diffdriver: Added --get option

Removed the dontCheck repoExists, because running it in a repo that has not
been initialized yet would update location log with nouuid. And I guess
it's ok for it to only support running in git-annex repos.

CHANGELOG

@@ -7,7 +7,6 @@ git-annex (10.20230803) UNRELEASED; urgency=medium
   * Fix behavior when importing a tree from a directory remote when the
     directory does not exist. An empty tree was imported, rather than the
     import failing.
-  * Stop bundling curl in the OSX dmg and linux standalone image.
   * sync, assist, push, pull: Skip more types of remotes when they
     are not present due to eg being on a drive that is offline.
     (directory, borg, bup, ddar, gcrypt, rsync)
@@ -18,6 +17,9 @@ git-annex (10.20230803) UNRELEASED; urgency=medium
   * Avoid using curl when annex.security.allowed-ip-addresses is set
     but neither annex.web-options nor annex.security.allowed-url-schemes
     is set to a value that needs curl.
+  * Stop bundling curl in the OSX dmg and linux standalone image.
+  * diffdriver: Added --get option.
+  * diffdriver: Refuse to run when not in a git-annex repository.
 
  -- Joey Hess <id@joeyh.name>  Mon, 07 Aug 2023 13:04:13 -0400
 

Command/DiffDriver.hs

@@ -11,15 +11,16 @@ import Command
 import Annex.Content
 import Annex.Link
 import Git.Types
+import qualified Command.Get
 
 cmd :: Command
-cmd = dontCheck repoExists $
-	command "diffdriver" SectionPlumbing 
-		"git diff driver"
-		("-- cmd --") (seek <$$> optParser)
+cmd = command "diffdriver" SectionPlumbing 
+	"git diff driver"
+	("-- cmd --") (seek <$$> optParser)
 
 data Options = Options
 	{ textDiff :: Bool
+	, getOption :: Bool
 	, restOptions :: CmdParams
 	}
 
@@ -29,16 +30,16 @@ optParser desc = Options
 		( long "text"
 		<> help "diff text files with diff(1)"
 		)
+	<*> switch
+		( long "get"
+		<> help "get file contents from remotes"
+		)
 	<*> cmdParams desc
 
 seek :: Options -> CommandSeek
-seek = commandAction . start
-
-start :: Options -> CommandStart
-start opts = do
+seek opts = do
 	let (req, differ) = parseReq opts
-	void $ liftIO . exitBool =<< liftIO . differ =<< fixupReq req
-	stop
+	void $ liftIO . exitBool =<< liftIO . differ =<< fixupReq req opts
 
 data Req 
 	= Req
@@ -99,22 +100,35 @@ parseReq opts
  -
  - In either case, adjust the Req to instead point to the actual
  - location of the annexed object (which may or may not be present).
+ -
+ - This also gets objects from remotes when the getOption is set.
  -}
-fixupReq :: Req -> Annex Req
-fixupReq req@(UnmergedReq {}) = return req
-fixupReq req@(Req {}) = 
+fixupReq :: Req -> Options -> Annex Req
+fixupReq req@(UnmergedReq {}) _ = return req
+fixupReq req@(Req {}) opts = 
 	check rOldFile rOldMode (\r f -> r { rOldFile = f }) req
 		>>= check rNewFile rNewMode (\r f -> r { rNewFile = f })
   where
 	check getfile getmode setfile r = case readTreeItemType (encodeBS (getmode r)) of
 		Just TreeSymlink -> do
 			v <- getAnnexLinkTarget' f False
-			maybe (return r) repoint (parseLinkTargetOrPointer =<< v)
-		_ -> maybe (return r) repoint =<< liftIO (isPointerFile f)
+			maybe (return r) go (parseLinkTargetOrPointer =<< v)
+		_ -> maybe (return r) go =<< liftIO (isPointerFile f)
 	  where
+		f = toRawFilePath (getfile r)
+	  	go k = do
+			when (getOption opts) $
+				unlessM (inAnnex k) $
+					commandAction $
+						starting "get" ai si $
+							Command.Get.perform k af
+			repoint k
+		  where
+			ai = OnlyActionOn k (ActionItemKey k)
+			si = SeekInput []
+			af = AssociatedFile (Just f)
 		repoint k = withObjectLoc k $
 			pure . setfile r . fromRawFilePath
-		f = toRawFilePath (getfile r)
 
 externalDiffer :: String -> [String] -> Differ
 externalDiffer c ps = \req -> boolSystem c (map Param ps ++ serializeReq req )

doc/git-annex-diffdriver.mdwn

@@ -4,9 +4,9 @@ git-annex diffdriver - git diff driver
 
 # SYNOPSIS
 
-git annex diffdriver --text [-- --opts --]
+`git annex diffdriver [--get,--text] [-- --diffopts --]`
 
-git annex diffdriver `-- cmd --opts --`
+`git annex diffdriver -- cmd --cmdopts --`
 
 # DESCRIPTION
 
@@ -41,7 +41,11 @@ set `GIT_EXTERNAL_DIFF="git-annex diffdriver -- j-c-diff --"`
 
 # OPTIONS
 
-To diff text files with diff(1), use the "--text" option.
+To get the contents of annexed files from remotes when they are not already
+present, use the `--get` option. The file contents will remain in the
+repository for later use until dropped in the usual ways.
+
+To diff text files with diff(1), use the `--text` option.
 To pass additional options to diff(1), use eg "--text -- --color --"
 
 To use an external diff driver command, the options must start with

doc/todo/--get_option_for_diffdriver.mdwn

@@ -1,3 +1,5 @@
 since there is no generic 'fuse' mode, I would like to request to have `--get` (or `--auto-get`) option for diffdriver.  I am trying to compare files across two branches on a repo I just cloned.  I cannot download all the files  and downloading differing keys across branches for the same file is a bit painful.  So I felt that it would be super nice if git annex could auto get those files from somewhere (well -- original clone)
 
 [[!tag confirmed]]
+
+> [[done]] --[[Joey]]