mirrors/git-annex
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages 1 Wiki Activity Actions

other 80% of avoding verification when hard linking to objects in shared repo

Browse source 
In c6632ee5c8, it actually only handled
uploading objects to a shared repository. To avoid verification when
downloading objects from a shared repository, was a lot harder.

On the plus side, if the process of downloading a file from a remote
is able to verify its content on the side, the remote can indicate this
now, and avoid the extra post-download verification.

As of yet, I don't have any remotes (except Git) using this ability.
Some more work would be needed to support it in special remotes.

It would make sense for tahoe to implicitly verify things downloaded from it;
as long as you trust your tahoe server (which typically runs locally),
there's cryptographic integrity. OTOH, despite bup being based on shas,
a bup repo under an attacker's control could have the git ref used for an
object changed, and so a bup repo shouldn't implicitly verify. Indeed,
tahoe seems unique in being trustworthy enough to implicitly verify.
This commit is contained in:
Joey Hess 2015-10-02 13:56:42 -04:00
parent 7c7fe895f9
commit 2def1d0a23
15 changed files with 100 additions and 77 deletions
Download patch file Download diff file Expand all files Collapse all files

37
Annex/Transfer.hs
View file

@ -5,7 +5,7 @@
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE CPP, FlexibleInstances #-}
module Annex.Transfer (
module X,
@ -24,20 +24,31 @@ import Annex.Notification as X
import Annex.Perms
import Utility.Metered
import Utility.LockPool
import Types.Remote (Verification(..))
import Control.Concurrent
type TransferAction = MeterUpdate -> Annex Bool
type TransferObserver = Bool -> Transfer -> TransferInfo -> Annex ()
class Observable a where
observeBool :: a -> Bool
observeFailure :: a
instance Observable Bool where
observeBool = id
observeFailure = False
instance Observable (Bool, Verification) where
observeBool = fst
observeFailure = (False, UnVerified)
noObserver :: TransferObserver
noObserver _ _ _ = noop
upload :: UUID -> Key -> AssociatedFile -> RetryDecider -> TransferObserver -> TransferAction -> NotifyWitness -> Annex Bool
upload :: Observable v => UUID -> Key -> AssociatedFile -> RetryDecider -> TransferObserver -> (MeterUpdate -> Annex v) -> NotifyWitness -> Annex v
upload u key f d o a _witness = runTransfer (Transfer Upload u key) f d o a
download :: UUID -> Key -> AssociatedFile -> RetryDecider -> TransferObserver -> TransferAction -> NotifyWitness -> Annex Bool
download :: Observable v => UUID -> Key -> AssociatedFile -> RetryDecider -> TransferObserver -> (MeterUpdate -> Annex v) -> NotifyWitness -> Annex v
download u key f d o a _witness = runTransfer (Transfer Download u key) f d o a
{- Runs a transfer action. Creates and locks the lock file while the
@ -52,7 +63,7 @@ download u key f d o a _witness = runTransfer (Transfer Download u key) f d o a
- An upload can be run from a read-only filesystem, and in this case
- no transfer information or lock file is used.
-}
runTransfer :: Transfer -> Maybe FilePath -> RetryDecider -> TransferObserver -> TransferAction -> Annex Bool
runTransfer :: Observable v => Transfer -> Maybe FilePath -> RetryDecider -> TransferObserver -> (MeterUpdate -> Annex v) -> Annex v
runTransfer = runTransfer' False
{- Like runTransfer, but ignores any existing transfer lock file for the
@ -60,10 +71,10 @@ runTransfer = runTransfer' False
-
- Note that this may result in confusing progress meter display in the
- webapp, if multiple processes are writing to the transfer info file. -}
alwaysRunTransfer :: Transfer -> Maybe FilePath -> RetryDecider -> TransferObserver -> TransferAction -> Annex Bool
alwaysRunTransfer :: Observable v => Transfer -> Maybe FilePath -> RetryDecider -> TransferObserver -> (MeterUpdate -> Annex v) -> Annex v
alwaysRunTransfer = runTransfer' True
runTransfer' :: Bool -> Transfer -> Maybe FilePath -> RetryDecider -> TransferObserver -> TransferAction -> Annex Bool
runTransfer' :: Observable v => Bool -> Transfer -> Maybe FilePath -> RetryDecider -> TransferObserver -> (MeterUpdate -> Annex v) -> Annex v
runTransfer' ignorelock t file shouldretry transferobserver transferaction = do
info <- liftIO $ startTransferInfo file
(meter, tfile, metervar) <- mkProgressUpdater t info
@ -72,12 +83,12 @@ runTransfer' ignorelock t file shouldretry transferobserver transferaction = do
if inprogress && not ignorelock
then do
showNote "transfer already in progress, or unable to take transfer lock"
return False
return observeFailure
else do
ok <- retry info metervar $ transferaction meter
v <- retry info metervar $ transferaction meter
liftIO $ cleanup tfile lck
transferobserver ok t info
return ok
transferobserver (observeBool v) t info
return v
where
#ifndef mingw32_HOST_OS
prep tfile mode info = do
@ -128,7 +139,7 @@ runTransfer' ignorelock t file shouldretry transferobserver transferaction = do
let newinfo = oldinfo { bytesComplete = Just b }
if shouldretry oldinfo newinfo
then retry newinfo metervar run
else return False
else return observeFailure
getbytescomplete metervar
| transferDirection t == Upload =
liftIO $ readMVar metervar