use DynamicConfig to handle cost-command

This commit was sponsored by Jake Vosloo on Patreon.

Config.hs

@@ -15,6 +15,7 @@ import qualified Git.Config
 import qualified Git.Command
 import qualified Annex
 import Config.Cost
+import Config.DynamicConfig
 import Types.Availability
 import Git.Types
 
@@ -70,10 +71,7 @@ remoteCost :: RemoteGitConfig -> Cost -> Annex Cost
 remoteCost c d = fromMaybe d <$> remoteCost' c
 
 remoteCost' :: RemoteGitConfig -> Annex (Maybe Cost)
-remoteCost' c = case remoteAnnexCostCommand c of
-	Just cmd | not (null cmd) -> liftIO $
-		readish <$> readProcess "sh" ["-c", cmd]
-	_ -> return $ remoteAnnexCost c
+remoteCost' = liftIO . getDynamicConfig . remoteAnnexCost
 
 setRemoteCost :: Git.Repo -> Cost -> Annex ()
 setRemoteCost r c = setConfig (remoteConfig r "cost") (show c)

Config/DynamicConfig.hs

@@ -7,9 +7,9 @@
 
 module Config.DynamicConfig where
 
-import Control.Concurrent.STM
+import Common
 
-import Utility.SafeCommand
+import Control.Concurrent.STM
 
 -- | A configuration value that may only be known after performing an IO
 -- action. The IO action will only be run the first time the configuration
@@ -42,3 +42,6 @@ successfullCommandRunner cmd = boolSystem "sh" [Param "-c", Param cmd]
 
 unsuccessfullCommandRunner :: CommandRunner Bool
 unsuccessfullCommandRunner cmd = not <$> successfullCommandRunner cmd
+
+readCommandRunner :: Read a => CommandRunner (Maybe a)
+readCommandRunner cmd = readish <$> readProcess "sh" ["-c", cmd]

Types/GitConfig.hs

@@ -192,8 +192,7 @@ mergeGitConfig gitconfig repoglobals = gitconfig
  - key such as <remote>.annex-foo, or if that is not set, a default from
  - annex.foo -}
 data RemoteGitConfig = RemoteGitConfig
-	{ remoteAnnexCost :: Maybe Cost
-	, remoteAnnexCostCommand :: Maybe String
+	{ remoteAnnexCost :: DynamicConfig (Maybe Cost)
 	, remoteAnnexIgnore :: DynamicConfig Bool
 	, remoteAnnexSync :: DynamicConfig Bool
 	, remoteAnnexPull :: Bool
@@ -231,6 +230,9 @@ data RemoteGitConfig = RemoteGitConfig
 
 extractRemoteGitConfig :: Git.Repo -> String -> STM RemoteGitConfig
 extractRemoteGitConfig r remotename = do
+	annexcost <- mkDynamicConfig readCommandRunner
+		(notempty $ getmaybe "cost-command")
+		(getmayberead "cost")
 	annexignore <- mkDynamicConfig unsuccessfullCommandRunner
 		(notempty $ getmaybe "ignore-command")
 		(getbool "ignore" False)
@@ -238,8 +240,7 @@ extractRemoteGitConfig r remotename = do
 		(notempty $ getmaybe "sync-command")
 		(getbool "sync" True)
 	return $ RemoteGitConfig
-		{ remoteAnnexCost = getmayberead "cost"
-		, remoteAnnexCostCommand = notempty $ getmaybe "cost-command"
+		{ remoteAnnexCost = annexcost
 		, remoteAnnexIgnore = annexignore
 		, remoteAnnexSync = annexsync
 		, remoteAnnexPull = getbool "pull" True