cache the trustmap

Doubles the speed of fsck, and speeds up drop as well.

Annex.hs

@@ -24,7 +24,7 @@ import Types.Backend
 import Types.Remote
 import Types.Crypto
 import Types.BranchState
-import TrustLevel
+import Types.TrustLevel
 import Types.UUID
 
 -- git-annex's monad
@@ -48,6 +48,7 @@ data AnnexState = AnnexState
 	, fromremote :: Maybe String
 	, exclude :: [String]
 	, forcetrust :: [(UUID, TrustLevel)]
+	, trustmap :: Maybe TrustMap
 	, cipher :: Maybe Cipher
 	}
 
@@ -69,6 +70,7 @@ newState allbackends gitrepo = AnnexState
 	, fromremote = Nothing
 	, exclude = []
 	, forcetrust = []
+	, trustmap = Nothing
 	, cipher = Nothing
 	}
 

GitAnnex.hs

@@ -14,7 +14,7 @@ import CmdLine
 import Command
 import Options
 import Utility
-import TrustLevel
+import Types.TrustLevel
 import qualified Annex
 import qualified Remote
 

Trust.hs

@@ -9,15 +9,13 @@ module Trust (
 	TrustLevel(..),
 	trustLog,
 	trustGet,
-	trustMap,
-	trustMapParse,
 	trustSet
 ) where
 
 import Control.Monad.State
 import qualified Data.Map as M
 
-import TrustLevel
+import Types.TrustLevel
 import qualified Branch
 import Types
 import UUID
@@ -35,11 +33,17 @@ trustGet level = do
 
 {- Read the trustLog into a map, overriding with any
  - values from forcetrust -}
-trustMap :: Annex (M.Map UUID TrustLevel)
+trustMap :: Annex TrustMap
 trustMap = do
+	cached <- Annex.getState Annex.trustmap
+	case cached of
+		Just m -> return m
+		Nothing -> do
 			overrides <- Annex.getState Annex.forcetrust
-	s <- Branch.get trustLog
+			l <- Branch.get trustLog
-	return $ M.fromList $ trustMapParse s ++ overrides
+			let m = M.fromList $ trustMapParse l ++ overrides
+			Annex.changeState $ \s -> s { Annex.trustmap = Just m }
+			return m
 
 {- Trust map parser. -}
 trustMapParse :: String -> [(UUID, TrustLevel)]
@@ -62,6 +66,7 @@ trustSet uuid level = do
 	when (M.lookup uuid m /= Just level) $ do
 		let m' = M.insert uuid level m
 		Branch.change trustLog (serialize m')
+		Annex.changeState $ \s -> s { Annex.trustmap = Just m' }
         where
                 serialize m = unlines $ map showpair $ M.toList m
 		showpair (u, t) = u ++ " " ++ show t

Types/TrustLevel.hs

@@ -5,10 +5,15 @@
  - Licensed under the GNU GPL version 3 or higher.
  -}
 
-module TrustLevel (
+module Types.TrustLevel (
 	TrustLevel(..),
+	TrustMap
 ) where
 
+import qualified Data.Map as M
+
+import Types.UUID
+
 data TrustLevel = SemiTrusted | UnTrusted | Trusted
 	deriving Eq
 
@@ -21,3 +26,5 @@ instance Read TrustLevel where
         readsPrec _ "1" = [(Trusted, "")]
         readsPrec _ "0" = [(UnTrusted, "")]
 	readsPrec _ _ = [(SemiTrusted, "")]
+
+type TrustMap = M.Map UUID TrustLevel