dropunused: Support --jobs

Sponsored-by: Kevin Mueller on Patreon

CHANGELOG

@@ -22,6 +22,7 @@ git-annex (10.20230627) UNRELEASED; urgency=medium
   * S3: Allow setting publicurl=yes without public=yes, to support
     buckets that are configured with a Bucket Policy that allows public
     access.
+  * dropunused: Support --jobs
 
  -- Joey Hess <id@joeyh.name>  Mon, 26 Jun 2023 13:10:40 -0400
 

Command/DropUnused.hs

@@ -20,7 +20,7 @@ import Annex.Content
 import qualified Utility.RawFilePath as R
 
 cmd :: Command
-cmd = withAnnexOptions [jsonOptions] $
+cmd = withAnnexOptions [jobsOption, jsonOptions] $
 	command "dropunused" SectionMaintenance
 		"drop unused file content"
 		(paramRepeating paramNumRange) (seek <$$> optParser)
@@ -36,7 +36,7 @@ optParser desc = DropUnusedOptions
 	<*> optional (Command.Drop.parseDropFromOption)
 
 seek :: DropUnusedOptions -> CommandSeek
-seek o = do
+seek o = startConcurrency commandStages $ do
 	numcopies <- getNumCopies
 	mincopies <- getMinCopies
 	from <- maybe (pure Nothing) (Just <$$> getParsed) (dropFrom o)

doc/git-annex-dropunused.mdwn

@@ -28,6 +28,14 @@ Or, specify "all" to drop all unused data.
   the last repository that is storing their content. Data loss can
   result from using this option.
 
+* `--jobs=N` `-JN`
+
+  Runs multiple drop jobs in parallel. This is particularly useful
+  when git-annex has to contact remotes to check if it can drop content.
+  For example: `-J4`  
+
+  Setting this to "cpus" will run one job per CPU core.
+
 * `--json`
 
   Enable JSON output. This is intended to be parsed by programs that use

doc/todo/add_--jobs_for_dropunused_command.mdwn

@@ -1 +1,3 @@
 Simple "drop" have it, but no for "dropunused". Missed?
+
+> [[fixed|done]] --[[Joey]]