git-annex/Command/Mirror.hs
Joey Hess 9d36c826c0
use fine-grained WorkerStages when transferring and verifying
This means that Command.Move and Command.Get don't need to
manually set the stage, and is a lot cleaner conceptually.

Also, this makes Command.Sync.syncFile use the worker pool better.
In the scenario where it first downloads content and then uploads it to
some other remotes, it will start in TransferStage, then enter VerifyStage
and then go back to TransferStage for each transfer to the remotes.
Before, it entered CleanupStage after the download, and stayed in it for
the upload, so too many transfer jobs could run at the same time.

Note that, in Remote.Git, it uses runTransfer and also verifyKeyContent
inside onLocal. That has a Annex state for the remote, with no worker pool.
So the resulting calls to enteringStage won't block in there.

While Remote.Git.copyToRemote does do checksum verification, I
realized that should not use a verification slot in the WorkerPool
to do it. Because, it's reading back from eg, a removable disk to checksum.
That will contend with other writes to that disk. It's best to treat
that checksum verification as just part of the transer. So, removed the todo
item about that, as there's nothing needing to be done.
2019-06-19 13:24:20 -04:00

78 lines
2.4 KiB
Haskell

{- git-annex command
-
- Copyright 2013 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Command.Mirror where
import Command
import qualified Command.Move
import qualified Command.Drop
import qualified Command.Get
import qualified Remote
import Annex.Content
import Annex.NumCopies
import Types.Transfer
cmd :: Command
cmd = withGlobalOptions [jobsOption, jsonOptions, jsonProgressOption, annexedMatchingOptions] $
command "mirror" SectionCommon
"mirror content of files to/from another repository"
paramPaths (seek <--< optParser)
data MirrorOptions = MirrorOptions
{ mirrorFiles :: CmdParams
, fromToOptions :: FromToOptions
, keyOptions :: Maybe KeyOptions
}
optParser :: CmdParamsDesc -> Parser MirrorOptions
optParser desc = MirrorOptions
<$> cmdParams desc
<*> parseFromToOptions
<*> optional (parseKeyOptions <|> parseFailedTransfersOption)
instance DeferredParseClass MirrorOptions where
finishParse v = MirrorOptions
<$> pure (mirrorFiles v)
<*> finishParse (fromToOptions v)
<*> pure (keyOptions v)
seek :: MirrorOptions -> CommandSeek
seek o = startConcurrency transferStages $
withKeyOptions (keyOptions o) False
(commandAction . startKey o (AssociatedFile Nothing))
(withFilesInGit (commandAction . (whenAnnexed $ start o)))
=<< workTreeItems (mirrorFiles o)
start :: MirrorOptions -> FilePath -> Key -> CommandStart
start o file k = startKey o afile (k, ai)
where
afile = AssociatedFile (Just file)
ai = mkActionItem (k, afile)
startKey :: MirrorOptions -> AssociatedFile -> (Key, ActionItem) -> CommandStart
startKey o afile (key, ai) = case fromToOptions o of
ToRemote r -> checkFailedTransferDirection ai Upload $ ifM (inAnnex key)
( Command.Move.toStart Command.Move.RemoveNever afile key ai =<< getParsed r
, do
numcopies <- getnumcopies
Command.Drop.startRemote afile ai numcopies key =<< getParsed r
)
FromRemote r -> checkFailedTransferDirection ai Download $ do
haskey <- flip Remote.hasKey key =<< getParsed r
case haskey of
Left _ -> stop
Right True -> Command.Get.start' (return True) Nothing key afile ai
Right False -> ifM (inAnnex key)
( do
numcopies <- getnumcopies
Command.Drop.startLocal afile ai numcopies key []
, stop
)
where
getnumcopies = case afile of
AssociatedFile Nothing -> getNumCopies
AssociatedFile (Just af) -> getFileNumCopies af