git-annex/Assistant/Pusher.hs
2012-06-23 01:20:40 -04:00

69 lines
2.2 KiB
Haskell

{- git-annex assistant git pushing thread
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Assistant.Pusher where
import Common.Annex
import Assistant.Commits
import Assistant.ThreadedMonad
import qualified Command.Sync
import Utility.ThreadScheduler
import Utility.Parallel
import Data.Time.Clock
data FailedPush = FailedPush
{ failedRemote :: Remote
, failedTimeStamp :: UTCTime
}
{- This thread pushes git commits out to remotes. -}
pushThread :: ThreadState -> CommitChan -> IO ()
pushThread st commitchan = do
remotes <- runThreadState st $ Command.Sync.syncRemotes []
runEveryWith (Seconds 2) [] $ \failedpushes -> do
-- We already waited two seconds as a simple rate limiter.
-- Next, wait until at least one commit has been made
commits <- getCommits commitchan
-- Now see if now's a good time to push.
time <- getCurrentTime
if shouldPush time commits failedpushes
then pushToRemotes time st remotes
else do
refillCommits commitchan commits
return failedpushes
{- Decide if now is a good time to push to remotes.
-
- Current strategy: Immediately push all commits. The commit machinery
- already determines batches of changes, so we can't easily determine
- batches better.
-
- TODO: FailedPushs are only retried the next time there's a commit.
- Should retry them periodically, or when a remote that was not available
- becomes available.
-}
shouldPush :: UTCTime -> [Commit] -> [FailedPush] -> Bool
shouldPush _now commits _failedremotes
| not (null commits) = True
| otherwise = False
{- Updates the local sync branch, then pushes it to all remotes, in
- parallel.
-
- Avoids running possibly long-duration commands in the Annex monad, so
- as not to block other threads. -}
pushToRemotes :: UTCTime -> ThreadState -> [Remote] -> IO [FailedPush]
pushToRemotes now st remotes = do
(g, branch) <- runThreadState st $
(,) <$> fromRepo id <*> Command.Sync.currentBranch
Command.Sync.updateBranch (Command.Sync.syncBranch branch) g
map (`FailedPush` now) <$> inParallel (push g branch) remotes
where
push g branch remote =
ifM (Command.Sync.pushBranch remote branch g)
( exitSuccess, exitFailure)