New --time-limit option, makes long git-annex commands stop after a specified amount of time.

GitAnnex.hs

@@ -141,9 +141,11 @@ options = Option.common ++
 		"skip files with fewer copies"
 	, Option ['B'] ["inbackend"] (ReqArg Limit.addInBackend paramName)
 		"skip files not using a key-value backend"
+	, Option ['T'] ["time-limit"] (ReqArg Limit.addTimeLimit paramTime)
+		"stop after the specified amount of time"
 	] ++ Option.matcher
 	where
-		setnumcopies v = Annex.changeState $ \s -> s {Annex.forcenumcopies = readish v }
+		setnumcopies v = Annex.changeState $ \s -> s { Annex.forcenumcopies = readish v }
 		setgitconfig :: String -> Annex ()
 		setgitconfig v = do
 			newg <- inRepo $ Git.Config.store v

Limit.hs

@@ -9,6 +9,7 @@ module Limit where
 
 import Text.Regex.PCRE.Light.Char8
 import System.Path.WildMatch
+import Data.Time.Clock.POSIX
 
 import Common.Annex
 import qualified Annex
@@ -17,6 +18,7 @@ import qualified Remote
 import qualified Backend
 import Annex.Content
 import Logs.Trust
+import Utility.HumanTime
 
 type Limit = Utility.Matcher.Token (FilePath -> Annex Bool)
 
@@ -106,3 +108,17 @@ addInBackend name = addLimit $ Backend.lookupFile >=> check
 	where
 		wanted = Backend.lookupBackendName name
 		check = return . maybe False ((==) wanted . snd)
+
+addTimeLimit :: String -> Annex ()
+addTimeLimit s = do
+	let seconds = fromMaybe (error "bad time-limit") $ parseDuration s
+	start <- liftIO getPOSIXTime
+	let cutoff = start + seconds
+	addLimit $ const $ do
+		now <- liftIO getPOSIXTime
+		if now > cutoff
+			then do
+				warning $ "Time limit (" ++ s ++ ") reached!"
+				liftIO $ exitWith $ ExitFailure 101
+			else return True
+		

Usage.hs

@@ -77,6 +77,8 @@ paramType :: String
 paramType = "TYPE"
 paramDate :: String
 paramDate = "DATE"
+paramTime :: String
+paramTime = "TIME"
 paramFormat :: String
 paramFormat = "FORMAT"
 paramFile :: String

Utility/HumanTime.hs

@@ -0,0 +1,26 @@
+{- Time for humans.
+ -
+ - Copyright 2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Utility.HumanTime where
+
+import Utility.PartialPrelude
+
+import Data.Time.Clock.POSIX (POSIXTime)
+
+{- Parses a human-input time duration, of the form "5h" or "1m". -}
+parseDuration :: String -> Maybe POSIXTime
+parseDuration s = do
+	num <- readish s :: Maybe Integer
+	units <- findUnits =<< lastMaybe s
+	return $ fromIntegral num * units
+	where
+		findUnits 's' = Just 1
+		findUnits 'm' = Just 60
+		findUnits 'h' = Just $ 60 * 60
+		findUnits 'd' = Just $ 60 * 60 * 24
+		findUnits 'y' = Just $ 60 * 60 * 24 * 365
+		findUnits _ = Nothing

debian/changelog

@@ -6,6 +6,8 @@ git-annex (3.20120925) UNRELEASED; urgency=low
     with git annex fsck --incremental. Now the fsck can be interrupted
     as desired, and resumed with git annex fsck --more.
     Thanks, Justin Azoff
+  * New --time-limit option, makes long git-annex commands stop after
+    a specified amount of time.
 
  -- Joey Hess <joeyh@debian.org>  Mon, 24 Sep 2012 19:58:07 -0400
 

doc/git-annex.mdwn

@@ -259,13 +259,13 @@ subdirectories).
 
   To check a remote to fsck, specify --from.
 
+  To avoid expensive checksum calculations (and expensive transfers when
+  fscking a remote), specify --fast.
+
   To start a new incremental fsck, specify --incremental. Then
   the next time you fsck, you can specify --more to skip over
   files that have already been checked, and continue where it left off.
 
-  To avoid expensive checksum calculations (and expensive transfers when
-  fscking a remote), specify --fast.
-
 * unused
 
   Checks the annex for data that does not correspond to any files present
@@ -514,6 +514,17 @@ subdirectories).
   Overrides the `annex.numcopies` setting, forcing git-annex to ensure the
   specified number of copies exist.
 
+* --time-limit=time
+
+  Limits how long a git-annex command runs. The time can be something
+  like "5h", or "30m" or even "45s" or "10d".
+
+  Note that git-annex may continue running a little past the specified
+  time limit, in order to finish processing a file.
+
+  Also, note that if the time limit prevents git-annex from doing all it 
+  was asked to, it will exit with a special code, 101.
+
 * --trust=repository
 * --semitrust=repository
 * --untrust=repository