detect renames during commit, and .. um, do nothing special because it's lunch time

But I'm well set up to fast-track direct mode adds for renames now.

4 files changed, 102 insertions, 19 deletions

diff --git a/Annex/Content/Direct.hs b/Annex/Content/Direct.hs
index 164cb64a4..bbf6e310d 100644
--- a/Annex/Content/Direct.hs
+++ b/Annex/Content/Direct.hs
@@ -14,6 +14,7 @@ module Annex.Content.Direct (
 	updateInodeCache,
 	writeInodeCache,
 	compareInodeCaches,
+	compareInodeCachesWith,
 	sameInodeCache,
 	sameFileStatus,
 	removeInodeCache,
@@ -147,12 +148,15 @@ sameFileStatus key status = do
 {- If the inodes have changed, only the size and mtime are compared. -}
 compareInodeCaches :: InodeCache -> InodeCache -> Annex Bool
 compareInodeCaches x y
-	| x `compareStrong` y = return True
+	| compareStrong x y = return True
 	| otherwise = ifM inodesChanged
 		( return $ compareWeak x y
 		, return False
 		)
 
+compareInodeCachesWith :: Annex InodeComparisonType
+compareInodeCachesWith = ifM inodesChanged ( return Weakly, return Strongly )
+
 {- Some filesystems get new inodes each time they are mounted.
  - In order to work on such a filesystem, a sentinal file is used to detect
  - when the inodes have changed.
diff --git a/Assistant/Threads/Committer.hs b/Assistant/Threads/Committer.hs
index b336f650b..5be190c4a 100644
--- a/Assistant/Threads/Committer.hs
+++ b/Assistant/Threads/Committer.hs
@@ -32,11 +32,15 @@ import Config
 import Annex.Exception
 import Annex.Content
 import Annex.Link
+import Annex.CatFile
 import qualified Annex
+import Utility.InodeCache
+import Annex.Content.Direct
 
 import Data.Time.Clock
 import Data.Tuple.Utils
 import qualified Data.Set as S
+import qualified Data.Map as M
 import Data.Either
 import Control.Concurrent
 
@@ -90,9 +94,13 @@ waitChangeTime a = runEvery (Seconds 1) <~> do
 	{- Did we perhaps only get one of the AddChange and RmChange pair
 	 - that make up a rename? -}
 	lonelychange [(PendingAddChange _ _)] = True
-	lonelychange [(Change { changeInfo = i })] | i == RmChange = True
+	lonelychange [c] | isRmChange c = True
 	lonelychange _ = False
 
+isRmChange :: Change -> Bool
+isRmChange (Change { changeInfo = i }) | i == RmChange = True
+isRmChange _ = False
+
 {- An amount of time that is hopefully imperceptably short for humans,
  - while long enough for a computer to get some work done. 
  - Note that 0.001 is a little too short for rename change batching to
@@ -200,7 +208,9 @@ handleAdds delayadd cs = returnWhen (null incomplete) $ do
 		refillChanges postponed
 
 	returnWhen (null toadd) $ do
-		added <- catMaybes <$> forM toadd add
+		added <- catMaybes <$> if direct
+			then adddirect toadd
+			else forM toadd add
 		if DirWatcher.eventsCoalesce || null added || direct
 			then return $ added ++ otherchanges
 			else do
@@ -238,6 +248,45 @@ handleAdds delayadd cs = returnWhen (null incomplete) $ do
 		ret _ = (True, Nothing)
 	add _ = return Nothing
 
+	{- In direct mode, avoid overhead of re-injesting a renamed
+	 - file, by examining the other Changes to see if a removed
+	 - file has the same InodeCache as the new file. If so,
+	 - we can just update bookkeeping, and stage the file in git.
+	 -}
+	adddirect :: [Change] -> Assistant [Maybe Change]
+	adddirect toadd = do
+		ct <- liftAnnex compareInodeCachesWith
+		m <- liftAnnex $ removedKeysMap ct cs
+		if M.null m
+			then forM toadd add
+			else forM toadd $ \c -> do
+				mcache <- liftIO $ genInodeCache $ changeFile c
+				case mcache of
+					Nothing -> add c
+					Just cache ->
+						case M.lookup (inodeCacheToKey ct cache) m of
+							Nothing -> add c
+							Just k -> fastadd c k cache
+
+	fastadd :: Change -> Key -> InodeCache -> Assistant (Maybe Change)
+	fastadd change key cache = do
+		-- TODO do fast method
+		debug ["rename detected", show change, show key, show cache]
+		add change
+		--return $ Just $ finishedChange change key
+
+	removedKeysMap :: InodeComparisonType -> [Change] -> Annex (M.Map InodeCacheKey Key)
+	removedKeysMap ct l = do
+		mks <- forM (filter isRmChange l) $ \c ->
+			catKeyFile $ changeFile c
+		M.fromList . catMaybes <$> forM (catMaybes mks) mkpair
+	  where
+		mkpair k = do
+			mcache <- recordedInodeCache k
+			case mcache of
+				Just cache -> return $ Just (inodeCacheToKey ct cache, k)
+				Nothing -> return Nothing
+
 	failedingest = do
 		liftAnnex showEndFail
 		return Nothing
diff --git a/Utility/InodeCache.hs b/Utility/InodeCache.hs
index 1d3f17887..e08abc6ad 100644
--- a/Utility/InodeCache.hs
+++ b/Utility/InodeCache.hs
@@ -11,22 +11,46 @@ import Common
 import System.Posix.Types
 import Utility.QuickCheck
 
-data InodeCache = InodeCache FileID FileOffset EpochTime
+data InodeCachePrim = InodeCachePrim FileID FileOffset EpochTime
+	deriving (Show, Eq, Ord)
+
+newtype InodeCache = InodeCache InodeCachePrim
 	deriving (Show)
 
+{- Inode caches can be compared in two different ways, either weakly
+ - or strongly. -}
+data InodeComparisonType = Weakly | Strongly
+	deriving (Eq, Ord)
+
+{- Strong comparison, including inodes. -}
 compareStrong :: InodeCache -> InodeCache -> Bool
-compareStrong (InodeCache inode1 size1 mtime1) (InodeCache inode2 size2 mtime2) =
-	inode1 == inode2 && size1 == size2 && mtime1 == mtime2
+compareStrong (InodeCache x) (InodeCache y) = x == y
 
-{- Weak comparison of the inode caches, comparing the size and mtime, but
- - not the actual inode.  Useful when inodes have changed, perhaps
+{- Weak comparison of the inode caches, comparing the size and mtime,
+ - but not the actual inode.  Useful when inodes have changed, perhaps
  - due to some filesystems being remounted. -}
 compareWeak :: InodeCache -> InodeCache -> Bool
-compareWeak (InodeCache _ size1 mtime1) (InodeCache _ size2 mtime2) =
+compareWeak (InodeCache (InodeCachePrim _ size1 mtime1)) (InodeCache (InodeCachePrim _ size2 mtime2)) =
 	size1 == size2 && mtime1 == mtime2
 
+compareBy :: InodeComparisonType -> InodeCache -> InodeCache -> Bool
+compareBy Strongly = compareStrong
+compareBy Weakly = compareWeak
+
+{- For use in a Map; it's determined at creation time whether this
+ - uses strong or weak comparison for Eq. -}
+data InodeCacheKey = InodeCacheKey InodeComparisonType InodeCachePrim
+	deriving (Ord)
+
+instance Eq InodeCacheKey where
+	(InodeCacheKey ctx x) == (InodeCacheKey cty y) =
+		compareBy (maximum [ctx,cty]) (InodeCache x ) (InodeCache y)
+
+inodeCacheToKey :: InodeComparisonType -> InodeCache -> InodeCacheKey 
+inodeCacheToKey ct (InodeCache prim) = InodeCacheKey ct prim
+
 showInodeCache :: InodeCache -> String
-showInodeCache (InodeCache inode size mtime) = unwords
+showInodeCache (InodeCache (InodeCachePrim inode size mtime)) = unwords
 	[ show inode
 	, show size
 	, show mtime
@@ -34,10 +58,12 @@ showInodeCache (InodeCache inode size mtime) = unwords
 
 readInodeCache :: String -> Maybe InodeCache
 readInodeCache s = case words s of
-	(inode:size:mtime:_) -> InodeCache
-		<$> readish inode
-		<*> readish size
-		<*> readish mtime
+	(inode:size:mtime:_) ->
+		let prim = InodeCachePrim
+			<$> readish inode
+			<*> readish size
+			<*> readish mtime
+		in InodeCache <$> prim
 	_ -> Nothing
 
 genInodeCache :: FilePath -> IO (Maybe InodeCache)
@@ -45,17 +71,19 @@ genInodeCache f = catchDefaultIO Nothing $ toInodeCache <$> getFileStatus f
 
 toInodeCache :: FileStatus -> Maybe InodeCache
 toInodeCache s
-	| isRegularFile s = Just $ InodeCache
+	| isRegularFile s = Just $ InodeCache $ InodeCachePrim
 		(fileID s)
 		(fileSize s)
 		(modificationTime s)
 	| otherwise = Nothing
 
 instance Arbitrary InodeCache where
-	arbitrary = InodeCache
-		<$> arbitrary
-		<*> arbitrary
-		<*> arbitrary
+	arbitrary =
+		let prim = InodeCachePrim
+			<$> arbitrary
+			<*> arbitrary
+			<*> arbitrary
+		in InodeCache <$> prim
 
 prop_read_show_inodecache :: InodeCache -> Bool
 prop_read_show_inodecache c = case readInodeCache (showInodeCache c) of
diff --git a/debian/changelog b/debian/changelog
index f8ff2d282..44d3bf68d 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -50,6 +50,8 @@ git-annex (4.20130228) UNRELEASED; urgency=low
     status of that directory, rather than the whole annex.
   * Added remote.<name>.annex-gnupg-options setting.
     Thanks, guilhem for the patch.
+  * assistant: Optimised handling of renamed files in direct mode,
+    avoiding re-checksumming.
 
  -- Joey Hess <joeyh@debian.org>  Wed, 27 Feb 2013 23:20:40 -0400