Improve behavior when unable to parse a preferred content expression (thanks, ion).

Fall back to "present" as the preferred conent expression, which will
not result in any content movement.
This commit is contained in:
Joey Hess 2014-03-20 00:10:12 -04:00
parent 9aa31b71f3
commit ed30b81e2c
4 changed files with 38 additions and 12 deletions

View file

@ -37,6 +37,7 @@ import Types.Remote (RemoteConfig)
import Logs.Group
import Logs.Remote
import Types.StandardGroups
import Limit
{- Checks if a file is preferred content for the specified repository
- (or the current repository if none is specified). -}
@ -67,29 +68,45 @@ preferredContentMapLoad = do
{- This intentionally never fails, even on unparsable expressions,
- because the configuration is shared among repositories and newer
- versions of git-annex may add new features. Instead, parse errors
- result in a Matcher that will always succeed. -}
makeMatcher :: GroupMap -> M.Map UUID RemoteConfig -> M.Map Group PreferredContentExpression -> UUID -> PreferredContentExpression -> FileMatcher
- versions of git-annex may add new features. -}
makeMatcher
:: GroupMap
-> M.Map UUID RemoteConfig
-> M.Map Group PreferredContentExpression
-> UUID
-> PreferredContentExpression
-> FileMatcher
makeMatcher groupmap configmap groupwantedmap u = go True True
where
go expandstandard expandgroupwanted expr
| null (lefts tokens) = Utility.Matcher.generate $ rights tokens
| otherwise = matchAll
| otherwise = unknownMatcher u
where
tokens = exprParser matchstandard matchgroupwanted groupmap configmap (Just u) expr
matchstandard
| expandstandard = maybe matchAll (go False False)
| expandstandard = maybe (unknownMatcher u) (go False False)
(standardPreferredContent <$> getStandardGroup mygroups)
| otherwise = matchAll
| otherwise = unknownMatcher u
matchgroupwanted
| expandgroupwanted = maybe matchAll (go True False)
| expandgroupwanted = maybe (unknownMatcher u) (go True False)
(groupwanted mygroups)
| otherwise = matchAll
| otherwise = unknownMatcher u
mygroups = fromMaybe S.empty (u `M.lookup` groupsByUUID groupmap)
groupwanted s = case M.elems $ M.filterWithKey (\k _ -> S.member k s) groupwantedmap of
[pc] -> Just pc
_ -> Nothing
{- When a preferred content expression cannot be parsed, but is already
- in the log (eg, put there by a newer version of git-annex),
- the fallback behavior is to match only files that are currently present.
-
- This avoid unwanted/expensive changes to the content, until the problem
- is resolved. -}
unknownMatcher :: UUID -> FileMatcher
unknownMatcher u = Utility.Matcher.generate [present]
where
present = Utility.Matcher.Operation $ matchPresent (Just u)
{- Checks if an expression can be parsed, if not returns Just error -}
checkPreferredContentExpression :: PreferredContentExpression -> Maybe String
checkPreferredContentExpression expr = case parsedToMatcher tokens of