merge git command queue when joining with concurrent thread

Annex/Concurrent.hs

@@ -12,6 +12,7 @@ import Annex
 import Annex.CatFile
 import Annex.CheckAttr
 import Annex.CheckIgnore
+import qualified Annex.Queue
 
 import qualified Data.Map as M
 
@@ -57,6 +58,7 @@ mergeState st = do
 	st' <- liftIO $ snd <$> run st closehandles
 	forM_ (M.toList $ Annex.cleanup st') $
 		uncurry addCleanup
+	Annex.Queue.mergeFrom st'
 	changeState $ \s -> s { errcounter = errcounter s + errcounter st' }
   where
 	closehandles = do

Annex/Queue.hs

@@ -5,12 +5,15 @@
  - Licensed under the GNU GPL version 3 or higher.
  -}
 
+{-# LANGUAGE BangPatterns #-}
+
 module Annex.Queue (
 	addCommand,
 	addUpdateIndex,
 	flush,
 	flushWhenFull,
-	size
+	size,
+	mergeFrom,
 ) where
 
 import Common.Annex
@@ -60,3 +63,12 @@ new = do
 
 store :: Git.Queue.Queue -> Annex ()
 store q = changeState $ \s -> s { repoqueue = Just q }
+
+mergeFrom :: AnnexState -> Annex ()
+mergeFrom st = case repoqueue st of
+	Nothing -> noop
+	Just newq -> do
+		q <- get
+		let !q' = Git.Queue.merge q newq
+		store q'
+		flushWhenFull

Git/Queue.hs

@@ -15,6 +15,7 @@ module Git.Queue (
 	size,
 	full,
 	flush,
+	merge,
 ) where
 
 import Utility.SafeCommand
@@ -25,14 +26,11 @@ import qualified Git.UpdateIndex
 
 import qualified Data.Map as M
 
-{- Queable actions that can be performed in a git repository.
+{- Queable actions that can be performed in a git repository. -}
- -}
 data Action
 	{- Updating the index file, using a list of streamers that can
 	 - be added to as the queue grows. -}
-	= UpdateIndexAction
+	= UpdateIndexAction [Git.UpdateIndex.Streamer] -- in reverse order
-		{ getStreamers :: [Git.UpdateIndex.Streamer] -- in reverse order
-		}
 	{- A git command to run, on a list of files that can be added to
 	 - as the queue grows. -}
 	| CommandAction 
@@ -84,13 +82,11 @@ addCommand :: String -> [CommandParam] -> [FilePath] -> Queue -> Repo -> IO Queu
 addCommand subcommand params files q repo =
 	updateQueue action different (length files) q repo
   where
-	key = actionKey action
 	action = CommandAction
 		{ getSubcommand = subcommand
 		, getParams = params
-		, getFiles = allfiles
+		, getFiles = map File files
 		}
-	allfiles = map File files ++ maybe [] getFiles (M.lookup key $ items q)
 	
 	different (CommandAction { getSubcommand = s }) = s /= subcommand
 	different _ = True
@@ -100,10 +96,8 @@ addUpdateIndex :: Git.UpdateIndex.Streamer -> Queue -> Repo -> IO Queue
 addUpdateIndex streamer q repo =
 	updateQueue action different 1 q repo
   where
-	key = actionKey action
 	-- the list is built in reverse order
-	action = UpdateIndexAction $ streamer : streamers
+	action = UpdateIndexAction [streamer]
-	streamers = maybe [] getStreamers $ M.lookup key $ items q
 
 	different (UpdateIndexAction _) = False
 	different _ = True
@@ -123,7 +117,23 @@ updateQueue !action different sizeincrease q repo
 			, items = newitems
 			}
 		!newsize = size q' + sizeincrease
-		!newitems = M.insertWith' const (actionKey action) action (items q')
+		!newitems = M.insertWith' combineNewOld (actionKey action) action (items q')
+
+combineNewOld :: Action -> Action -> Action
+combineNewOld (CommandAction _sc1 _ps1 fs1) (CommandAction sc2 ps2 fs2) =
+	CommandAction sc2 ps2 (fs1++fs2)
+combineNewOld (UpdateIndexAction s1) (UpdateIndexAction s2) =
+	UpdateIndexAction (s1++s2)
+combineNewOld anew _aold = anew
+
+{- Merges the contents of the second queue into the first.
+ - This should only be used when the two queues are known to contain
+ - non-conflicting actions. -}
+merge :: Queue -> Queue -> Queue
+merge origq newq = origq
+	{ size = size origq + size newq
+	, items = M.unionWith combineNewOld (items newq) (items origq)
+	}
 
 {- Is a queue large enough that it should be flushed? -}
 full :: Queue -> Bool