Mercurial > hg
view tests/test-lfs-test-server.t @ 35569:964212780daf
rust: implementation of `hg`
This commit provides a mostly-working implementation of the
`hg` script in Rust along with scaffolding to support Rust in
the repository.
If you are familiar with Rust, the contents of the added rust/
directory should be pretty straightforward. We create an "hgcli"
package that implements a binary application to run Mercurial.
The output of this package is an "hg" binary.
Our Rust `hg` (henceforth "rhg") essentially is a port of the existing
`hg` Python script. The main difference is the creation of the embedded
CPython interpreter is handled by the binary itself instead of relying
on the shebang. In that sense, rhg is more similar to the "exe wrapper"
we currently use on Windows. However, unlike the exe wrapper, rhg does
not call the `hg` Python script. Instead, it uses the CPython APIs to
import mercurial modules and call appropriate functions. The amount of
code here is surprisingly small.
It is my intent to replace the existing C-based exe wrapper with rhg.
Preferably in the next Mercurial release. This should be achievable -
at least for some Mercurial distributions. The future/timeline for
rhg on other platforms is less clear. We already ship a hg.exe on
Windows. So if we get the quirks with Rust worked out, shipping a
Rust-based hg.exe should hopefully not be too contentious.
Now onto the implementation.
We're using python27-sys and the cpython crates for talking to the
CPython API. We currently don't use too much functionality of the
cpython crate and could have probably cut it out. However, it does
provide a reasonable abstraction over unsafe {} CPython function
calls. While we still have our fair share of those, at least we're
not dealing with too much refcounting, error checking, etc. So I
think the use of the cpython crate is justified. Plus, there is
not-yet-implemented functionality that could benefit from cpython. I
see our use of this crate only increasing.
The cpython and python27-sys crates are not without their issues.
The cpython crate didn't seem to account for the embedding use case
in its design. Instead, it seems to assume that you are building
a Python extension. It is making some questionable decisions around
certain CPython APIs. For example, it insists that
PyEval_ThreadsInitialized() is called and that the Python code
likely isn't the main thread in the underlying application. It
is also missing some functionality that is important for embedded
use cases (such as exporting the path to the Python interpreter
from its build script). After spending several hours trying to
wrangle python27-sys and cpython, I gave up and forked the project
on GitHub. Our Cargo.toml tracks this fork. I'm optimistic that
the upstream project will accept our contributions and we can
eventually unfork.
There is a non-trivial amount of code in our custom Cargo build
script. Our build.rs (which is called as part of building the hgcli
crate):
* Validates that the Python interpreter that was detected by the
python27-sys crate provides a shared library (we only support
shared library linking at this time - although this restriction
could be loosened).
* Validates that the Python is built with UCS-4 support. This ensures
maximum Unicode compatibility.
* Exports variables to the crate build allowing the built crate to e.g.
find the path to the Python interpreter.
The produced rhg should be considered alpha quality. There are several
known deficiencies. Many of these are documented with inline TODOs.
Probably the biggest limitation of rhg is that it assumes it is
running from the ./rust/target/<target> directory of a source
distribution. So, rhg is currently not very practical for real-world
use. But, if you can `cargo build` it, running the binary *should*
yield a working Mercurial CLI.
In order to support using rhg with the test harness, we needed to hack
up run-tests.py so the path to Mercurial's Python files is set properly.
The change is extremely hacky and is only intended to be a stop-gap
until the test harness gains first-class support for installing rhg.
This will likely occur after we support running rhg outside the
source directory.
Despite its officially alpha quality, rhg copes extremely well with
the test harness (at least on Linux). Using
`run-tests.py --with-hg ../rust/target/debug/hg`, I only encounter
the following failures:
* test-run-tests.t -- Warnings emitted about using an unexpected
Mercurial library. This is due to the hacky nature of setting the
Python directory when run-tests.py detected rhg.
* test-devel-warnings.t -- Expected stack trace missing frame for `hg`
(This is expected since we no longer have an `hg` script!)
* test-convert.t -- Test running `$PYTHON "$BINDIR"/hg`, which obviously
assumes `hg` is a Python script.
* test-merge-tools.t -- Same assumption about `hg` being executable with
Python.
* test-http-bad-server.t -- Seeing exit code 255 instead of 1 around
line 358.
* test-blackbox.t -- Exit code 255 instead of 1.
* test-basic.t -- Exit code 255 instead of 1.
It certainly looks like we have a bug around exit code handling. I
don't think it is severe enough to hold up review and landing of this
initial implementation. Perfect is the enemy of good.
Differential Revision: https://phab.mercurial-scm.org/D1581
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Wed, 10 Jan 2018 08:53:22 -0800 |
parents | ebf14075a5c1 |
children | c780e0649e41 |
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#require lfs-test-server $ LFS_LISTEN="tcp://:$HGPORT" $ LFS_HOST="localhost:$HGPORT" $ LFS_PUBLIC=1 $ export LFS_LISTEN LFS_HOST LFS_PUBLIC #if no-windows $ lfs-test-server &> lfs-server.log & $ echo $! >> $DAEMON_PIDS #else $ cat >> $TESTTMP/spawn.py <<EOF > import os > import subprocess > import sys > > for path in os.environ["PATH"].split(os.pathsep): > exe = os.path.join(path, 'lfs-test-server.exe') > if os.path.exists(exe): > with open('lfs-server.log', 'wb') as out: > p = subprocess.Popen(exe, stdout=out, stderr=out) > sys.stdout.write('%s\n' % p.pid) > sys.exit(0) > sys.exit(1) > EOF $ $PYTHON $TESTTMP/spawn.py >> $DAEMON_PIDS #endif $ cat >> $HGRCPATH <<EOF > [extensions] > lfs= > [lfs] > url=http://foo:bar@$LFS_HOST/ > threshold=1 > EOF $ hg init repo1 $ cd repo1 $ echo THIS-IS-LFS > a $ hg commit -m a -A a A push can be serviced directly from the usercache if it isn't in the local store. $ hg init ../repo2 $ mv .hg/store/lfs .hg/store/lfs_ $ hg push ../repo2 -v pushing to ../repo2 searching for changes lfs: uploading 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b (12 bytes) lfs: processed: 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b 1 changesets found uncompressed size of bundle content: * (changelog) (glob) * (manifests) (glob) * a (glob) adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files calling hook pretxnchangegroup.lfs: hgext.lfs.checkrequireslfs $ mv .hg/store/lfs_ .hg/store/lfs Clear the cache to force a download $ rm -rf `hg config lfs.usercache` $ cd ../repo2 $ hg update tip -v resolving manifests getting a lfs: downloading 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b (12 bytes) lfs: adding 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b to the usercache lfs: processed: 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b lfs: found 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b in the local lfs store 1 files updated, 0 files merged, 0 files removed, 0 files unresolved When the server has some blobs already $ hg mv a b $ echo ANOTHER-LARGE-FILE > c $ echo ANOTHER-LARGE-FILE2 > d $ hg commit -m b-and-c -A b c d $ hg push ../repo1 -v | grep -v '^ ' pushing to ../repo1 searching for changes lfs: need to transfer 2 objects (39 bytes) lfs: uploading 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19 (20 bytes) lfs: processed: 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19 lfs: uploading d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 (19 bytes) lfs: processed: d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 1 changesets found uncompressed size of bundle content: adding changesets adding manifests adding file changes added 1 changesets with 3 changes to 3 files Clear the cache to force a download $ rm -rf `hg config lfs.usercache` $ hg --repo ../repo1 update tip -v resolving manifests getting b lfs: found 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b in the local lfs store getting c lfs: downloading d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 (19 bytes) lfs: adding d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 to the usercache lfs: processed: d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 lfs: found d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 in the local lfs store getting d lfs: downloading 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19 (20 bytes) lfs: adding 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19 to the usercache lfs: processed: 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19 lfs: found 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19 in the local lfs store 3 files updated, 0 files merged, 0 files removed, 0 files unresolved Test a corrupt file download, but clear the cache first to force a download. $ rm -rf `hg config lfs.usercache` $ cp $TESTTMP/lfs-content/d1/1e/1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 blob $ echo 'damage' > $TESTTMP/lfs-content/d1/1e/1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 $ rm ../repo1/.hg/store/lfs/objects/d1/1e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 $ rm ../repo1/* $ hg --repo ../repo1 update -C tip -v resolving manifests getting a lfs: found 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b in the local lfs store getting b lfs: found 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b in the local lfs store getting c lfs: downloading d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 (19 bytes) abort: corrupt remote lfs object: d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 [255] The corrupted blob is not added to the usercache or local store $ test -f ../repo1/.hg/store/lfs/objects/d1/1e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 [1] $ test -f `hg config lfs.usercache`/d1/1e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 [1] $ cp blob $TESTTMP/lfs-content/d1/1e/1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 Test a corrupted file upload $ echo 'another lfs blob' > b $ hg ci -m 'another blob' $ echo 'damage' > .hg/store/lfs/objects/e6/59058e26b07b39d2a9c7145b3f99b41f797b6621c8076600e9cb7ee88291f0 $ hg push -v ../repo1 pushing to ../repo1 searching for changes lfs: uploading e659058e26b07b39d2a9c7145b3f99b41f797b6621c8076600e9cb7ee88291f0 (17 bytes) abort: detected corrupt lfs object: e659058e26b07b39d2a9c7145b3f99b41f797b6621c8076600e9cb7ee88291f0 (run hg verify) [255] Check error message when the remote missed a blob: $ echo FFFFF > b $ hg commit -m b -A b $ echo FFFFF >> b $ hg commit -m b b $ rm -rf .hg/store/lfs $ rm -rf `hg config lfs.usercache` $ hg update -C '.^' abort: LFS server claims required objects do not exist: 8e6ea5f6c066b44a0efa43bcce86aea73f17e6e23f0663df0251e7524e140a13! [255] Check error message when object does not exist: $ hg init test && cd test $ echo "[extensions]" >> .hg/hgrc $ echo "lfs=" >> .hg/hgrc $ echo "[lfs]" >> .hg/hgrc $ echo "threshold=1" >> .hg/hgrc $ echo a > a $ hg add a $ hg commit -m 'test' $ echo aaaaa > a $ hg commit -m 'largefile' $ hg debugdata .hg/store/data/a.i 1 # verify this is no the file content but includes "oid", the LFS "pointer". version https://git-lfs.github.com/spec/v1 oid sha256:bdc26931acfb734b142a8d675f205becf27560dc461f501822de13274fe6fc8a size 6 x-is-binary 0 $ cd .. $ rm -rf `hg config lfs.usercache` $ hg --config 'lfs.url=https://dewey-lfs.vip.facebook.com/lfs' clone test test2 updating to branch default abort: LFS server error. Remote object for "a" not found:(.*)! (re) [255] $ $PYTHON $RUNTESTDIR/killdaemons.py $DAEMON_PIDS