git-annex/Logs/Chunk.hs
Joey Hess 2cecc8d2a3
Added GIT_ANNEX_VECTOR_CLOCK environment variable
Can be used to override the default timestamps used in log files in the
git-annex branch. This is a dangerous environment variable; use with
caution.

Note that this only affects writing to the logs on the git-annex branch.
It is not used for metadata in git commits (other env vars can be set for
that).

There are many other places where timestamps are still used, that don't
get committed to git, but do touch disk. Including regular timestamps
of files, and timestamps embedded in some files in .git/annex/, including
the last fsck timestamp and timestamps in transfer log files.

A good way to find such things in git-annex is to get for getPOSIXTime and
getCurrentTime, although some of the results are of course false positives
that never hit disk (unless git-annex gets swapped out..)

So this commit does NOT necessarily make git-annex comply with some HIPPA
privacy regulations; it's up to the user to determine if they can use it in
a way compliant with such regulations.

Benchmarking: It takes 0.00114 milliseconds to call getEnv
"GIT_ANNEX_VECTOR_CLOCK" when that env var is not set. So, 100 thousand log
files can be written with an added overhead of only 0.114 seconds. That
should be by far swamped by the actual overhead of writing the log files
and making the commit containing them.

This commit was supported by the NSF-funded DataLad project.
2017-08-14 14:19:58 -04:00

54 lines
1.5 KiB
Haskell

{- Chunk logs.
-
- An object can be stored in chunked for on a remote; these logs keep
- track of the chunk size used, and the number of chunks.
-
- It's possible for a single object to be stored multiple times on the
- same remote using different chunk sizes. So, while this is a MapLog, it
- is not a normal UUIDBased log. Intead, it's a map from UUID and chunk
- size to number of chunks.
-
- Format: "timestamp uuid:chunksize chunkcount"
-
- Copyright 2014 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Logs.Chunk (
ChunkMethod(..),
ChunkSize,
ChunkCount,
chunksStored,
chunksRemoved,
getCurrentChunks,
) where
import Annex.Common
import Logs
import Logs.MapLog
import qualified Annex.Branch
import Logs.Chunk.Pure
import qualified Annex
import qualified Data.Map as M
chunksStored :: UUID -> Key -> ChunkMethod -> ChunkCount -> Annex ()
chunksStored u k chunkmethod chunkcount = do
c <- liftIO currentVectorClock
config <- Annex.getGitConfig
Annex.Branch.change (chunkLogFile config k) $
showLog . changeMapLog c (u, chunkmethod) chunkcount . parseLog
chunksRemoved :: UUID -> Key -> ChunkMethod -> Annex ()
chunksRemoved u k chunkmethod = chunksStored u k chunkmethod 0
getCurrentChunks :: UUID -> Key -> Annex [(ChunkMethod, ChunkCount)]
getCurrentChunks u k = do
config <- Annex.getGitConfig
select . parseLog <$> Annex.Branch.get (chunkLogFile config k)
where
select = filter (\(_m, ct) -> ct > 0)
. map (\((_ku, m), l) -> (m, value l))
. M.toList
. M.filterWithKey (\(ku, _m) _ -> ku == u)