git-annex/Logs/View.hs
Joey Hess fa62c98910
simplify and speed up Utility.FileSystemEncoding
This eliminates the distinction between decodeBS and decodeBS', encodeBS
and encodeBS', etc. The old implementation truncated at NUL, and the
primed versions had to do extra work to avoid that problem. The new
implementation does not truncate at NUL, and is also a lot faster.
(Benchmarked at 2x faster for decodeBS and 3x for encodeBS; more for the
primed versions.)

Note that filepath-bytestring 1.4.2.1.8 contains the same optimisation,
and upgrading to it will speed up to/fromRawFilePath.

AFAIK, nothing relied on the old behavior of truncating at NUL. Some
code used the faster versions in places where I was sure there would not
be a NUL. So this change is unlikely to break anything.

Also, moved s2w8 and w82s out of the module, as they do not involve
filesystem encoding really.

Sponsored-by: Shae Erisson on Patreon
2021-08-11 12:13:31 -04:00

102 lines
2.8 KiB
Haskell

{- git-annex recent views log
-
- The most recently accessed view comes first.
-
- This file is stored locally in .git/annex/, not in the git-annex branch.
-
- Copyright 2014 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE OverloadedStrings #-}
module Logs.View (
currentView,
setView,
removeView,
recentViews,
branchView,
is_branchView,
prop_branchView_legal,
) where
import Annex.Common
import Types.View
import Types.MetaData
import qualified Git
import qualified Git.Branch
import qualified Git.Ref
import Git.Types
import Logs.File
import qualified Data.Text as T
import qualified Data.Set as S
import Data.Char
import qualified Data.ByteString as B
setView :: View -> Annex ()
setView v = do
old <- take 99 . filter (/= v) <$> recentViews
writeViews (v : old)
writeViews :: [View] -> Annex ()
writeViews l = do
f <- fromRepo gitAnnexViewLog
writeLogFile f $ unlines $ map show l
removeView :: View -> Annex ()
removeView v = writeViews =<< filter (/= v) <$> recentViews
recentViews :: Annex [View]
recentViews = do
f <- fromRawFilePath <$> fromRepo gitAnnexViewLog
liftIO $ mapMaybe readish . lines <$> catchDefaultIO [] (readFile f)
{- Gets the currently checked out view, if there is one. -}
currentView :: Annex (Maybe View)
currentView = go =<< inRepo Git.Branch.current
where
go (Just b) | branchViewPrefix `B.isPrefixOf` fromRef' b =
headMaybe . filter (\v -> branchView v == b) <$> recentViews
go _ = return Nothing
branchViewPrefix :: B.ByteString
branchViewPrefix = "refs/heads/views"
{- Generates a git branch name for a View.
-
- There is no guarantee that each view gets a unique branch name,
- but the branch name is used to express the view as well as possible.
-}
branchView :: View -> Git.Branch
branchView view
| B.null name = Git.Ref branchViewPrefix
| otherwise = Git.Ref $ branchViewPrefix <> "/" <> name
where
name = encodeBS $
intercalate ";" $ map branchcomp (viewComponents view)
branchcomp c
| viewVisible c = branchcomp' c
| otherwise = "(" ++ branchcomp' c ++ ")"
branchcomp' (ViewComponent metafield viewfilter _) = concat
[ forcelegal (T.unpack (fromMetaField metafield))
, branchvals viewfilter
]
branchvals (FilterValues set) = '=' : branchset set
branchvals (FilterGlob glob) = '=' : forcelegal glob
branchvals (ExcludeValues set) = "!=" ++ branchset set
branchset = intercalate ","
. map (forcelegal . decodeBS . fromMetaValue)
. S.toList
forcelegal s
| Git.Ref.legal True s = s
| otherwise = map (\c -> if isAlphaNum c then c else '_') s
is_branchView :: Git.Branch -> Bool
is_branchView (Ref b)
| b == branchViewPrefix = True
| otherwise = (branchViewPrefix <> "/") `B.isPrefixOf` b
prop_branchView_legal :: View -> Bool
prop_branchView_legal = Git.Ref.legal False . fromRef . branchView