matchexpression: New plumbing command to check if a preferred content expression matches some data.

CmdLine/GitAnnex.hs

@@ -27,6 +27,7 @@ import qualified Command.Fsck
 import qualified Command.LookupKey
 import qualified Command.ContentLocation
 import qualified Command.ExamineKey
+import qualified Command.MatchExpression
 import qualified Command.FromKey
 import qualified Command.RegisterUrl
 import qualified Command.SetKey
@@ -166,6 +167,7 @@ cmds testoptparser testrunner =
 	, Command.LookupKey.cmd
 	, Command.ContentLocation.cmd
 	, Command.ExamineKey.cmd
+	, Command.MatchExpression.cmd
 	, Command.FromKey.cmd
 	, Command.RegisterUrl.cmd
 	, Command.SetKey.cmd

Command/MatchExpression.hs

@@ -0,0 +1,75 @@
+{- git-annex command
+ -
+ - Copyright 2016 Joey Hess <id@joeyh.name>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Command.MatchExpression where
+
+import Command
+import Annex.FileMatcher
+import Types.FileMatcher
+import Utility.DataUnits
+import Utility.Matcher
+import Annex.UUID
+import Logs.Group
+
+import qualified Data.Map as M
+import qualified Data.Set as S
+
+cmd :: Command
+cmd = noCommit $
+	command "matchexpression" SectionPlumbing 
+		"checks if a preferred content expression matches"
+		paramExpression
+		(seek <$$> optParser)
+
+data MatchExpressionOptions = MatchExpressionOptions
+	{ matchexpr :: String
+	, matchinfo :: MatchInfo
+	}
+
+optParser :: CmdParamsDesc -> Parser MatchExpressionOptions
+optParser desc = MatchExpressionOptions
+	<$> argument str (metavar desc)
+	<*> (addkeysize <$> dataparser)
+  where
+	dataparser = MatchingInfo
+		<$> optinfo "file" (strOption
+			( long "file" <> metavar paramFile
+			<> help "specify filename to match against"
+			))
+		<*> optinfo "key" (option (str >>= parseKey)
+			( long "key" <> metavar paramKey
+			<> help "specify key to match against"
+			))
+		<*> optinfo "size" (option (str >>= maybe (fail "parse error") return . readSize dataUnits)
+			( long "size" <> metavar paramSize
+			<> help "specify size to match against"
+			))
+	optinfo datadesc mk = (Right <$> mk)
+		<|> (pure $ Left $ missingdata datadesc)
+	missingdata datadesc = bail $ "cannot match this expression without " ++ datadesc ++ " data"
+	-- When a key is provided, use its size.
+	addkeysize i@(MatchingInfo f (Right k) _) = case keySize k of
+		Just sz -> MatchingInfo f (Right k) (Right sz)
+		Nothing -> i
+	addkeysize i = i
+
+seek :: MatchExpressionOptions -> CommandSeek
+seek o = do
+	u <- getUUID
+	case parsedToMatcher $ exprParser matchAll matchAll groupMap M.empty (Just u) (matchexpr o) of
+		Left e -> liftIO $ bail $ "bad expression: " ++ e
+		Right matcher -> ifM (checkmatcher matcher)
+			( liftIO exitSuccess
+			, liftIO exitFailure
+			)
+  where
+	checkmatcher matcher = matchMrun matcher $ \a -> a S.empty (matchinfo o)
+
+bail :: String -> IO a
+bail s = do
+	hPutStrLn stderr s
+	exitWith $ ExitFailure 42

Limit.hs

@@ -73,21 +73,22 @@ addInclude :: String -> Annex ()
 addInclude = addLimit . limitInclude
 
 limitInclude :: MkLimit Annex
-limitInclude glob = Right $ const $ return . matchGlobFile glob
+limitInclude glob = Right $ const $ matchGlobFile glob
 
 {- Add a limit to skip files that match the glob. -}
 addExclude :: String -> Annex ()
 addExclude = addLimit . limitExclude
 
 limitExclude :: MkLimit Annex
-limitExclude glob = Right $ const $ return . not . matchGlobFile glob
+limitExclude glob = Right $ const $ not <$$> matchGlobFile glob
 
-matchGlobFile :: String -> MatchInfo -> Bool
+matchGlobFile :: String -> MatchInfo -> Annex Bool
 matchGlobFile glob = go
 	where
 		cglob = compileGlob glob CaseSensative -- memoized
-		go (MatchingKey _) = False
+		go (MatchingKey _) = pure False
-		go (MatchingFile fi) = matchGlob cglob (matchFile fi)
+		go (MatchingFile fi) = pure $ matchGlob cglob (matchFile fi)
+		go (MatchingInfo af _ _) = matchGlob cglob <$> getInfo af
 
 {- Adds a limit to skip files not believed to be present
  - in a specfied repository. Optionally on a prior date. -}
@@ -133,8 +134,10 @@ matchPresent u _ = checkKey $ \key -> do
 limitInDir :: FilePath -> MkLimit Annex
 limitInDir dir = const $ Right $ const go
   where
-	go (MatchingFile fi) = return $ elem dir $ splitPath $ takeDirectory $ matchFile fi
+	go (MatchingFile fi) = checkf $ matchFile fi
 	go (MatchingKey _) = return False
+	go (MatchingInfo af _ _) = checkf =<< getInfo af
+	checkf = return . elem dir . splitPath . takeDirectory
 
 {- Adds a limit to skip files not believed to have the specified number
  - of copies. -}
@@ -177,8 +180,9 @@ limitLackingCopies approx want = case readish want of
 		NumCopies numcopies <- if approx
 			then approxNumCopies
 			else case mi of
-				MatchingKey _ -> approxNumCopies
 				MatchingFile fi -> getGlobalFileNumCopies $ matchFile fi
+				MatchingKey _ -> approxNumCopies
+				MatchingInfo _ _ _ -> approxNumCopies
 		us <- filter (`S.notMember` notpresent)
 			<$> (trustExclude UnTrusted =<< Remote.keyLocations key)
 		return $ numcopies - length us >= needed
@@ -192,6 +196,9 @@ limitLackingCopies approx want = case readish want of
 limitUnused :: MatchFiles Annex
 limitUnused _ (MatchingFile _) = return False
 limitUnused _ (MatchingKey k) = S.member k <$> unusedKeys
+limitUnused _ (MatchingInfo _ ak _) = do
+	k <- getInfo ak
+	S.member k <$> unusedKeys
 
 {- Limit that matches any version of any file. -}
 limitAnything :: MatchFiles Annex
@@ -240,6 +247,8 @@ limitSize vs s = case readSize dataUnits s of
   where
 	go sz _ (MatchingFile fi) = lookupFileKey fi >>= check fi sz
 	go sz _ (MatchingKey key) = checkkey sz key
+	go sz _ (MatchingInfo _ _ as) =
+		getInfo as >>= \sz' -> return (Just sz' `vs` Just sz)
 	checkkey sz key = return $ keySize key `vs` Just sz
 	check _ sz (Just key) = checkkey sz key
 	check fi sz Nothing = do
@@ -281,3 +290,4 @@ lookupFileKey = lookupFile . currFile
 checkKey :: (Key -> Annex Bool) -> MatchInfo -> Annex Bool
 checkKey a (MatchingFile fi) = lookupFileKey fi >>= maybe (return False) a
 checkKey a (MatchingKey k) = a k
+checkKey a (MatchingInfo _ ak _) = a =<< getInfo ak

Limit/Wanted.hs

@@ -21,3 +21,4 @@ addWantDrop = addLimit $ Right $ const $ checkWant $ wantDrop False Nothing Noth
 checkWant :: (Maybe FilePath -> Annex Bool) -> MatchInfo -> Annex Bool
 checkWant a (MatchingFile fi) = a (Just $ matchFile fi)
 checkWant _ (MatchingKey _) = return False
+checkWant _ (MatchingInfo {}) = return False

Types/FileMatcher.hs

@@ -1,6 +1,6 @@
 {- git-annex file matcher types
  -
- - Copyright 2013 Joey Hess <id@joeyh.name>
+ - Copyright 2013-2016 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU GPL version 3 or higher.
  -}
@@ -10,13 +10,16 @@ module Types.FileMatcher where
 import Types.UUID (UUID)
 import Types.Key (Key)
 import Utility.Matcher (Matcher, Token)
+import Utility.FileSize
 
+import Control.Monad.IO.Class
 import qualified Data.Map as M
 import qualified Data.Set as S
 
 data MatchInfo
 	= MatchingFile FileInfo
 	| MatchingKey Key
+	| MatchingInfo (OptInfo FilePath) (OptInfo Key) (OptInfo FileSize)
 
 data FileInfo = FileInfo
 	{ currFile :: FilePath
@@ -25,6 +28,14 @@ data FileInfo = FileInfo
 	-- ^ filepath to match on; may be relative to top of repo or cwd
 	}
 
+type OptInfo a = Either (IO a) a
+
+-- If the OptInfo is not available, accessing it may result in eg an
+-- exception being thrown.
+getInfo :: MonadIO m => OptInfo a -> m a
+getInfo (Right i) = pure i
+getInfo (Left e) = liftIO e
+
 type FileMatcherMap a = M.Map UUID (Utility.Matcher.Matcher (S.Set UUID -> MatchInfo -> a Bool))
 
 type MkLimit a = String -> Either String (MatchFiles a)

Utility/FileSize.hs

@@ -13,13 +13,15 @@ import Control.Exception (bracket)
 import System.IO
 #endif
 
+type FileSize = Integer
+
 {- Gets the size of a file.
  -
  - This is better than using fileSize, because on Windows that returns a
  - FileOffset which maxes out at 2 gb.
  - See https://github.com/jystic/unix-compat/issues/16
  -}
-getFileSize :: FilePath -> IO Integer
+getFileSize :: FilePath -> IO FileSize
 #ifndef mingw32_HOST_OS
 getFileSize f = fmap (fromIntegral . fileSize) (getFileStatus f)
 #else
@@ -27,7 +29,7 @@ getFileSize f = bracket (openFile f ReadMode) hClose hFileSize
 #endif
 
 {- Gets the size of the file, when its FileStatus is already known. -}
-getFileSize' :: FilePath -> FileStatus -> IO Integer
+getFileSize' :: FilePath -> FileStatus -> IO FileSize
 #ifndef mingw32_HOST_OS
 getFileSize' _ s = return $ fromIntegral $ fileSize s
 #else

debian/changelog

@@ -16,6 +16,8 @@ git-annex (6.20160115) UNRELEASED; urgency=medium
   * assistant: Use udisks2 dbus events to detect when disks are mounted,
     instead of relying on gnome/kde stuff that is not stable.
   * Fix build with QuickCheck 2.8.2
+  * matchexpression: New plumbing command to check if a preferred content
+    expression matches some data.
 
  -- Joey Hess <id@joeyh.name>  Fri, 15 Jan 2016 14:05:01 -0400
 

doc/bugs/treatment_of_largefiles_is_not_working_for_addurl_--fast___40__or_--relaxed__41__/comment_4_00dfd040f4d8b9f1ed765ee38dbc67b9._comment

@@ -0,0 +1,16 @@
+[[!comment format=mdwn
+ username="joey"
+ subject="""comment 4"""
+ date="2016-01-25T20:15:05Z"
+ content="""
+Implemented the matchexpression command.
+
+	time for x in $(seq 1 100); do git annex matchexpression "include=*.png and largerthan=100mb" --file=foo.png --size=10mb --debug; done
+	
+	real	0m5.167s
+	user	0m2.688s
+	sys	0m1.860s
+
+Don't know if that's fast enough or if it will need further optimisation
+or a --batch option..
+"""]]

doc/git-annex-matchexpression.mdwn

@@ -0,0 +1,51 @@
+# NAME
+
+git-annex matchexpression - checks if a preferred content expression matches
+
+# SYNOPSIS
+
+git annex matchexpression `expression [data]`
+
+# DESCRIPTION
+
+This plumbing-level command is given a prefferred content expression,
+and some data, and checks if the expression matches the data. It exits 0 if
+it matches, and 1 if not. If not enough data was provided, it displays an
+error and exits with special code 42.
+
+For example, this will exit 0:
+
+	git annex matchexpression "include=*.png and largerthan=1mb" --file=foo.png --size=10mb
+
+# OPTIONS
+
+* `--file=`
+
+  Provide the filename to match against. Note that the file does not have
+  to actually exist on disk.
+
+* `--size=`
+
+  Tell what the size of the file is. The size can be specified with any
+  commonly used units, for example, "0.5 gb" or "100 KiloBytes".
+
+* `--key=`
+
+  Tell what key is being matched against. This is needed for
+  matching expressions like "copies=N" and "metadata=tag=foo" and
+  "present", which all need to look up the information on file for a key.
+
+  Many keys have a known size, and so --size is not needed when specifying
+  such a key.
+
+# SEE ALSO
+
+[[git-annex]](1)
+
+[[git-annex-preferred-content]](1)
+
+# AUTHOR
+
+Joey Hess <id@joeyh.name>
+
+Warning: Automatically converted into a man page by mdwn2man. Edit with care.

doc/git-annex.mdwn

@@ -535,6 +535,12 @@ subdirectories).
   
   See [[git-annex-examinekey]](1) for details.
 
+* `matchexpression`
+
+  Checks if a preferred content expression matches provided data.
+  
+  See [[git-annex-matchexpression]](1) for details.
+
 * `fromkey [key file]`
 
   Manually set up a file in the git repository to link to a specified key.
@@ -553,7 +559,6 @@ subdirectories).
   
   See [[git-annex-setkey]](1) for details.
 
-
 * `dropkey [key ...]`
 
   Drops annexed content for specified keys.