367 lines
14 KiB
Haskell
367 lines
14 KiB
Haskell
{- git-annex remotes types
|
|
-
|
|
- Most things should not need this, using Types instead
|
|
-
|
|
- Copyright 2011-2020 Joey Hess <id@joeyh.name>
|
|
-
|
|
- Licensed under the GNU AGPL version 3 or higher.
|
|
-}
|
|
|
|
{-# LANGUAGE RankNTypes #-}
|
|
|
|
module Types.Remote
|
|
( module Types.RemoteConfig
|
|
, RemoteTypeA(..)
|
|
, RemoteA(..)
|
|
, RemoteStateHandle
|
|
, SetupStage(..)
|
|
, Availability(..)
|
|
, Verification(..)
|
|
, unVerified
|
|
, RetrievalSecurityPolicy(..)
|
|
, isExportSupported
|
|
, isImportSupported
|
|
, ExportActions(..)
|
|
, ImportActions(..)
|
|
, ByteSize
|
|
)
|
|
where
|
|
|
|
import Data.Ord
|
|
|
|
import qualified Git
|
|
import Types.Key
|
|
import Types.UUID
|
|
import Types.GitConfig
|
|
import Types.Availability
|
|
import Types.Creds
|
|
import Types.RemoteState
|
|
import Types.UrlContents
|
|
import Types.NumCopies
|
|
import Types.Export
|
|
import Types.Import
|
|
import Types.RemoteConfig
|
|
import Config.Cost
|
|
import Utility.Metered
|
|
import Git.Types (RemoteName)
|
|
import Utility.SafeCommand
|
|
import Utility.Url
|
|
import Utility.DataUnits
|
|
|
|
data SetupStage = Init | Enable RemoteConfig
|
|
|
|
{- There are different types of remotes. -}
|
|
data RemoteTypeA a = RemoteType
|
|
-- human visible type name
|
|
{ typename :: String
|
|
-- enumerates remotes of this type
|
|
-- The Bool is True if automatic initialization of remotes is desired
|
|
, enumerate :: Bool -> a [Git.Repo]
|
|
-- generates a remote of this type
|
|
, generate :: Git.Repo -> UUID -> RemoteConfig -> RemoteGitConfig -> RemoteStateHandle -> a (Maybe (RemoteA a))
|
|
-- parse configs of remotes of this type
|
|
, configParser :: RemoteConfig -> a RemoteConfigParser
|
|
-- initializes or enables a remote
|
|
, setup :: SetupStage -> Maybe UUID -> Maybe CredPair -> RemoteConfig -> RemoteGitConfig -> a (RemoteConfig, UUID)
|
|
-- check if a remote of this type is able to support export
|
|
, exportSupported :: ParsedRemoteConfig -> RemoteGitConfig -> a Bool
|
|
-- check if a remote of this type is able to support import
|
|
, importSupported :: ParsedRemoteConfig -> RemoteGitConfig -> a Bool
|
|
}
|
|
|
|
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 :: RemoteName
|
|
-- Remotes have a use cost; higher is more expensive
|
|
, cost :: Cost
|
|
|
|
-- Transfers a key's contents from disk to the remote.
|
|
-- The key should not appear to be present on the remote until
|
|
-- all of its contents have been transferred.
|
|
-- Throws exception on failure.
|
|
, storeKey :: Key -> AssociatedFile -> MeterUpdate -> a ()
|
|
-- Retrieves a key's contents to a file.
|
|
-- (The MeterUpdate does not need to be used if it writes
|
|
-- sequentially to the file.)
|
|
-- Throws exception on failure.
|
|
, retrieveKeyFile :: Key -> AssociatedFile -> FilePath -> MeterUpdate -> a Verification
|
|
-- Retrieves a key's contents to a tmp file, if it can be done cheaply.
|
|
-- It's ok to create a symlink or hardlink.
|
|
-- Throws exception on failure.
|
|
, retrieveKeyFileCheap :: Maybe (Key -> AssociatedFile -> FilePath -> a ())
|
|
-- Security policy for reteiving keys from this remote.
|
|
, retrievalSecurityPolicy :: RetrievalSecurityPolicy
|
|
-- Removes a key's contents (succeeds even the contents are not present)
|
|
-- Can throw exception if unable to access remote, or if remote
|
|
-- refuses to remove the content.
|
|
, removeKey :: Key -> a ()
|
|
-- Uses locking to prevent removal of a key's contents,
|
|
-- thus producing a VerifiedCopy, which is passed to the callback.
|
|
-- If unable to lock, does not run the callback, and throws an
|
|
-- exception.
|
|
-- This is optional; remotes do not have to support locking.
|
|
, lockContent :: forall r. Maybe (Key -> (VerifiedCopy -> a r) -> a r)
|
|
-- Checks if a key is present in the remote.
|
|
-- Throws an exception if the remote cannot be accessed.
|
|
, checkPresent :: Key -> a Bool
|
|
-- Some remotes can checkPresent without an expensive network
|
|
-- operation.
|
|
, checkPresentCheap :: Bool
|
|
-- Some remotes support export of trees.
|
|
, exportActions :: ExportActions a
|
|
-- Some remotes support import of trees.
|
|
, importActions :: ImportActions a
|
|
-- Some remotes can provide additional details for whereis.
|
|
, whereisKey :: Maybe (Key -> a [String])
|
|
-- Some remotes can run a fsck operation on the remote,
|
|
-- without transferring all the data to the local repo
|
|
-- The parameters are passed to the fsck command on the remote.
|
|
, remoteFsck :: Maybe ([CommandParam] -> a (IO Bool))
|
|
-- Runs an action to repair the remote's git repository.
|
|
, repairRepo :: Maybe (a Bool -> a (IO Bool))
|
|
-- a Remote has a persistent configuration store
|
|
, config :: ParsedRemoteConfig
|
|
-- Get the git repo for the Remote.
|
|
, getRepo :: a 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 allow writes but not have a way to delete content
|
|
-- from it. Note that an export remote that supports removeExport
|
|
-- to remove a file from the exported tree, but still retains the
|
|
-- content in accessible form should set this to True.
|
|
, appendonly :: Bool
|
|
-- a Remote can be globally available. (Ie, "in the cloud".)
|
|
, availability :: Availability
|
|
-- the type of the remote
|
|
, remotetype :: RemoteTypeA a
|
|
-- For testing, makes a version of this remote that is not
|
|
-- available for use. All its actions should fail.
|
|
, mkUnavailable :: a (Maybe (RemoteA a))
|
|
-- Information about the remote, for git annex info to display.
|
|
, getInfo :: a [(String, String)]
|
|
-- Some remotes can download from an url (or uri). This asks the
|
|
-- remote if it can handle a particular url. The actual download
|
|
-- will be done using retrieveKeyFile, and the remote can look up
|
|
-- up the url to download for a key using Logs.Web.getUrls.
|
|
, claimUrl :: Maybe (URLString -> a Bool)
|
|
-- Checks that the url is accessible, and gets information about
|
|
-- its contents, without downloading the full content.
|
|
-- Throws an exception if the url is inaccessible.
|
|
, checkUrl :: Maybe (URLString -> a UrlContents)
|
|
, remoteStateHandle :: RemoteStateHandle
|
|
}
|
|
|
|
instance RemoteNameable (RemoteA a) where
|
|
getRemoteName = name
|
|
|
|
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
|
|
|
|
-- Order by cost since that is the important order of remotes
|
|
-- when deciding which to use. But since remotes often have the same cost
|
|
-- and Ord must be total, do a secondary ordering by uuid.
|
|
instance Ord (RemoteA a) where
|
|
compare a b
|
|
| cost a == cost b = comparing uuid a b
|
|
| otherwise = comparing cost a b
|
|
|
|
instance ToUUID (RemoteA a) where
|
|
toUUID = uuid
|
|
|
|
data Verification
|
|
= UnVerified
|
|
-- ^ Content was not verified during transfer, but is probably
|
|
-- ok, so if verification is disabled, don't verify it
|
|
| Verified
|
|
-- ^ Content was verified during transfer, so don't verify it
|
|
-- again.
|
|
| MustVerify
|
|
-- ^ Content likely to have been altered during transfer,
|
|
-- verify even if verification is normally disabled
|
|
deriving (Show)
|
|
|
|
unVerified :: Monad m => m a -> m (a, Verification)
|
|
unVerified a = do
|
|
ok <- a
|
|
return (ok, UnVerified)
|
|
|
|
-- Security policy indicating what keys can be safely retrieved from a
|
|
-- remote.
|
|
data RetrievalSecurityPolicy
|
|
= RetrievalVerifiableKeysSecure
|
|
-- ^ Transfer of keys whose content can be verified
|
|
-- with a hash check is secure; transfer of unverifiable keys is
|
|
-- not secure and should not be allowed.
|
|
--
|
|
-- This is used eg, when HTTP to a remote could be redirected to a
|
|
-- local private web server or even a file:// url, causing private
|
|
-- data from it that is not the intended content of a key to make
|
|
-- its way into the git-annex repository.
|
|
--
|
|
-- It's also used when content is stored encrypted on a remote,
|
|
-- which could replace it with a different encrypted file, and
|
|
-- trick git-annex into decrypting it and leaking the decryption
|
|
-- into the git-annex repository.
|
|
--
|
|
-- It's not (currently) used when the remote could alter the
|
|
-- content stored on it, because git-annex does not provide
|
|
-- strong guarantees about the content of keys that cannot be
|
|
-- verified with a hash check.
|
|
-- (But annex.securehashesonly does provide such guarantees.)
|
|
| RetrievalAllKeysSecure
|
|
-- ^ Any key can be securely retrieved.
|
|
|
|
isExportSupported :: RemoteA a -> a Bool
|
|
isExportSupported r = exportSupported (remotetype r) (config r) (gitconfig r)
|
|
|
|
isImportSupported :: RemoteA a -> a Bool
|
|
isImportSupported r = importSupported (remotetype r) (config r) (gitconfig r)
|
|
|
|
data ExportActions a = ExportActions
|
|
-- Exports content to an ExportLocation.
|
|
-- The exported file should not appear to be present on the remote
|
|
-- until all of its contents have been transferred.
|
|
-- Throws exception on failure.
|
|
{ storeExport :: FilePath -> Key -> ExportLocation -> MeterUpdate -> a ()
|
|
-- Retrieves exported content to a file.
|
|
-- (The MeterUpdate does not need to be used if it writes
|
|
-- sequentially to the file.)
|
|
-- Throws exception on failure.
|
|
, retrieveExport :: Key -> ExportLocation -> FilePath -> MeterUpdate -> a ()
|
|
-- Removes an exported file (succeeds if the contents are not present)
|
|
-- Can throw exception if unable to access remote, or if remote
|
|
-- refuses to remove the content.
|
|
, removeExport :: Key -> ExportLocation -> a ()
|
|
-- Removes an exported directory. Typically the directory will be
|
|
-- empty, but it could possibly contain files or other directories,
|
|
-- and it's ok to delete those (but not required to).
|
|
-- If the remote does not use directories, or automatically cleans
|
|
-- up empty directories, this can be Nothing.
|
|
--
|
|
-- Should not fail if the directory was already removed.
|
|
--
|
|
-- Throws exception if unable to contact the remote, or perhaps if
|
|
-- the remote refuses to let the directory be removed.
|
|
, removeExportDirectory :: Maybe (ExportDirectory -> a ())
|
|
-- Checks if anything is exported to the remote at the specified
|
|
-- ExportLocation.
|
|
-- Throws an exception if the remote cannot be accessed.
|
|
, checkPresentExport :: Key -> ExportLocation -> a Bool
|
|
-- Renames an already exported file.
|
|
--
|
|
-- If the remote does not support renames, it can return Nothing.
|
|
--
|
|
-- Throws an exception if the remote cannot be accessed, or
|
|
-- the file doesn't exist or cannot be renamed.
|
|
, renameExport :: Key -> ExportLocation -> ExportLocation -> a (Maybe ())
|
|
}
|
|
|
|
data ImportActions a = ImportActions
|
|
-- Finds the current set of files that are stored in the remote,
|
|
-- along with their content identifiers and size.
|
|
--
|
|
-- May also find old versions of files that are still stored in the
|
|
-- remote.
|
|
{ listImportableContents :: a (Maybe (ImportableContents (ContentIdentifier, ByteSize)))
|
|
-- Imports a file from the remote, without downloading it,
|
|
-- by generating a Key (of any type).
|
|
--
|
|
-- May update the progress meter if it needs to perform an
|
|
-- expensive operation, such as hashing a local file.
|
|
--
|
|
-- Ensures that the key corresponds to the ContentIdentifier,
|
|
-- bearing in mind that the file on the remote may have changed
|
|
-- since the ContentIdentifier was generated.
|
|
--
|
|
-- Throws exception on failure.
|
|
, importKey :: Maybe (ExportLocation -> ContentIdentifier -> MeterUpdate -> a Key)
|
|
-- Retrieves a file from the remote. Ensures that the file
|
|
-- it retrieves has the requested ContentIdentifier.
|
|
--
|
|
-- This has to be used rather than retrieveExport
|
|
-- when a special remote supports imports, since files on such a
|
|
-- special remote can be changed at any time.
|
|
--
|
|
-- Throws exception on failure.
|
|
, retrieveExportWithContentIdentifier
|
|
:: ExportLocation
|
|
-> ContentIdentifier
|
|
-- file to write content to
|
|
-> FilePath
|
|
-- callback that generates a key from the downloaded content
|
|
-> a Key
|
|
-> MeterUpdate
|
|
-> a Key
|
|
-- Exports content to an ExportLocation, and returns the
|
|
-- ContentIdentifier corresponding to the content it stored.
|
|
--
|
|
-- This is used rather than storeExport when a special remote
|
|
-- supports imports, since files on such a special remote can be
|
|
-- changed at any time.
|
|
--
|
|
-- Since other things can modify the same file on the special
|
|
-- remote, this must take care to not overwrite such modifications,
|
|
-- and only overwrite a file that has one of the ContentIdentifiers
|
|
-- passed to it, unless listContents can recover an overwritten file.
|
|
--
|
|
-- Also, since there can be concurrent writers, the implementation
|
|
-- needs to make sure that the ContentIdentifier it returns
|
|
-- corresponds to what it wrote, not to what some other writer
|
|
-- wrote.
|
|
--
|
|
-- Throws exception on failure.
|
|
, storeExportWithContentIdentifier
|
|
:: FilePath
|
|
-> Key
|
|
-> ExportLocation
|
|
-- old content that it's safe to overwrite
|
|
-> [ContentIdentifier]
|
|
-> MeterUpdate
|
|
-> a ContentIdentifier
|
|
-- This is used rather than removeExport when a special remote
|
|
-- supports imports.
|
|
--
|
|
-- It should only remove a file from the remote when it has one
|
|
-- of the ContentIdentifiers passed to it, unless listContents
|
|
-- can recover an overwritten file.
|
|
--
|
|
-- It needs to handle races similar to storeExportWithContentIdentifier.
|
|
--
|
|
-- Throws an exception when unable to remove.
|
|
, removeExportWithContentIdentifier
|
|
:: Key
|
|
-> ExportLocation
|
|
-> [ContentIdentifier]
|
|
-> a ()
|
|
-- Removes a directory from the export, but only when it's empty.
|
|
-- Used instead of removeExportDirectory when a special remote
|
|
-- supports imports.
|
|
--
|
|
-- If the directory is not empty, it should succeed.
|
|
--
|
|
-- Throws exception if unable to contact the remote, or perhaps if
|
|
-- the remote refuses to let the directory be removed.
|
|
, removeExportDirectoryWhenEmpty :: Maybe (ExportDirectory -> a ())
|
|
-- Checks if the specified ContentIdentifier is exported to the
|
|
-- remote at the specified ExportLocation.
|
|
-- Throws an exception if the remote cannot be accessed.
|
|
, checkPresentExportWithContentIdentifier
|
|
:: Key
|
|
-> ExportLocation
|
|
-> [ContentIdentifier]
|
|
-> a Bool
|
|
}
|