split out two more Git modules

3 files changed, 130 insertions, 1 deletions

diff --git a/Git/CheckAttr.hs b/Git/CheckAttr.hs
new file mode 100644
index 000000000..e9269b1ed
--- /dev/null
+++ b/Git/CheckAttr.hs
@@ -0,0 +1,44 @@
+{- git check-attr interface
+ -
+ - Copyright 2010, 2011 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Git.CheckAttr where
+
+import System.Exit
+
+import Common
+import Git
+import qualified Git.Filename
+
+{- Efficiently looks up a gitattributes value for each file in a list. -}
+lookup :: String -> [FilePath] -> Repo -> IO [(FilePath, String)]
+lookup attr files repo = do
+	-- git check-attr needs relative filenames input; it will choke
+	-- on some absolute filenames. This also means it will output
+	-- all relative filenames.
+	cwd <- getCurrentDirectory
+	let relfiles = map (relPathDirToFile cwd . absPathFrom cwd) files
+	(_, fromh, toh) <- hPipeBoth "git" (toCommand params)
+        _ <- forkProcess $ do
+		hClose fromh
+                hPutStr toh $ join "\0" relfiles
+                hClose toh
+                exitSuccess
+        hClose toh
+	(map topair . lines) <$> hGetContents fromh
+	where
+		params = gitCommandLine 
+				[ Param "check-attr"
+				, Param attr
+				, Params "-z --stdin"
+				] repo
+		topair l = (file, value)
+			where 
+				file = Git.Filename.decode $ join sep $ take end bits
+				value = bits !! end
+				end = length bits - 1
+				bits = split sep l
+				sep = ": " ++ attr ++ ": "
diff --git a/Git/Filename.hs b/Git/Filename.hs
new file mode 100644
index 000000000..69f36d086
--- /dev/null
+++ b/Git/Filename.hs
@@ -0,0 +1,84 @@
+{- Some git commands output encoded filenames, in a rather annoyingly complex
+ - C-style encoding.
+ -
+ - Copyright 2010, 2011 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Git.Filename where
+
+import qualified Codec.Binary.UTF8.String
+import Data.Char
+import Data.Word (Word8)
+import Text.Printf
+
+decode :: String -> FilePath
+decode [] = []
+decode f@(c:s)
+	-- encoded strings will be inside double quotes
+	| c == '"' = unescape ("", middle)
+	| otherwise = f
+	where
+		e = '\\'
+		middle = init s
+		unescape (b, []) = b
+		-- look for escapes starting with '\'
+		unescape (b, v) = b ++ beginning ++ unescape (handle rest)
+			where
+				pair = span (/= e) v
+				beginning = fst pair
+				rest = snd pair
+		isescape x = x == e
+		-- \NNN is an octal encoded character
+		handle (x:n1:n2:n3:rest)
+			| isescape x && alloctal = (fromoctal, rest)
+				where
+					alloctal = isOctDigit n1 &&
+						isOctDigit n2 &&
+						isOctDigit n3
+					fromoctal = [chr $ readoctal [n1, n2, n3]]
+					readoctal o = read $ "0o" ++ o :: Int
+		-- \C is used for a few special characters
+		handle (x:nc:rest)
+			| isescape x = ([echar nc], rest)
+			where
+				echar 'a' = '\a'
+				echar 'b' = '\b'
+				echar 'f' = '\f'
+				echar 'n' = '\n'
+				echar 'r' = '\r'
+				echar 't' = '\t'
+				echar 'v' = '\v'
+				echar a = a
+		handle n = ("", n)
+
+{- Should not need to use this, except for testing decode. -}
+encode :: FilePath -> String
+encode s = foldl (++) "\"" (map echar s) ++ "\""
+	where
+		e c = '\\' : [c]
+		echar '\a' = e 'a'
+		echar '\b' = e 'b'
+		echar '\f' = e 'f'
+		echar '\n' = e 'n'
+		echar '\r' = e 'r'
+		echar '\t' = e 't'
+		echar '\v' = e 'v'
+		echar '\\' = e '\\'
+		echar '"'  = e '"'
+		echar x
+			| ord x < 0x20 = e_num x -- low ascii
+			| ord x >= 256 = e_utf x
+			| ord x > 0x7E = e_num x -- high ascii
+			| otherwise = [x]        -- printable ascii
+			where 
+				showoctal i = '\\' : printf "%03o" i
+				e_num c = showoctal $ ord c
+				-- unicode character is decomposed to
+				-- Word8s and each is shown in octal
+				e_utf c = showoctal =<< (Codec.Binary.UTF8.String.encode [c] :: [Word8])
+
+{- for quickcheck -}
+prop_idempotent_deencode :: String -> Bool
+prop_idempotent_deencode s = s == decode (encode s)
diff --git a/Git/LsTree.hs b/Git/LsTree.hs
index 8aa16a308..342a125eb 100644
--- a/Git/LsTree.hs
+++ b/Git/LsTree.hs
@@ -17,6 +17,7 @@ import System.Posix.Types
 import qualified Data.ByteString.Lazy.Char8 as L
 
 import Git
+import qualified Git.Filename
 import Utility.SafeCommand
 
 data TreeItem = TreeItem
@@ -38,7 +39,7 @@ parseLsTree l = TreeItem
 	{ mode = fst $ head $ readOct $ L.unpack m
 	, typeobj = L.unpack t
 	, sha = L.unpack s
-	, file = decodeGitFile $ L.unpack f
+	, file = Git.Filename.decode $ L.unpack f
 	}
 	where
 		-- l = <mode> SP <type> SP <sha> TAB <file>