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.

Logs/NumCopies.hs

@@ -1,6 +1,6 @@
 {- git-annex numcopies log
  -
- - Copyright 2014 Joey Hess <id@joeyh.name>
+ - Copyright 2014-2021 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -9,8 +9,11 @@
 
 module Logs.NumCopies (
 	setGlobalNumCopies,
+	setGlobalMinCopies,
 	getGlobalNumCopies,
+	getGlobalMinCopies,
 	globalNumCopiesLoad,
+	globalMinCopiesLoad,
 ) where
 
 import Annex.Common
@@ -23,19 +26,40 @@ instance SingleValueSerializable NumCopies where
 	serialize (NumCopies n) = encodeBS (show n)
 	deserialize = NumCopies <$$> readish . decodeBS
 
+instance SingleValueSerializable MinCopies where
+	serialize (MinCopies n) = encodeBS (show n)
+	deserialize = MinCopies <$$> readish . decodeBS
+
 setGlobalNumCopies :: NumCopies -> Annex ()
 setGlobalNumCopies new = do
 	curr <- getGlobalNumCopies
 	when (curr /= Just new) $
 		setLog numcopiesLog new
 
+setGlobalMinCopies :: MinCopies -> Annex ()
+setGlobalMinCopies new = do
+	curr <- getGlobalMinCopies
+	when (curr /= Just new) $
+		setLog mincopiesLog new
+
 {- Value configured in the numcopies log. Cached for speed. -}
 getGlobalNumCopies :: Annex (Maybe NumCopies)
 getGlobalNumCopies = maybe globalNumCopiesLoad (return . Just)
 	=<< Annex.getState Annex.globalnumcopies
 
+{- Value configured in the mincopies log. Cached for speed. -}
+getGlobalMinCopies :: Annex (Maybe MinCopies)
+getGlobalMinCopies = maybe globalMinCopiesLoad (return . Just)
+	=<< Annex.getState Annex.globalmincopies
+
 globalNumCopiesLoad :: Annex (Maybe NumCopies)
 globalNumCopiesLoad = do
 	v <- getLog numcopiesLog
 	Annex.changeState $ \s -> s { Annex.globalnumcopies = v }
 	return v
+
+globalMinCopiesLoad :: Annex (Maybe MinCopies)
+globalMinCopiesLoad = do
+	v <- getLog mincopiesLog
+	Annex.changeState $ \s -> s { Annex.globalmincopies = v }
+	return v