git-annex/Git/Hook.hs
Joey Hess 177e45517f
improve back-compat of post-receive hook
* init: Improve generated post-receive hook, so it won't fail when
  run on a system whose git-annex is too old to support git-annex post-receive
* init: Update the post-receive hook when re-run in an existing repository.

This commit was sponsored by Jack Hill on Patreon.
2018-09-25 15:02:12 -04:00

90 lines
2 KiB
Haskell

{- git hooks
-
- Copyright 2013-2018 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
module Git.Hook where
import Common
import Git
import Utility.Tmp
import Utility.Shell
#ifndef mingw32_HOST_OS
import Utility.FileMode
#endif
data Hook = Hook
{ hookName :: FilePath
, hookScript :: String
, hookOldScripts :: [String]
}
deriving (Ord)
instance Eq Hook where
a == b = hookName a == hookName b
hookFile :: Hook -> Repo -> FilePath
hookFile h r = localGitDir r </> "hooks" </> hookName h
{- Writes a hook. Returns False if the hook already exists with a different
- content. Upgrades old scripts. -}
hookWrite :: Hook -> Repo -> IO Bool
hookWrite h r = ifM (doesFileExist f)
( expectedContent h r >>= \case
UnexpectedContent -> return False
ExpectedContent -> return True
OldExpectedContent -> go
, go
)
where
f = hookFile h r
go = do
viaTmp writeFile f (hookScript h)
p <- getPermissions f
setPermissions f $ p {executable = True}
return True
{- Removes a hook. Returns False if the hook contained something else, and
- could not be removed. -}
hookUnWrite :: Hook -> Repo -> IO Bool
hookUnWrite h r = ifM (doesFileExist f)
( expectedContent h r >>= \case
UnexpectedContent -> return False
_ -> do
removeFile f
return True
, return True
)
where
f = hookFile h r
data ExpectedContent = UnexpectedContent | ExpectedContent | OldExpectedContent
expectedContent :: Hook -> Repo -> IO ExpectedContent
expectedContent h r = do
content <- readFile $ hookFile h r
return $ if content == hookScript h
then ExpectedContent
else if any (content ==) (hookOldScripts h)
then OldExpectedContent
else UnexpectedContent
hookExists :: Hook -> Repo -> IO Bool
hookExists h r = do
let f = hookFile h r
catchBoolIO $
#ifndef mingw32_HOST_OS
isExecutable . fileMode <$> getFileStatus f
#else
doesFileExist f
#endif
runHook :: Hook -> Repo -> IO Bool
runHook h r = do
let f = hookFile h r
(c, ps) <- findShellCommand f
boolSystem c ps