add additional debug info about reasons for transfers

Assistant/TransferQueue.hs

@@ -33,6 +33,8 @@ import Annex.Wanted
 import Control.Concurrent.STM
 import qualified Data.Map as M
 
+type Reason = String
+
 {- Reads the queue's content without blocking or changing it. -}
 getTransferQueue :: Assistant [(Transfer, TransferInfo)]
 getTransferQueue = (atomically . readTVar . queuelist) <<~ transferQueue
@@ -45,13 +47,13 @@ stubInfo f r = stubTransferInfo
 
 {- Adds transfers to queue for some of the known remotes.
  - Honors preferred content settings, only transferring wanted files. -}
-queueTransfers :: Schedule -> Key -> AssociatedFile -> Direction -> Assistant ()
+queueTransfers :: Reason -> Schedule -> Key -> AssociatedFile -> Direction -> Assistant ()
 queueTransfers = queueTransfersMatching (const True)
 
 {- Adds transfers to queue for some of the known remotes, that match a
  - condition. Honors preferred content settings. -}
-queueTransfersMatching :: (UUID -> Bool) -> Schedule -> Key -> AssociatedFile -> Direction -> Assistant ()
-queueTransfersMatching matching schedule k f direction
+queueTransfersMatching :: (UUID -> Bool) -> Reason -> Schedule -> Key -> AssociatedFile -> Direction -> Assistant ()
+queueTransfersMatching matching reason schedule k f direction
 	| direction == Download = whenM (liftAnnex $ wantGet True f) go
 	| otherwise = go
   where
@@ -62,7 +64,7 @@ queueTransfersMatching matching schedule k f direction
 		if null matchingrs
 			then defer
 			else forM_ matchingrs $ \r ->
-				enqueue schedule (gentransfer r) (stubInfo f r)
+				enqueue reason schedule (gentransfer r) (stubInfo f r)
 	sufficientremotes rs
 		{- Queue downloads from all remotes that
 		 - have the key, with the cheapest ones first.
@@ -90,8 +92,8 @@ queueTransfersMatching matching schedule k f direction
 
 {- Queues any deferred downloads that can now be accomplished, leaving
  - any others in the list to try again later. -}
-queueDeferredDownloads :: Schedule -> Assistant ()
-queueDeferredDownloads schedule = do
+queueDeferredDownloads :: Reason -> Schedule -> Assistant ()
+queueDeferredDownloads reason schedule = do
 	q <- getAssistant transferQueue
 	l <- liftIO $ atomically $ swapTVar (deferreddownloads q) []
 	rs <- syncDataRemotes <$> getDaemonStatus
@@ -105,7 +107,7 @@ queueDeferredDownloads schedule = do
 		let sources = filter (\r -> uuid r `elem` uuids) rs
 		unless (null sources) $
 			forM_ sources $ \r ->
-				enqueue schedule (gentransfer r) (stubInfo f r)
+				enqueue reason schedule (gentransfer r) (stubInfo f r)
 		return $ null sources
 	  where
 		gentransfer r = Transfer
@@ -114,8 +116,8 @@ queueDeferredDownloads schedule = do
 			, transferUUID = Remote.uuid r
 			}
 
-enqueue :: Schedule -> Transfer -> TransferInfo -> Assistant ()
-enqueue schedule t info
+enqueue :: Reason -> Schedule -> Transfer -> TransferInfo -> Assistant ()
+enqueue reason schedule t info
 	| schedule == Next = go (new:)
 	| otherwise = go (\l -> l++[new])
   where
@@ -125,31 +127,33 @@ enqueue schedule t info
 		liftIO $ atomically $ do
 			void $ modifyTVar' (queuesize q) succ
 			void $ modifyTVar' (queuelist q) modlist
+		debug [ "queued", describeTransfer t info, ": " ++ reason ]
 		notifyTransfer
 
 {- Adds a transfer to the queue. -}
-queueTransfer :: Schedule -> AssociatedFile -> Transfer -> Remote -> Assistant ()
-queueTransfer schedule f t remote = enqueue schedule t (stubInfo f remote)
+queueTransfer :: Reason -> Schedule -> AssociatedFile -> Transfer -> Remote -> Assistant ()
+queueTransfer reason schedule f t remote =
+	enqueue reason schedule t (stubInfo f remote)
 
 {- Blocks until the queue is no larger than a given size, and then adds a
  - transfer to the queue. -}
-queueTransferAt :: Int -> Schedule -> AssociatedFile -> Transfer -> Remote -> Assistant ()
-queueTransferAt wantsz schedule f t remote = do
+queueTransferAt :: Int -> Reason -> Schedule -> AssociatedFile -> Transfer -> Remote -> Assistant ()
+queueTransferAt wantsz reason schedule f t remote = do
 	q <- getAssistant transferQueue
 	liftIO $ atomically $ do
 		sz <- readTVar (queuesize q)
 		unless (sz <= wantsz) $
 			retry -- blocks until queuesize changes
-	enqueue schedule t (stubInfo f remote)
+	enqueue reason schedule t (stubInfo f remote)
 
-queueTransferWhenSmall :: AssociatedFile -> Transfer -> Remote -> Assistant ()
-queueTransferWhenSmall = queueTransferAt 10 Later
+queueTransferWhenSmall :: Reason -> AssociatedFile -> Transfer -> Remote -> Assistant ()
+queueTransferWhenSmall reason = queueTransferAt 10 reason Later
 
 {- Blocks until a pending transfer is available in the queue,
  - and removes it.
  -
  - Checks that it's acceptable, before adding it to the
- - the currentTransfers map. If it's not acceptable, it's discarded.
+ - currentTransfers map. If it's not acceptable, it's discarded.
  -
  - This is done in a single STM transaction, so there is no window
  - where an observer sees an inconsistent status. -}