1 files changed, 65 insertions, 0 deletions
diff --git a/Git/LsTree.hs b/Git/LsTree.hs
new file mode 100644
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--- /dev/null
+++ b/Git/LsTree.hs
@@ -0,0 +1,65 @@
+{- git ls-tree interface
+ -
+ - Copyright 2011 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Git.LsTree (
+	TreeItem(..),
+	lsTree,
+	lsTreeParams,
+	lsTreeFiles,
+	parseLsTree
+) where
+
+import Numeric
+import Control.Applicative
+import System.Posix.Types
+
+import Common
+import Git
+import Git.Command
+import Git.Sha
+import Git.FilePath
+import qualified Git.Filename
+
+data TreeItem = TreeItem
+	{ mode :: FileMode
+	, typeobj :: String
+	, sha :: String
+	, file :: TopFilePath
+	} deriving Show
+
+{- Lists the complete contents of a tree, recursing into sub-trees,
+ - with lazy output. -}
+lsTree :: Ref -> Repo -> IO [TreeItem]
+lsTree t repo = map parseLsTree
+	<$> pipeNullSplitZombie (lsTreeParams t) repo
+
+lsTreeParams :: Ref -> [CommandParam]
+lsTreeParams t = [ Params "ls-tree --full-tree -z -r --", File $ show t ]
+
+{- Lists specified files in a tree. -}
+lsTreeFiles :: Ref -> [FilePath] -> Repo -> IO [TreeItem]
+lsTreeFiles t fs repo = map parseLsTree <$> pipeNullSplitStrict ps repo
+  where
+  	ps = [Params "ls-tree --full-tree -z --", File $ show t] ++ map File fs
+
+{- Parses a line of ls-tree output.
+ - (The --long format is not currently supported.) -}
+parseLsTree :: String -> TreeItem
+parseLsTree l = TreeItem 
+	{ mode = fst $ Prelude.head $ readOct m
+	, typeobj = t
+	, sha = s
+	, file = asTopFilePath $ Git.Filename.decode f
+	}
+  where
+	-- l = <mode> SP <type> SP <sha> TAB <file>
+	-- All fields are fixed, so we can pull them out of
+	-- specific positions in the line.
+	(m, past_m) = splitAt 7 l
+	(t, past_t) = splitAt 4 past_m
+	(s, past_s) = splitAt shaSize $ Prelude.tail past_t
+	f = Prelude.tail past_s