3e68c1c2fd
This allows a remote to store a piece of arbitrary state associated with a key. This is needed to support Tahoe, where the file-cap is calculated from the data stored in it, and used to retrieve a key later. Glacier also would be much improved by using this. GETSTATE and SETSTATE are added to the external special remote protocol. Note that the state is left as-is even when a key is removed from a remote. It's up to the remote to decide when it wants to clear the state. The remote state log, $KEY.log.rmt, is a UUID-based log. However, rather than using the old UUID-based log format, I created a new variant of that format. The new varient is more space efficient (since it lacks the "timestamp=" hack, and easier to parse (and the parser doesn't mess with whitespace in the value), and avoids compatability cruft in the old one. This seemed worth cleaning up for these new files, since there could be a lot of them, while before UUID-based logs were only used for a few log files at the top of the git-annex branch. The transition code has also been updated to handle these new UUID-based logs. This commit was sponsored by Daniel Hofer.
55 lines
1.9 KiB
Haskell
55 lines
1.9 KiB
Haskell
{- git-annex branch transitions
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-
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- Copyright 2013 Joey Hess <joey@kitenet.net>
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-
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- Licensed under the GNU GPL version 3 or higher.
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-}
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module Annex.Branch.Transitions (
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FileTransition(..),
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getTransitionCalculator
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) where
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import Logs
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import Logs.Transitions
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import Logs.UUIDBased as UUIDBased
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import Logs.Presence.Pure as Presence
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import Types.TrustLevel
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import Types.UUID
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import qualified Data.Map as M
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data FileTransition
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= ChangeFile String
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| RemoveFile
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| PreserveFile
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type TransitionCalculator = FilePath -> String -> TrustMap -> FileTransition
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getTransitionCalculator :: Transition -> Maybe TransitionCalculator
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getTransitionCalculator ForgetGitHistory = Nothing
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getTransitionCalculator ForgetDeadRemotes = Just dropDead
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dropDead :: FilePath -> String -> TrustMap -> FileTransition
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dropDead f content trustmap = case getLogVariety f of
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Just UUIDBasedLog -> ChangeFile $
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UUIDBased.showLog id $ dropDeadFromUUIDBasedLog trustmap $ UUIDBased.parseLog Just content
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Just NewUUIDBasedLog -> ChangeFile $
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UUIDBased.showLogNew id $ dropDeadFromUUIDBasedLog trustmap $ UUIDBased.parseLogNew Just content
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Just (PresenceLog _) ->
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let newlog = Presence.compactLog $ dropDeadFromPresenceLog trustmap $ Presence.parseLog content
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in if null newlog
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then RemoveFile
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else ChangeFile $ Presence.showLog newlog
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Nothing -> PreserveFile
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dropDeadFromUUIDBasedLog :: TrustMap -> UUIDBased.Log String -> UUIDBased.Log String
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dropDeadFromUUIDBasedLog trustmap = M.filterWithKey $ notDead trustmap . const
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{- Presence logs can contain UUIDs or other values. Any line that matches
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- a dead uuid is dropped; any other values are passed through. -}
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dropDeadFromPresenceLog :: TrustMap -> [Presence.LogLine] -> [Presence.LogLine]
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dropDeadFromPresenceLog trustmap = filter $ notDead trustmap (toUUID . Presence.info)
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notDead :: TrustMap -> (v -> UUID) -> v -> Bool
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notDead trustmap a v = M.findWithDefault SemiTrusted (a v) trustmap /= DeadTrusted
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