nautilus hooks even when ~/.local/share/nautilus/ does not yet
    exist, since it is not automatically created for Gnome 3 users.
  * Windows: Move .vbs files out of git\bin, to avoid that being in the
    PATH, which caused some weird breakage. (Thanks, divB)
  * Windows: Fix locking issue that prevented the webapp starting
    (since 5.20140707).

# imported from the archive
2014-07-17 11:27:25 -04:00

85 lines
2.8 KiB
Haskell

{- DBus utilities
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- License: BSD-2-clause
-}
{-# LANGUAGE OverloadedStrings, ScopedTypeVariables #-}
module Utility.DBus where
import Utility.PartialPrelude
import Utility.Exception
import DBus.Client
import DBus
import Data.Maybe
import Control.Concurrent
import Control.Exception as E
type ServiceName = String
listServiceNames :: Client -> IO [ServiceName]
listServiceNames client = do
reply <- callDBus client "ListNames" []
return $ fromMaybe [] $ fromVariant =<< headMaybe (methodReturnBody reply)
callDBus :: Client -> MemberName -> [Variant] -> IO MethodReturn
callDBus client name params = call_ client $
(methodCall "/org/freedesktop/DBus" "org.freedesktop.DBus" name)
{ methodCallDestination = Just "org.freedesktop.DBus"
, methodCallBody = params
}
{- Connects to the bus, and runs the client action.
-
- Throws a ClientError, and closes the connection if it fails to
- process an incoming message, or if the connection is lost.
- Unlike DBus's usual interface, this error is thrown at the top level,
- rather than inside the clientThreadRunner, so it can be caught, and
- runClient re-run as needed. -}
runClient :: IO (Maybe Address) -> (Client -> IO ()) -> IO ()
runClient getaddr clientaction = do
env <- getaddr
case env of
Nothing -> throwIO (clientError "runClient: unable to determine DBUS address")
Just addr -> do
{- The clientaction will set up listeners, which
- run in a different thread. We block while
- they're running, until our threadrunner catches
- a ClientError, which it will put into the MVar
- to be rethrown here. -}
mv <- newEmptyMVar
let tr = threadrunner (putMVar mv)
let opts = defaultClientOptions { clientThreadRunner = tr }
client <- connectWith opts addr
clientaction client
e <- takeMVar mv
disconnect client
throw e
where
threadrunner storeerr io = loop
where
loop = catchClientError (io >> loop) storeerr
{- Connects to the bus, and runs the client action.
-
- If the connection is lost, runs onretry, which can do something like
- a delay, or printing a warning, and has a state value (useful for
- exponential backoff). Once onretry returns, the connection is retried.
-}
persistentClient :: IO (Maybe Address) -> v -> (SomeException -> v -> IO v) -> (Client -> IO ()) -> IO ()
persistentClient getaddr v onretry clientaction =
{- runClient can fail with not just ClientError, but also other
- things, if dbus is not running. Let async exceptions through. -}
runClient getaddr clientaction `catchNonAsync` retry
where
retry e = do
v' <- onretry e v
persistentClient getaddr v' onretry clientaction
{- Catches only ClientError -}
catchClientError :: IO () -> (ClientError -> IO ()) -> IO ()
catchClientError io handler =
either handler return =<< (E.try io :: IO (Either ClientError ()))