improved messages when a file is not available in remotes

Backend/File.hs

@@ -55,15 +55,15 @@ copyKeyFile key file = do
 	remotes <- Remotes.withKey key
 	if (0 == length remotes)
 		then do
-			showNote $ "No available git remotes have the file."
+			showNote "not available"
 			showLocations key
 			return False
 		else trycopy remotes remotes
 	where
 		trycopy full [] = do
-			showNote $
-				"need access to one of these remotes: " ++
-				(Remotes.list full)
+			showNote "not available"
+			showTriedRemotes full
+			showLocations key
 			return False
 		trycopy full (r:rs) = do
 			-- annexLocation needs the git config to have been
@@ -71,8 +71,8 @@ copyKeyFile key file = do
 			-- if it hasn't been already
 			result <- Remotes.tryGitConfigRead r
 			case (result) of
-				Nothing -> trycopy full rs
-				Just r' -> do
+				Left err -> trycopy full rs
+				Right r' -> do
 					showNote $ "copying from " ++ (Git.repoDescribe r ) ++ "..."
 					liftIO $ copyFromRemote r' key file
 
@@ -98,6 +98,10 @@ showLocations key = do
 		then showLongNote $ "Try making some of these repositories available:\n" ++ ppuuids
 		else showLongNote $ "No other repository is known to contain the file."
 		
+showTriedRemotes remotes =
+	showLongNote $ "I was unable to access these remotes: " ++
+		(Remotes.list remotes)
+
 {- Checks remotes to verify that enough copies of a key exist to allow
  - for a key to be safely removed (with no data loss), and fails with an
  - error if not. -}
@@ -108,46 +112,37 @@ checkRemoveKey key = do
 		then return True
 		else do
 			g <- Annex.gitRepo
-			let numcopies = read $ Git.configGet g config "1"
 			remotes <- Remotes.withKey key
+			let numcopies = read $ Git.configGet g config "1"
 			if (numcopies > length remotes)
-				then retNotEnoughCopiesKnown remotes numcopies
-				else findcopies numcopies remotes []
+				then notEnoughCopies numcopies (length remotes) []
+				else findcopies numcopies 0 remotes []
 	where
 		config = "annex.numcopies"
-
-		findcopies 0 _ _ = return True -- success, enough copies found
-		findcopies _ [] bad = notEnoughCopiesSeen bad
-		findcopies n (r:rs) bad = do
+		findcopies need have [] bad = 
+			if (have >= need)
+				then return True
+				else notEnoughCopies need have bad
+		findcopies need have (r:rs) bad = do
 			all <- Annex.supportedBackends
 			result <- liftIO $ ((try $ remoteHasKey r all)::IO (Either SomeException Bool))
 			case (result) of
-				Right True	-> findcopies (n-1) rs bad
-				Right False	-> findcopies n rs bad
-				Left _		-> findcopies n rs (r:bad)
+				Right True	-> findcopies need (have+1) rs bad
+				Right False	-> findcopies need have rs bad
+				Left _		-> findcopies need have rs (r:bad)
 		remoteHasKey r all = do
 			-- To check if a remote has a key, construct a new
 			-- Annex monad and query its backend.
 			a <- Annex.new r all
 			(result, _) <- Annex.run a (Backend.hasKey key)
 			return result
-		notEnoughCopiesSeen bad = do
-			unsafe
-			if (0 /= length bad) then listbad bad else return ()
-			showLocations key
-			hint
-			return False
-		listbad bad =
-			showLongNote $ 
-				"I was unable to access these remotes: " ++
-				(Remotes.list bad)
-		retNotEnoughCopiesKnown remotes numcopies = do
+		notEnoughCopies need have bad = do
 			unsafe
 			showLongNote $
 				"Could only verify the existence of " ++
-				(show $ length remotes) ++ 
-				" out of " ++ (show numcopies) ++ 
+				(show have) ++ " out of " ++ (show need) ++ 
 				" necessary copies"
+			if (0 /= length bad) then showTriedRemotes bad else return ()
 			showLocations key
 			hint
 			return False

Remotes.hs

@@ -10,6 +10,7 @@ import Control.Exception
 import Control.Monad.State (liftIO)
 import qualified Data.Map as Map
 import Data.String.Utils
+import Data.Either.Utils
 import List
 import Maybe
 
@@ -42,8 +43,8 @@ withKey key = do
 	where
 		tryharder allremotes uuids = do
 			-- more expensive; read each remote's config
-			mayberemotes <- mapM tryGitConfigRead allremotes
-			let allremotes' = catMaybes mayberemotes
+			eitherremotes <- mapM tryGitConfigRead allremotes
+			let allremotes' = map fromEither eitherremotes
 			remotes' <- reposByUUID allremotes' uuids
 			Annex.flagChange RemotesRead True
 			return remotes'
@@ -86,7 +87,7 @@ repoCost r = do
  - because reading it may be expensive. This function tries to read the
  - config for a specified remote, and updates state. If successful, it
  - returns the updated git repo. -}
-tryGitConfigRead :: Git.Repo -> Annex (Maybe Git.Repo)
+tryGitConfigRead :: Git.Repo -> Annex (Either Git.Repo Git.Repo)
 tryGitConfigRead r = do
 	if (Map.null $ Git.configMap r)
 		then do
@@ -94,15 +95,15 @@ tryGitConfigRead r = do
 			-- for other reasons; catch all possible exceptions
 			result <- liftIO $ (try (Git.configRead r)::IO (Either SomeException (Git.Repo)))
 			case (result) of
-				Left err -> return Nothing
+				Left err -> return $ Left r
 				Right r' -> do
 					g <- Annex.gitRepo
 					let l = Git.remotes g
 					let g' = Git.remotesAdd g $
 						exchange l r'
 					Annex.gitRepoChange g'
-					return $ Just r'
-		else return $ Just r
+					return $ Right r'
+		else return $ Right r -- config already read
 	where 
 		exchange [] new = []
 		exchange (old:ls) new =