fix recompute of renamed files

When a computed file has been renamed, a recompute needs to write to the
new filename.

I decided to remove --others because it's not clear what it should do in
the face of renames. Should it update only other files that have not
been renamed? Or update files that use the old key to the new key
anywhere in the tree? Or write the other files to the cwd, ignoring
renames? Since --others is just a way to save on compute time, adding
this complexity at this point seems like a bad idea. May revisit later.

Added temporary TODO-compute file

Command/AddComputed.hs

@@ -96,11 +96,11 @@ perform o r = do
 	Remote.Compute.runComputeProgram program state
 		(Remote.Compute.ImmutableState False)
 		(getInputContent fast)
-		(addComputed "adding" True r (reproducible o) (const True) fast)
+		(addComputed "adding" True r (reproducible o) Just fast)
 	next $ return True
 
-addComputed :: StringContainingQuotedPath -> Bool -> Remote -> Maybe Reproducible -> (OsPath -> Bool) -> Bool -> Remote.Compute.ComputeState -> OsPath -> NominalDiffTime -> Annex ()
-addComputed addaction stagefiles r reproducibleconfig wantfile fast state tmpdir ts = do
+addComputed :: StringContainingQuotedPath -> Bool -> Remote -> Maybe Reproducible -> (OsPath -> Maybe OsPath) -> Bool -> Remote.Compute.ComputeState -> OsPath -> NominalDiffTime -> Annex ()
+addComputed addaction stagefiles r reproducibleconfig destfile fast state tmpdir ts = do
 	let outputs = Remote.Compute.computeOutputs state
 	when (M.null outputs) $
 		giveup "The computation succeeded, but it did not generate any files."
@@ -120,29 +120,29 @@ addComputed addaction stagefiles r reproducibleconfig wantfile fast state tmpdir
   where
 	addfile outputfile
 		| fast = do
-			when (wantfile outputfile) $
-				if stagefiles
-					then addSymlink outputfile stateurlk Nothing
-					else makelink stateurlk
+			case destfile outputfile of
+				Nothing -> noop
+				Just f
+					| stagefiles -> addSymlink f stateurlk Nothing
+					| otherwise -> makelink f stateurlk
 			return stateurlk
 		| isreproducible = do
 			sz <- liftIO $ getFileSize outputfile'
 			metered Nothing sz Nothing $ \_ p ->
-				if wantfile outputfile
-					then ingesthelper p Nothing
-					else genkey p
-		| otherwise =
-			if wantfile outputfile
-				then ingesthelper nullMeterUpdate
-					(Just stateurlk)
-				else return stateurlk
+				case destfile outputfile of
+					Just f -> ingesthelper f p Nothing
+					Nothing -> genkey outputfile p
+		| otherwise = case destfile outputfile of
+			Just f -> ingesthelper f nullMeterUpdate
+				(Just stateurlk)
+			Nothing -> return stateurlk
 	  where
 	  	stateurl = Remote.Compute.computeStateUrl r state outputfile
 		stateurlk = fromUrl stateurl Nothing True
 		outputfile' = tmpdir </> outputfile
-		ld = LockedDown ldc ks
-		ks = KeySource
-			{ keyFilename = outputfile
+		ld f = LockedDown ldc (ks f)
+		ks f = KeySource
+			{ keyFilename = f
 			, contentLocation = outputfile'
 			, inodeCache = Nothing
 			}
@@ -151,16 +151,16 @@ addComputed addaction stagefiles r reproducibleconfig wantfile fast state tmpdir
 			Just k -> do
 				logStatus NoLiveUpdate k InfoPresent
 				return k
-		genkey p = do
+		genkey f p = do
 			backend <- chooseBackend outputfile
-			fst <$> genKey ks p backend
-		makelink k = void $ makeLink outputfile k Nothing
-		ingesthelper p mk
+			fst <$> genKey (ks f) p backend
+		makelink f k = void $ makeLink f k Nothing
+		ingesthelper f p mk
 			| stagefiles = ingestwith $
-				ingestAdd' p (Just ld) mk
+				ingestAdd' p (Just (ld f)) mk
 			| otherwise = ingestwith $ do
-				mk' <- fst <$> ingest p (Just ld) mk
-				maybe noop makelink mk'
+				mk' <- fst <$> ingest p (Just (ld f)) mk
+				maybe noop (makelink f) mk'
 				return mk'
 	
 	ldc = LockDownConfig

Command/Recompute.hs

@@ -29,7 +29,6 @@ cmd = notBareRepo $
 data RecomputeOptions = RecomputeOptions
 	{ recomputeThese :: CmdParams
 	, originalOption :: Bool
-	, othersOption :: Bool
 	, reproducible :: Maybe Reproducible
 	, computeRemote :: Maybe (DeferredParse Remote)
 	}
@@ -41,10 +40,6 @@ optParser desc = RecomputeOptions
 		( long "original"
 		<> help "recompute using original content of input files"
 		)
-	<*> switch
-		( long "others"
-		<> help "stage other files that are recomputed in passing"
-		)
 	<*> parseReproducible
 	<*> optional (mkParseRemoteOption <$> parseRemoteOption)
 
@@ -111,25 +106,28 @@ start' o r si file key =
 -- TODO When reproducible is not set, preserve the
 -- reproducible/unreproducible of the input key.
 perform :: RecomputeOptions -> Remote -> OsPath -> Key -> Remote.Compute.ComputeState -> CommandPerform
-perform o r file key oldstate = do
+perform o r file key origstate = do
 	program <- Remote.Compute.getComputeProgram r
 	fast <- Annex.getRead Annex.fast
 	showOutput
-	Remote.Compute.runComputeProgram program oldstate
+	Remote.Compute.runComputeProgram program origstate
 		(Remote.Compute.ImmutableState True)
 		(getinputcontent program fast)
-		(addComputed "processing" False r (reproducible o) wantfile fast)
+		(addComputed "processing" False r (reproducible o) destfile fast)
 	next $ return True
   where
 	getinputcontent program fast p
 		| originalOption o =
-			case M.lookup p (Remote.Compute.computeInputs oldstate) of
+			case M.lookup p (Remote.Compute.computeInputs origstate) of
 				Just inputkey -> getInputContent' fast inputkey
 					(fromOsPath p ++ "(key " ++ serializeKey inputkey ++ ")")
 				Nothing -> Remote.Compute.computationBehaviorChangeError program
 					"requesting a new input file" p
 		| otherwise = getInputContent fast p
 	
-	wantfile outputfile
-		| othersOption o = True
-		| otherwise = outputfile == file
+	destfile outputfile
+		| Just outputfile == origfile = Just file
+		| otherwise = Nothing
+	
+	origfile = headMaybe $ M.keys $ M.filter (== Just key)
+		(Remote.Compute.computeOutputs origstate)

TODO-compute

@@ -0,0 +1,36 @@
+* recompute could ingest keys for other files than the one being
+  recomputed, and remember them. Then recomputing those files could just
+  use those keys, without re-running a computation. (Better than --others
+  which got removed.)
+
+* `git-annex recompute foo bar baz`, when foo depends on bar which depends
+  on baz, and when baz has changed, will not recompute foo, because bar has
+  not changed. It then recomputes bar. So running the command again is
+  needed to recompute foo. 
+
+  What it could do is, after it recomputes bar, notice that it already
+  considered foo, and revisit foo, and recompute it then. It could either
+  use a bloom filter to remember the files it considered but did not
+  compute, or it could just notice that the command line includes foo
+  (or includes a directory that contains foo), and then foo is not
+  modified.
+
+  Or it could build a DAG and traverse it, but building a DAG of a large
+  directory tree has its own problems.
+
+* recompute should use the same key backend for a file that it used before
+  (except when --reproducible/--unreproducible is passed).
+
+* Check recompute's handling of --reproducible and --unreproducible.
+
+* addcomputed should honor annex.addunlocked.
+
+* Perhaps recompute should write a new version of a file as an unlocked
+  file when the file is currently unlocked?
+
+* Support non-annexed files as inputs to computations.
+
+* Should addcomputed honor annex.smallfiles? That would seem to imply
+  that recompute should also support recomputing non-annexed files.
+  Otherwise, adding a file and then recomputing it would vary in
+  what the content of the file is, depending on annex.smallfiles setting.

doc/git-annex-recompute.mdwn

@@ -23,11 +23,6 @@ updated with the new content.
 
   Use the original content of input files.
 
-* `--others`
-
-  When recomputing one file also generates new versions of other files,
-  update those other files too.
-
 * `--unreproducible`, `-u`
 
   Convert files that were added with `git-annex addcomputed --reproducible`