implement annex.privateremote and remote.name.private configs

The slightly unusual parsing in Types.GitConfig avoids the need to look
at the remote list to get configs of remotes. annexPrivateRepos combines
all the configs, and will only be calculated once, so it's nice and
fast.

privateUUIDsKnown and regardingPrivateUUID now need to read from the
annex mvar, so are not entirely free. But that overhead can be optimised
away, as seen in getJournalFileStale. The other call sites didn't seem
worth optimising to save a single MVar access. The feature should have
impreceptable speed overhead when not being used.

Types/GitConfig.hs

@@ -30,6 +30,7 @@ import qualified Git.Config
 import qualified Git.Construct
 import Git.Types
 import Git.ConfigTypes
+import Git.Remote (isRemoteKey, remoteKeyToRemoteName)
 import Git.Branch (CommitMode(..))
 import Utility.DataUnits
 import Config.Cost
@@ -50,6 +51,7 @@ import Utility.Url (Scheme, mkScheme)
 
 import Control.Concurrent.STM
 import qualified Data.Set as S
+import qualified Data.Map as M
 import qualified Data.ByteString as B
 
 -- | A configurable value, that may not be fully determined yet because
@@ -136,12 +138,13 @@ data GitConfig = GitConfig
 	, gcryptId :: Maybe String
 	, gpgCmd :: GpgCmd
 	, mergeDirectoryRenames :: Maybe String
+	, annexPrivateRepos :: S.Set UUID
 	}
 
 extractGitConfig :: ConfigSource -> Git.Repo -> GitConfig
 extractGitConfig configsource r = GitConfig
 	{ annexVersion = RepoVersion <$> getmayberead (annexConfig "version")
-	, annexUUID = maybe NoUUID toUUID $ getmaybe (annexConfig "uuid")
+	, annexUUID = hereuuid
 	, annexNumCopies = NumCopies <$> getmayberead (annexConfig "numcopies")
 	, annexDiskReserve = fromMaybe onemegabyte $
 		readSize dataUnits =<< getmaybe (annexConfig "diskreserve")
@@ -239,6 +242,19 @@ extractGitConfig configsource r = GitConfig
 	, gcryptId = getmaybe "core.gcrypt-id"
 	, gpgCmd = mkGpgCmd (getmaybe "gpg.program")
 	, mergeDirectoryRenames = getmaybe "directoryrenames"
+	, annexPrivateRepos = S.fromList $ concat
+		[ if getbool (annexConfig "private") False
+			then [hereuuid]
+			else []
+		, let get (k, v)
+			| Git.Config.isTrueFalse' v /= Just True = Nothing
+			| isRemoteKey (remoteAnnexConfigEnd "private") k = do
+				remotename <- remoteKeyToRemoteName k
+				toUUID <$> Git.Config.getMaybe
+					(remoteAnnexConfig remotename "uuid") r
+			| otherwise = Nothing
+		  in mapMaybe get (M.toList (Git.config r))
+		]
 	}
   where
 	getbool k d = fromMaybe d $ getmaybebool k
@@ -255,6 +271,8 @@ extractGitConfig configsource r = GitConfig
 		FromGlobalConfig -> HasGlobalConfig v
 
 	onemegabyte = 1000000
+	
+	hereuuid = maybe NoUUID toUUID $ getmaybe (annexConfig "uuid")
 
 {- Merge a GitConfig that comes from git-config with one containing
  - repository-global defaults. -}
@@ -443,7 +461,10 @@ instance RemoteNameable RemoteName where
 
 {- A per-remote annex setting in git config. -}
 remoteAnnexConfig :: RemoteNameable r => r -> UnqualifiedConfigKey -> ConfigKey
-remoteAnnexConfig r key = remoteConfig r ("annex-" <> key)
+remoteAnnexConfig r = remoteConfig r . remoteAnnexConfigEnd
+
+remoteAnnexConfigEnd :: UnqualifiedConfigKey -> UnqualifiedConfigKey
+remoteAnnexConfigEnd key = "annex-" <> key
 
 {- A per-remote setting in git config. -}
 remoteConfig :: RemoteNameable r => r -> UnqualifiedConfigKey -> ConfigKey