use P2P protocol for drop

Not yet used for everything else, but this is enough to
verify that it works, and do some benchmarking.

Some bugfixes included, which got it working. Also fallback to old
actions has been verified to work correctly.

Benchmarked dropping one thousand files from a ssh remote on localhost.
Using the old git-annex	40.867 seconds.
With the P2P protocol	9.905 seconds!

This commit was sponsored by Jochen Bartl on Patreon.

1 files changed, 18 insertions, 14 deletions

diff --git a/Remote/Git.hs b/Remote/Git.hs
index 328f64217..0edd04117 100644
--- a/Remote/Git.hs
+++ b/Remote/Git.hs
@@ -54,10 +54,11 @@ import Remote.Helper.Export
 import qualified Remote.Helper.Ssh as Ssh
 import qualified Remote.GCrypt
 import qualified Remote.P2P
-import P2P.Address
+import qualified Remote.Helper.P2P as P2PHelper
 import qualified P2P.Protocol as P2P
 import qualified P2P.Annex as P2P
 import qualified P2P.IO as P2P
+import P2P.Address
 import Annex.Path
 import Creds
 import Messages.Progress
@@ -150,11 +151,12 @@ gen r u c gc
 	| otherwise = case repoP2PAddress r of
 		Nothing -> do
 			duc <- mkDeferredUUIDCheck r u gc
-			go duc <$> remoteCost gc defcst
+			connpool <- Ssh.mkP2PSshConnectionPool
+			go duc connpool <$> remoteCost gc defcst
 		Just addr -> Remote.P2P.chainGen addr r u c gc
   where
 	defcst = if repoCheap r then cheapRemoteCost else expensiveRemoteCost
-	go duc cst = Just new
+	go duc connpool cst = Just new
 	  where
 		new = Remote 
 			{ uuid = u
@@ -163,7 +165,7 @@ gen r u c gc
 			, storeKey = copyToRemote new duc
 			, retrieveKeyFile = copyFromRemote new
 			, retrieveKeyFileCheap = copyFromRemoteCheap new
-			, removeKey = dropKey new duc
+			, removeKey = dropKey new duc connpool
 			, lockContent = Just (lockKey new duc)
 			, checkPresent = inAnnex new duc
 			, checkPresentCheap = repoCheap r
@@ -368,8 +370,8 @@ keyUrls r key = map tourl locs'
 	remoteconfig = gitconfig r
 	cfg = remoteGitConfig remoteconfig
 
-dropKey :: Remote -> DeferredUUIDCheck -> Key -> Annex Bool
-dropKey r duc key
+dropKey :: Remote -> DeferredUUIDCheck -> Ssh.P2PSshConnectionPool -> Key -> Annex Bool
+dropKey r duc connpool key
 	| not $ Git.repoIsUrl (repo r) = ifM duc
 		( guardUsable (repo r) (return False) $
 			commitOnCleanup r $ onLocalFast r $ do
@@ -383,7 +385,9 @@ dropKey r duc key
 		, return False
 		)
 	| Git.repoIsHttp (repo r) = giveup "dropping from http remote not supported"
-	| otherwise = commitOnCleanup r $ Ssh.dropKey (repo r) key
+	| otherwise = commitOnCleanup r $ do
+		let fallback = Ssh.dropKey (repo r) key
+		P2PHelper.remove (runProto r connpool fallback) key
 
 lockKey :: Remote -> DeferredUUIDCheck -> Key -> (VerifiedCopy -> Annex r) -> Annex r
 lockKey r duc key callback
@@ -758,12 +762,12 @@ mkDeferredUUIDCheck r u gc
 
 -- Runs a P2P Proto action on a remote when it supports that,
 -- otherwise the fallback action.
-runSsh :: Remote -> Ssh.P2PSshConnectionPool -> Annex a -> P2P.Proto a -> Annex a
-runSsh r connpool fallback proto =
-	Ssh.getP2PSshConnection r connpool >>= maybe fallback go
+runProto :: Remote -> Ssh.P2PSshConnectionPool -> Annex a -> P2P.Proto a -> Annex (Maybe a)
+runProto r connpool fallback proto = Just <$>
+	(Ssh.getP2PSshConnection r connpool >>= maybe fallback go)
   where
 	go c = do
-		(c', v) <- runSsh' proto c
+		(c', v) <- runProtoConn proto c
 		case v of
 			Just res -> do
 				liftIO $ Ssh.storeP2PSshConnection connpool c'
@@ -773,9 +777,9 @@ runSsh r connpool fallback proto =
 			-- connection, and run the fallback.
 			Nothing -> fallback
 
-runSsh' :: P2P.Proto a -> Ssh.P2PSshConnection -> Annex (Ssh.P2PSshConnection, Maybe a)
-runSsh' _ P2P.ClosedConnection = return (P2P.ClosedConnection, Nothing)
-runSsh' a conn@(P2P.OpenConnection (c, _pid)) =
+runProtoConn :: P2P.Proto a -> Ssh.P2PSshConnection -> Annex (Ssh.P2PSshConnection, Maybe a)
+runProtoConn _ P2P.ClosedConnection = return (P2P.ClosedConnection, Nothing)
+runProtoConn a conn@(P2P.OpenConnection (c, _pid)) =
 	P2P.runFullProto P2P.Client c a >>= \case
 		Right r -> return (conn, Just r)
 		-- When runFullProto fails, the connection is no longer