git-annex/Utility/Path/AbsRel.hs
Joey Hess 4bf7940d6b
fileRef: make paths relative and simplified
Fix behavior of several commands, including reinject, addurl, and rmurl
when given an absolute path to an unlocked file, or a relative path that
leaves and re-enters the repository.

To avoid slowing down all the cases where the paths are already ok
with an unncessary call to getCurrentDirectory, put in an optimisation
in relPathCwdToFile. That will probably also speed up other parts of
git-annex by some small amount, but I have not benchmarked.

Note that I did not convert branchFileRef, because it seems likely that
it will be used with a file that is not provided by the user, so is already
in a sane format. This is certainly true for the way git-annex uses it,
though maybe arguable to the extent Git.Ref is a reusable library.
2021-05-07 13:25:59 -04:00

99 lines
2.8 KiB
Haskell

{- absolute and relative path manipulation
-
- Copyright 2010-2021 Joey Hess <id@joeyh.name>
-
- License: BSD-2-clause
-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE CPP #-}
{-# OPTIONS_GHC -fno-warn-tabs #-}
module Utility.Path.AbsRel (
absPathFrom,
absPath,
relPathCwdToFile,
relPathDirToFile,
relPathDirToFileAbs,
relHome,
) where
import System.FilePath.ByteString
import qualified Data.ByteString as B
#ifdef mingw32_HOST_OS
import System.Directory (getCurrentDirectory)
#else
import System.Posix.Directory.ByteString (getWorkingDirectory)
#endif
import Control.Applicative
import Prelude
import Utility.Path
import Utility.UserInfo
import Utility.FileSystemEncoding
{- Makes a path absolute.
-
- Also simplifies it using simplifyPath.
-
- The first parameter is a base directory (ie, the cwd) to use if the path
- is not already absolute, and should itsef be absolute.
-
- Does not attempt to deal with edge cases or ensure security with
- untrusted inputs.
-}
absPathFrom :: RawFilePath -> RawFilePath -> RawFilePath
absPathFrom dir path = simplifyPath (combine dir path)
{- Converts a filename into an absolute path.
-
- Also simplifies it using simplifyPath.
-
- Unlike Directory.canonicalizePath, this does not require the path
- already exists. -}
absPath :: RawFilePath -> IO RawFilePath
absPath file
-- Avoid unncessarily getting the current directory when the path
-- is already absolute. absPathFrom uses simplifyPath
-- so also used here for consistency.
| isAbsolute file = return $ simplifyPath file
| otherwise = do
#ifdef mingw32_HOST_OS
cwd <- toRawFilePath <$> getCurrentDirectory
#else
cwd <- getWorkingDirectory
#endif
return $ absPathFrom cwd file
{- Constructs the minimal relative path from the CWD to a file.
-
- For example, assuming CWD is /tmp/foo/bar:
- relPathCwdToFile "/tmp/foo" == ".."
- relPathCwdToFile "/tmp/foo/bar" == ""
- relPathCwdToFile "../bar/baz" == "baz"
-}
relPathCwdToFile :: RawFilePath -> IO RawFilePath
relPathCwdToFile f
-- Optimisation: Avoid doing any IO when the path is relative
-- and does not contain any ".." component.
| isRelative f && not (".." `B.isInfixOf` f) = return f
| otherwise = do
#ifdef mingw32_HOST_OS
c <- toRawFilePath <$> getCurrentDirectory
#else
c <- getWorkingDirectory
#endif
relPathDirToFile c f
{- Constructs a minimal relative path from a directory to a file. -}
relPathDirToFile :: RawFilePath -> RawFilePath -> IO RawFilePath
relPathDirToFile from to = relPathDirToFileAbs <$> absPath from <*> absPath to
{- Converts paths in the home directory to use ~/ -}
relHome :: FilePath -> IO String
relHome path = do
let path' = toRawFilePath path
home <- toRawFilePath <$> myHomeDir
return $ if dirContains home path'
then fromRawFilePath ("~/" <> relPathDirToFileAbs home path')
else path