git-annex/Assistant/Threads/Pusher.hs
Joey Hess 522f568450 add TransferScanner thread
Efficiently finding transfers that need to be done to get two repos back
in sync seems like an interesting problem.
2012-07-22 23:16:56 -04:00

117 lines
3.5 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.Threads.Pusher where
import Assistant.Common
import Assistant.Commits
import Assistant.Pushes
import Assistant.DaemonStatus
import Assistant.ThreadedMonad
import Assistant.Threads.Merger
import qualified Command.Sync
import Utility.ThreadScheduler
import Utility.Parallel
import Data.Time.Clock
import qualified Data.Map as M
thisThread :: ThreadName
thisThread = "Pusher"
{- This thread retries pushes that failed before. -}
pushRetryThread :: ThreadState -> FailedPushMap -> IO ()
pushRetryThread st pushmap = runEvery (Seconds halfhour) $ do
-- We already waited half an hour, now wait until there are failed
-- pushes to retry.
topush <- getFailedPushesBefore pushmap (fromIntegral halfhour)
unless (null topush) $ do
debug thisThread
[ "retrying"
, show (length topush)
, "failed pushes"
]
now <- getCurrentTime
pushToRemotes thisThread now st (Just pushmap) topush
where
halfhour = 1800
{- This thread pushes git commits out to remotes soon after they are made. -}
pushThread :: ThreadState -> DaemonStatusHandle -> CommitChan -> FailedPushMap -> IO ()
pushThread st daemonstatus commitchan pushmap = do
runEvery (Seconds 2) $ 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.
now <- getCurrentTime
if shouldPush now commits
then do
remotes <- runThreadState st $
knownRemotes <$> getDaemonStatus daemonstatus
pushToRemotes thisThread now st (Just pushmap) remotes
else do
debug thisThread
[ "delaying push of"
, show (length commits)
, "commits"
]
refillCommits commitchan commits
{- 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.
-}
shouldPush :: UTCTime -> [Commit] -> Bool
shouldPush _now commits
| 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 :: ThreadName -> UTCTime -> ThreadState -> (Maybe FailedPushMap) -> [Remote] -> IO ()
pushToRemotes threadname now st mpushmap remotes = do
(g, branch) <- runThreadState st $
(,) <$> fromRepo id <*> Command.Sync.currentBranch
go True branch g remotes
where
go shouldretry branch g rs = do
debug threadname
[ "pushing to"
, show rs
]
Command.Sync.updateBranch (Command.Sync.syncBranch branch) g
(succeeded, failed) <- inParallel (push g branch) rs
case mpushmap of
Nothing -> noop
Just pushmap ->
changeFailedPushMap pushmap $ \m ->
M.union (makemap failed) $
M.difference m (makemap succeeded)
unless (null failed) $
debug threadname
[ "failed to push to"
, show failed
]
unless (null failed || not shouldretry) $
retry branch g failed
makemap l = M.fromList $ zip l (repeat now)
push g branch remote =
ifM (Command.Sync.pushBranch remote branch g)
( exitSuccess, exitFailure)
retry branch g rs = do
debug threadname [ "trying manual pull to resolve failed pushes" ]
runThreadState st $ manualPull branch rs
go False branch g rs