git-annex/Annex/Startup.hs

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remove dead nodes when loading the cluster log This is to avoid inserting a cluster uuid into the location log when only dead nodes in the cluster contain the content of a key. One reason why this is necessary is Remote.keyLocations, which excludes dead repositories from the list. But there are probably many more. Implementing this was challenging, because Logs.Location importing Logs.Cluster which imports Logs.Trust which imports Remote.List resulted in an import cycle through several other modules. Resorted to making Logs.Location not import Logs.Cluster, and instead it assumes that Annex.clusters gets populated when necessary before it's called. That's done in Annex.Startup, which is run by the git-annex command (but not other commands) at early startup in initialized repos. Or, is run after initialization. Note that is Remote.Git, it is unable to import Annex.Startup, because Remote.Git importing Logs.Cluster leads the the same import cycle. So ensureInitialized is not passed annexStartup in there. Other commands, like git-annex-shell currently don't run annexStartup either. So there are cases where Logs.Location will not see clusters. So it won't add any cluster UUIDs when loading the log. That's ok, the only reason to do that is to make display of where objects are located include clusters, and to make commands like git-annex get --from treat keys as being located in a cluster. git-annex-shell certainly does not do anything like that, and I'm pretty sure Remote.Git (and callers to Remote.Git.onLocalRepo) don't either.
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{- git-annex startup
-
- Copyright 2010-2024 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
module Annex.Startup where
import Annex.Common
import qualified Annex
import Logs.Cluster
#ifndef mingw32_HOST_OS
import Control.Concurrent.STM
import System.Posix.Signals
#endif
{- Run when starting up the main git-annex program. -}
startup :: Annex ()
startup = do
startupSignals
gc <- Annex.getGitConfig
when (isinitialized gc)
startupAnnex
where
isinitialized gc = annexUUID gc /= NoUUID
&& isJust (annexVersion gc)
{- Run when starting up the main git-annex program when
- git-annex has already been initialized.
- Alternatively, run after initialization.
-}
startupAnnex :: Annex ()
startupAnnex = doQuietAction $
-- Logs.Location needs this before it is used, in order for a
-- cluster to be treated as the location of keys
remove dead nodes when loading the cluster log This is to avoid inserting a cluster uuid into the location log when only dead nodes in the cluster contain the content of a key. One reason why this is necessary is Remote.keyLocations, which excludes dead repositories from the list. But there are probably many more. Implementing this was challenging, because Logs.Location importing Logs.Cluster which imports Logs.Trust which imports Remote.List resulted in an import cycle through several other modules. Resorted to making Logs.Location not import Logs.Cluster, and instead it assumes that Annex.clusters gets populated when necessary before it's called. That's done in Annex.Startup, which is run by the git-annex command (but not other commands) at early startup in initialized repos. Or, is run after initialization. Note that is Remote.Git, it is unable to import Annex.Startup, because Remote.Git importing Logs.Cluster leads the the same import cycle. So ensureInitialized is not passed annexStartup in there. Other commands, like git-annex-shell currently don't run annexStartup either. So there are cases where Logs.Location will not see clusters. So it won't add any cluster UUIDs when loading the log. That's ok, the only reason to do that is to make display of where objects are located include clusters, and to make commands like git-annex get --from treat keys as being located in a cluster. git-annex-shell certainly does not do anything like that, and I'm pretty sure Remote.Git (and callers to Remote.Git.onLocalRepo) don't either.
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-- that are located in any of its nodes.
preLoadClusters
remove dead nodes when loading the cluster log This is to avoid inserting a cluster uuid into the location log when only dead nodes in the cluster contain the content of a key. One reason why this is necessary is Remote.keyLocations, which excludes dead repositories from the list. But there are probably many more. Implementing this was challenging, because Logs.Location importing Logs.Cluster which imports Logs.Trust which imports Remote.List resulted in an import cycle through several other modules. Resorted to making Logs.Location not import Logs.Cluster, and instead it assumes that Annex.clusters gets populated when necessary before it's called. That's done in Annex.Startup, which is run by the git-annex command (but not other commands) at early startup in initialized repos. Or, is run after initialization. Note that is Remote.Git, it is unable to import Annex.Startup, because Remote.Git importing Logs.Cluster leads the the same import cycle. So ensureInitialized is not passed annexStartup in there. Other commands, like git-annex-shell currently don't run annexStartup either. So there are cases where Logs.Location will not see clusters. So it won't add any cluster UUIDs when loading the log. That's ok, the only reason to do that is to make display of where objects are located include clusters, and to make commands like git-annex get --from treat keys as being located in a cluster. git-annex-shell certainly does not do anything like that, and I'm pretty sure Remote.Git (and callers to Remote.Git.onLocalRepo) don't either.
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startupSignals :: Annex ()
startupSignals = do
#ifndef mingw32_HOST_OS
av <- Annex.getRead Annex.signalactions
let propagate sig = liftIO $ installhandleronce sig av
propagate sigINT
propagate sigQUIT
propagate sigTERM
propagate sigTSTP
propagate sigCONT
propagate sigHUP
-- sigWINCH is not propagated; it should not be needed,
-- and the concurrent-output library installs its own signal
-- handler for it.
-- sigSTOP and sigKILL cannot be caught, so will not be propagated.
where
installhandleronce sig av = void $
installHandler sig (CatchOnce (gotsignal sig av)) Nothing
gotsignal sig av = do
mapM_ (\a -> a (fromIntegral sig)) =<< atomically (readTVar av)
raiseSignal sig
installhandleronce sig av
#else
return ()
#endif