mincopies

This is conceptually very simple, just making a 1 that was hard coded be
exposed as a config option. The hard part was plumbing all that, and
dealing with complexities like reading it from git attributes at the
same time that numcopies is read.

Behavior change: When numcopies is set to 0, git-annex used to drop
content without requiring any copies. Now to get that (highly unsafe)
behavior, mincopies also needs to be set to 0. It seemed better to
remove that edge case, than complicate mincopies by ignoring it when
numcopies is 0.

This commit was sponsored by Denis Dzyubenko on Patreon.

Command/Drop.hs

@@ -1,6 +1,6 @@
 {- git-annex command
  -
- - Copyright 2010-2020 Joey Hess <id@joeyh.name>
+ - Copyright 2010-2021 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -84,11 +84,11 @@ start o from si file key = start' o from key afile ai si
 
 start' :: DropOptions -> Maybe Remote -> Key -> AssociatedFile -> ActionItem -> SeekInput -> CommandStart
 start' o from key afile ai si = 
-	checkDropAuto (autoMode o) from afile key $ \numcopies ->
+	checkDropAuto (autoMode o) from afile key $ \numcopies mincopies ->
 		stopUnless want $
 			case from of
-				Nothing -> startLocal afile ai si numcopies key []
-				Just remote -> startRemote afile ai si numcopies key remote
+				Nothing -> startLocal afile ai si numcopies mincopies key []
+				Just remote -> startRemote afile ai si numcopies mincopies key remote
   where
 	want
 		| autoMode o = wantDrop False (Remote.uuid <$> from) (Just key) afile
@@ -97,21 +97,21 @@ start' o from key afile ai si =
 startKeys :: DropOptions -> Maybe Remote -> (SeekInput, Key, ActionItem) -> CommandStart
 startKeys o from (si, key, ai) = start' o from key (AssociatedFile Nothing) ai si
 
-startLocal :: AssociatedFile -> ActionItem -> SeekInput -> NumCopies -> Key -> [VerifiedCopy] -> CommandStart
-startLocal afile ai si numcopies key preverified =
+startLocal :: AssociatedFile -> ActionItem -> SeekInput -> NumCopies -> MinCopies -> Key -> [VerifiedCopy] -> CommandStart
+startLocal afile ai si numcopies mincopies key preverified =
 	starting "drop" (OnlyActionOn key ai) si $
-		performLocal key afile numcopies preverified
+		performLocal key afile numcopies mincopies preverified
 
-startRemote :: AssociatedFile -> ActionItem -> SeekInput -> NumCopies -> Key -> Remote -> CommandStart
-startRemote afile ai si numcopies key remote = 
+startRemote :: AssociatedFile -> ActionItem -> SeekInput -> NumCopies -> MinCopies -> Key -> Remote -> CommandStart
+startRemote afile ai si numcopies mincopies key remote = 
 	starting ("drop " ++ Remote.name remote) (OnlyActionOn key ai) si $
-		performRemote key afile numcopies remote
+		performRemote key afile numcopies mincopies remote
 
-performLocal :: Key -> AssociatedFile -> NumCopies -> [VerifiedCopy] -> CommandPerform
-performLocal key afile numcopies preverified = lockContentForRemoval key fallback $ \contentlock -> do
+performLocal :: Key -> AssociatedFile -> NumCopies -> MinCopies -> [VerifiedCopy] -> CommandPerform
+performLocal key afile numcopies mincopies preverified = lockContentForRemoval key fallback $ \contentlock -> do
 	u <- getUUID
 	(tocheck, verified) <- verifiableCopies key [u]
-	doDrop u (Just contentlock) key afile numcopies [] (preverified ++ verified) tocheck
+	doDrop u (Just contentlock) key afile numcopies mincopies [] (preverified ++ verified) tocheck
 		( \proof -> do
 			liftIO $ debugM "drop" $ unwords
 				[ "Dropping from here"
@@ -133,12 +133,12 @@ performLocal key afile numcopies preverified = lockContentForRemoval key fallbac
 	-- to be done except for cleaning up.
 	fallback = next $ cleanupLocal key
 
-performRemote :: Key -> AssociatedFile -> NumCopies -> Remote -> CommandPerform
-performRemote key afile numcopies remote = do
+performRemote :: Key -> AssociatedFile -> NumCopies -> MinCopies -> Remote -> CommandPerform
+performRemote key afile numcopies mincopies remote = do
 	-- Filter the uuid it's being dropped from out of the lists of
 	-- places assumed to have the key, and places to check.
 	(tocheck, verified) <- verifiableCopies key [uuid]
-	doDrop uuid Nothing key afile numcopies [uuid] verified tocheck
+	doDrop uuid Nothing key afile numcopies mincopies [uuid] verified tocheck
 		( \proof -> do 
 			liftIO $ debugM "drop" $ unwords
 				[ "Dropping from remote"
@@ -178,17 +178,18 @@ doDrop
 	-> Key
 	-> AssociatedFile
 	-> NumCopies
+	-> MinCopies
 	-> [UUID]
 	-> [VerifiedCopy]
 	-> [UnVerifiedCopy]
 	-> (Maybe SafeDropProof -> CommandPerform, CommandPerform)
 	-> CommandPerform
-doDrop dropfrom contentlock key afile numcopies skip preverified check (dropaction, nodropaction) = 
+doDrop dropfrom contentlock key afile numcopies mincopies skip preverified check (dropaction, nodropaction) = 
 	ifM (Annex.getState Annex.force)
 		( dropaction Nothing
 		, ifM (checkRequiredContent dropfrom key afile)
 			( verifyEnoughCopiesToDrop nolocmsg key 
-				contentlock numcopies
+				contentlock numcopies mincopies
 				skip preverified check
 					(dropaction . Just)
 					(forcehint nodropaction)
@@ -216,17 +217,17 @@ requiredContent = do
 
 {- In auto mode, only runs the action if there are enough
  - copies on other semitrusted repositories. -}
-checkDropAuto :: Bool -> Maybe Remote -> AssociatedFile -> Key -> (NumCopies -> CommandStart) -> CommandStart
+checkDropAuto :: Bool -> Maybe Remote -> AssociatedFile -> Key -> (NumCopies -> MinCopies -> CommandStart) -> CommandStart
 checkDropAuto automode mremote afile key a =
-	go =<< getAssociatedFileNumCopies afile
+	go =<< getAssociatedFileNumMinCopies afile
   where
-	go numcopies
+	go (numcopies, mincopies)
 		| automode = do
 			locs <- Remote.keyLocations key
 			uuid <- getUUID
 			let remoteuuid = fromMaybe uuid $ Remote.uuid <$> mremote
 			locs' <- trustExclude UnTrusted $ filter (/= remoteuuid) locs
 			if NumCopies (length locs') >= numcopies
-				then a numcopies
+				then a numcopies mincopies
 				else stop
-		| otherwise = a numcopies
+		| otherwise = a numcopies mincopies