Mercurial > hg
view tests/test-http-clone-r.t @ 46667:93e9f448273c
rhg: Add support for automatic fallback to Python
`rhg` is a command-line application that can do a small subset of what
`hg` can. It is written entirely in Rust, which avoids the cost of starting
a Python interpreter and importing many Python modules.
In a script that runs many `hg` commands, this cost can add up.
However making users decide when to use `rhg` instead of `hg` is
not practical as we want the subset of supported functionality
to grow over time.
Instead we introduce "fallback" behavior where, when `rhg` encounters
something (a sub-command, a repository format, …) that is not implemented
in Rust-only, it does nothing but silently start a subprocess of
Python-based `hg` running the same command.
That way `rhg` becomes a drop-in replacement for `hg` that sometimes
goes faster. Whether Python is used should be an implementation detail
not apparent to users (other than through speed).
A new `fallback` value is added to the previously introduced
`rhg.on-unsupported` configuration key. When in this mode, the new
`rhg.fallback-executable` config is determine what command to use
to run a Python-based `hg`.
The previous `rhg.on-unsupported = abort-silent` configuration was designed
to let a wrapper script call `rhg` and then fall back to `hg` based on the
exit code. This is still available, but having fallback behavior built-in
in rhg might be easier for users instead of leaving that script "as an
exercise for the reader".
Using a subprocess like this is not idea, especially when `rhg` is to be
installed in `$PATH` as `hg`, since the other `hg.py` executable needs
to still be available… somewhere. Eventually this could be replaced
by using PyOxidizer to a have a single executable that embeds a Python
interpreter, but only starts it when needed.
Differential Revision: https://phab.mercurial-scm.org/D10093
| author | Simon Sapin <simon.sapin@octobus.net> |
|---|---|
| date | Mon, 01 Mar 2021 20:36:06 +0100 |
| parents | d68618954ade |
| children | 2f2682f40ea0 |
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#require serve creating 'remote $ hg init remote $ cd remote $ hg unbundle "$TESTDIR/bundles/remote.hg" adding changesets adding manifests adding file changes added 9 changesets with 7 changes to 4 files (+1 heads) new changesets bfaf4b5cbf01:916f1afdef90 (9 drafts) (run 'hg heads' to see heads, 'hg merge' to merge) $ hg up tip 1 files updated, 0 files merged, 0 files removed, 0 files unresolved Starting server $ hg serve -p $HGPORT -E ../error.log -d --pid-file=../hg1.pid $ cd .. $ cat hg1.pid >> $DAEMON_PIDS clone remote via stream $ for i in 0 1 2 3 4 5 6 7 8; do > hg clone -r "$i" http://localhost:$HGPORT/ test-"$i" > if cd test-"$i"; then > hg verify > cd .. > fi > done adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files new changesets bfaf4b5cbf01 updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 1 changesets with 1 changes to 1 files adding changesets adding manifests adding file changes added 2 changesets with 2 changes to 1 files new changesets bfaf4b5cbf01:21f32785131f updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 2 changesets with 2 changes to 1 files adding changesets adding manifests adding file changes added 3 changesets with 3 changes to 1 files new changesets bfaf4b5cbf01:4ce51a113780 updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 3 changesets with 3 changes to 1 files adding changesets adding manifests adding file changes added 4 changesets with 4 changes to 1 files new changesets bfaf4b5cbf01:93ee6ab32777 updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 4 changesets with 4 changes to 1 files adding changesets adding manifests adding file changes added 2 changesets with 2 changes to 1 files new changesets bfaf4b5cbf01:c70afb1ee985 updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 2 changesets with 2 changes to 1 files adding changesets adding manifests adding file changes added 3 changesets with 3 changes to 1 files new changesets bfaf4b5cbf01:f03ae5a9b979 updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 3 changesets with 3 changes to 1 files adding changesets adding manifests adding file changes added 4 changesets with 5 changes to 2 files new changesets bfaf4b5cbf01:095cb14b1b4d updating to branch default 2 files updated, 0 files merged, 0 files removed, 0 files unresolved checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 4 changesets with 5 changes to 2 files adding changesets adding manifests adding file changes added 5 changesets with 6 changes to 3 files new changesets bfaf4b5cbf01:faa2e4234c7a updating to branch default 2 files updated, 0 files merged, 0 files removed, 0 files unresolved checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 5 changesets with 6 changes to 3 files adding changesets adding manifests adding file changes added 5 changesets with 5 changes to 2 files new changesets bfaf4b5cbf01:916f1afdef90 updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 5 changesets with 5 changes to 2 files $ cd test-8 $ hg pull ../test-7 pulling from ../test-7 searching for changes adding changesets adding manifests adding file changes added 4 changesets with 2 changes to 3 files (+1 heads) new changesets c70afb1ee985:faa2e4234c7a (run 'hg heads' to see heads, 'hg merge' to merge) $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 9 changesets with 7 changes to 4 files $ cd .. $ cd test-1 $ hg pull -r 4 http://localhost:$HGPORT/ pulling from http://localhost:$HGPORT/ searching for changes adding changesets adding manifests adding file changes added 1 changesets with 0 changes to 0 files (+1 heads) new changesets c70afb1ee985 (run 'hg heads' to see heads, 'hg merge' to merge) $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 3 changesets with 2 changes to 1 files $ hg pull http://localhost:$HGPORT/ pulling from http://localhost:$HGPORT/ searching for changes adding changesets adding manifests adding file changes added 6 changesets with 5 changes to 4 files new changesets 4ce51a113780:916f1afdef90 (run 'hg update' to get a working copy) $ cd .. $ cd test-2 $ hg pull -r 5 http://localhost:$HGPORT/ pulling from http://localhost:$HGPORT/ searching for changes adding changesets adding manifests adding file changes added 2 changesets with 0 changes to 0 files (+1 heads) new changesets c70afb1ee985:f03ae5a9b979 (run 'hg heads' to see heads, 'hg merge' to merge) $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 5 changesets with 3 changes to 1 files $ hg pull http://localhost:$HGPORT/ pulling from http://localhost:$HGPORT/ searching for changes adding changesets adding manifests adding file changes added 4 changesets with 4 changes to 4 files new changesets 93ee6ab32777:916f1afdef90 (run 'hg update' to get a working copy) $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files checked 9 changesets with 7 changes to 4 files $ cd .. no default destination if url has no path: $ hg clone http://localhost:$HGPORT/ abort: empty destination path is not valid [10] $ cat error.log