git-annex/Logs/MapLog.hs
Joey Hess e213ef310f git-annex (5.20140717) unstable; urgency=high
* Fix minor FD leak in journal code. Closes: #754608
  * direct: Fix handling of case where a work tree subdirectory cannot
    be written to due to permissions.
  * migrate: Avoid re-checksumming when migrating from hashE to hash backend.
  * uninit: Avoid failing final removal in some direct mode repositories
    due to file modes.
  * S3: Deal with AWS ACL configurations that do not allow creating or
    checking the location of a bucket, but only reading and writing content to
    it.
  * resolvemerge: New plumbing command that runs the automatic merge conflict
    resolver.
  * Deal with change in git 2.0 that made indirect mode merge conflict
    resolution leave behind old files.
  * sync: Fix git sync with local git remotes even when they don't have an
    annex.uuid set. (The assistant already did so.)
  * Set gcrypt-publish-participants when setting up a gcrypt repository,
    to avoid unncessary passphrase prompts.
    This is a security/usability tradeoff. To avoid exposing the gpg key
    ids who can decrypt the repository, users can unset
    gcrypt-publish-participants.
  * Install nautilus hooks even when ~/.local/share/nautilus/ does not yet
    exist, since it is not automatically created for Gnome 3 users.
  * Windows: Move .vbs files out of git\bin, to avoid that being in the
    PATH, which caused some weird breakage. (Thanks, divB)
  * Windows: Fix locking issue that prevented the webapp starting
    (since 5.20140707).

# imported from the archive
2014-07-17 11:27:25 -04:00

81 lines
2.4 KiB
Haskell

{- git-annex Map log
-
- This is used to store a Map, in a way that can be union merged.
-
- A line of the log will look like: "timestamp field value"
-
- Copyright 2014 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Logs.MapLog where
import qualified Data.Map as M
import Data.Time.Clock.POSIX
import Data.Time
import System.Locale
import Common
data TimeStamp = Unknown | Date POSIXTime
deriving (Eq, Ord, Show)
data LogEntry v = LogEntry
{ changed :: TimeStamp
, value :: v
} deriving (Eq, Show)
type MapLog f v = M.Map f (LogEntry v)
showMapLog :: (f -> String) -> (v -> String) -> MapLog f v -> String
showMapLog fieldshower valueshower = unlines . map showpair . M.toList
where
showpair (f, LogEntry (Date p) v) =
unwords [show p, fieldshower f, valueshower v]
showpair (f, LogEntry Unknown v) =
unwords ["0", fieldshower f, valueshower v]
parseMapLog :: Ord f => (String -> Maybe f) -> (String -> Maybe v) -> String -> MapLog f v
parseMapLog fieldparser valueparser = M.fromListWith best . mapMaybe parse . lines
where
parse line = do
let (ts, rest) = splitword line
(sf, sv) = splitword rest
date <- Date . utcTimeToPOSIXSeconds <$> parseTime defaultTimeLocale "%s%Qs" ts
f <- fieldparser sf
v <- valueparser sv
Just (f, LogEntry date v)
splitword = separate (== ' ')
changeMapLog :: Ord f => POSIXTime -> f -> v -> MapLog f v -> MapLog f v
changeMapLog t f v = M.insert f $ LogEntry (Date t) v
{- Only add an LogEntry if it's newer (or at least as new as) than any
- existing LogEntry for a field. -}
addMapLog :: Ord f => f -> LogEntry v -> MapLog f v -> MapLog f v
addMapLog = M.insertWith' best
{- Converts a MapLog into a simple Map without the timestamp information.
- This is a one-way trip, but useful for code that never needs to change
- the log. -}
simpleMap :: MapLog f v -> M.Map f v
simpleMap = M.map value
best :: LogEntry v -> LogEntry v -> LogEntry v
best new old
| changed old > changed new = old
| otherwise = new
-- Unknown is oldest.
prop_TimeStamp_sane :: Bool
prop_TimeStamp_sane = Unknown < Date 1
prop_addMapLog_sane :: Bool
prop_addMapLog_sane = newWins && newestWins
where
newWins = addMapLog ("foo") (LogEntry (Date 1) "new") l == l2
newestWins = addMapLog ("foo") (LogEntry (Date 1) "newest") l2 /= l2
l = M.fromList [("foo", LogEntry (Date 0) "old")]
l2 = M.fromList [("foo", LogEntry (Date 1) "new")]