git-annex/Logs/Location.hs
2013-09-04 21:37:13 -04:00

63 lines
1.7 KiB
Haskell

{-# LANGUAGE BangPatterns #-}
{- git-annex location log
-
- git-annex keeps track of which repositories have the contents of annexed
- files.
-
- Repositories record their UUID and the date when they --get or --drop
- a value.
-
- Copyright 2010-2011 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Logs.Location (
LogStatus(..),
logStatus,
logChange,
loggedLocations,
loggedKeys,
loggedKeysFor,
) where
import Common.Annex
import qualified Annex.Branch
import Logs
import Logs.Presence
import Annex.UUID
{- Log a change in the presence of a key's value in current repository. -}
logStatus :: Key -> LogStatus -> Annex ()
logStatus key s = do
u <- getUUID
logChange key u s
{- Log a change in the presence of a key's value in a repository. -}
logChange :: Key -> UUID -> LogStatus -> Annex ()
logChange key (UUID u) s = addLog (locationLogFile key) =<< logNow s u
logChange _ NoUUID _ = noop
{- Returns a list of repository UUIDs that, according to the log, have
- the value of a key.
-}
loggedLocations :: Key -> Annex [UUID]
loggedLocations key = map toUUID <$> (currentLog . locationLogFile) key
{- Finds all keys that have location log information.
- (There may be duplicate keys in the list.) -}
loggedKeys :: Annex [Key]
loggedKeys = mapMaybe locationLogFileKey <$> Annex.Branch.files
{- Finds all keys that have location log information indicating
- they are present for the specified repository. -}
loggedKeysFor :: UUID -> Annex [Key]
loggedKeysFor u = filterM isthere =<< loggedKeys
where
{- This should run strictly to avoid the filterM
- building many thunks containing keyLocations data. -}
isthere k = do
us <- loggedLocations k
let !there = u `elem` us
return there