git-annex/Utility/Directory/Create.hs
Joey Hess 23c6e350cb
improve createDirectoryUnder to allow alternate top directories
This should not change the behavior of it, unless there are multiple top
directories, and then it should behave the same as if there was a single
top directory that was actually above the directory to be created.

Sponsored-by: Dartmouth College's Datalad project
2022-08-12 12:52:37 -04:00

105 lines
3.6 KiB
Haskell

{- directory creating
-
- Copyright 2011-2020 Joey Hess <id@joeyh.name>
-
- License: BSD-2-clause
-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE LambdaCase #-}
{-# OPTIONS_GHC -fno-warn-tabs #-}
module Utility.Directory.Create (
createDirectoryUnder,
createDirectoryUnder',
) where
import Control.Monad
import Control.Applicative
import Control.Monad.IO.Class
import Control.Monad.IfElse
import System.IO.Error
import Data.Maybe
import qualified System.FilePath.ByteString as P
import Prelude
import Utility.SystemDirectory
import Utility.Path.AbsRel
import Utility.Exception
import Utility.FileSystemEncoding
import qualified Utility.RawFilePath as R
import Utility.PartialPrelude
{- Like createDirectoryIfMissing True, but it will only create
- missing parent directories up to but not including a directory
- from the first parameter.
-
- For example, createDirectoryUnder ["/tmp/foo"] "/tmp/foo/bar/baz"
- will create /tmp/foo/bar if necessary, but if /tmp/foo does not exist,
- it will throw an exception.
-
- The exception thrown is the same that createDirectory throws if the
- parent directory does not exist.
-
- If the second FilePath is not under the first
- FilePath (or the same as it), it will fail with an exception
- even if the second FilePath's parent directory already exists.
-
- The FilePaths can be relative, or absolute.
- They will be normalized as necessary.
-
- Note that, the second FilePath, if relative, is relative to the current
- working directory.
-}
createDirectoryUnder :: [RawFilePath] -> RawFilePath -> IO ()
createDirectoryUnder topdirs dir =
createDirectoryUnder' topdirs dir R.createDirectory
createDirectoryUnder'
:: (MonadIO m, MonadCatch m)
=> [RawFilePath]
-> RawFilePath
-> (RawFilePath -> m ())
-> m ()
createDirectoryUnder' topdirs dir0 mkdir = do
relps <- liftIO $ forM topdirs $ \topdir -> relPathDirToFile topdir dir0
let relparts = map P.splitDirectories relps
-- Catch cases where dir0 is not beneath a topdir.
-- If the relative path between them starts with "..",
-- it's not. And on Windows, if they are on different drives,
-- the path will not be relative.
let notbeneath = \(_topdir, (relp, dirs)) ->
headMaybe dirs /= Just ".." && not (P.isAbsolute relp)
case filter notbeneath $ zip topdirs (zip relps relparts) of
((topdir, (_relp, dirs)):_)
-- If dir0 is the same as the topdir, don't try to
-- create it, but make sure it does exist.
| null dirs ->
liftIO $ unlessM (doesDirectoryExist (fromRawFilePath topdir)) $
ioError $ customerror doesNotExistErrorType $
"createDirectoryFrom: " ++ fromRawFilePath topdir ++ " does not exist"
| otherwise -> createdirs $
map (topdir P.</>) (reverse (scanl1 (P.</>) dirs))
_ -> liftIO $ ioError $ customerror userErrorType
("createDirectoryFrom: not located in " ++ unwords (map fromRawFilePath topdirs))
where
customerror t s = mkIOError t s Nothing (Just (fromRawFilePath dir0))
createdirs [] = pure ()
createdirs (dir:[]) = createdir dir (liftIO . ioError)
createdirs (dir:dirs) = createdir dir $ \_ -> do
createdirs dirs
createdir dir (liftIO . ioError)
-- This is the same method used by createDirectoryIfMissing,
-- in particular the handling of errors that occur when the
-- directory already exists. See its source for explanation
-- of several subtleties.
createdir dir notexisthandler = tryIO (mkdir dir) >>= \case
Right () -> pure ()
Left e
| isDoesNotExistError e -> notexisthandler e
| isAlreadyExistsError e || isPermissionError e ->
liftIO $ unlessM (doesDirectoryExist (fromRawFilePath dir)) $
ioError e
| otherwise -> liftIO $ ioError e