rethought --relaxed change

Better to make it not be surprising and slow, than surprising and fast.
--raw can be used when it needs to be really fast.

Implemented adding a youtube-dl supported url to an existing file.

This commit was sponsored by andrea rota.

Annex/Content.hs

@@ -1017,10 +1017,10 @@ pruneTmpWorkDirBefore f action = do
 {- Runs an action, passing it a temporary work directory where
  - it can write files while receiving the content of a key.
  -
- - On exception, or when the action returns a Left value,
+ - On exception, or when the action returns Nothing,
  - the temporary work directory is left, so resumes can use it.
  -}
-withTmpWorkDir :: Key -> (FilePath -> Annex (Either a b)) -> Annex (Either a b)
+withTmpWorkDir :: Key -> (FilePath -> Annex (Maybe a)) -> Annex (Maybe a)
 withTmpWorkDir key action = do
 	-- Create the object file if it does not exist. This way,
 	-- staleKeysPrune only has to look for object files, and can
@@ -1034,8 +1034,8 @@ withTmpWorkDir key action = do
 	setAnnexDirPerm tmpdir
 	res <- action tmpdir
 	case res of
-		Right _ -> liftIO $ removeDirectoryRecursive tmpdir
-		Left _ -> noop
+		Just _ -> liftIO $ removeDirectoryRecursive tmpdir
+		Nothing -> noop
 	return res
 
 {- Finds items in the first, smaller list, that are not

Annex/YoutubeDl.hs

@@ -71,14 +71,12 @@ youtubeDlTo key url dest = do
 		case dl of
 			Right (Just mediafile) -> do
 				liftIO $ renameFile mediafile dest
-				return (Right True)
-			Right Nothing -> return (Right False)
-			Left msg -> return (Left msg)
-	case res of
-		Left msg -> do
-			warning msg
-			return False
-		Right r -> return r
+				return (Just True)
+			Right Nothing -> return (Just False)
+			Left msg -> do
+				warning msg
+				return Nothing
+	return (fromMaybe False res)
 
 youtubeDlSupported :: URLString -> Annex Bool
 youtubeDlSupported url = either (const False) id <$> youtubeDlCheck url

CHANGELOG

@@ -3,10 +3,10 @@ git-annex (6.20171125) UNRELEASED; urgency=medium
   * Use youtube-dl rather than quvi to download media from web pages,
     since quvi is not being actively developed and youtube-dl supports
     many more sites.
-  * addurl --relaxed no longer checks for embedded media, since youtube-dl
-    does not allow doing so without hitting the network, which would make
-    this no faster than addurl --fast. Use addurl --fast instead if you
-    want embedded media to be downloaded.
+  * addurl --relaxed got slower, since youtube-dl has to hit the network
+    to check for embedded media. If you relied on --relaxed not hitting the
+    network for speed reasons, using --relaxed --raw will get the old level
+    of speed, but can't be used for urls with embedded videos.
   * importfeed now downloads things linked to by feeds, even when they are
     not media files.
 

Command/AddUrl.hs

@@ -1,6 +1,6 @@
 {- git-annex command
  -
- - Copyright 2011-2014 Joey Hess <id@joeyh.name>
+ - Copyright 2011-2017 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU GPL version 3 or higher.
  -}
@@ -155,8 +155,8 @@ performRemote r relaxed uri file sz = ifAnnexed file adduri geturi
 	loguri = setDownloader uri OtherDownloader
 	adduri = addUrlChecked relaxed loguri (Remote.uuid r) checkexistssize
 	checkexistssize key = return $ case sz of
-		Nothing -> (True, True)
-		Just n -> (True, n == fromMaybe n (keySize key))
+		Nothing -> (True, True, uri)
+		Just n -> (True, n == fromMaybe n (keySize key), uri)
 	geturi = next $ isJust <$> downloadRemoteFile r relaxed uri file sz
 
 downloadRemoteFile :: Remote -> Bool -> URLString -> FilePath -> Maybe Integer -> Annex (Maybe Key)
@@ -210,22 +210,23 @@ performWeb :: AddUrlOptions -> URLString -> FilePath -> Url.UrlInfo -> CommandPe
 performWeb o url file urlinfo = ifAnnexed file addurl geturl
   where
 	geturl = next $ isJust <$> addUrlFile (Just o) (relaxedOption o) url urlinfo file
-	-- TODO youtube-dl
-	addurl = addUrlChecked (relaxedOption o) url webUUID $ \k -> return $
-		(Url.urlExists urlinfo, Url.urlSize urlinfo == keySize k)
+	addurl = addUrlChecked (relaxedOption o) url webUUID $ \k -> 
+		ifM (youtubeDlSupported url)
+			( return (True, True, setDownloader url YoutubeDownloader)
+			, return (Url.urlExists urlinfo, Url.urlSize urlinfo == keySize k, url)
+			)
 
-addUrlChecked :: Bool -> URLString -> UUID -> (Key -> Annex (Bool, Bool)) -> Key -> CommandPerform
-addUrlChecked relaxed url u checkexistssize key
-	| relaxed = do
-		setUrlPresent u key url
-		next $ return True
-	| otherwise = ifM ((elem url <$> getUrls key) <&&> (elem u <$> loggedLocations key))
+{- Check that the url exists, and has the same size as the key,
+ - and add it as an url to the key. -}
+addUrlChecked :: Bool -> URLString -> UUID -> (Key -> Annex (Bool, Bool, URLString)) -> Key -> CommandPerform
+addUrlChecked relaxed url u checkexistssize key =
+	ifM ((elem url <$> getUrls key) <&&> (elem u <$> loggedLocations key))
 		( next $ return True -- nothing to do
 		, do
-			(exists, samesize) <- checkexistssize key
-			if exists && samesize
+			(exists, samesize, url') <- checkexistssize key
+			if exists && (samesize || relaxed)
 				then do
-					setUrlPresent u key url
+					setUrlPresent u key url'
 					next $ return True
 				else do
 					warning $ "while adding a new url to an already annexed file, " ++ if exists
@@ -234,20 +235,16 @@ addUrlChecked relaxed url u checkexistssize key
 					stop
 		)
 
-{- Downloads an url and adds it to the repository, normally at the specified
- - FilePath. But, if youtube-dl supports the url, it will be written to a
+{- Downloads an url (except in fast or relaxed mode) and adds it to the
+ - repository, normally at the specified FilePath. 
+ - But, if youtube-dl supports the url, it will be written to a
  - different file, based on the title of the media. Unless the user
  - specified fileOption, which then forces using the FilePath.
  -}
 addUrlFile :: Maybe AddUrlOptions -> Bool -> URLString -> Url.UrlInfo -> FilePath -> Annex (Maybe Key)
-addUrlFile mo relaxed url urlinfo file
-	| relaxed = checkCanAdd file $ do
-		liftIO $ createDirectoryIfMissing True (parentDir file)
-		nodownload url urlinfo file
-	| otherwise = ifM (Annex.getState Annex.fast)
-		( checkCanAdd file $ do
-			liftIO $ createDirectoryIfMissing True (parentDir file)
-			nodownload url urlinfo file
+addUrlFile mo relaxed url urlinfo file =
+	ifM (Annex.getState Annex.fast <||> pure relaxed)
+		( nodownloadWeb url urlinfo file
 		, downloadWeb mo url urlinfo file
 		)
 
@@ -266,33 +263,31 @@ downloadWeb mo url urlinfo file =
 		( tryyoutubedl tmp
 		, normalfinish tmp
 		)
-	normalfinish tmp = do
+	normalfinish tmp = checkCanAdd file $ do
 		showDestinationFile file
 		liftIO $ createDirectoryIfMissing True (parentDir file)
 		finishDownloadWith tmp webUUID url file
-	tryyoutubedl tmp = do
-		let mediaurl = setDownloader url YoutubeDownloader
-		let mediakey = Backend.URL.fromUrl mediaurl Nothing
-		res <- withTmpWorkDir mediakey $ \workdir ->
-			Transfer.notifyTransfer Transfer.Download url $
-				Transfer.download webUUID mediakey (AssociatedFile Nothing) Transfer.noRetry $ \_p -> do
-					dl <- youtubeDl url workdir
-					case dl of
-						Right (Just mediafile) -> do
-							pruneTmpWorkDirBefore tmp (liftIO . nukeFile)
-							let dest = if isJust (fileOption <$> mo)
-								then file
-								else takeFileName mediafile
+	tryyoutubedl tmp = withTmpWorkDir mediakey $ \workdir ->
+		Transfer.notifyTransfer Transfer.Download url $
+			Transfer.download webUUID mediakey (AssociatedFile Nothing) Transfer.noRetry $ \_p -> do
+				dl <- youtubeDl url workdir
+				case dl of
+					Right (Just mediafile) -> do
+						pruneTmpWorkDirBefore tmp (liftIO . nukeFile)
+						let dest = if isJust (fileOption <$> mo)
+							then file
+							else takeFileName mediafile
+						checkCanAdd dest $ do
 							showDestinationFile dest
 							addWorkTree webUUID mediaurl dest mediakey (Just mediafile)
-							return $ Right $ Just mediakey
-						Right Nothing -> Right <$> normalfinish tmp
-						Left msg -> return $ Left msg
-		case res of
-			Left msg -> do
-				warning msg
-				return Nothing
-			Right r -> return r
+							return $ Just mediakey
+					Right Nothing -> normalfinish tmp
+					Left msg -> do
+						warning msg
+						return Nothing
+	  where
+		mediaurl = setDownloader url YoutubeDownloader
+		mediakey = Backend.URL.fromUrl mediaurl Nothing
 
 showDestinationFile :: FilePath -> Annex ()
 showDestinationFile file = do
@@ -378,9 +373,10 @@ addWorkTree u url file key mtmp = case mtmp of
 			)
 
 -- TODO youtube-dl
-nodownload :: URLString -> Url.UrlInfo -> FilePath -> Annex (Maybe Key)
-nodownload url urlinfo file
-	| Url.urlExists urlinfo = do
+nodownloadWeb :: URLString -> Url.UrlInfo -> FilePath -> Annex (Maybe Key)
+nodownloadWeb url urlinfo file
+	| Url.urlExists urlinfo = checkCanAdd file $ do
+		liftIO $ createDirectoryIfMissing True (parentDir file)
 		let key = Backend.URL.fromUrl url (Url.urlSize urlinfo)
 		addWorkTree webUUID url file key Nothing
 		return (Just key)

Command/ImportFeed.hs

@@ -272,19 +272,17 @@ performDownload opts cache todownload = case location todownload of
 					ok <- rundownload linkurl ext $ \f -> do
 						addWorkTree webUUID mediaurl f mediakey (Just mediafile)
 						return [mediakey]
-					return (Right ok)
+					return (Just ok)
 				-- youtude-dl didn't support it, so
 				-- download it as if the link were
 				-- an enclosure.
-				Right Nothing -> Right <$> 
+				Right Nothing -> Just <$> 
 					performDownload opts cache todownload
 						{ location = Enclosure linkurl }
-				Left msg -> return (Left msg)
-		case r of
-			Left msg -> do
-				warning msg
-				return False
-			Right b -> return b
+				Left msg -> do
+					warning msg
+					return Nothing
+		return (fromMaybe False r)
 
 	addmediafast linkurl mediaurl mediakey = ifM (youtubeDlSupported linkurl)
 		( rundownload linkurl ".m" $ \f -> do

Types/Transfer.hs

@@ -87,7 +87,7 @@ instance Observable (Either e Bool) where
 	observeBool (Right b) = b
 	observeFailure = Right False
 
-instance Observable (Either e (Maybe a)) where
-	observeBool (Right (Just _)) = True
-	observeBool _ = False
-	observeFailure = Right Nothing
+instance Observable (Maybe a) where
+	observeBool (Just _) = True
+	observeBool Nothing = False
+	observeFailure = Nothing

doc/git-annex-addurl.mdwn

@@ -32,13 +32,12 @@ be used to get better filenames.
 
   Don't immediately download the url, and avoid storing the size of the
   url's content. This makes git-annex accept whatever content is there
-  at a future point. This is also the fastest option, since it does not
-  hit the network at all.
-
-  Note that this does *not* check for embedded videos using `youtube-dl`,
-  although it used to in previous versions of git-annex. 
-  Use --fast instead if you want to do that.
+  at a future point.
 
+  This is the fastest option, but it still has to access the network
+  to check if the url contains embedded media. When adding large numbers
+  of urls, using `--relaxed --raw` is much faster.
+  
 * `--raw`
 
   Prevent special handling of urls by youtube-dl, bittorrent, and other