git-annex/Command/Get.hs
Joey Hess 9f1577f746 remove unused backend machinery
The only remaining vestiage of backends is different types of keys. These
are still called "backends", mostly to avoid needing to change user interface
and configuration. But everything to do with storing keys in different
backends was gone; instead different types of remotes are used.

In the refactoring, lots of code was moved out of odd corners like
Backend.File, to closer to where it's used, like Command.Drop and
Command.Fsck. Quite a lot of dead code was removed. Several data structures
became simpler, which may result in better runtime efficiency. There should
be no user-visible changes.
2011-07-05 19:57:46 -04:00

82 lines
1.9 KiB
Haskell

{- git-annex command
-
- Copyright 2010 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Command.Get where
import Command
import qualified Annex
import qualified Remote
import Types
import Content
import Messages
import qualified Command.Move
command :: [Command]
command = [repoCommand "get" paramPath seek
"make content of annexed files available"]
seek :: [CommandSeek]
seek = [withFilesInGit start]
start :: CommandStartString
start file = isAnnexed file $ \(key, _) -> do
inannex <- inAnnex key
if inannex
then stop
else do
showStart "get" file
from <- Annex.getState Annex.fromremote
case from of
Nothing -> next $ perform key
Just name -> do
src <- Remote.byName name
next $ Command.Move.fromPerform src False key
perform :: Key -> CommandPerform
perform key = do
ok <- getViaTmp key (getKeyFile key)
if ok
then next $ return True -- no cleanup needed
else stop
{- Try to find a copy of the file in one of the remotes,
- and copy it to here. -}
getKeyFile :: Key -> FilePath -> Annex Bool
getKeyFile key file = do
remotes <- Remote.keyPossibilities key
if null remotes
then do
showNote "not available"
Remote.showLocations key []
return False
else trycopy remotes remotes
where
trycopy full [] = do
Remote.showTriedRemotes full
Remote.showLocations key []
return False
trycopy full (r:rs) = do
probablythere <- probablyPresent r
if probablythere
then docopy r (trycopy full rs)
else trycopy full rs
-- This check is to avoid an ugly message if a remote is a
-- drive that is not mounted.
probablyPresent r =
if Remote.hasKeyCheap r
then do
res <- Remote.hasKey r key
case res of
Right b -> return b
Left _ -> return False
else return True
docopy r continue = do
showNote $ "from " ++ Remote.name r ++ "..."
copied <- Remote.retrieveKeyFile r key file
if copied
then return True
else continue