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)
```
#require gpg
Test the GPG extension
$ cat <<EOF >> $HGRCPATH
> [extensions]
> gpg=
>
> [gpg]
> cmd=gpg --no-permission-warning --no-secmem-warning --no-auto-check-trustdb
> EOF
$ GNUPGHOME="$TESTTMP/gpg"; export GNUPGHOME
$ cp -R "$TESTDIR/gpg" "$GNUPGHOME"
Start gpg-agent, which is required by GnuPG v2
#if gpg21
$ gpg-connect-agent -q --subst /serverpid '/echo ${get serverpid}' /bye \
> >> $DAEMON_PIDS
#endif
and migrate secret keys
#if gpg2
$ gpg --no-permission-warning --no-secmem-warning --list-secret-keys \
> > /dev/null 2>&1
#endif
$ hg init r
$ cd r
$ echo foo > foo
$ hg ci -Amfoo
adding foo
$ hg sigs
$ HGEDITOR=cat hg sign -e 0
gpg: error retrieving key fingerprint from card: Invalid name (?)
signing 0:e63c23eaa88a
Added signature for changeset e63c23eaa88a
HG: Enter commit message. Lines beginning with 'HG:' are removed.
HG: Leave message empty to abort commit.
HG: --
HG: user: test
HG: branch 'default'
HG: added .hgsigs
$ hg sigs
hgtest 0:e63c23eaa88ae77967edcf4ea194d31167c478b0
$ hg sigcheck 0
e63c23eaa88a is signed by:
hgtest
The signature is different each time, so avoid signing the previous signature so
that the cset hashes are unchanging.
$ hg up -q '.^'
$ HGEDITOR=cat hg sign -f -e .
gpg: error retrieving key fingerprint from card: Invalid name (?)
signing 0:e63c23eaa88a
Added signature for changeset e63c23eaa88a
HG: Enter commit message. Lines beginning with 'HG:' are removed.
HG: Leave message empty to abort commit.
HG: --
HG: user: test
HG: branch 'default'
HG: added .hgsigs
$ cd ..