git-annex/Remote/Directory.hs
Joey Hess 7c1a9cdeb9 partially complete gcrypt remote (local send done; rest not)
This is a git-remote-gcrypt encrypted special remote. Only sending files
in to the remote works, and only for local repositories.

Most of the work so far has involved making initremote work. A particular
problem is that remote setup in this case needs to generate its own uuid,
derivied from the gcrypt-id. That required some larger changes in the code
to support.

For ssh remotes, this will probably just reuse Remote.Rsync's code, so
should be easy enough. And for downloading from a web remote, I will need
to factor out the part of Remote.Git that does that.

One particular thing that will need work is supporting hot-swapping a local
gcrypt remote. I think it needs to store the gcrypt-id in the git config of the
local remote, so that it can check it every time, and compare with the
cached annex-uuid for the remote. If there is a mismatch, it can change
both the cached annex-uuid and the gcrypt-id. That should work, and I laid
some groundwork for it by already reading the remote's config when it's
local. (Also needed for other reasons.)

This commit was sponsored by Daniel Callahan.
2013-09-07 18:38:00 -04:00

249 lines
8.5 KiB
Haskell
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

{- A "remote" that is just a filesystem directory.
-
- Copyright 2011-2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
module Remote.Directory (remote) where
import qualified Data.ByteString.Lazy as L
import qualified Data.ByteString as S
import qualified Data.Map as M
import qualified Control.Exception as E
import Data.Int
import Common.Annex
import Types.Remote
import qualified Git
import Config.Cost
import Config
import Utility.FileMode
import Remote.Helper.Special
import Remote.Helper.Encryptable
import Remote.Helper.Chunked
import Crypto
import Annex.Content
import Annex.UUID
import Utility.Metered
remote :: RemoteType
remote = RemoteType {
typename = "directory",
enumerate = findSpecialRemotes "directory",
generate = gen,
setup = directorySetup
}
gen :: Git.Repo -> UUID -> RemoteConfig -> RemoteGitConfig -> Annex Remote
gen r u c gc = do
cst <- remoteCost gc cheapRemoteCost
let chunksize = chunkSize c
return $ encryptableRemote c
(storeEncrypted dir (getGpgEncParams (c,gc)) chunksize)
(retrieveEncrypted dir chunksize)
Remote {
uuid = u,
cost = cst,
name = Git.repoDescribe r,
storeKey = store dir chunksize,
retrieveKeyFile = retrieve dir chunksize,
retrieveKeyFileCheap = retrieveCheap dir chunksize,
removeKey = remove dir,
hasKey = checkPresent dir chunksize,
hasKeyCheap = True,
whereisKey = Nothing,
config = M.empty,
repo = r,
gitconfig = gc,
localpath = Just dir,
readonly = False,
globallyAvailable = False,
remotetype = remote
}
where
dir = fromMaybe (error "missing directory") $ remoteAnnexDirectory gc
directorySetup :: Maybe UUID -> RemoteConfig -> Annex (RemoteConfig, UUID)
directorySetup mu c = do
u <- maybe (liftIO genUUID) return mu
-- verify configuration is sane
let dir = fromMaybe (error "Specify directory=") $
M.lookup "directory" c
absdir <- liftIO $ absPath dir
liftIO $ unlessM (doesDirectoryExist absdir) $
error $ "Directory does not exist: " ++ absdir
c' <- encryptionSetup c
-- The directory is stored in git config, not in this remote's
-- persistant state, so it can vary between hosts.
gitConfigSpecialRemote u c' "directory" absdir
return (M.delete "directory" c', u)
{- Locations to try to access a given Key in the Directory.
- We try more than since we used to write to different hash directories. -}
locations :: FilePath -> Key -> [FilePath]
locations d k = map (d </>) (keyPaths k)
{- Directory where the file(s) for a key are stored. -}
storeDir :: FilePath -> Key -> FilePath
storeDir d k = addTrailingPathSeparator $ d </> hashDirLower k </> keyFile k
{- Where we store temporary data for a key as it's being uploaded. -}
tmpDir :: FilePath -> Key -> FilePath
tmpDir d k = addTrailingPathSeparator $ d </> "tmp" </> keyFile k
withCheckedFiles :: (FilePath -> IO Bool) -> ChunkSize -> FilePath -> Key -> ([FilePath] -> IO Bool) -> IO Bool
withCheckedFiles _ _ [] _ _ = return False
withCheckedFiles check Nothing d k a = go $ locations d k
where
go [] = return False
go (f:fs) = ifM (check f) ( a [f] , go fs )
withCheckedFiles check (Just _) d k a = go $ locations d k
where
go [] = return False
go (f:fs) = do
let chunkcount = f ++ chunkCount
ifM (check chunkcount)
( do
chunks <- listChunks f <$> readFile chunkcount
ifM (all id <$> mapM check chunks)
( a chunks , return False )
, go fs
)
withStoredFiles :: ChunkSize -> FilePath -> Key -> ([FilePath] -> IO Bool) -> IO Bool
withStoredFiles = withCheckedFiles doesFileExist
store :: FilePath -> ChunkSize -> Key -> AssociatedFile -> MeterUpdate -> Annex Bool
store d chunksize k _f p = sendAnnex k (void $ remove d k) $ \src ->
metered (Just p) k $ \meterupdate ->
storeHelper d chunksize k k $ \dests ->
case chunksize of
Nothing -> do
let dest = Prelude.head dests
meteredWriteFile meterupdate dest
=<< L.readFile src
return [dest]
Just _ ->
storeSplit meterupdate chunksize dests
=<< L.readFile src
storeEncrypted :: FilePath -> [CommandParam] -> ChunkSize -> (Cipher, Key) -> Key -> MeterUpdate -> Annex Bool
storeEncrypted d gpgOpts chunksize (cipher, enck) k p = sendAnnex k (void $ remove d enck) $ \src ->
metered (Just p) k $ \meterupdate ->
storeHelper d chunksize enck k $ \dests ->
encrypt gpgOpts cipher (feedFile src) $ readBytes $ \b ->
case chunksize of
Nothing -> do
let dest = Prelude.head dests
meteredWriteFile meterupdate dest b
return [dest]
Just _ -> storeSplit meterupdate chunksize dests b
{- Splits a ByteString into chunks and writes to dests, obeying configured
- chunk size (not to be confused with the L.ByteString chunk size).
- Note: Must always write at least one file, even for empty ByteString. -}
storeSplit :: MeterUpdate -> ChunkSize -> [FilePath] -> L.ByteString -> IO [FilePath]
storeSplit _ Nothing _ _ = error "bad storeSplit call"
storeSplit _ _ [] _ = error "bad storeSplit call"
storeSplit meterupdate (Just chunksize) alldests@(firstdest:_) b
| L.null b = do
-- must always write at least one file, even for empty
L.writeFile firstdest b
return [firstdest]
| otherwise = storeSplit' meterupdate chunksize alldests (L.toChunks b) []
storeSplit' :: MeterUpdate -> Int64 -> [FilePath] -> [S.ByteString] -> [FilePath] -> IO [FilePath]
storeSplit' _ _ [] _ _ = error "ran out of dests"
storeSplit' _ _ _ [] c = return $ reverse c
storeSplit' meterupdate chunksize (d:dests) bs c = do
bs' <- E.bracket (openFile d WriteMode) hClose $
feed zeroBytesProcessed chunksize bs
storeSplit' meterupdate chunksize dests bs' (d:c)
where
feed _ _ [] _ = return []
feed bytes sz (l:ls) h = do
let len = S.length l
let s = fromIntegral len
if s <= sz || sz == chunksize
then do
S.hPut h l
let bytes' = addBytesProcessed bytes len
meterupdate bytes'
feed bytes' (sz - s) ls h
else return (l:ls)
storeHelper :: FilePath -> ChunkSize -> Key -> Key -> ([FilePath] -> IO [FilePath]) -> Annex Bool
storeHelper d chunksize key origkey storer = check <&&> go
where
tmpdir = tmpDir d key
destdir = storeDir d key
{- An encrypted key does not have a known size,
- so check that the size of the original key is available as free
- space. -}
check = do
liftIO $ createDirectoryIfMissing True tmpdir
checkDiskSpace (Just tmpdir) origkey 0
go = liftIO $ catchBoolIO $
storeChunks key tmpdir destdir chunksize storer recorder finalizer
finalizer tmp dest = do
void $ tryIO $ allowWrite dest -- may already exist
void $ tryIO $ removeDirectoryRecursive dest -- or not exist
createDirectoryIfMissing True (parentDir dest)
renameDirectory tmp dest
-- may fail on some filesystems
void $ tryIO $ do
mapM_ preventWrite =<< dirContents dest
preventWrite dest
recorder f s = do
void $ tryIO $ allowWrite f
writeFile f s
void $ tryIO $ preventWrite f
retrieve :: FilePath -> ChunkSize -> Key -> AssociatedFile -> FilePath -> MeterUpdate -> Annex Bool
retrieve d chunksize k _ f p = metered (Just p) k $ \meterupdate ->
liftIO $ withStoredFiles chunksize d k $ \files ->
catchBoolIO $ do
meteredWriteFileChunks meterupdate f files $ L.readFile
return True
retrieveEncrypted :: FilePath -> ChunkSize -> (Cipher, Key) -> Key -> FilePath -> MeterUpdate -> Annex Bool
retrieveEncrypted d chunksize (cipher, enck) k f p = metered (Just p) k $ \meterupdate ->
liftIO $ withStoredFiles chunksize d enck $ \files ->
catchBoolIO $ do
decrypt cipher (feeder files) $
readBytes $ meteredWriteFile meterupdate f
return True
where
feeder files h = forM_ files $ \file -> L.hPut h =<< L.readFile file
retrieveCheap :: FilePath -> ChunkSize -> Key -> FilePath -> Annex Bool
retrieveCheap _ (Just _) _ _ = return False -- no cheap retrieval for chunks
#ifndef mingw32_HOST_OS
retrieveCheap d _ k f = liftIO $ withStoredFiles Nothing d k go
where
go [file] = catchBoolIO $ createSymbolicLink file f >> return True
go _files = return False
#else
retrieveCheap _ _ _ _ = return False
#endif
remove :: FilePath -> Key -> Annex Bool
remove d k = liftIO $ do
void $ tryIO $ allowWrite dir
#ifdef mingw32_HOST_OS
{- Windows needs the files inside the directory to be writable
- before it can delete them. -}
void $ tryIO $ mapM_ allowWrite =<< dirContents dir
#endif
catchBoolIO $ do
removeDirectoryRecursive dir
return True
where
dir = storeDir d k
checkPresent :: FilePath -> ChunkSize -> Key -> Annex (Either String Bool)
checkPresent d chunksize k = liftIO $ catchMsgIO $ withStoredFiles chunksize d k $
const $ return True -- withStoredFiles checked that it exists