Use separate stages for download and upload. In the common case where
it downloads the file from one remote and then uploads to the other,
those are by far the most expensive operations, and there's a decent
chance the two remotes bottleneck on different resources.
Suppose it's being run with -J2 and a bunch of 10 mb files. Two threads
will be started both downloading from the src remote. They will probably
finish at the same time. Then two threads will be started uploading to
the dst remote. They will probably take the same time as well. Before
this change, it would alternate back and forth, bottlenecking on src and dst.
With this change, as soon as the two threads start uploading to dst, two
more threads are able to start, downloading from src. So bandwidth to
both remotes is saturated more often.
Other commands that use transferStages only send in one direction at a
time. So the worker threads for the other direction will sit idle, and
there will be no change in their behavior.
Sponsored-by: Dartmouth College's DANDI project
Finally builds (oh the agoncy of making it build), but still very
unmergable, only Command.Find is included and lots of stuff is badly
hacked to make it compile.
Benchmarking vs master, this git-annex find is significantly faster!
Specifically:
num files old new speedup
48500 4.77 3.73 28%
12500 1.36 1.02 66%
20 0.075 0.074 0% (so startup time is unchanged)
That's without really finishing the optimization. Things still to do:
* Eliminate all the fromRawFilePath, toRawFilePath, encodeBS,
decodeBS conversions.
* Use versions of IO actions like getFileStatus that take a RawFilePath.
* Eliminate some Data.ByteString.Lazy.toStrict, which is a slow copy.
* Use ByteString for parsing git config to speed up startup.
It's likely several of those will speed up git-annex find further.
And other commands will certianly benefit even more.
This will speed up the common case where a Key is deserialized from
disk, but is then serialized to build eg, the path to the annex object.
Previously attempted in 4536c93bb2
and reverted in 96aba8eff7.
The problems mentioned in the latter commit are addressed now:
Read/Show of KeyData is backwards-compatible with Read/Show of Key from before
this change, so Types.Distribution will keep working.
The Eq instance is fixed.
Also, Key has smart constructors, avoiding needing to remember to update
the cached serialization.
Used git-annex benchmark:
find is 7% faster
whereis is 3% faster
get when all files are already present is 5% faster
Generally, the benchmarks are running 0.1 seconds faster per 2000 files,
on a ram disk in my laptop.
This does not change the overall license of the git-annex program, which
was already AGPL due to a number of sources files being AGPL already.
Legally speaking, I'm adding a new license under which these files are
now available; I already released their current contents under the GPL
license. Now they're dual licensed GPL and AGPL. However, I intend
for all my future changes to these files to only be released under the
AGPL license, and I won't be tracking the dual licensing status, so I'm
simply changing the license statement to say it's AGPL.
(In some cases, others wrote parts of the code of a file and released it
under the GPL; but in all cases I have contributed a significant portion
of the code in each file and it's that code that is getting the AGPL
license; the GPL license of other contributors allows combining with
AGPL code.)
Better to make it not be surprising and slow, than surprising and fast.
--raw can be used when it needs to be really fast.
Implemented adding a youtube-dl supported url to an existing file.
This commit was sponsored by andrea rota.
Including resuming and cleanup of incomplete downloads.
Still todo: --fast, --relaxed, importfeed, disk reserve checking,
quvi code cleanup.
This commit was sponsored by Anthony DeRobertis on Patreon.
This avoids all the complication about redundant work discussed in
the previous try at fixing this. At the expense of needing each command
that could have the problem to be patched to simply wrap the action in
onlyActionOn once the key is known. But there do not seem to be many
such commands.
onlyActionOn' should not be used with a CommandStart (or CommandPerform),
although the types do allow it. onlyActionOn handles running the whole
CommandStart chain. I couldn't immediately see a way to avoid mistken
use of onlyActionOn'.
This commit was supported by the NSF-funded DataLad project.
After a false start, I found a fairly non-intrusive way to deal with it.
Although it only handles transfers -- there may be issues with eg
concurrent dropping of the same key, or other operations.
There is no added overhead when -J is not used, other than an added
inAnnex check. When -J is used, it has to maintain and check a small
Set, which should be negligible overhead.
It could output some message saying that the transfer is being done by
another thread. Or it could even display the same progress info for both
files that are being downloaded since they have the same content. But I
opted to keep it simple, since this is rather an edge case, so it just
doesn't say anything about the transfer of the file until the other
thread finishes.
Since the deferred transfer action still runs, actions that do more than
transfer content will still get a chance to do their other work. (An
example of something that needs to do such other work is P2P.Annex,
where the download always needs to receive the content from the peer.)
And, if the first thread fails to complete a transfer, the second thread
can resume it.
But, this unfortunately means that there's a risk of redundant work
being done to transfer a key that just got transferred.
That's not ideal, but should never cause breakage; the same
thing can occur when running two separate git-annex processes.
The get/move/copy/mirror --from commands had extra inAnnex checks added,
inside the download actions. Without those checks, the first thread
downloaded the content, and then the second thread woke up and
downloaded the same content redundantly.
move/copy/mirror --to is left doing redundant uploads for now. It
would need a second checkPresent of the remote inside the upload
to avoid them, which would be expensive. A better way to avoid
redundant work needs to be found..
This commit was supported by the NSF-funded DataLad project.
9c4650358c changed the Read instance for
Key.
I've checked all uses of that instance (by removing it and seeing what
breaks), and they're all limited to the webapp, except one.
That is GitAnnexDistribution's Read instance.
So, 9c4650358c would have broken upgrades
of git-annex from downloads.kitenet.net. Once the .info files there got
updated for a new release, old releases would have failed to parse them
and never upgraded.
To fix this, I found a way to make the .info files that contain
GitAnnexDistribution values be readable by the old version of git-annex.
This commit was sponsored by Ewen McNeill.
Note that get --from foo --failed will get things that a previous get --from bar
tried and failed to get, etc. I considered making --failed only retry
transfers from the same remote, but it was easier, and seems more useful,
to not have the same remote requirement.
Noisy due to some refactoring into Types/
