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)
```
$ mkdir folder
$ cd folder
$ hg init
$ mkdir x x/l x/m x/n x/l/u x/l/u/a
$ touch a b x/aa.o x/bb.o
$ hg status
? a
? b
? x/aa.o
? x/bb.o
$ hg status --terse u
? a
? b
? x/
$ hg status --terse maudric
? a
? b
? x/
$ hg status --terse madric
? a
? b
? x/aa.o
? x/bb.o
$ hg status --terse f
abort: 'f' not recognized
[10]
Add a .hgignore so that we can also have ignored files
$ echo ".*\.o" > .hgignore
$ hg status
? .hgignore
? a
? b
$ hg status -i
I x/aa.o
I x/bb.o
Tersing ignored files
$ hg status -t i --ignored
I x/
Adding more files
$ mkdir y
$ touch x/aa x/bb y/l y/m y/l.o y/m.o
$ touch x/l/aa x/m/aa x/n/aa x/l/u/bb x/l/u/a/bb
$ hg status
? .hgignore
? a
? b
? x/aa
? x/bb
? x/l/aa
? x/l/u/a/bb
? x/l/u/bb
? x/m/aa
? x/n/aa
? y/l
? y/m
$ hg status --terse u
? .hgignore
? a
? b
? x/
? y/
Run from subdirectory
$ hg status --terse u --cwd x/l
? .hgignore
? a
? b
? x/
? y/
$ relstatus() {
> hg status --terse u --config commands.status.relative=1 "$@";
> }
This should probably have {"l/", "m/", "n/"} instead of {"."}. They should
probably come after "../y/".
$ relstatus --cwd x
? ../.hgignore
? ../a
? ../b
? .
? ../y/
This should probably have {"u/", "../m/", "../n/"} instead of {"../"}.
$ relstatus --cwd x/l
? ../../.hgignore
? ../../a
? ../../b
? ../
? ../../y/
This should probably have {"a/", "bb", "../aa", "../../m/", "../../n/"}
instead of {"../../"}.
$ relstatus --cwd x/l/u
? ../../../.hgignore
? ../../../a
? ../../../b
? ../../
? ../../../y/
This should probably have {"bb", "../bb", "../../aa", "../../../m/",
"../../../n/"} instead of {"../../../"}.
$ relstatus --cwd x/l/u/a
? ../../../../.hgignore
? ../../../../a
? ../../../../b
? ../../../
? ../../../../y/
$ hg add x/aa x/bb .hgignore
$ hg status --terse au
A .hgignore
A x/aa
A x/bb
? a
? b
? x/l/
? x/m/
? x/n/
? y/
Including ignored files
$ hg status --terse aui
A .hgignore
A x/aa
A x/bb
? a
? b
? x/l/
? x/m/
? x/n/
? y/l
? y/m
$ hg status --terse au -i
I x/aa.o
I x/bb.o
I y/l.o
I y/m.o
Committing some of the files
$ hg commit x/aa x/bb .hgignore -m "First commit"
$ hg status
? a
? b
? x/l/aa
? x/l/u/a/bb
? x/l/u/bb
? x/m/aa
? x/n/aa
? y/l
? y/m
$ hg status --terse mardu
? a
? b
? x/l/
? x/m/
? x/n/
? y/
Modifying already committed files
$ echo "Hello" >> x/aa
$ echo "World" >> x/bb
$ hg status --terse maurdc
M x/aa
M x/bb
? a
? b
? x/l/
? x/m/
? x/n/
? y/
Respecting other flags
$ hg status --terse marduic --all
M x/aa
M x/bb
? a
? b
? x/l/
? x/m/
? x/n/
? y/l
? y/m
I x/aa.o
I x/bb.o
I y/l.o
I y/m.o
C .hgignore
$ hg status --terse marduic -a
$ hg status --terse marduic -c
C .hgignore
$ hg status --terse marduic -m
M x/aa
M x/bb
Passing 'i' in terse value will consider the ignored files while tersing
$ hg status --terse marduic -u
? a
? b
? x/l/
? x/m/
? x/n/
? y/l
? y/m
Omitting 'i' in terse value does not consider ignored files while tersing
$ hg status --terse marduc -u
? a
? b
? x/l/
? x/m/
? x/n/
? y/
Trying with --rev
$ hg status --terse marduic --rev 0 --rev 1
abort: cannot use --terse with --rev
[10]
Config item to set the default terseness
$ cat <<EOF >> $HGRCPATH
> [commands]
> status.terse = u
> EOF
$ hg status -mu
M x/aa
M x/bb
? a
? b
? x/l/
? x/m/
? x/n/
? y/
Command line flag overrides the default
$ hg status --terse=
M x/aa
M x/bb
? a
? b
? x/l/aa
? x/l/u/a/bb
? x/l/u/bb
? x/m/aa
? x/n/aa
? y/l
? y/m
$ hg status --terse=mardu
M x/aa
M x/bb
? a
? b
? x/l/
? x/m/
? x/n/
? y/
Specifying --rev should still work, with the terseness disabled.
$ hg status --rev 0
M x/aa
M x/bb
? a
? b
? x/l/aa
? x/l/u/a/bb
? x/l/u/bb
? x/m/aa
? x/n/aa
? y/l
? y/m