added git-annex satisfy

This ended up having an interface like sync, rather than like get/copy/drop.
That let it be implemented in terms of sync, which took a lot less code.
Also, it lets it handle many of the edge cases that sync does, such as
getting files that are not visible in a --hide-missing branch, and sending
files to exporttree remotes.

As well as being easier to implement, `git-annex satisfy myremote` makes
sense as it satisfies the preferred content settings of the remote.
`git-annex satisfy somefile` does not form a sentence that makes sense. So
while -C can be a little bit annoying, it still makes sense to have this
syntax.

Note that, while I initially thought this would also satisfy numcopies, it
does not. Arguably it ought to. But, sync does not send files in order to
satisfy numcopies, it only sends files to satisfy preferred content. And
it's important that this transfer the same files as sync does, because
it will probably be used in a workflow where the user sometimes syncs and
sometimes satisfies, and does not expect satisfy to do things that sync
would not do.

(Also opened a new bug that also affects sync et all, not only this command.)

Sponsored-by: Nicholas Golder-Manning on Patreon

Command/Sync.hs

@@ -95,7 +95,7 @@ cmd = withAnnexOptions [jobsOption, backendOption] $
 		"synchronize local repository with remotes"
 		(paramRepeating paramRemote) (seek <--< optParser SyncMode)
 
-data OperationMode = SyncMode | PullMode | PushMode | AssistMode
+data OperationMode = SyncMode | PullMode | PushMode | SatisfyMode | AssistMode
 	deriving (Eq, Show)
 
 data SyncOptions = SyncOptions
@@ -143,15 +143,17 @@ optParser mode desc = SyncOptions
 		( metavar desc
 		<> completeRemotes
 		))
-	<*> switch 
-		( long "only-annex"
-		<> short 'a'
-		<> help "do not operate on git branches"
-		)
-	<*> switch 
-		( long "not-only-annex"
-		<> help "operate on git branches as well as annex"
-		)
+	<*> whenmode [SatisfyMode] True 
+		(switch 
+			( long "only-annex"
+			<> short 'a'
+			<> help "do not operate on git branches"
+			))
+	<*> whenmode [SatisfyMode] False 
+		( switch 
+			( long "not-only-annex"
+			<> help "operate on git branches as well as annex"
+			))
 	<*> case mode of
 		SyncMode -> switch
 			( long "commit"
@@ -159,21 +161,25 @@ optParser mode desc = SyncOptions
 			)
 		PushMode -> pure False
 		PullMode -> pure False
+		SatisfyMode -> pure False
 		AssistMode -> pure True
-	<*> unlessmode [SyncMode] True (switch
-		( long "no-commit"
-		<> help "avoid git commit" 
-		))
-	<*> unlessmode [SyncMode, AssistMode] Nothing (optional (strOption
-		( long "message" <> short 'm' <> metavar "MSG"
-		<> help "commit message"
-		)))
+	<*> unlessmode [SyncMode] True 
+		(switch
+			( long "no-commit"
+			<> help "avoid git commit" 
+			))
+	<*> unlessmode [SyncMode, AssistMode] Nothing
+		(optional (strOption
+			( long "message" <> short 'm' <> metavar "MSG"
+			<> help "commit message"
+			)))
 	<*> case mode of
 		SyncMode -> invertableSwitch "pull" True
 			( help "avoid git pulls from remotes" 
 			)
 		PullMode -> pure True
 		PushMode -> pure False
+		SatisfyMode -> pure False
 		AssistMode -> pure True
 	<*> case mode of
 		SyncMode -> invertableSwitch "push" True
@@ -181,31 +187,36 @@ optParser mode desc = SyncOptions
 			)
 		PullMode -> pure False
 		PushMode -> pure True
+		SatisfyMode -> pure False
 		AssistMode -> pure True
-	<*> optional (flag' True 
-		( long "content"
-		<> help "transfer annexed file contents" 
-		))
-	<*> optional (flag' True
-		( long "no-content"
-		<> short 'g'
-		<> help "do not transfer annexed file contents"
-		))
+	<*> whenmode [SatisfyMode] (Just True)
+		(optional (flag' True 
+			( long "content"
+			<> help "transfer annexed file contents" 
+			)))
+	<*> whenmode [SatisfyMode] Nothing
+		(optional (flag' True
+			( long "no-content"
+			<> short 'g'
+			<> help "do not transfer annexed file contents"
+			)))
 	<*> many (strOption
 		( long "content-of"
 		<> short 'C'
 		<> help "transfer contents of annexed files in a given location"
 		<> metavar paramPath
 		))
-	<*> whenmode [PullMode] False (switch
-		( long "cleanup"
-		<> help "remove synced/ branches"
-		))
+	<*> whenmode [PullMode, SatisfyMode] False 
+		(switch
+			( long "cleanup"
+			<> help "remove synced/ branches"
+			))
 	<*> optional parseAllOption
-	<*> whenmode [PushMode] False (invertableSwitch "resolvemerge" True
-		( help "do not automatically resolve merge conflicts"
-		))
-	<*> whenmode [PushMode] False
+	<*> whenmode [PushMode, SatisfyMode] False 
+		(invertableSwitch "resolvemerge" True
+			( help "do not automatically resolve merge conflicts"
+			))
+	<*> whenmode [PushMode, SatisfyMode] False
 		parseUnrelatedHistoriesOption
 	<*> pure mode
   where
@@ -838,6 +849,7 @@ seekSyncContent o rs currbranch = do
 			SyncMode -> "sync"
 			PullMode -> "pull"
 			PushMode -> "push"
+			SatisfyMode -> "satisfy"
 			AssistMode -> "assist"
 
 	gofile bloom mvar _ f k = 
@@ -910,7 +922,7 @@ syncFile o ebloom rs af k = do
 	return (got || not (null putrs))
   where
 	wantget have inhere = allM id 
-		[ pure (pullOption o)
+		[ pure (pullOption o || operationMode o == SatisfyMode)
 		, pure (not $ null have)
 		, pure (not inhere)
 		, wantGet True (Just k) af
@@ -924,7 +936,7 @@ syncFile o ebloom rs af k = do
 			next $ return True
 
 	wantput r
-		| pushOption o == False = return False
+		| pushOption o == False && operationMode o /= SatisfyMode = return False
 		| Remote.readonly r || remoteAnnexReadOnly (Remote.gitconfig r) = return False
 		| isExport r = return False
 		| isThirdPartyPopulated r = return False
@@ -949,6 +961,7 @@ syncFile o ebloom rs af k = do
  - of the branch. (If the branch is not currently checked out, anything
  - imported from the remote will not yet have been merged into it yet and
  - so exporting would delete files from the remote unexpectedly.)
+ - (This is not done in SatifyMode.)
  -
  - Otherwise, transfer any files that were part of a previous export
  - but are not in the remote yet.
@@ -959,12 +972,14 @@ seekExportContent :: Maybe SyncOptions -> [Remote] -> CurrBranch -> Annex Bool
 seekExportContent o rs (currbranch, _) = or <$> forM rs go
   where
 	go r
+		| maybe False (\o' -> operationMode o' == SatisfyMode) o =
+			case remoteAnnexTrackingBranch (Remote.gitconfig r) of
+				Nothing -> return False
+				Just b -> withdb r $ \db ->
+					cannotupdateexport r db (Just b) False
 		| not (maybe True pushOption o) = return False
 		| not (remoteAnnexPush (Remote.gitconfig r)) = return False
-		| otherwise = bracket
-			(Export.openDb (Remote.uuid r))
-			Export.closeDb
-			(\db -> Export.writeLockDbWhile db (go' r db))
+		| otherwise = withdb r (go' r)
 	go' r db = case remoteAnnexTrackingBranch (Remote.gitconfig r) of
 		Nothing -> cannotupdateexport r db Nothing True
 		Just b -> do
@@ -986,6 +1001,11 @@ seekExportContent o rs (currbranch, _) = or <$> forM rs go
 					| otherwise -> cannotupdateexport r db (Just b) False
 				_ -> cannotupdateexport r db (Just b) True
 	
+	withdb r a = bracket
+		(Export.openDb (Remote.uuid r))
+		Export.closeDb
+		(\db -> Export.writeLockDbWhile db (a db))
+	
 	cannotupdateexport r db mtb showwarning = do
 		exported <- getExport (Remote.uuid r)
 		when showwarning $
@@ -1056,6 +1076,7 @@ cleanupRemote remote (Just b, _) =
 shouldSyncContent :: SyncOptions -> Annex Bool
 shouldSyncContent o
 	| fromMaybe False (noContentOption o) = pure False
+	| operationMode o == SatisfyMode = pure True
 	-- For git-annex pull and git-annex push and git-annex assist,
 	-- annex.syncontent defaults to True unless set
 	| operationMode o /= SyncMode = annexsynccontent True