git-annex/Remote/List.hs
Joey Hess 6c565ec905 external special remotes mostly implemented (untested)
This has not been tested at all. It compiles!

The only known missing things are support for encryption, and for get/set
of special remote configuration, and of key state. (The latter needs
separate work to add a new per-key log file to store that state.)

Only thing I don't much like is that initremote needs to be passed both
type=external and externaltype=foo. It would be better to have just
type=foo

Most of this is quite straightforward code, that largely wrote itself given
the types. The only tricky parts were:

* Need to lock the remote when using it to eg make a request, because
  in theory git-annex could have multiple threads that each try to use
  a remote at the same time. I don't think that git-annex ever does
  that currently, but better safe than sorry.

* Rather than starting up every external special remote program when
  git-annex starts, they are started only on demand, when first used.
  This will avoid slowdown, especially when running fast git-annex query
  commands. Once started, they keep running until git-annex stops, currently,
  which may not be ideal, but it's hard to know a better time to stop them.

* Bit of a chicken and egg problem with caching the cost of the remote,
  because setting annex-cost in the git config needs the remote to already
  be set up. Managed to finesse that.

This commit was sponsored by Lukas Anzinger.
2013-12-26 18:23:13 -04:00

109 lines
2.6 KiB
Haskell

{-# LANGUAGE CPP #-}
{- git-annex remote list
-
- Copyright 2011,2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Remote.List where
import qualified Data.Map as M
import Common.Annex
import qualified Annex
import Logs.Remote
import Types.Remote
import Types.GitConfig
import Annex.UUID
import Remote.Helper.Hooks
import qualified Git
import qualified Git.Config
import qualified Remote.Git
import qualified Remote.GCrypt
#ifdef WITH_S3
import qualified Remote.S3
#endif
import qualified Remote.Bup
import qualified Remote.Directory
import qualified Remote.Rsync
import qualified Remote.Web
#ifdef WITH_WEBDAV
import qualified Remote.WebDAV
#endif
import qualified Remote.Glacier
import qualified Remote.Hook
import qualified Remote.External
remoteTypes :: [RemoteType]
remoteTypes =
[ Remote.Git.remote
, Remote.GCrypt.remote
#ifdef WITH_S3
, Remote.S3.remote
#endif
, Remote.Bup.remote
, Remote.Directory.remote
, Remote.Rsync.remote
, Remote.Web.remote
#ifdef WITH_WEBDAV
, Remote.WebDAV.remote
#endif
, Remote.Glacier.remote
, Remote.Hook.remote
, Remote.External.remote
]
{- Builds a list of all available Remotes.
- Since doing so can be expensive, the list is cached. -}
remoteList :: Annex [Remote]
remoteList = do
rs <- Annex.getState Annex.remotes
if null rs
then do
m <- readRemoteLog
rs' <- concat <$> mapM (process m) remoteTypes
Annex.changeState $ \s -> s { Annex.remotes = rs' }
return rs'
else return rs
where
process m t = enumerate t >>= mapM (remoteGen m t) >>= return . catMaybes
{- Forces the remoteList to be re-generated, re-reading the git config. -}
remoteListRefresh :: Annex [Remote]
remoteListRefresh = do
newg <- inRepo Git.Config.reRead
Annex.changeState $ \s -> s
{ Annex.remotes = []
, Annex.repo = newg
}
remoteList
{- Generates a Remote. -}
remoteGen :: M.Map UUID RemoteConfig -> RemoteType -> Git.Repo -> Annex (Maybe Remote)
remoteGen m t r = do
u <- getRepoUUID r
g <- fromRepo id
let gc = extractRemoteGitConfig g (Git.repoDescribe r)
let c = fromMaybe M.empty $ M.lookup u m
mrmt <- generate t r u c gc
return $ addHooks <$> mrmt
{- Updates a local git Remote, re-reading its git config. -}
updateRemote :: Remote -> Annex (Maybe Remote)
updateRemote remote = do
m <- readRemoteLog
remote' <- updaterepo $ repo remote
remoteGen m (remotetype remote) remote'
where
updaterepo r
| Git.repoIsLocal r || Git.repoIsLocalUnknown r =
Remote.Git.configRead r
| otherwise = return r
{- Checks if a remote is syncable using git. -}
syncableRemote :: Remote -> Bool
syncableRemote r = remotetype r `elem`
[ Remote.Git.remote, Remote.GCrypt.remote ]