update: add a Rust fast-path when updating from null (and clean)
This case is easy to detect and we have all we need to generate a valid
working copy and dirstate entirely in Rust, which speeds things up
considerably:
On my machine updating a repo of ~300k files goes from 10.00s down to 4.2s,
all while consuming 50% less system time, with all caches hot.
Something to note is that further improvements will probably happen
with the upcoming `InnerRevlog` series that does smarter
mmap hanlding, especially for filelogs.
Here are benchmark numbers on a machine with only 4 cores (and no SMT enabled)
```
### data-env-vars.name = heptapod-public-2024-03-25-ds2-pnm
# benchmark.name = hg.command.update
# bin-env-vars.hg.py-re2-module = default
# bin-env-vars.hg.changeset.node = <this change>
# benchmark.variants.atomic-update = no
# benchmark.variants.scenario = null-to-tip
# benchmark.variants.worker = default
default: 5.328762 ~~~~~
rust: 1.308654 (-75.44%, -4.02)
### data-env-vars.name = mercurial-devel-2024-03-22-ds2-pnm
# benchmark.name = hg.command.update
# bin-env-vars.hg.py-re2-module = default
# bin-env-vars.hg.changeset.node = <this change>
# benchmark.variants.atomic-update = no
# benchmark.variants.scenario = null-to-tip
# benchmark.variants.worker = default
default: 1.693271 ~~~~~
rust: 1.151053 (-32.02%, -0.54)
### data-env-vars.name = mozilla-unified-2024-03-22-ds2-pnm
# benchmark.name = hg.command.update
# bin-env-vars.hg.py-re2-module = default
# bin-env-vars.hg.changeset.node = <this change>
# benchmark.variants.atomic-update = no
# benchmark.variants.scenario = null-to-tip
# benchmark.variants.worker = default
default: 38.901613 ~~~~~
rust: 11.637880 (-70.08%, -27.26)
### data-env-vars.name = netbsd-xsrc-public-2024-09-19-ds2-pnm
# benchmark.name = hg.command.update
# bin-env-vars.hg.py-re2-module = default
# bin-env-vars.hg.changeset.node = <this change>
# benchmark.variants.atomic-update = no
# benchmark.variants.scenario = null-to-tip
# benchmark.variants.worker = default
default: 4.793727 ~~~~~
rust: 1.505905 (-68.59%, -3.29)
```
====================================
Testing head checking code: Case E-3
====================================
Mercurial checks for the introduction of new heads on push. Evolution comes
into play to detect if existing branches on the server are being replaced by
some of the new one we push.
This case is part of a series of tests checking this behavior.
Category E: case involving changeset on multiple branch
TestCase 8: moving only part of the interleaved branch away, creating 2 heads
.. old-state:
..
.. * 2-changeset on branch default
.. * 1-changeset on branch Z (between the two other)
..
.. new-state:
..
.. * 2-changeset on branch default, on untouched, the other moved
.. * 1-changeset on branch Z (at the same location)
..
.. expected-result:
..
.. * push rejected
..
.. graph-summary:
..
.. C ø⇠◔ C'
.. | |
.. B ◔ |
.. | |
.. A ◔ |
.. |/
.. ●
$ . $TESTDIR/testlib/push-checkheads-util.sh
Test setup
----------
$ mkdir E1
$ cd E1
$ setuprepos
creating basic server and client repo
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd client
$ hg branch Z
marked working directory as branch Z
(branches are permanent and global, did you want a bookmark?)
$ mkcommit B0
$ hg branch default --force
marked working directory as branch default
$ mkcommit C0
created new head
$ hg push --new-branch
pushing to $TESTTMP/E1/server
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 2 files
$ hg up 0
0 files updated, 0 files merged, 3 files removed, 0 files unresolved
$ mkcommit C1
created new head
$ hg debugobsolete `getid "desc(C0)" ` `getid "desc(C1)"`
1 new obsolescence markers
obsoleted 1 changesets
$ hg log -G --hidden
@ dc44c53142f0 (draft): C1
|
| x afc55ba2ce61 (draft): C0
| |
| o 93e5c1321ece (draft): B0
| |
| o 8aaa48160adc (draft): A0
|/
o 1e4be0697311 (public): root
Actual testing
--------------
$ hg push -r 'desc("C1")'
pushing to $TESTTMP/E1/server
searching for changes
abort: push creates new remote head dc44c53142f0
(merge or see 'hg help push' for details about pushing new heads)
[20]
$ cd ../..