Mercurial > hg
view tests/test-mq-qrefresh-interactive.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 | d65e246100ed |
children | f802a75da585 |
line wrap: on
line source
Create configuration $ echo "[ui]" >> $HGRCPATH $ echo "interactive=true" >> $HGRCPATH help qrefresh (no record) $ echo "[extensions]" >> $HGRCPATH $ echo "mq=" >> $HGRCPATH $ hg help qrefresh hg qrefresh [-I] [-X] [-e] [-m TEXT] [-l FILE] [-s] [FILE]... update the current patch If any file patterns are provided, the refreshed patch will contain only the modifications that match those patterns; the remaining modifications will remain in the working directory. If -s/--short is specified, files currently included in the patch will be refreshed just like matched files and remain in the patch. If -e/--edit is specified, Mercurial will start your configured editor for you to enter a message. In case qrefresh fails, you will find a backup of your message in ".hg/last-message.txt". hg add/remove/copy/rename work as usual, though you might want to use git- style patches (-g/--git or [diff] git=1) to track copies and renames. See the diffs help topic for more information on the git diff format. Returns 0 on success. options ([+] can be repeated): -e --edit invoke editor on commit messages -g --git use git extended diff format -s --short refresh only files already in the patch and specified files -U --currentuser add/update author field in patch with current user -u --user USER add/update author field in patch with given user -D --currentdate add/update date field in patch with current date -d --date DATE add/update date field in patch with given date -I --include PATTERN [+] include names matching the given patterns -X --exclude PATTERN [+] exclude names matching the given patterns -m --message TEXT use text as commit message -l --logfile FILE read commit message from file (some details hidden, use --verbose to show complete help) help qrefresh (record) $ echo "record=" >> $HGRCPATH $ hg help qrefresh hg qrefresh [-I] [-X] [-e] [-m TEXT] [-l FILE] [-s] [FILE]... update the current patch If any file patterns are provided, the refreshed patch will contain only the modifications that match those patterns; the remaining modifications will remain in the working directory. If -s/--short is specified, files currently included in the patch will be refreshed just like matched files and remain in the patch. If -e/--edit is specified, Mercurial will start your configured editor for you to enter a message. In case qrefresh fails, you will find a backup of your message in ".hg/last-message.txt". hg add/remove/copy/rename work as usual, though you might want to use git- style patches (-g/--git or [diff] git=1) to track copies and renames. See the diffs help topic for more information on the git diff format. Returns 0 on success. options ([+] can be repeated): -e --edit invoke editor on commit messages -g --git use git extended diff format -s --short refresh only files already in the patch and specified files -U --currentuser add/update author field in patch with current user -u --user USER add/update author field in patch with given user -D --currentdate add/update date field in patch with current date -d --date DATE add/update date field in patch with given date -I --include PATTERN [+] include names matching the given patterns -X --exclude PATTERN [+] exclude names matching the given patterns -m --message TEXT use text as commit message -l --logfile FILE read commit message from file -i --interactive interactively select changes to refresh (some details hidden, use --verbose to show complete help) $ hg init a $ cd a Base commit $ cat > 1.txt <<EOF > 1 > 2 > 3 > 4 > 5 > EOF $ cat > 2.txt <<EOF > a > b > c > d > e > f > EOF $ mkdir dir $ cat > dir/a.txt <<EOF > hello world > > someone > up > there > loves > me > EOF $ hg add 1.txt 2.txt dir/a.txt $ hg commit -m aaa $ hg qrecord --config ui.interactive=false patch abort: running non-interactively, use qnew instead [255] $ hg qnew -i --config ui.interactive=false patch abort: running non-interactively [255] $ hg qnew -d '0 0' patch Changing files $ sed -e 's/2/2 2/;s/4/4 4/' 1.txt > 1.txt.new $ sed -e 's/b/b b/' 2.txt > 2.txt.new $ sed -e 's/hello world/hello world!/' dir/a.txt > dir/a.txt.new $ mv -f 1.txt.new 1.txt $ mv -f 2.txt.new 2.txt $ mv -f dir/a.txt.new dir/a.txt Whole diff $ hg diff --nodates diff -r ed27675cb5df 1.txt --- a/1.txt +++ b/1.txt @@ -1,5 +1,5 @@ 1 -2 +2 2 3 -4 +4 4 5 diff -r ed27675cb5df 2.txt --- a/2.txt +++ b/2.txt @@ -1,5 +1,5 @@ a -b +b b c d e diff -r ed27675cb5df dir/a.txt --- a/dir/a.txt +++ b/dir/a.txt @@ -1,4 +1,4 @@ -hello world +hello world! someone up partial qrefresh $ hg qrefresh -i --config ui.interactive=false abort: running non-interactively [255] $ hg qrefresh -i -d '0 0' <<EOF > y > y > n > y > y > n > EOF diff --git a/1.txt b/1.txt 2 hunks, 2 lines changed examine changes to '1.txt'? [Ynesfdaq?] y @@ -1,3 +1,3 @@ 1 -2 +2 2 3 record change 1/4 to '1.txt'? [Ynesfdaq?] y @@ -3,3 +3,3 @@ 3 -4 +4 4 5 record change 2/4 to '1.txt'? [Ynesfdaq?] n diff --git a/2.txt b/2.txt 1 hunks, 1 lines changed examine changes to '2.txt'? [Ynesfdaq?] y @@ -1,5 +1,5 @@ a -b +b b c d e record change 3/4 to '2.txt'? [Ynesfdaq?] y diff --git a/dir/a.txt b/dir/a.txt 1 hunks, 1 lines changed examine changes to 'dir/a.txt'? [Ynesfdaq?] n After partial qrefresh 'tip' $ hg tip -p changeset: 1:0738af1a8211 tag: patch tag: qbase tag: qtip tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: [mq]: patch diff -r 1fd39ab63a33 -r 0738af1a8211 1.txt --- a/1.txt Thu Jan 01 00:00:00 1970 +0000 +++ b/1.txt Thu Jan 01 00:00:00 1970 +0000 @@ -1,5 +1,5 @@ 1 -2 +2 2 3 4 5 diff -r 1fd39ab63a33 -r 0738af1a8211 2.txt --- a/2.txt Thu Jan 01 00:00:00 1970 +0000 +++ b/2.txt Thu Jan 01 00:00:00 1970 +0000 @@ -1,5 +1,5 @@ a -b +b b c d e After partial qrefresh 'diff' $ hg diff --nodates diff -r 0738af1a8211 1.txt --- a/1.txt +++ b/1.txt @@ -1,5 +1,5 @@ 1 2 2 3 -4 +4 4 5 diff -r 0738af1a8211 dir/a.txt --- a/dir/a.txt +++ b/dir/a.txt @@ -1,4 +1,4 @@ -hello world +hello world! someone up qrefresh interactively everything else $ hg qrefresh -i -d '0 0' <<EOF > y > y > y > y > EOF diff --git a/1.txt b/1.txt 1 hunks, 1 lines changed examine changes to '1.txt'? [Ynesfdaq?] y @@ -1,5 +1,5 @@ 1 2 2 3 -4 +4 4 5 record change 1/2 to '1.txt'? [Ynesfdaq?] y diff --git a/dir/a.txt b/dir/a.txt 1 hunks, 1 lines changed examine changes to 'dir/a.txt'? [Ynesfdaq?] y @@ -1,4 +1,4 @@ -hello world +hello world! someone up record change 2/2 to 'dir/a.txt'? [Ynesfdaq?] y After final qrefresh 'tip' $ hg tip -p changeset: 1:2c3f66afeed9 tag: patch tag: qbase tag: qtip tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: [mq]: patch diff -r 1fd39ab63a33 -r 2c3f66afeed9 1.txt --- a/1.txt Thu Jan 01 00:00:00 1970 +0000 +++ b/1.txt Thu Jan 01 00:00:00 1970 +0000 @@ -1,5 +1,5 @@ 1 -2 +2 2 3 -4 +4 4 5 diff -r 1fd39ab63a33 -r 2c3f66afeed9 2.txt --- a/2.txt Thu Jan 01 00:00:00 1970 +0000 +++ b/2.txt Thu Jan 01 00:00:00 1970 +0000 @@ -1,5 +1,5 @@ a -b +b b c d e diff -r 1fd39ab63a33 -r 2c3f66afeed9 dir/a.txt --- a/dir/a.txt Thu Jan 01 00:00:00 1970 +0000 +++ b/dir/a.txt Thu Jan 01 00:00:00 1970 +0000 @@ -1,4 +1,4 @@ -hello world +hello world! someone up After qrefresh 'diff' $ hg diff --nodates $ cd ..