implement journalledRepoSizes

Plan is to run this when populating Annex.reposizes on demand.
So Annex.reposizes will be up-to-date with the journal, including
crucially journal entries for private repositories. But also
anything that has been written to the journal by another process,
especially if the process was ran with annex.alwayscommit=false.

From there, Annex.reposizes can be kept up to date with changes made
by the running process.

Annex/RepoSize.hs

@@ -22,23 +22,43 @@ import qualified Data.Map.Strict as M
  -
  - The map includes the UUIDs of all known repositories, including
  - repositories that are empty.
+ -
+ - Note that private repositories, which do not get recorded in
+ - the git-annex branch, will have 0 size. journalledRepoSizes
+ - takes care of getting repo sizes for those.
  -}
 calcBranchRepoSizes :: Annex (M.Map UUID RepoSize, Sha)
 calcBranchRepoSizes = do
 	knownuuids <- M.keys <$> uuidDescMap
 	let startmap = M.fromList $ map (\u -> (u, RepoSize 0)) knownuuids
-	overLocationLogs True startmap accum >>= \case
+	overLocationLogs True startmap accumsizes >>= \case
 		UnmergedBranches v -> return v
 		NoUnmergedBranches v -> return v
   where
-	addksz ksz (Just (RepoSize sz)) = Just $ RepoSize $ sz + ksz
-	addksz ksz Nothing = Just $ RepoSize ksz
-	accum k locs m = return $ 
-		let sz = fromMaybe 0 $ fromKey keySize k
-		in foldl' (flip $ M.alter $ addksz sz) m locs
+	accumsizes k locs m = return $
+		foldl' (flip $ M.alter $ addKeyRepoSize k) m locs
 
 {- Given the RepoSizes calculated from the git-annex branch, updates it with
  - data from journalled location logs.
   -}
 journalledRepoSizes :: M.Map UUID RepoSize -> Sha -> Annex (M.Map UUID RepoSize)
-journalledRepoSizes m branchsha = undefined --- XXX 
+journalledRepoSizes startmap branchsha =
+	overLocationLogsJournal startmap branchsha accumsizes
+  where
+	accumsizes k (newlocs, removedlocs) m = return $
+		let m' = foldl' (flip $ M.alter $ addKeyRepoSize k) m newlocs
+		in foldl' (flip $ M.alter $ removeKeyRepoSize k) m' removedlocs
+
+addKeyRepoSize :: Key -> Maybe RepoSize -> Maybe RepoSize
+addKeyRepoSize k mrs = case mrs of
+	Just (RepoSize sz) -> Just $ RepoSize $ sz + ksz
+	Nothing -> Just $ RepoSize ksz
+  where
+	ksz = fromMaybe 0 $ fromKey keySize k
+
+removeKeyRepoSize :: Key -> Maybe RepoSize -> Maybe RepoSize
+removeKeyRepoSize k mrs = case mrs of
+	Just (RepoSize sz) -> Just $ RepoSize $ sz - ksz
+	Nothing -> Nothing
+  where
+	ksz = fromMaybe 0 $ fromKey keySize k