gcrypt: now supports rsync

Use rsync for gcrypt remotes that are not local to the disk.
(Note that I have punted on supporting http transport for now, it doesn't
seem likely to be very useful.)

This was mostly quite easy, it just uses the rsync special remote to handle
the transfers. The git repository url is converted to a RsyncOptions
structure, which required parsing it separately, since the rsync special
remote only supports rsync urls, which use a different format.

Note that annexed objects are now stored at the top of the gcrypt repo,
rather than inside annex/objects. This simplified the rsync suport,
since it doesn't have to arrange to create that directory. And git-annex
is not going to be run directly within gcrypt repos -- or if in some
strance scenario it was, it would make sense for it to not see the
encrypted objects.

This commit was sponsored by Sheila Miguez

2 files changed, 100 insertions, 64 deletions

diff --git a/Remote/GCrypt.hs b/Remote/GCrypt.hs
index 396cb367e..2ff137f57 100644
--- a/Remote/GCrypt.hs
+++ b/Remote/GCrypt.hs
@@ -28,6 +28,9 @@ import Remote.Helper.Encryptable
 import Utility.Metered
 import Crypto
 import Annex.UUID
+import Annex.Ssh
+import qualified Remote.Rsync
+import Utility.Rsync
 
 remote :: RemoteType
 remote = RemoteType {
@@ -52,33 +55,47 @@ gen gcryptr u c gc = do
 	gen' r'' u c gc
 
 gen' :: Git.Repo -> UUID -> RemoteConfig -> RemoteGitConfig -> Annex Remote
-gen' r u c gc = new <$> remoteCost gc defcst
-  where
-	defcst = if repoCheap r then nearlyCheapRemoteCost else expensiveRemoteCost
-	new cst = encryptableRemote c
-		(store this)
-		(retrieve this)
+gen' r u c gc = do
+	cst <- remoteCost gc $
+		if repoCheap r then nearlyCheapRemoteCost else expensiveRemoteCost
+	(rsynctransport, rsyncurl) <- rsyncTransport r
+	let rsyncopts = Remote.Rsync.genRsyncOpts c gc rsynctransport rsyncurl
+	let this = Remote 
+		{ uuid = u
+		, cost = cst
+		, name = Git.repoDescribe r
+		, storeKey = \_ _ _ -> noCrypto
+		, retrieveKeyFile = \_ _ _ _ -> noCrypto
+		, retrieveKeyFileCheap = \_ _ -> return False
+		, removeKey = remove this rsyncopts
+		, hasKey = checkPresent this rsyncopts
+		, hasKeyCheap = repoCheap r
+		, whereisKey = Nothing
+		, config = M.empty
+		, localpath = localpathCalc r
+		, repo = r
+		, gitconfig = gc { remoteGitConfig = Just $ extractGitConfig r }
+		, readonly = Git.repoIsHttp r
+		, globallyAvailable = globallyAvailableCalc r
+		, remotetype = remote
+	}
+	return $ encryptableRemote c
+		(store this rsyncopts)
+		(retrieve this rsyncopts)
 		this
-	  where
-		this = Remote 
-			{ uuid = u
-			, cost = cst
-			, name = Git.repoDescribe r
-			, storeKey = \_ _ _ -> noCrypto
-			, retrieveKeyFile = \_ _ _ _ -> noCrypto
-			, retrieveKeyFileCheap = \_ _ -> return False
-			, removeKey = remove this
-			, hasKey = checkPresent this
-			, hasKeyCheap = repoCheap r
-			, whereisKey = Nothing
-			, config = M.empty
-			, localpath = localpathCalc r
-			, repo = r
-			, gitconfig = gc { remoteGitConfig = Just $ extractGitConfig r }
-			, readonly = Git.repoIsHttp r
-			, globallyAvailable = globallyAvailableCalc r
-			, remotetype = remote
-			}
+
+rsyncTransport :: Git.Repo -> Annex ([CommandParam], String)
+rsyncTransport r
+	| "ssh://" `isPrefixOf` loc = sshtransport $ break (== '/') $ drop (length "ssh://") loc
+	| "//:" `isInfixOf` loc = othertransport
+	| ":" `isInfixOf` loc = sshtransport $ separate (== ':') loc
+	| otherwise = othertransport
+  where
+  	loc = Git.repoLocation r
+	sshtransport (host, path) = do
+		opts <- sshCachingOptions (host, Nothing) []
+		return (rsyncShell $ Param "ssh" : opts, host ++ ":" ++ path)
+	othertransport = return ([], loc)
 
 noCrypto :: Annex a
 noCrypto = error "cannot use gcrypt remote without encryption enabled"
@@ -131,28 +148,29 @@ gCryptSetup mu c = go $ M.lookup "gitrepo" c
 					then return (c', u)
 					else error "uuid mismatch"
 
-store :: Remote -> (Cipher, Key) -> Key -> MeterUpdate -> Annex Bool
-store r (cipher, enck) k p
+store :: Remote -> Remote.Rsync.RsyncOpts -> (Cipher, Key) -> Key -> MeterUpdate -> Annex Bool
+store r rsyncopts (cipher, enck) k p
 	| not $ Git.repoIsUrl (repo r) = guardUsable (repo r) False $
 		sendwith $ \meterupdate h -> do
 			createDirectoryIfMissing True $ parentDir dest
 			readBytes (meteredWriteFile meterupdate dest) h
 			return True
-	| Git.repoIsSsh (repo r) = sendwith $ \meterupdate h -> undefined
+	| Git.repoIsSsh (repo r) = Remote.Rsync.storeEncrypted rsyncopts gpgopts (cipher, enck) k p
 	| otherwise = unsupportedUrl
   where
+  	gpgopts = getGpgEncParams r
 	dest = gCryptLocation r enck
   	sendwith a = metered (Just p) k $ \meterupdate ->
 		Annex.Content.sendAnnex k noop $ \src ->
 			liftIO $ catchBoolIO $
-				encrypt (getGpgEncParams r) cipher (feedFile src) (a meterupdate)
+				encrypt gpgopts cipher (feedFile src) (a meterupdate)
 
-retrieve :: Remote -> (Cipher, Key) -> Key -> FilePath -> MeterUpdate -> Annex Bool
-retrieve r (cipher, enck) k d p
+retrieve :: Remote -> Remote.Rsync.RsyncOpts -> (Cipher, Key) -> Key -> FilePath -> MeterUpdate -> Annex Bool
+retrieve r rsyncopts (cipher, enck) k d p
 	| not $ Git.repoIsUrl (repo r) = guardUsable (repo r) False $ do
 		retrievewith $ L.readFile src
 		return True
-	| Git.repoIsSsh (repo r) = undefined
+	| Git.repoIsSsh (repo r) = Remote.Rsync.retrieveEncrypted rsyncopts (cipher, enck) k d p
 	| otherwise = unsupportedUrl
   where
 	src = gCryptLocation r enck
@@ -161,26 +179,29 @@ retrieve r (cipher, enck) k d p
 			decrypt cipher (feedBytes b)
 				(readBytes $ meteredWriteFile meterupdate d)
 
-remove :: Remote -> Key -> Annex Bool
-remove r k
+remove :: Remote -> Remote.Rsync.RsyncOpts -> Key -> Annex Bool
+remove r rsyncopts k
 	| not $ Git.repoIsUrl (repo r) = guardUsable (repo r) False $ do
 		liftIO $ removeDirectoryRecursive (parentDir dest)
 		return True
-	| Git.repoIsSsh (repo r) = undefined
+	| Git.repoIsSsh (repo r) = Remote.Rsync.remove rsyncopts k
 	| otherwise = unsupportedUrl
   where
 	dest = gCryptLocation r k
 
-checkPresent :: Remote -> Key -> Annex (Either String Bool)
-checkPresent r k
+checkPresent :: Remote -> Remote.Rsync.RsyncOpts -> Key -> Annex (Either String Bool)
+checkPresent r rsyncopts k
 	| not $ Git.repoIsUrl (repo r) =
 		guardUsable (repo r) unknown $
 			liftIO $ catchDefaultIO unknown $
 				Right <$> doesFileExist (gCryptLocation r k)
-	| Git.repoIsSsh (repo r) = undefined
+	| Git.repoIsSsh (repo r) = Remote.Rsync.checkPresent (repo r) rsyncopts k
 	| otherwise = unsupportedUrl
   where
 	unknown = Left $ "unable to check " ++ Git.repoDescribe (repo r) ++ show (repo r)
 
+{- Annexed objects are stored directly under the top of the gcrypt repo
+ - (not in annex/objects), and are hashed using lower-case directories for max
+ - portability. -}
 gCryptLocation :: Remote -> Key -> FilePath
-gCryptLocation r key = Git.repoLocation (repo r) </> annexLocation key hashDirLower
+gCryptLocation r key = Git.repoLocation (repo r) </> keyPath key hashDirLower
diff --git a/Remote/Rsync.hs b/Remote/Rsync.hs
index 0887877e9..b328f6560 100644
--- a/Remote/Rsync.hs
+++ b/Remote/Rsync.hs
@@ -7,7 +7,16 @@
 
 {-# LANGUAGE CPP #-}
 
-module Remote.Rsync (remote) where
+module Remote.Rsync (
+	remote,
+	storeEncrypted,
+	retrieveEncrypted,
+	remove,
+	checkPresent,
+	withRsyncScratchDir,
+	genRsyncOpts,
+	RsyncOpts
+) where
 
 import qualified Data.ByteString.Lazy as L
 import qualified Data.Map as M
@@ -52,9 +61,10 @@ remote = RemoteType {
 gen :: Git.Repo -> UUID -> RemoteConfig -> RemoteGitConfig -> Annex Remote
 gen r u c gc = do
 	cst <- remoteCost gc expensiveRemoteCost
-	(transport, url) <- rsyncTransport
-	let o = RsyncOpts url (transport ++ opts) escape
-	    islocal = rsyncUrlIsPath $ rsyncUrl o
+	(transport, url) <- rsyncTransport gc $
+		fromMaybe (error "missing rsyncurl") $ remoteAnnexRsyncUrl gc
+	let o = genRsyncOpts c gc transport url
+	let islocal = rsyncUrlIsPath $ rsyncUrl o
 	return $ encryptableRemote c
 		(storeEncrypted o $ getGpgEncParams (c,gc))
 		(retrieveEncrypted o)
@@ -79,6 +89,9 @@ gen r u c gc = do
 			, globallyAvailable = not $ islocal
 			, remotetype = remote
 			}
+
+genRsyncOpts :: RemoteConfig -> RemoteGitConfig -> [CommandParam] -> RsyncUrl -> RsyncOpts
+genRsyncOpts c gc transport url = RsyncOpts url (transport ++ opts) escape
   where
 	opts = map Param $ filter safe $ remoteAnnexRsyncOptions gc
 	escape = M.lookup "shellescape" c /= Just "no"
@@ -89,28 +102,30 @@ gen r u c gc = do
 		| opt == "--delete" = False
 		| opt == "--delete-excluded" = False
 		| otherwise = True
-	rawurl = fromMaybe (error "missing rsyncurl") $ remoteAnnexRsyncUrl gc
+
+rsyncTransport :: RemoteGitConfig -> RsyncUrl -> Annex ([CommandParam], RsyncUrl)
+rsyncTransport gc rawurl
+	| rsyncUrlIsShell rawurl =
+		(\rsh -> return (rsyncShell rsh, resturl)) =<<
+		case fromNull ["ssh"] (remoteAnnexRsyncTransport gc) of
+			"ssh":sshopts -> do
+				let (port, sshopts') = sshReadPort sshopts
+				    host = takeWhile (/=':') resturl
+				-- Connection caching
+				(Param "ssh":) <$> sshCachingOptions
+					(host, port)
+					(map Param $ loginopt ++ sshopts')
+			"rsh":rshopts -> return $ map Param $ "rsh" :
+				loginopt ++ rshopts
+			rsh -> error $ "Unknown Rsync transport: "
+				++ unwords rsh
+	| otherwise = return ([], rawurl)
+  where
 	(login,resturl) = case separate (=='@') rawurl of
-			(h, "") -> (Nothing, h)
-			(l, h)  -> (Just l, h)
+		(h, "") -> (Nothing, h)
+		(l, h)  -> (Just l, h)
 	loginopt = maybe [] (\l -> ["-l",l]) login
-	fromNull as xs | null xs = as
-		       | otherwise = xs
-	rsyncTransport = if rsyncUrlIsShell rawurl
-		then (\rsh -> return (rsyncShell rsh, resturl)) =<<
-			case fromNull ["ssh"] (remoteAnnexRsyncTransport gc) of
-				"ssh":sshopts -> do
-					let (port, sshopts') = sshReadPort sshopts
-					    host = takeWhile (/=':') resturl
-					-- Connection caching
-					(Param "ssh":) <$> sshCachingOptions
-						(host, port)
-						(map Param $ loginopt ++ sshopts')
-				"rsh":rshopts -> return $ map Param $ "rsh" :
-					loginopt ++ rshopts
-				rsh -> error $ "Unknown Rsync transport: "
-					++ unwords rsh
-		else return ([], rawurl)
+	fromNull as xs = if null xs then as else xs
 
 rsyncSetup :: Maybe UUID -> RemoteConfig -> Annex (RemoteConfig, UUID)
 rsyncSetup mu c = do