Improved temp file handling

* Improved temp file handling. Transfers of content can now be resumed
  from temp files later; the resume does not have to be the immediate
  next git-annex run.
* unused: Include partially transferred content in the list.

8 files changed, 86 insertions, 39 deletions

diff --git a/CmdLine.hs b/CmdLine.hs
index 68d1e0dd3..82a21d0fc 100644
--- a/CmdLine.hs
+++ b/CmdLine.hs
@@ -105,13 +105,3 @@ shutdown errnum = do
 	unless (q == GitQueue.empty) $ do
 		showSideAction "Recording state in git..."
 		Annex.queueRun
-
-	-- If nothing failed, clean up any files left in the temp directory,
-	-- but leave the directory itself. If something failed, temp files
-	-- are left behind to allow resuming on re-run.
-	when (errnum == 0) $ do
-		g <- Annex.gitRepo
-		let tmp = gitAnnexTmpDir g
-		exists <- liftIO $ doesDirectoryExist tmp
-		when exists $ liftIO $ removeDirectoryRecursive tmp
-		liftIO $ createDirectoryIfMissing True tmp
diff --git a/Command/DropUnused.hs b/Command/DropUnused.hs
index 9427f8103..63216ce4f 100644
--- a/Command/DropUnused.hs
+++ b/Command/DropUnused.hs
@@ -7,6 +7,7 @@
 
 module Command.DropUnused where
 
+import Control.Monad (when)
 import Control.Monad.State (liftIO)
 import qualified Data.Map as M
 import System.Directory
@@ -33,8 +34,14 @@ start s = do
 	case M.lookup s m of
 		Nothing -> return Nothing
 		Just key -> do
+			g <- Annex.gitRepo
 			showStart "dropunused" s
 			backend <- keyBackend key
+			-- drop both content in the backend and any tmp
+			-- file for the key
+			let tmp = gitAnnexTmpLocation g key
+			tmp_exists <- liftIO $ doesFileExist tmp
+			when tmp_exists $ liftIO $ removeFile tmp
 			return $ Just $ Command.Drop.perform key backend (Just 0)
 
 readUnusedLog :: Annex (M.Map String Key)
diff --git a/Command/Unused.hs b/Command/Unused.hs
index b9dc62a32..4ffa6a17f 100644
--- a/Command/Unused.hs
+++ b/Command/Unused.hs
@@ -7,9 +7,12 @@
 
 module Command.Unused where
 
+import Control.Monad (filterM, unless)
 import Control.Monad.State (liftIO)
 import qualified Data.Map as M
 import Data.Maybe
+import System.FilePath
+import System.Directory
 
 import Command
 import Types
@@ -41,49 +44,71 @@ perform = do
 checkUnused :: Annex Bool
 checkUnused = do
 	showNote "checking for unused data..."
-	unused <- unusedKeys
-	let list = number 1 unused
+	(unused, staletmp) <- unusedKeys
+	let unusedlist = number 0 unused
+	let staletmplist = number (length unused) staletmp
+	let list = unusedlist ++ staletmplist
 	g <- Annex.gitRepo
 	liftIO $ safeWriteFile (gitAnnexUnusedLog g) $ unlines $ 
 		map (\(n, k) -> show n ++ " " ++ show k) list
-	if null unused
-		then return True
-		else do
-			showLongNote $ w list
-			return False
+	unless (null unused) $
+		showLongNote $ unusedmsg unusedlist
+	unless (null staletmp) $
+		showLongNote $ staletmpmsg staletmplist
+	unless (null list) $
+		showLongNote $ "\n"
+	return $ null list
+
 	where
-		w u = unlines $
-			["Some annexed data is no longer pointed to by any files in the repository:",
-			 "  NUMBER  KEY"]
-			++ map cols u ++
-			["(To see where data was previously used, try: git log --stat -S'KEY')",
-			 "(To remove unwanted data: git-annex dropunused NUMBER)",
-			 ""]
+		unusedmsg u = unlines $
+			["Some annexed data is no longer pointed to by any files in the repository:"]
+			++ table u ++
+			["(To see where data was previously used, try: git log --stat -S'KEY')"] ++
+			dropmsg
+		staletmpmsg t = unlines $ 
+			["Some partially transferred data exists in temporary files:"]
+			++ table t ++ dropmsg
+		dropmsg = ["(To remove unwanted data: git-annex dropunused NUMBER)"]
+			
+		table l = ["  NUMBER  KEY"] ++ map cols l
 		cols (n,k) = "  " ++ pad 6 (show n) ++ "  " ++ show k
 		pad n s = s ++ replicate (n - length s) ' '
 
-number :: Integer -> [a] -> [(Integer, a)]
+number :: Int -> [a] -> [(Int, a)]
 number _ [] = []
-number n (x:xs) = (n, x):(number (n+1) xs)
+number n (x:xs) = (n+1, x):(number (n+1) xs)
 
 {- Finds keys whose content is present, but that do not seem to be used
- - by any files in the git repo. -}
-unusedKeys :: Annex [Key]
+ - by any files in the git repo, or that are only present as tmp files. -}
+unusedKeys :: Annex ([Key], [Key])
 unusedKeys = do
+	g <- Annex.gitRepo
 	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
+	let unused = present `exclude` referenced
+
+	-- Some tmp files may be dups copies of content that is fully present.
+	-- Simply delete those, while including the keys for the rest of
+	-- the temp files in the returned list for the user to deal with.
+	tmps <- tmpKeys
+	let staletmp = tmps `exclude` present
+	let duptmp = tmps `exclude` staletmp
+	_ <- liftIO $ mapM (\t -> removeFile $ gitAnnexTmpLocation g t) duptmp
+
+	return (unused, staletmp)
+
 	where
-		remove a b = foldl (flip M.delete) b a
+		-- 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.
+		exclude [] _ = [] -- optimisation
+		exclude smaller larger = M.keys $ remove larger $ existsMap smaller
+
+		existsMap :: Ord k => [k] -> M.Map k Int
+		existsMap l = M.fromList $ map (\k -> (k, 1)) l
 
-existsMap :: Ord k => [k] -> M.Map k Int
-existsMap l = M.fromList $ map (\k -> (k, 1)) l
+		remove a b = foldl (flip M.delete) b a
 
 {- List of keys referenced by symlinks in the git repo. -}
 getKeysReferenced :: Annex [Key]
@@ -92,3 +117,17 @@ getKeysReferenced = do
 	files <- liftIO $ Git.inRepo g [Git.workTree g]
 	keypairs <- mapM Backend.lookupFile files
 	return $ map fst $ catMaybes keypairs
+
+{- List of keys that have temp files in the git repo. -}
+tmpKeys :: Annex [Key]
+tmpKeys = do
+	g <- Annex.gitRepo
+	let tmp = gitAnnexTmpDir g
+	exists <- liftIO $ doesDirectoryExist tmp
+	if (not exists)
+		then return []
+		else do
+			contents <- liftIO $ getDirectoryContents tmp
+			files <- liftIO $ filterM doesFileExist $
+				map (tmp </>) contents
+			return $ map (fileKey . takeFileName) files
diff --git a/Content.hs b/Content.hs
index d0ed8d861..e16ad883c 100644
--- a/Content.hs
+++ b/Content.hs
@@ -67,7 +67,7 @@ logStatus key status = do
 getViaTmp :: Key -> (FilePath -> Annex Bool) -> Annex Bool
 getViaTmp key action = do
 	g <- Annex.gitRepo
-	let tmp = gitAnnexTmpDir g </> keyFile key
+	let tmp = gitAnnexTmpLocation g key
 	liftIO $ createDirectoryIfMissing True (parentDir tmp)
 	success <- action tmp
 	if success
diff --git a/Locations.hs b/Locations.hs
index 75843c29e..d30ceb136 100644
--- a/Locations.hs
+++ b/Locations.hs
@@ -15,6 +15,7 @@ module Locations (
 	gitAnnexDir,
 	gitAnnexObjectDir,
 	gitAnnexTmpDir,
+	gitAnnexTmpLocation,
 	gitAnnexBadDir,
 	gitAnnexUnusedLog,
 	isLinkToAnnex,
@@ -83,6 +84,10 @@ gitAnnexObjectDir r = addTrailingPathSeparator $ Git.workTree r </> objectDir
 gitAnnexTmpDir :: Git.Repo -> FilePath
 gitAnnexTmpDir r = addTrailingPathSeparator $ gitAnnexDir r </> "tmp"
 
+{- The temp file to use for a given key. -}
+gitAnnexTmpLocation :: Git.Repo -> Key -> FilePath
+gitAnnexTmpLocation r key = gitAnnexTmpDir r </> keyFile key
+
 {- .git-annex/bad/ is used for bad files found during fsck -}
 gitAnnexBadDir :: Git.Repo -> FilePath
 gitAnnexBadDir r = addTrailingPathSeparator $ gitAnnexDir r </> "bad"
diff --git a/debian/changelog b/debian/changelog
index 92b21173c..cf17e8a00 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -8,6 +8,10 @@ git-annex (0.19) UNRELEASED; urgency=low
   * fsck, drop: Take untrusted repositories into account.
   * Bugfix: Files were copied from trusted remotes first even if their
     annex.cost was higher than other remotes.
+  * Improved temp file handling. Transfers of content can now be resumed
+    from temp files later; the resume does not have to be the immediate
+    next git-annex run.
+  * unused: Include partially transferred content in the list.
 
  -- Joey Hess <joeyh@debian.org>  Wed, 19 Jan 2011 18:07:51 -0400
 
diff --git a/doc/bugs/tmp_file_handling.mdwn b/doc/bugs/tmp_file_handling.mdwn
index 3c6c2a597..9db932e57 100644
--- a/doc/bugs/tmp_file_handling.mdwn
+++ b/doc/bugs/tmp_file_handling.mdwn
@@ -9,3 +9,5 @@ This presents 2 problems:
    finished.
 
 --[[Joey]] 
+
+[[done]]
diff --git a/doc/git-annex.mdwn b/doc/git-annex.mdwn
index d2cde35a0..83a286b0e 100644
--- a/doc/git-annex.mdwn
+++ b/doc/git-annex.mdwn
@@ -132,7 +132,7 @@ Many git-annex commands will stage changes for later `git commit` by you.
 * unused
 
   Checks the annex for data that is not used by any files currently
-  in the annex, and prints a numbered list of the data. 
+  in the annex, and prints a numbered list of the data.
 
 * dropunused [number ...]