git-annex/Types/Remote.hs
Joey Hess 5fe49b98f8 Support hot-swapping of removable drives containing gcrypt repositories.
To support this, a core.gcrypt-id is stored by git-annex inside the git
config of a local gcrypt repository, when setting it up.

That is compared with the remote's cached gcrypt-id. When different, a
drive has been changed. git-annex then looks up the remote config for
the uuid mapped from the core.gcrypt-id, and tweaks the configuration
appropriately. When there is no known config for the uuid, it will refuse to
use the remote.
2013-09-12 15:54:35 -04:00

90 lines
2.8 KiB
Haskell

{- git-annex remotes types
-
- Most things should not need this, using Types instead
-
- Copyright 2011 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Types.Remote where
import Data.Map as M
import Data.Ord
import qualified Git
import Types.Key
import Types.UUID
import Types.GitConfig
import Config.Cost
import Utility.Metered
type RemoteConfigKey = String
type RemoteConfig = M.Map RemoteConfigKey String
{- There are different types of remotes. -}
data RemoteTypeA a = RemoteType {
-- human visible type name
typename :: String,
-- enumerates remotes of this type
enumerate :: a [Git.Repo],
-- generates a remote of this type
generate :: Git.Repo -> UUID -> RemoteConfig -> RemoteGitConfig -> a (Maybe (RemoteA a)),
-- initializes or changes a remote
setup :: Maybe UUID -> RemoteConfig -> a (RemoteConfig, UUID)
}
instance Eq (RemoteTypeA a) where
x == y = typename x == typename y
{- An individual remote. -}
data RemoteA a = Remote {
-- each Remote has a unique uuid
uuid :: UUID,
-- each Remote has a human visible name
name :: String,
-- Remotes have a use cost; higher is more expensive
cost :: Cost,
-- Transfers a key to the remote.
storeKey :: Key -> AssociatedFile -> MeterUpdate -> a Bool,
-- Retrieves a key's contents to a file.
-- (The MeterUpdate does not need to be used if it retrieves
-- directly to the file, and not to an intermediate file.)
retrieveKeyFile :: Key -> AssociatedFile -> FilePath -> MeterUpdate -> a Bool,
-- retrieves a key's contents to a tmp file, if it can be done cheaply
retrieveKeyFileCheap :: Key -> FilePath -> a Bool,
-- removes a key's contents
removeKey :: Key -> a Bool,
-- Checks if a key is present in the remote; if the remote
-- cannot be accessed returns a Left error message.
hasKey :: Key -> a (Either String Bool),
-- Some remotes can check hasKey without an expensive network
-- operation.
hasKeyCheap :: Bool,
-- Some remotes can provide additional details for whereis.
whereisKey :: Maybe (Key -> a [String]),
-- a Remote has a persistent configuration store
config :: RemoteConfig,
-- git repo for the Remote
repo :: Git.Repo,
-- a Remote's configuration from git
gitconfig :: RemoteGitConfig,
-- a Remote can be assocated with a specific local filesystem path
localpath :: Maybe FilePath,
-- a Remote can be known to be readonly
readonly :: Bool,
-- a Remote can be globally available. (Ie, "in the cloud".)
globallyAvailable :: Bool,
-- the type of the remote
remotetype :: RemoteTypeA a
}
instance Show (RemoteA a) where
show remote = "Remote { name =\"" ++ name remote ++ "\" }"
-- two remotes are the same if they have the same uuid
instance Eq (RemoteA a) where
x == y = uuid x == uuid y
instance Ord (RemoteA a) where
compare = comparing uuid