git-annex/Git/Command.hs
Joey Hess cd865c3b8f Switch to using relative paths to the git repository.
This allows the git repository to be moved while git-annex is running in
it, with fewer problems.

On Windows, this avoids some of the problems with the absurdly small
MAX_PATH of 260 bytes. In particular, git-annex repositories should
work in deeper/longer directory structures than before. See
http://git-annex.branchable.com/bugs/__34__git-annex:_direct:_1_failed__34___on_Windows/

There are several possible ways this change could break git-annex:

1. If it changes its working directory while it's running, that would
   be Bad News. Good news everyone! git-annex never does so. It would also
   break thread safety, so all such things were stomped out long ago.

2. parentDir "." -> "" which is not a valid path. I had to fix one
   instace of this, and I should probably wipe all calls to parentDir out
   of the git-annex code base; it was never a good idea.

3. Things like relPathDirToFile require absolute input paths,
   and code assumes that the git repo path is absolute and passes it to it
   as-is. In the case of relPathDirToFile, I converted it to not make
   this assumption.

Currently, the test suite has 16 failures.
2015-01-06 16:19:41 -04:00

128 lines
4.4 KiB
Haskell

{- running git commands
-
- Copyright 2010-2013 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
module Git.Command where
import Common
import Git
import Git.Types
import qualified Utility.CoProcess as CoProcess
{- Constructs a git command line operating on the specified repo. -}
gitCommandLine :: [CommandParam] -> Repo -> [CommandParam]
gitCommandLine params r@(Repo { location = l@(Local { } ) }) =
setdir : settree ++ gitGlobalOpts r ++ params
where
setdir = Param $ "--git-dir=" ++ gitdir l
settree = case worktree l of
Nothing -> []
Just t -> [Param $ "--work-tree=" ++ t]
gitCommandLine _ repo = assertLocal repo $ error "internal"
{- Runs git in the specified repo. -}
runBool :: [CommandParam] -> Repo -> IO Bool
runBool params repo = assertLocal repo $
boolSystemEnv "git" (gitCommandLine params repo) (gitEnv repo)
{- Runs git in the specified repo, throwing an error if it fails. -}
run :: [CommandParam] -> Repo -> IO ()
run params repo = assertLocal repo $
unlessM (runBool params repo) $
error $ "git " ++ show params ++ " failed"
{- Runs git and forces it to be quiet, throwing an error if it fails. -}
runQuiet :: [CommandParam] -> Repo -> IO ()
runQuiet params repo = withQuietOutput createProcessSuccess $
(proc "git" $ toCommand $ gitCommandLine (params) repo)
{ env = gitEnv repo }
{- Runs a git command and returns its output, lazily.
-
- Also returns an action that should be used when the output is all
- read (or no more is needed), that will wait on the command, and
- return True if it succeeded. Failure to wait will result in zombies.
-}
pipeReadLazy :: [CommandParam] -> Repo -> IO (String, IO Bool)
pipeReadLazy params repo = assertLocal repo $ do
(_, Just h, _, pid) <- createProcess p { std_out = CreatePipe }
fileEncoding h
c <- hGetContents h
return (c, checkSuccessProcess pid)
where
p = gitCreateProcess params repo
{- Runs a git command, and returns its output, strictly.
-
- Nonzero exit status is ignored.
-}
pipeReadStrict :: [CommandParam] -> Repo -> IO String
pipeReadStrict params repo = assertLocal repo $
withHandle StdoutHandle (createProcessChecked ignoreFailureProcess) p $ \h -> do
fileEncoding h
output <- hGetContentsStrict h
hClose h
return output
where
p = gitCreateProcess params repo
{- Runs a git command, feeding it an input, and returning its output,
- which is expected to be fairly small, since it's all read into memory
- strictly. -}
pipeWriteRead :: [CommandParam] -> Maybe (Handle -> IO ()) -> Repo -> IO String
pipeWriteRead params writer repo = assertLocal repo $
writeReadProcessEnv "git" (toCommand $ gitCommandLine params repo)
(gitEnv repo) writer (Just adjusthandle)
where
adjusthandle h = do
fileEncoding h
hSetNewlineMode h noNewlineTranslation
{- Runs a git command, feeding it input on a handle with an action. -}
pipeWrite :: [CommandParam] -> Repo -> (Handle -> IO ()) -> IO ()
pipeWrite params repo = withHandle StdinHandle createProcessSuccess $
gitCreateProcess params repo
{- Reads null terminated output of a git command (as enabled by the -z
- parameter), and splits it. -}
pipeNullSplit :: [CommandParam] -> Repo -> IO ([String], IO Bool)
pipeNullSplit params repo = do
(s, cleanup) <- pipeReadLazy params repo
return (filter (not . null) $ split sep s, cleanup)
where
sep = "\0"
pipeNullSplitStrict :: [CommandParam] -> Repo -> IO [String]
pipeNullSplitStrict params repo = do
s <- pipeReadStrict params repo
return $ filter (not . null) $ split sep s
where
sep = "\0"
pipeNullSplitZombie :: [CommandParam] -> Repo -> IO [String]
pipeNullSplitZombie params repo = leaveZombie <$> pipeNullSplit params repo
{- Doesn't run the cleanup action. A zombie results. -}
leaveZombie :: (a, IO Bool) -> a
leaveZombie = fst
{- Runs a git command as a coprocess. -}
gitCoProcessStart :: Bool -> [CommandParam] -> Repo -> IO CoProcess.CoProcessHandle
gitCoProcessStart restartable params repo = CoProcess.start numrestarts "git"
(toCommand $ gitCommandLine params repo)
(gitEnv repo)
where
{- If a long-running git command like cat-file --batch
- crashes, it will likely start up again ok. If it keeps crashing
- 10 times, something is badly wrong. -}
numrestarts = if restartable then 10 else 0
gitCreateProcess :: [CommandParam] -> Repo -> CreateProcess
gitCreateProcess params repo =
(proc "git" $ toCommand $ gitCommandLine params repo)
{ env = gitEnv repo }