unused: New subcommand, finds unused data (the global part of fsck).

5 files changed, 78 insertions, 50 deletions

diff --git a/CmdLine.hs b/CmdLine.hs
index caf727946..cc163fff5 100644
--- a/CmdLine.hs
+++ b/CmdLine.hs
@@ -25,6 +25,7 @@ import qualified Command.SetKey
 import qualified Command.Fix
 import qualified Command.Init
 import qualified Command.Fsck
+import qualified Command.Unused
 import qualified Command.Unlock
 import qualified Command.Lock
 import qualified Command.PreCommit
@@ -62,6 +63,8 @@ subCmds =
 		"fix up symlinks to point to annexed content"
 	, SubCommand "fsck" maybepath	Command.Fsck.seek
 		"check for problems"
+	, SubCommand "unused" nothing	Command.Unused.seek
+		"look for unused file content"
 	, SubCommand "find" maybepath	Command.Find.seek
 		"lists available files"
 	]
@@ -70,6 +73,7 @@ subCmds =
 		maybepath = "[PATH ...]"
 		key = "KEY ..."
 		desc = "DESCRIPTION"
+		nothing = ""
 
 -- Each dashed command-line option results in generation of an action
 -- in the Annex monad that performs the necessary setting.
diff --git a/Command/Fsck.hs b/Command/Fsck.hs
index 5b731a696..02b66d01a 100644
--- a/Command/Fsck.hs
+++ b/Command/Fsck.hs
@@ -14,55 +14,7 @@ import Types
 import Core
 import Messages
 import qualified Command.FsckFile
+import qualified Command.Unused
 
 seek :: [SubCmdSeek]
-seek = [withNothing start, withAll withFilesInGit Command.FsckFile.start]
-
-{- Checks the whole annex for problems, only if specific files were not
- - specified. -}
-start :: SubCmdStartNothing
-start = do
-	showStart "fsck" ""
-	return $ Just perform
-
-perform :: SubCmdPerform
-perform = do
-	ok <- checkUnused
-	if ok
-		then return $ Just $ return True
-		else return Nothing
-
-checkUnused :: Annex Bool
-checkUnused = do
-	showNote "checking for unused data..."
-	unused <- unusedKeys
-	if (null unused)
-		then return True
-		else do
-			showLongNote $ w unused
-			return False
-	where
-		w u = unlines $ [
-			"Some annexed data is no longer pointed to by any files in the repository.",
-			"If this data is no longer needed, it can be removed using git-annex dropkey:"
-			] ++ map (\k -> "  " ++ show k) u
-
-{- Finds keys whose content is present, but that do not seem to be used
- - by any files in the git repo. -}
-unusedKeys :: Annex [Key]
-unusedKeys = do
-	present <- getKeysPresent
-	referenced <- getKeysReferenced
-	
-	-- Constructing a single map, of the set that tends to be smaller,
-	-- appears more efficient in both memory and CPU than constructing
-	-- and taking the M.difference of two maps.
-	let present_m = existsMap present
-	let unused_m = remove referenced present_m
-	return $ M.keys unused_m
-	where
-		remove [] m = m
-		remove (x:xs) m = remove xs $ M.delete x m
-
-existsMap :: Ord k => [k] -> M.Map k Int
-existsMap l = M.fromList $ map (\k -> (k, 1)) l
+seek = [withNothing Command.Unused.start, withAll withFilesInGit Command.FsckFile.start]
diff --git a/Command/Unused.hs b/Command/Unused.hs
new file mode 100644
index 000000000..ed3de5d57
--- /dev/null
+++ b/Command/Unused.hs
@@ -0,0 +1,66 @@
+{- git-annex command
+ -
+ - Copyright 2010 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Command.Unused where
+
+import qualified Data.Map as M
+
+import Command
+import Types
+import Core
+import Messages
+
+seek :: [SubCmdSeek]
+seek = [withNothing start]
+
+{- Finds unused content in the annex. -} 
+start :: SubCmdStartNothing
+start = do
+	showStart "unused" ""
+	return $ Just perform
+
+perform :: SubCmdPerform
+perform = do
+	ok <- checkUnused
+	if ok
+		then return $ Just $ return True
+		else return Nothing
+
+checkUnused :: Annex Bool
+checkUnused = do
+	showNote "checking for unused data..."
+	unused <- unusedKeys
+	if (null unused)
+		then return True
+		else do
+			showLongNote $ w unused
+			return False
+	where
+		w u = unlines $ [
+			"Some annexed data is no longer pointed to by any files in the repository.",
+			"If this data is no longer needed, it can be removed using git-annex dropkey:"
+			] ++ map (\k -> "  " ++ show k) u
+
+{- Finds keys whose content is present, but that do not seem to be used
+ - by any files in the git repo. -}
+unusedKeys :: Annex [Key]
+unusedKeys = do
+	present <- getKeysPresent
+	referenced <- getKeysReferenced
+	
+	-- Constructing a single map, of the set that tends to be smaller,
+	-- appears more efficient in both memory and CPU than constructing
+	-- and taking the M.difference of two maps.
+	let present_m = existsMap present
+	let unused_m = remove referenced present_m
+	return $ M.keys unused_m
+	where
+		remove [] m = m
+		remove (x:xs) m = remove xs $ M.delete x m
+
+existsMap :: Ord k => [k] -> M.Map k Int
+existsMap l = M.fromList $ map (\k -> (k, 1)) l
diff --git a/debian/changelog b/debian/changelog
index 07eceae6c..dcdbe15e2 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,6 +1,7 @@
 git-annex (0.07) UNRELEASED; urgency=low
 
   * find: New subcommand.
+  * unused: New subcommand, finds unused data (the global part of fsck).
 
  -- Joey Hess <joeyh@debian.org>  Sun, 14 Nov 2010 12:34:49 -0400
 
diff --git a/doc/git-annex.mdwn b/doc/git-annex.mdwn
index c496ca0d8..a522534da 100644
--- a/doc/git-annex.mdwn
+++ b/doc/git-annex.mdwn
@@ -166,6 +166,11 @@ Many git-annex subcommands will stage changes for later `git commit` by you.
 
   With parameters, only the specified files are checked.
 
+* unused
+
+  Checks the annex for data that is not used by any files currently
+  in the annex, and prints a report.
+
 * find [path ...]
 
   Outputs a list of annexed files whose content is currently present.