implement 3 level trust storage in trust.log

1 files changed, 86 insertions, 0 deletions

diff --git a/Trust.hs b/Trust.hs
new file mode 100644
index 000000000..9474d47d7
--- /dev/null
+++ b/Trust.hs
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+{- git-annex trust levels
+ -
+ - Copyright 2010 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Trust (
+	TrustLevel(..),
+	trustLog,
+	trustGet,
+	trustMap,
+	trustMapParse,
+	trustSet
+) where
+
+import Control.Monad.State
+import qualified Data.Map as M
+
+import qualified GitRepo as Git
+import Types
+import UUID
+import Locations
+import qualified Annex
+import Utility
+
+data TrustLevel = SemiTrusted | UnTrusted | Trusted
+	deriving Eq
+
+instance Show TrustLevel where
+        show SemiTrusted = "?"
+        show UnTrusted = "0"
+        show Trusted = "1"
+
+instance Read TrustLevel where
+        readsPrec _ "1" = [(Trusted, "")]
+        readsPrec _ "0" = [(UnTrusted, "")]
+	readsPrec _ _ = [(SemiTrusted, "")]
+
+{- Filename of trust.log. -}
+trustLog :: Annex FilePath
+trustLog = do
+	g <- Annex.gitRepo
+	return $ gitStateDir g ++ "trust.log"
+
+{- Returns a list of UUIDs at the specified trust level. -}
+trustGet :: TrustLevel -> Annex [UUID]
+trustGet level = do
+	m <- trustMap
+	return $ M.keys $ M.filter (== level) m
+
+{- Read the trustLog into a map. -}
+trustMap :: Annex (M.Map UUID TrustLevel)
+trustMap = do
+	logfile <- trustLog
+	s <- liftIO $ catch (readFile logfile) ignoreerror
+	return $ trustMapParse s
+	where
+                ignoreerror _ = return ""
+
+{- Trust map parser. -}
+trustMapParse :: String -> M.Map UUID TrustLevel
+trustMapParse s = M.fromList $ map pair $ filter (not . null) $ lines s
+	where
+		pair l
+			| length w > 1 = (w !! 0, read (w !! 1) :: TrustLevel)
+			-- for back-compat; the trust log used to only
+			-- list trusted uuids
+			| otherwise = (w !! 0, Trusted)
+			where
+				w = words l
+
+{- Changes the trust level for a uuid in the trustLog, and commits it. -}
+trustSet :: UUID -> TrustLevel -> Annex ()
+trustSet uuid level = do
+        m <- trustMap
+	when (M.lookup uuid m /= Just level) $ do
+		let m' = M.insert uuid level m
+	        logfile <- trustLog
+	        liftIO $ safeWriteFile logfile (serialize m')
+		g <- Annex.gitRepo
+		liftIO $ Git.run g ["add", logfile]
+		liftIO $ Git.run g ["commit", "-q", "-m", "git annex trust change", logfile]
+        where
+                serialize m = unlines $ map showpair $ M.toList m
+		showpair (u, t) = u ++ " " ++ show t