git-annex/Logs/Presence.hs
Joey Hess 40ecf58d4b
update licenses from GPL to AGPL
This does not change the overall license of the git-annex program, which
was already AGPL due to a number of sources files being AGPL already.

Legally speaking, I'm adding a new license under which these files are
now available; I already released their current contents under the GPL
license. Now they're dual licensed GPL and AGPL. However, I intend
for all my future changes to these files to only be released under the
AGPL license, and I won't be tracking the dual licensing status, so I'm
simply changing the license statement to say it's AGPL.

(In some cases, others wrote parts of the code of a file and released it
under the GPL; but in all cases I have contributed a significant portion
of the code in each file and it's that code that is getting the AGPL
license; the GPL license of other contributors allows combining with
AGPL code.)
2019-03-13 15:48:14 -04:00

71 lines
2.1 KiB
Haskell

{- git-annex presence log
-
- This is used to store presence information in the git-annex branch in
- a way that can be union merged.
-
- A line of the log will look like: "date N INFO"
- Where N=1 when the INFO is present, 0 otherwise.
-
- Copyright 2010-2014 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Logs.Presence (
module X,
addLog,
maybeAddLog,
readLog,
logNow,
currentLog,
currentLogInfo,
historicalLogInfo,
) where
import Logs.Presence.Pure as X
import Annex.Common
import Annex.VectorClock
import qualified Annex.Branch
import Git.Types (RefDate)
{- Adds a LogLine to the log, removing any LogLines that are obsoleted by
- adding it. -}
addLog :: FilePath -> LogLine -> Annex ()
addLog file line = Annex.Branch.change file $ \b ->
buildLog $ compactLog (line : parseLog b)
{- When a LogLine already exists with the same status and info, but an
- older timestamp, that LogLine is preserved, rather than updating the log
- with a newer timestamp.
-}
maybeAddLog :: FilePath -> LogLine -> Annex ()
maybeAddLog file line = Annex.Branch.maybeChange file $ \s -> do
m <- insertNewStatus line $ logMap $ parseLog s
return $ buildLog $ mapLog m
{- Reads a log file.
- Note that the LogLines returned may be in any order. -}
readLog :: FilePath -> Annex [LogLine]
readLog = parseLog <$$> Annex.Branch.get
{- Generates a new LogLine with the current time. -}
logNow :: LogStatus -> LogInfo -> Annex LogLine
logNow s i = do
c <- liftIO currentVectorClock
return $ LogLine c s i
{- Reads a log and returns only the info that is still in effect. -}
currentLogInfo :: FilePath -> Annex [LogInfo]
currentLogInfo file = map info <$> currentLog file
currentLog :: FilePath -> Annex [LogLine]
currentLog file = filterPresent <$> readLog file
{- Reads a historical version of a log and returns the info that was in
- effect at that time.
-
- The date is formatted as shown in gitrevisions man page.
-}
historicalLogInfo :: RefDate -> FilePath -> Annex [LogInfo]
historicalLogInfo refdate file = map info . filterPresent . parseLog
<$> Annex.Branch.getHistorical refdate file