add RemoteStateHandle

This solves the problem of sameas remotes trampling over per-remote
state. Used for:

* per-remote state, of course
* per-remote metadata, also of course
* per-remote content identifiers, because two remote implementations
  could in theory generate the same content identifier for two different
  peices of content

While chunk logs are per-remote data, they don't use this, because the
number and size of chunks stored is a common property across sameas
remotes.

External special remote had a complication, where it was theoretically
possible for a remote to send SETSTATE or GETSTATE during INITREMOTE or
EXPORTSUPPORTED. Since the uuid of the remote is typically generate in
Remote.setup, it would only be possible to pass a Maybe
RemoteStateHandle into it, and it would otherwise have to construct its
own. Rather than go that route, I decided to send an ERROR in this case.
It seems unlikely that any existing external special remote will be
affected. They would have to make up a git-annex key, and set state for
some reason during INITREMOTE. I can imagine such a hack, but it doesn't
seem worth complicating the code in such an ugly way to support it.

Unfortunately, both TestRemote and Annex.Import needed the Remote
to have a new field added that holds its RemoteStateHandle.
This commit is contained in:
Joey Hess 2019-10-14 12:33:27 -04:00
parent 37f0abbca8
commit 9828f45d85
No known key found for this signature in database
GPG key ID: DB12DB0FF05F8F38
31 changed files with 274 additions and 209 deletions

View file

@ -11,6 +11,7 @@ module Logs.RemoteState (
) where
import Annex.Common
import Types.RemoteState
import Logs
import Logs.UUIDBased
import qualified Annex.Branch
@ -23,8 +24,8 @@ import Data.ByteString.Builder
type RemoteState = String
setRemoteState :: UUID -> Key -> RemoteState -> Annex ()
setRemoteState u k s = do
setRemoteState :: RemoteStateHandle -> Key -> RemoteState -> Annex ()
setRemoteState (RemoteStateHandle u) k s = do
c <- liftIO currentVectorClock
config <- Annex.getGitConfig
Annex.Branch.change (remoteStateLogFile config k) $
@ -33,8 +34,8 @@ setRemoteState u k s = do
buildRemoteState :: Log RemoteState -> Builder
buildRemoteState = buildLogNew (byteString . encodeBS)
getRemoteState :: UUID -> Key -> Annex (Maybe RemoteState)
getRemoteState u k = do
getRemoteState :: RemoteStateHandle -> Key -> Annex (Maybe RemoteState)
getRemoteState (RemoteStateHandle u) k = do
config <- Annex.getGitConfig
extract . parseRemoteState
<$> Annex.Branch.get (remoteStateLogFile config k)