git-annex/Command/Get.hs
Joey Hess 8dcf79694d
enable forwardRetry for command-line transfers
If a transfer fails for some reason, but some data managed to be sent, the
transfer will be retried. (The assistant already did this.)

Possible impacts:

* More ssh prompts if ssh needs to prompt for a password to connect to a
  host, or is prompting about some other problem like a ssh key mismatch.

* More data transfer due to retrying, epecially when a remote does not
  support resuming a transfer.

  In the worst case, a lot of data will be transferred but it fails before
  the end, and then all that data gets transferred again plus one byte more;
  repeat until it manages to get the whole file.
2016-10-26 15:38:27 -04:00

116 lines
3.5 KiB
Haskell

{- git-annex command
-
- Copyright 2010, 2013 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Command.Get where
import Command
import qualified Remote
import Annex.Content
import Annex.Transfer
import Annex.NumCopies
import Annex.Wanted
import qualified Command.Move
cmd :: Command
cmd = withGlobalOptions (jobsOption : jsonOption : jsonProgressOption : annexedMatchingOptions) $
command "get" SectionCommon
"make content of annexed files available"
paramPaths (seek <$$> optParser)
data GetOptions = GetOptions
{ getFiles :: CmdParams
, getFrom :: Maybe (DeferredParse Remote)
, autoMode :: Bool
, keyOptions :: Maybe KeyOptions
, batchOption :: BatchMode
}
optParser :: CmdParamsDesc -> Parser GetOptions
optParser desc = GetOptions
<$> cmdParams desc
<*> optional parseFromOption
<*> parseAutoOption
<*> optional (parseIncompleteOption <|> parseKeyOptions <|> parseFailedTransfersOption)
<*> parseBatchOption
seek :: GetOptions -> CommandSeek
seek o = allowConcurrentOutput $ do
from <- maybe (pure Nothing) (Just <$$> getParsed) (getFrom o)
let go = whenAnnexed $ start o from
case batchOption o of
Batch -> batchInput Right (batchCommandAction . go)
NoBatch -> withKeyOptions (keyOptions o) (autoMode o)
(startKeys from)
(withFilesInGit go)
(getFiles o)
start :: GetOptions -> Maybe Remote -> FilePath -> Key -> CommandStart
start o from file key = start' expensivecheck from key afile (mkActionItem afile)
where
afile = Just file
expensivecheck
| autoMode o = numCopiesCheck file key (<) <||> wantGet False (Just key) (Just file)
| otherwise = return True
startKeys :: Maybe Remote -> Key -> ActionItem -> CommandStart
startKeys from key ai = checkFailedTransferDirection ai Download $
start' (return True) from key Nothing ai
start' :: Annex Bool -> Maybe Remote -> Key -> AssociatedFile -> ActionItem -> CommandStart
start' expensivecheck from key afile ai = stopUnless (not <$> inAnnex key) $
stopUnless expensivecheck $
case from of
Nothing -> go $ perform key afile
Just src ->
stopUnless (Command.Move.fromOk src key) $
go $ Command.Move.fromPerform src False key afile
where
go a = do
showStart' "get" key ai
next a
perform :: Key -> AssociatedFile -> CommandPerform
perform key afile = stopUnless (getKey key afile) $
next $ return True -- no cleanup needed
{- Try to find a copy of the file in one of the remotes,
- and copy it to here. -}
getKey :: Key -> AssociatedFile -> Annex Bool
getKey key afile = getKey' key afile =<< Remote.keyPossibilities key
getKey' :: Key -> AssociatedFile -> [Remote] -> Annex Bool
getKey' key afile = dispatch
where
dispatch [] = do
showNote "not available"
showlocs
return False
dispatch remotes = notifyTransfer Download afile $ \witness -> do
ok <- pickRemote remotes $ \r -> ifM (probablyPresent r)
( docopy r witness
, return False
)
if ok
then return ok
else do
Remote.showTriedRemotes remotes
showlocs
return False
showlocs = Remote.showLocations False key []
"No other repository is known to contain the file."
-- This check is to avoid an ugly message if a remote is a
-- drive that is not mounted.
probablyPresent r
| Remote.hasKeyCheap r =
either (const False) id <$> Remote.hasKey r key
| otherwise = return True
docopy r witness = getViaTmp (RemoteVerify r) key $ \dest ->
download (Remote.uuid r) key afile forwardRetry
(\p -> do
showAction $ "from " ++ Remote.name r
Remote.retrieveKeyFile r key afile dest p
) witness