git-annex/Remote/Helper/Special.hs
Joey Hess a0297915c1 add per-remote-type info
Now `git annex info $remote` shows info specific to the type of the remote,
for example, it shows the rsync url.

Remote types that support encryption or chunking also include that in their
info.

This commit was sponsored by Ævar Arnfjörð Bjarmason.
2014-10-21 14:36:09 -04:00

275 lines
8.6 KiB
Haskell

{- helpers for special remotes
-
- Copyright 2011-2014 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Remote.Helper.Special (
findSpecialRemotes,
gitConfigSpecialRemote,
Preparer,
Storer,
Retriever,
Remover,
CheckPresent,
simplyPrepare,
ContentSource,
checkPrepare,
resourcePrepare,
fileStorer,
byteStorer,
fileRetriever,
byteRetriever,
storeKeyDummy,
retreiveKeyFileDummy,
removeKeyDummy,
checkPresentDummy,
SpecialRemoteCfg(..),
specialRemoteCfg,
specialRemote,
specialRemote',
module X
) where
import Common.Annex
import Types.StoreRetrieve
import Types.Remote
import Crypto
import Config.Cost
import Utility.Metered
import Remote.Helper.Chunked as X
import Remote.Helper.Encryptable as X
import Remote.Helper.Messages
import Annex.Content
import qualified Git
import qualified Git.Command
import qualified Git.Construct
import qualified Data.ByteString.Lazy as L
import qualified Data.Map as M
{- Special remotes don't have a configured url, so Git.Repo does not
- automatically generate remotes for them. This looks for a different
- configuration key instead.
-}
findSpecialRemotes :: String -> Annex [Git.Repo]
findSpecialRemotes s = do
m <- fromRepo Git.config
liftIO $ mapM construct $ remotepairs m
where
remotepairs = M.toList . M.filterWithKey match
construct (k,_) = Git.Construct.remoteNamedFromKey k Git.Construct.fromUnknown
match k _ = startswith "remote." k && endswith (".annex-"++s) k
{- Sets up configuration for a special remote in .git/config. -}
gitConfigSpecialRemote :: UUID -> RemoteConfig -> String -> String -> Annex ()
gitConfigSpecialRemote u c k v = do
set ("annex-"++k) v
set ("annex-uuid") (fromUUID u)
where
set a b = inRepo $ Git.Command.run
[Param "config", Param (configsetting a), Param b]
remotename = fromJust (M.lookup "name" c)
configsetting s = "remote." ++ remotename ++ "." ++ s
-- Use when nothing needs to be done to prepare a helper.
simplyPrepare :: helper -> Preparer helper
simplyPrepare helper _ a = a $ Just helper
-- Use to run a check when preparing a helper.
checkPrepare :: (Key -> Annex Bool) -> helper -> Preparer helper
checkPrepare checker helper k a = ifM (checker k)
( a (Just helper)
, a Nothing
)
-- Use to acquire a resource when preparing a helper.
resourcePrepare :: (Key -> (r -> Annex Bool) -> Annex Bool) -> (r -> helper) -> Preparer helper
resourcePrepare withr helper k a = withr k $ \r ->
a (Just (helper r))
-- A Storer that expects to be provided with a file containing
-- the content of the key to store.
fileStorer :: (Key -> FilePath -> MeterUpdate -> Annex Bool) -> Storer
fileStorer a k (FileContent f) m = a k f m
fileStorer a k (ByteContent b) m = withTmp k $ \f -> do
liftIO $ L.writeFile f b
a k f m
-- A Storer that expects to be provided with a L.ByteString of
-- the content to store.
byteStorer :: (Key -> L.ByteString -> MeterUpdate -> Annex Bool) -> Storer
byteStorer a k c m = withBytes c $ \b -> a k b m
-- A Retriever that writes the content of a Key to a provided file.
-- It is responsible for updating the progress meter as it retrieves data.
fileRetriever :: (FilePath -> Key -> MeterUpdate -> Annex ()) -> Retriever
fileRetriever a k m callback = do
f <- prepTmp k
a f k m
callback (FileContent f)
-- A Retriever that generates a lazy ByteString containing the Key's
-- content, and passes it to a callback action which will fully consume it
-- before returning.
byteRetriever :: (Key -> (L.ByteString -> Annex Bool) -> Annex Bool) -> Retriever
byteRetriever a k _m callback = a k (callback . ByteContent)
{- The base Remote that is provided to specialRemote needs to have
- storeKey, retrieveKeyFile, removeKey, and checkPresent methods,
- but they are never actually used (since specialRemote replaces them).
- Here are some dummy ones.
-}
storeKeyDummy :: Key -> AssociatedFile -> MeterUpdate -> Annex Bool
storeKeyDummy _ _ _ = return False
retreiveKeyFileDummy :: Key -> AssociatedFile -> FilePath -> MeterUpdate -> Annex Bool
retreiveKeyFileDummy _ _ _ _ = return False
removeKeyDummy :: Key -> Annex Bool
removeKeyDummy _ = return False
checkPresentDummy :: Key -> Annex Bool
checkPresentDummy _ = error "missing checkPresent implementation"
type RemoteModifier
= RemoteConfig
-> Preparer Storer
-> Preparer Retriever
-> Preparer Remover
-> Preparer CheckPresent
-> Remote
-> Remote
data SpecialRemoteCfg = SpecialRemoteCfg
{ chunkConfig :: ChunkConfig
, displayProgress :: Bool
}
specialRemoteCfg :: RemoteConfig -> SpecialRemoteCfg
specialRemoteCfg c = SpecialRemoteCfg (getChunkConfig c) True
-- Modifies a base Remote to support both chunking and encryption,
-- which special remotes typically should support.
specialRemote :: RemoteModifier
specialRemote c = specialRemote' (specialRemoteCfg c) c
specialRemote' :: SpecialRemoteCfg -> RemoteModifier
specialRemote' cfg c preparestorer prepareretriever prepareremover preparecheckpresent baser = encr
where
encr = baser
{ storeKey = \k _f p -> cip >>= storeKeyGen k p
, retrieveKeyFile = \k _f d p -> cip >>= retrieveKeyFileGen k d p
, retrieveKeyFileCheap = \k d -> cip >>= maybe
(retrieveKeyFileCheap baser k d)
-- retrieval of encrypted keys is never cheap
(\_ -> return False)
, removeKey = \k -> cip >>= removeKeyGen k
, checkPresent = \k -> cip >>= checkPresentGen k
, cost = maybe
(cost baser)
(const $ cost baser + encryptedRemoteCostAdj)
(extractCipher c)
, getInfo = do
l <- getInfo baser
return $ l ++
[ ("encryption", describeEncryption c)
, ("chunking", describeChunkConfig (chunkConfig cfg))
]
}
cip = cipherKey c
gpgopts = getGpgEncParams encr
safely a = catchNonAsync a (\e -> warning (show e) >> return False)
-- chunk, then encrypt, then feed to the storer
storeKeyGen k p enc = safely $ preparestorer k $ safely . go
where
go (Just storer) = sendAnnex k rollback $ \src ->
displayprogress p k $ \p' ->
storeChunks (uuid baser) chunkconfig k src p'
(storechunk enc storer)
(checkPresent baser)
go Nothing = return False
rollback = void $ removeKey encr k
storechunk Nothing storer k content p = storer k content p
storechunk (Just (cipher, enck)) storer k content p =
withBytes content $ \b ->
encrypt gpgopts cipher (feedBytes b) $
readBytes $ \encb ->
storer (enck k) (ByteContent encb) p
-- call retrieve-r to get chunks; decrypt them; stream to dest file
retrieveKeyFileGen k dest p enc =
safely $ prepareretriever k $ safely . go
where
go (Just retriever) = displayprogress p k $ \p' ->
retrieveChunks retriever (uuid baser) chunkconfig
enck k dest p' (sink dest enc)
go Nothing = return False
enck = maybe id snd enc
removeKeyGen k enc = safely $ prepareremover k $ safely . go
where
go (Just remover) = removeChunks remover (uuid baser) chunkconfig enck k
go Nothing = return False
enck = maybe id snd enc
checkPresentGen k enc = preparecheckpresent k go
where
go (Just checker) = checkPresentChunks checker (uuid baser) chunkconfig enck k
go Nothing = cantCheck baser
enck = maybe id snd enc
chunkconfig = chunkConfig cfg
displayprogress p k a
| displayProgress cfg = metered (Just p) k a
| otherwise = a p
{- Sink callback for retrieveChunks. Stores the file content into the
- provided Handle, decrypting it first if necessary.
-
- If the remote did not store the content using chunks, no Handle
- will be provided, and it's up to us to open the destination file.
-
- Note that when neither chunking nor encryption is used, and the remote
- provides FileContent, that file only needs to be renamed
- into place. (And it may even already be in the right place..)
-}
sink
:: FilePath
-> Maybe (Cipher, EncKey)
-> Maybe Handle
-> Maybe MeterUpdate
-> ContentSource
-> Annex Bool
sink dest enc mh mp content = do
case (enc, mh, content) of
(Nothing, Nothing, FileContent f)
| f == dest -> noop
| otherwise -> liftIO $ moveFile f dest
(Just (cipher, _), _, ByteContent b) ->
decrypt cipher (feedBytes b) $
readBytes write
(Just (cipher, _), _, FileContent f) -> do
withBytes content $ \b ->
decrypt cipher (feedBytes b) $
readBytes write
liftIO $ nukeFile f
(Nothing, _, FileContent f) -> do
withBytes content write
liftIO $ nukeFile f
(Nothing, _, ByteContent b) -> write b
return True
where
write b = case mh of
Just h -> liftIO $ b `streamto` h
Nothing -> liftIO $ bracket opendest hClose (b `streamto`)
streamto b h = case mp of
Just p -> meteredWrite p h b
Nothing -> L.hPut h b
opendest = openBinaryFile dest WriteMode
withBytes :: ContentSource -> (L.ByteString -> Annex a) -> Annex a
withBytes (ByteContent b) a = a b
withBytes (FileContent f) a = a =<< liftIO (L.readFile f)