425 lines
15 KiB
Haskell
425 lines
15 KiB
Haskell
{- metadata based branch views
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-
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- Copyright 2014 Joey Hess <id@joeyh.name>
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-
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- Licensed under the GNU GPL version 3 or higher.
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-}
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module Annex.View where
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import Annex.Common
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import Annex.View.ViewedFile
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import Types.View
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import Types.MetaData
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import Annex.MetaData
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import qualified Git
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import qualified Git.DiffTree as DiffTree
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import qualified Git.Branch
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import qualified Git.LsFiles
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import qualified Git.Ref
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import Git.UpdateIndex
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import Git.Sha
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import Annex.HashObject
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import Git.Types
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import Git.FilePath
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import Annex.WorkTree
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import Annex.GitOverlay
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import Annex.Link
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import Annex.CatFile
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import Logs.MetaData
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import Logs.View
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import Utility.Glob
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import Utility.FileMode
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import Types.Command
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import CmdLine.Action
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import qualified Data.Set as S
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import qualified Data.Map as M
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import "mtl" Control.Monad.Writer
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{- Each visible ViewFilter in a view results in another level of
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- subdirectory nesting. When a file matches multiple ways, it will appear
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- in multiple subdirectories. This means there is a bit of an exponential
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- blowup with a single file appearing in a crazy number of places!
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-
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- Capping the view size to 5 is reasonable; why wants to dig
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- through 5+ levels of subdirectories to find anything?
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-}
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viewTooLarge :: View -> Bool
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viewTooLarge view = visibleViewSize view > 5
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visibleViewSize :: View -> Int
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visibleViewSize = length . filter viewVisible . viewComponents
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{- Parses field=value, field!=value, tag, and !tag
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-
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- Note that the field may not be a legal metadata field name,
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- but it's let through anyway.
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- This is useful when matching on directory names with spaces,
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- which are not legal MetaFields.
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-}
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parseViewParam :: String -> (MetaField, ViewFilter)
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parseViewParam s = case separate (== '=') s of
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('!':tag, []) | not (null tag) ->
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( tagMetaField
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, mkExcludeValues tag
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)
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(tag, []) ->
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( tagMetaField
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, mkFilterValues tag
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)
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(field, wanted)
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| end field == "!" ->
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( mkMetaFieldUnchecked (beginning field)
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, mkExcludeValues wanted
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)
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| otherwise ->
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( mkMetaFieldUnchecked field
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, mkFilterValues wanted
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)
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where
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mkFilterValues v
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| any (`elem` v) "*?" = FilterGlob v
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| otherwise = FilterValues $ S.singleton $ toMetaValue v
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mkExcludeValues = ExcludeValues . S.singleton . toMetaValue
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data ViewChange = Unchanged | Narrowing | Widening
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deriving (Ord, Eq, Show)
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{- Updates a view, adding new fields to filter on (Narrowing),
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- or allowing new values in an existing field (Widening). -}
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refineView :: View -> [(MetaField, ViewFilter)] -> (View, ViewChange)
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refineView origview = checksize . calc Unchanged origview
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where
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calc c v [] = (v, c)
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calc c v ((f, vf):rest) =
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let (v', c') = refine v f vf
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in calc (max c c') v' rest
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refine view field vf
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| field `elem` map viewField (viewComponents view) =
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let (components', viewchanges) = runWriter $
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mapM (\c -> updateViewComponent c field vf) (viewComponents view)
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viewchange = if field `elem` map viewField (viewComponents origview)
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then maximum viewchanges
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else Narrowing
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in (view { viewComponents = components' }, viewchange)
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| otherwise =
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let component = mkViewComponent field vf
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view' = view { viewComponents = component : viewComponents view }
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in (view', Narrowing)
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checksize r@(v, _)
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| viewTooLarge v = error $ "View is too large (" ++ show (visibleViewSize v) ++ " levels of subdirectories)"
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| otherwise = r
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updateViewComponent :: ViewComponent -> MetaField -> ViewFilter -> Writer [ViewChange] ViewComponent
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updateViewComponent c field vf
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| viewField c == field = do
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let (newvf, viewchange) = combineViewFilter (viewFilter c) vf
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tell [viewchange]
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return $ mkViewComponent field newvf
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| otherwise = return c
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{- Adds an additional filter to a view. This can only result in narrowing
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- the view. Multivalued filters are added in non-visible form. -}
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filterView :: View -> [(MetaField, ViewFilter)] -> View
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filterView v vs = v { viewComponents = viewComponents f' ++ viewComponents v}
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where
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f = fst $ refineView (v {viewComponents = []}) vs
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f' = f { viewComponents = map toinvisible (viewComponents f) }
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toinvisible c = c { viewVisible = False }
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{- Combine old and new ViewFilters, yielding a result that matches
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- either old+new, or only new.
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-
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- If we have FilterValues and change to a FilterGlob,
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- it's always a widening change, because the glob could match other
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- values. OTOH, going the other way, it's a Narrowing change if the old
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- glob matches all the new FilterValues.
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-
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- With two globs, the old one is discarded, and the new one is used.
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- We can tell if that's a narrowing change by checking if the old
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- glob matches the new glob. For example, "*" matches "foo*",
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- so that's narrowing. While "f?o" does not match "f??", so that's
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- widening.
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-}
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combineViewFilter :: ViewFilter -> ViewFilter -> (ViewFilter, ViewChange)
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combineViewFilter old@(FilterValues olds) (FilterValues news)
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| combined == old = (combined, Unchanged)
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| otherwise = (combined, Widening)
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where
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combined = FilterValues (S.union olds news)
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combineViewFilter old@(ExcludeValues olds) (ExcludeValues news)
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| combined == old = (combined, Unchanged)
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| otherwise = (combined, Narrowing)
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where
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combined = ExcludeValues (S.union olds news)
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combineViewFilter (FilterValues _) newglob@(FilterGlob _) =
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(newglob, Widening)
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combineViewFilter (FilterGlob oldglob) new@(FilterValues s)
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| all (matchGlob (compileGlob oldglob CaseInsensative) . fromMetaValue) (S.toList s) = (new, Narrowing)
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| otherwise = (new, Widening)
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combineViewFilter (FilterGlob old) newglob@(FilterGlob new)
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| old == new = (newglob, Unchanged)
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| matchGlob (compileGlob old CaseInsensative) new = (newglob, Narrowing)
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| otherwise = (newglob, Widening)
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combineViewFilter (FilterGlob _) new@(ExcludeValues _) = (new, Narrowing)
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combineViewFilter (ExcludeValues _) new@(FilterGlob _) = (new, Widening)
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combineViewFilter (FilterValues _) new@(ExcludeValues _) = (new, Narrowing)
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combineViewFilter (ExcludeValues _) new@(FilterValues _) = (new, Widening)
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{- Generates views for a file from a branch, based on its metadata
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- and the filename used in the branch.
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-
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- Note that a file may appear multiple times in a view, when it
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- has multiple matching values for a MetaField used in the View.
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-
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- Of course if its MetaData does not match the View, it won't appear at
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- all.
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-
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- Note that for efficiency, it's useful to partially
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- evaluate this function with the view parameter and reuse
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- the result. The globs in the view will then be compiled and memoized.
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-}
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viewedFiles :: View -> MkViewedFile -> FilePath -> MetaData -> [ViewedFile]
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viewedFiles view =
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let matchers = map viewComponentMatcher (viewComponents view)
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in \mkviewedfile file metadata ->
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let matches = map (\m -> m metadata) matchers
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in if any isNothing matches
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then []
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else
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let paths = pathProduct $
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map (map toViewPath) (visible matches)
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in if null paths
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then [mkviewedfile file]
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else map (</> mkviewedfile file) paths
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where
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visible = map (fromJust . snd) .
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filter (viewVisible . fst) .
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zip (viewComponents view)
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{- Checks if metadata matches a ViewComponent filter, and if so
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- returns the value, or values that match. Self-memoizing on ViewComponent. -}
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viewComponentMatcher :: ViewComponent -> (MetaData -> Maybe [MetaValue])
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viewComponentMatcher viewcomponent = \metadata ->
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matcher (currentMetaDataValues metafield metadata)
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where
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metafield = viewField viewcomponent
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matcher = case viewFilter viewcomponent of
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FilterValues s -> \values -> setmatches $
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S.intersection s values
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FilterGlob glob ->
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let cglob = compileGlob glob CaseInsensative
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in \values -> setmatches $
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S.filter (matchGlob cglob . fromMetaValue) values
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ExcludeValues excludes -> \values ->
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if S.null (S.intersection values excludes)
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then Just []
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else Nothing
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setmatches s
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| S.null s = Nothing
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| otherwise = Just (S.toList s)
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-- This is '∕', a unicode character that displays the same as '/' but is
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-- not it. It is encoded using the filesystem encoding, which allows it
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-- to be used even when not in a unicode capable locale.
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pseudoSlash :: String
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pseudoSlash = "\56546\56456\56469"
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-- And this is '╲' similarly.
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pseudoBackslash :: String
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pseudoBackslash = "\56546\56469\56498"
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toViewPath :: MetaValue -> FilePath
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toViewPath = escapeslash [] . fromMetaValue
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where
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escapeslash s ('/':cs) = escapeslash (pseudoSlash:s) cs
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escapeslash s ('\\':cs) = escapeslash (pseudoBackslash:s) cs
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escapeslash s ('%':cs) = escapeslash ("%%":s) cs
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escapeslash s (c1:c2:c3:cs)
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| [c1,c2,c3] == pseudoSlash = escapeslash ("%":pseudoSlash:s) cs
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| [c1,c2,c3] == pseudoBackslash = escapeslash ("%":pseudoBackslash:s) cs
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| otherwise = escapeslash ([c1]:s) (c2:c3:cs)
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escapeslash s cs = concat (reverse (cs:s))
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fromViewPath :: FilePath -> MetaValue
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fromViewPath = toMetaValue . deescapeslash []
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where
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deescapeslash s ('%':escapedc:cs) = deescapeslash ([escapedc]:s) cs
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deescapeslash s (c1:c2:c3:cs)
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| [c1,c2,c3] == pseudoSlash = deescapeslash ("/":s) cs
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| [c1,c2,c3] == pseudoBackslash = deescapeslash ("\\":s) cs
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| otherwise = deescapeslash ([c1]:s) (c2:c3:cs)
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deescapeslash s cs = concat (reverse (cs:s))
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prop_viewPath_roundtrips :: MetaValue -> Bool
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prop_viewPath_roundtrips v = fromViewPath (toViewPath v) == v
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pathProduct :: [[FilePath]] -> [FilePath]
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pathProduct [] = []
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pathProduct (l:ls) = foldl combinel l ls
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where
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combinel xs ys = [combine x y | x <- xs, y <- ys]
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{- Extracts the metadata from a ViewedFile, based on the view that was used
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- to construct it.
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-
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- Derived metadata is excluded.
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-}
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fromView :: View -> ViewedFile -> MetaData
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fromView view f = MetaData $
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M.fromList (zip fields values) `M.difference` derived
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where
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visible = filter viewVisible (viewComponents view)
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fields = map viewField visible
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paths = splitDirectories (dropFileName f)
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values = map (S.singleton . fromViewPath) paths
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MetaData derived = getViewedFileMetaData f
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{- Constructing a view that will match arbitrary metadata, and applying
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- it to a file yields a set of ViewedFile which all contain the same
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- MetaFields that were present in the input metadata
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- (excluding fields that are not visible). -}
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prop_view_roundtrips :: FilePath -> MetaData -> Bool -> Bool
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prop_view_roundtrips f metadata visible = null f || viewTooLarge view ||
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all hasfields (viewedFiles view viewedFileFromReference f metadata)
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where
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view = View (Git.Ref "master") $
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map (\(mf, mv) -> ViewComponent mf (FilterValues $ S.filter (not . null . fromMetaValue) mv) visible)
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(fromMetaData metadata)
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visiblefields = sort (map viewField $ filter viewVisible (viewComponents view))
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hasfields fv = sort (map fst (fromMetaData (fromView view fv))) == visiblefields
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{- A directory foo/bar/baz/ is turned into metadata fields
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- /=foo, foo/=bar, foo/bar/=baz.
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-
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- Note that this may generate MetaFields that legalField rejects.
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- This is necessary to have a 1:1 mapping between directory names and
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- fields. So this MetaData cannot safely be serialized. -}
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getDirMetaData :: FilePath -> MetaData
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getDirMetaData d = MetaData $ M.fromList $ zip fields values
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where
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dirs = splitDirectories d
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fields = map (mkMetaFieldUnchecked . addTrailingPathSeparator . joinPath)
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(inits dirs)
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values = map (S.singleton . toMetaValue . fromMaybe "" . headMaybe)
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(tails dirs)
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getWorkTreeMetaData :: FilePath -> MetaData
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getWorkTreeMetaData = getDirMetaData . dropFileName
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getViewedFileMetaData :: FilePath -> MetaData
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getViewedFileMetaData = getDirMetaData . dirFromViewedFile . takeFileName
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{- Applies a view to the currently checked out branch, generating a new
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- branch for the view.
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-}
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applyView :: View -> Annex Git.Branch
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applyView = applyView' viewedFileFromReference getWorkTreeMetaData
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{- Generates a new branch for a View, which must be a more narrow
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- version of the View originally used to generate the currently
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- checked out branch. That is, it must match a subset of the files
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- in view, not any others.
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-}
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narrowView :: View -> Annex Git.Branch
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narrowView = applyView' viewedFileReuse getViewedFileMetaData
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{- Go through each file in the currently checked out branch.
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- If the file is not annexed, skip it, unless it's a dotfile in the top.
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- Look up the metadata of annexed files, and generate any ViewedFiles,
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- and stage them.
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-
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- Must be run from top of repository.
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-}
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applyView' :: MkViewedFile -> (FilePath -> MetaData) -> View -> Annex Git.Branch
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applyView' mkviewedfile getfilemetadata view = do
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top <- fromRepo Git.repoPath
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(l, clean) <- inRepo $ Git.LsFiles.inRepo [top]
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liftIO . nukeFile =<< fromRepo gitAnnexViewIndex
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uh <- withViewIndex $ inRepo Git.UpdateIndex.startUpdateIndex
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forM_ l $ \f -> do
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relf <- getTopFilePath <$> inRepo (toTopFilePath f)
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go uh relf =<< lookupFile f
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liftIO $ do
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void $ stopUpdateIndex uh
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void clean
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genViewBranch view
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where
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genviewedfiles = viewedFiles view mkviewedfile -- enables memoization
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go uh f (Just k) = do
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metadata <- getCurrentMetaData k
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let metadata' = getfilemetadata f `unionMetaData` metadata
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forM_ (genviewedfiles f metadata') $ \fv -> do
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f' <- fromRepo $ fromTopFilePath $ asTopFilePath fv
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stagesymlink uh f' =<< calcRepo (gitAnnexLink f' k)
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go uh f Nothing
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| "." `isPrefixOf` f = do
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s <- liftIO $ getSymbolicLinkStatus f
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if isSymbolicLink s
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then stagesymlink uh f =<< liftIO (readSymbolicLink f)
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else do
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sha <- hashFile f
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let blobtype = if isExecutable (fileMode s)
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then ExecutableBlob
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else FileBlob
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liftIO . Git.UpdateIndex.streamUpdateIndex' uh
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=<< inRepo (Git.UpdateIndex.stageFile sha blobtype f)
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| otherwise = noop
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stagesymlink uh f linktarget = do
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sha <- hashSymlink linktarget
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liftIO . Git.UpdateIndex.streamUpdateIndex' uh
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=<< inRepo (Git.UpdateIndex.stageSymlink f sha)
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{- Diff between currently checked out branch and staged changes, and
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- update metadata to reflect the changes that are being committed to the
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- view.
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-
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- Adding a file to a directory adds the metadata represented by
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- that directory to the file, and removing a file from a directory
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- removes the metadata.
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-
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- Note that removes must be handled before adds. This is so
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- that moving a file from x/foo/ to x/bar/ adds back the metadata for x.
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-}
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withViewChanges :: (ViewedFile -> Key -> CommandStart) -> (ViewedFile -> Key -> CommandStart) -> Annex ()
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withViewChanges addmeta removemeta = do
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(diffs, cleanup) <- inRepo $ DiffTree.diffIndex Git.Ref.headRef
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forM_ diffs handleremovals
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forM_ diffs handleadds
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void $ liftIO cleanup
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where
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handleremovals item
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| DiffTree.srcsha item /= nullSha =
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handlechange item removemeta
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=<< catKey (DiffTree.srcsha item)
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| otherwise = noop
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handleadds item
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| DiffTree.dstsha item /= nullSha =
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handlechange item addmeta
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=<< catKey (DiffTree.dstsha item)
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| otherwise = noop
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handlechange item a = maybe noop
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(void . commandAction . a (getTopFilePath $ DiffTree.file item))
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{- Runs an action using the view index file.
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- Note that the file does not necessarily exist, or can contain
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- info staged for an old view. -}
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withViewIndex :: Annex a -> Annex a
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withViewIndex a = do
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f <- fromRepo gitAnnexViewIndex
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withIndexFile f a
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{- Generates a branch for a view, using the view index file
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- to make a commit to the view branch. The view branch is not
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- checked out, but entering it will display the view. -}
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genViewBranch :: View -> Annex Git.Branch
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genViewBranch view = withViewIndex $ do
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let branch = branchView view
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void $ inRepo $ Git.Branch.commit Git.Branch.AutomaticCommit True (fromRef branch) branch []
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return branch
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withCurrentView :: (View -> Annex a) -> Annex a
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withCurrentView a = maybe (error "Not in a view.") a =<< currentView
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