This is a massive win on OSX, which doesn't have a sha256sum normally.
Only use external hash commands when the file is > 1 mb,
since cryptohash is quite close to them in speed.
SHA is still used to calculate HMACs. I don't quite understand
cryptohash's API for those.
Used the following benchmark to arrive at the 1 mb number.
1 mb file:
benchmarking sha256/internal
mean: 13.86696 ms, lb 13.83010 ms, ub 13.93453 ms, ci 0.950
std dev: 249.3235 us, lb 162.0448 us, ub 458.1744 us, ci 0.950
found 5 outliers among 100 samples (5.0%)
4 (4.0%) high mild
1 (1.0%) high severe
variance introduced by outliers: 10.415%
variance is moderately inflated by outliers
benchmarking sha256/external
mean: 14.20670 ms, lb 14.17237 ms, ub 14.27004 ms, ci 0.950
std dev: 230.5448 us, lb 150.7310 us, ub 427.6068 us, ci 0.950
found 3 outliers among 100 samples (3.0%)
2 (2.0%) high mild
1 (1.0%) high severe
2 mb file:
benchmarking sha256/internal
mean: 26.44270 ms, lb 26.23701 ms, ub 26.63414 ms, ci 0.950
std dev: 1.012303 ms, lb 925.8921 us, ub 1.122267 ms, ci 0.950
variance introduced by outliers: 35.540%
variance is moderately inflated by outliers
benchmarking sha256/external
mean: 26.84521 ms, lb 26.77644 ms, ub 26.91433 ms, ci 0.950
std dev: 347.7867 us, lb 210.6283 us, ub 571.3351 us, ci 0.950
found 6 outliers among 100 samples (6.0%)
import Crypto.Hash
import Data.ByteString.Lazy as L
import Criterion.Main
import Common
testfile :: FilePath
testfile = "/run/shm/data" -- on ram disk
main = defaultMain
[ bgroup "sha256"
[ bench "internal" $ whnfIO internal
, bench "external" $ whnfIO external
]
]
sha256 :: L.ByteString -> Digest SHA256
sha256 = hashlazy
internal :: IO String
internal = show . sha256 <$> L.readFile testfile
external :: IO String
external = do
s <- readProcess "sha256sum" [testfile]
return $ fst $ separate (== ' ') s
Done using a mode witness, which ensures it's fixed everywhere.
Fixing catFileKey was a bear, because git cat-file does not provide a
nice way to query for the mode of a file and there is no other efficient
way to do it. Oh, for libgit2..
Note that I am looking at tree objects from HEAD, rather than the index.
Because I cat-file cannot show a tree object for the index.
So this fix is technically incomplete. The only cases where it matters
are:
1. A new large file has been directly staged in git, but not committed.
2. A file that was committed to HEAD as a symlink has been staged
directly in the index.
This could be fixed a lot better using libgit2.
To support this, a core.gcrypt-id is stored by git-annex inside the git
config of a local gcrypt repository, when setting it up.
That is compared with the remote's cached gcrypt-id. When different, a
drive has been changed. git-annex then looks up the remote config for
the uuid mapped from the core.gcrypt-id, and tweaks the configuration
appropriately. When there is no known config for the uuid, it will refuse to
use the remote.
Note that it would be possible to extend the display to show all
repositories. But there can be a lot of repositories that are not set up as
remotes, and it would significantly clutter the display to show them all.
Since we're not showing all repositories, it's not worth trying to show
numcopies count either.
I decided to embrace these limitations and call the command remotes.
Use rsync for gcrypt remotes that are not local to the disk.
(Note that I have punted on supporting http transport for now, it doesn't
seem likely to be very useful.)
This was mostly quite easy, it just uses the rsync special remote to handle
the transfers. The git repository url is converted to a RsyncOptions
structure, which required parsing it separately, since the rsync special
remote only supports rsync urls, which use a different format.
Note that annexed objects are now stored at the top of the gcrypt repo,
rather than inside annex/objects. This simplified the rsync suport,
since it doesn't have to arrange to create that directory. And git-annex
is not going to be run directly within gcrypt repos -- or if in some
strance scenario it was, it would make sense for it to not see the
encrypted objects.
This commit was sponsored by Sheila Miguez
Wrote nice pure transition calculator, and ugly code to stage its results
into the git-annex branch. Also had to split up several Log modules
that Annex.Branch needed to use, but that themselves used Annex.Branch.
The transition calculator is limited to looking at and changing one file at
a time. While this made the implementation relatively easy, it precludes
transitions that do stuff like deleting old url log files for keys that are
being removed because they are no longer present anywhere.
When quvi is installed, git-annex addurl automatically uses it to detect
when an page is a video, and downloads the video file.
web special remote: Also support using quvi, for getting files,
or checking if files exist in the web.
This commit was sponsored by Mark Hepburn. Thanks!
<RichiH> i richih@eudyptes (git)-[master] ~git/debconf-share/debconf13/photos/chrysn % rm /home/richih/work/git/debconf-share/.git/annex/tmp/SHA256E-s3044235--693b74fcb12db06b5e79a8b99d03e2418923866506ee62d24a4e9ae8c5236758.JPG
<RichiH> richih@eudyptes (git)-[master] ~git/debconf-share/debconf13/photos/chrysn % git annex get P8060008.JPG
<RichiH> get P8060008.JPG (from website...) --2013-08-21 21:42:45-- http://annex.debconf.org/debconf-share/.git//annex/objects/1a4/67d/SHA256E-s3044235--693b74fcb12db06b5e79a8b99d03e2418923866506ee62d24a4e9ae8c5236758.JPG/SHA256E-s3044235--693b74fcb12db06b5e79a8b99d03e2418923866506ee62d24a4e9ae8c5236758.JPG
<RichiH> Resolving annex.debconf.org (annex.debconf.org)... 5.153.231.227, 2001:41c8:1000:19::227:2
<RichiH> Connecting to annex.debconf.org (annex.debconf.org)|5.153.231.227|:80... connected.
<RichiH> HTTP request sent, awaiting response... 404 Not Found
<RichiH> 2013-08-21 21:42:45 ERROR 404: Not Found.
<RichiH> File `/home/richih/work/git/debconf-share/.git/annex/tmp/SHA256E-s3044235--693b74fcb12db06b5e79a8b99d03e2418923866506ee62d24a4e9ae8c5236758.JPG' already there; not retrieving.
<RichiH> Unable to access these remotes: website
<RichiH> Try making some of these repositories available:
<RichiH> 3e0356ac-0743-11e3-83a5-1be63124a102 -- website (annex.debconf.org)
<RichiH> a7495021-9f2d-474e-80c7-34d29d09fec6 -- chrysn@hephaistos:~/data/projects/debconf13/debconf-share
<RichiH> eb8990f7-84cd-4e6b-b486-a5e71efbd073 -- joeyh passport usb drive
<RichiH> f415f118-f428-4c68-be66-c91501da3a93 -- joeyh laptop
<RichiH> failed
<RichiH> git-annex: get: 1 failed
<RichiH> richih@eudyptes (git)-[master] ~git/debconf-share/debconf13/photos/chrysn %
I was not able to reproduce the failure, but I did reproduce that
wget -O http://404/ results in an empty file being written.
This is a simple approach for setting up a mirroring repository.
It will work with any type of remotes.
Mirror --from is more expensive than mirror --to in general.
OTOH, mirror --from will get the file from any remote that has it, not only
the named mirror remote. And if the named mirror remote is not the fastest
available remote with a file, that can speed things up.
It would be possible to make the assistant or watch command do a more
dynamic mirroring, that didn't need to scan every time.
