git-annex/Assistant/Threads/ConfigMonitor.hs
Joey Hess a1bd5b1fa0 don't delay at startup
Still wait 1 minute after a change before waiting on the next change, but don't
wait at the start, when we might get a pull that contains config changes
right away.
2012-10-30 17:23:42 -04:00

88 lines
2.7 KiB
Haskell

{- git-annex assistant config monitor thread
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Assistant.Threads.ConfigMonitor where
import Assistant.Common
import Assistant.BranchChange
import Assistant.DaemonStatus
import Assistant.Commits
import Utility.ThreadScheduler
import Logs.UUID
import Logs.Trust
import Logs.Remote
import Logs.PreferredContent
import Logs.Group
import Remote.List (remoteListRefresh)
import qualified Git.LsTree as LsTree
import qualified Annex.Branch
import qualified Data.Set as S
thisThread :: ThreadName
thisThread = "ConfigMonitor"
{- This thread detects when configuration changes have been made to the
- git-annex branch and reloads cached configuration.
-
- If the branch is frequently changing, it's checked for configuration
- changes no more often than once every 60 seconds. On the other hand,
- if the branch has not changed in a while, configuration changes will
- be detected immediately.
-}
configMonitorThread :: NamedThread
configMonitorThread = NamedThread "ConfigMonitor" $ loop =<< getConfigs
where
loop old = do
waitBranchChange
new <- getConfigs
when (old /= new) $ do
let changedconfigs = new `S.difference` old
debug $ "reloading config" :
map fst (S.toList changedconfigs)
reloadConfigs new
{- Record a commit to get this config
- change pushed out to remotes. -}
recordCommit
liftIO $ threadDelaySeconds (Seconds 60)
loop new
{- Config files, and their checksums. -}
type Configs = S.Set (FilePath, String)
{- All git-annex's config files, and actions to run when they change. -}
configFilesActions :: [(FilePath, Annex ())]
configFilesActions =
[ (uuidLog, void $ uuidMapLoad)
, (remoteLog, void remoteListRefresh)
, (trustLog, void trustMapLoad)
, (groupLog, void groupMapLoad)
-- Preferred content settings depend on most of the other configs,
-- so will be reloaded whenever any configs change.
, (preferredContentLog, noop)
]
reloadConfigs :: Configs -> Assistant ()
reloadConfigs changedconfigs = do
liftAnnex $ do
sequence_ as
void preferredContentMapLoad
{- Changes to the remote log, or the trust log, can affect the
- syncRemotes list -}
when (Logs.Remote.remoteLog `elem` fs || Logs.Trust.trustLog `elem` fs) $
updateSyncRemotes
where
(fs, as) = unzip $ filter (flip S.member changedfiles . fst)
configFilesActions
changedfiles = S.map fst changedconfigs
getConfigs :: Assistant Configs
getConfigs = S.fromList . map extract
<$> liftAnnex (inRepo $ LsTree.lsTreeFiles Annex.Branch.fullname files)
where
files = map fst configFilesActions
extract treeitem = (LsTree.file treeitem, LsTree.sha treeitem)