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)
```
$ cat >> $HGRCPATH <<EOF
> [extensions]
> rebase=
> mq=
>
> [mq]
> plain=true
>
> [alias]
> tglog = log -G --template "{rev}: {node|short} '{desc}' tags: {tags}\n"
> EOF
$ hg init a
$ cd a
$ hg qinit -c
$ echo c1 > f
$ hg add f
$ hg ci -m C1
$ echo r1 > f
$ hg ci -m R1
$ hg up -q 0
$ hg qnew f.patch -d '1 0'
$ echo mq1 > f
$ hg qref -m P0
$ hg qnew f2.patch
$ echo mq2 > f
$ hg qref -m P1 -d '2 0'
$ hg tglog
@ 3: 929394423cd3 'P1' tags: f2.patch qtip tip
|
o 2: 3504f44bffc0 'P0' tags: f.patch qbase
|
| o 1: bac9ed9960d8 'R1' tags:
|/
o 0: 36f36ddbca61 'C1' tags: qparent
Rebase - try to rebase on an applied mq patch:
$ hg rebase -s 1 -d 3
abort: cannot rebase onto an applied mq patch
[20]
Rebase - same thing, but mq patch is default dest:
$ hg up -q 1
$ hg rebase
abort: cannot rebase onto an applied mq patch
[20]
$ hg up -q qtip
Rebase - generate a conflict:
$ hg rebase -s 2 -d 1
rebasing 2:3504f44bffc0 f.patch qbase "P0"
merging f
warning: conflicts while merging f! (edit, then use 'hg resolve --mark')
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
Fix the 1st conflict:
$ echo mq1r1 > f
$ hg resolve -m f
(no more unresolved files)
continue: hg rebase --continue
$ hg rebase -c
rebasing 2:3504f44bffc0 f.patch qbase "P0"
rebasing 3:929394423cd3 f2.patch qtip tip "P1"
merging f
warning: conflicts while merging f! (edit, then use 'hg resolve --mark')
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
Fix the 2nd conflict:
$ echo mq1r1mq2 > f
$ hg resolve -m f
(no more unresolved files)
continue: hg rebase --continue
$ hg rebase -c
already rebased 2:3504f44bffc0 f.patch qbase "P0" as ebe9914c0d1c
rebasing 3:929394423cd3 f2.patch qtip "P1"
saved backup bundle to $TESTTMP/a/.hg/strip-backup/3504f44bffc0-30595b40-rebase.hg
$ hg tglog
@ 3: 462012cf340c 'P1' tags: f2.patch qtip tip
|
o 2: ebe9914c0d1c 'P0' tags: f.patch qbase
|
o 1: bac9ed9960d8 'R1' tags: qparent
|
o 0: 36f36ddbca61 'C1' tags:
$ hg up -q qbase
$ cat f
mq1r1
$ cat .hg/patches/f.patch
# HG changeset patch
# User test
# Date 1 0
# Thu Jan 01 00:00:01 1970 +0000
# Node ID ebe9914c0d1c3f60096e952fa4dbb3d377dea3ab
# Parent bac9ed9960d8992bcad75864a879fa76cadaf1b0
P0
diff -r bac9ed9960d8 -r ebe9914c0d1c f
--- a/f Thu Jan 01 00:00:00 1970 +0000
+++ b/f Thu Jan 01 00:00:01 1970 +0000
@@ -1,1 +1,1 @@
-r1
+mq1r1
Update to qtip:
$ hg up -q qtip
$ cat f
mq1r1mq2
$ cat .hg/patches/f2.patch
# HG changeset patch
# User test
# Date 2 0
# Thu Jan 01 00:00:02 1970 +0000
# Node ID 462012cf340c97d44d62377c985a423f6bb82f07
# Parent ebe9914c0d1c3f60096e952fa4dbb3d377dea3ab
P1
diff -r ebe9914c0d1c -r 462012cf340c f
--- a/f Thu Jan 01 00:00:01 1970 +0000
+++ b/f Thu Jan 01 00:00:02 1970 +0000
@@ -1,1 +1,1 @@
-mq1r1
+mq1r1mq2
Adding one git-style patch and one normal:
$ hg qpop -a
popping f2.patch
popping f.patch
patch queue now empty
$ rm -fr .hg/patches
$ hg qinit -c
$ hg up -q 0
$ hg qnew --git f_git.patch -d '3 0'
$ echo mq1 > p
$ hg add p
$ hg qref --git -m 'P0 (git)'
$ hg qnew f.patch -d '4 0'
$ echo mq2 > p
$ hg qref -m P1
$ hg qci -m 'save patch state'
$ hg qseries -s
f_git.patch: P0 (git)
f.patch: P1
$ hg -R .hg/patches manifest
.hgignore
f.patch
f_git.patch
series
$ cat .hg/patches/f_git.patch
Date: 3 0
P0 (git)
diff --git a/p b/p
new file mode 100644
--- /dev/null
+++ b/p
@@ -0,0 +1,1 @@
+mq1
$ cat .hg/patches/f.patch
Date: 4 0
P1
diff -r ???????????? p (glob)
--- a/p ??? ??? ?? ??:??:?? ???? ????? (glob)
+++ b/p ??? ??? ?? ??:??:?? ???? ????? (glob)
@@ -1,1 +1,1 @@
-mq1
+mq2
Rebase the applied mq patches:
$ hg rebase -s 2 -d 1
rebasing 2:0c587ffcb480 f_git.patch qbase "P0 (git)"
rebasing 3:c7f18665e4bc f.patch qtip tip "P1"
saved backup bundle to $TESTTMP/a/.hg/strip-backup/0c587ffcb480-0ea5695f-rebase.hg
$ hg qci -m 'save patch state'
$ hg qseries -s
f_git.patch: P0 (git)
f.patch: P1
$ hg -R .hg/patches manifest
.hgignore
f.patch
f_git.patch
series
$ cat .hg/patches/f_git.patch
# HG changeset patch
# User test
# Date 3 0
# Thu Jan 01 00:00:03 1970 +0000
# Node ID 12d9f6a3bbe560dee50c7c454d434add7fb8e837
# Parent bac9ed9960d8992bcad75864a879fa76cadaf1b0
P0 (git)
diff --git a/p b/p
new file mode 100644
--- /dev/null
+++ b/p
@@ -0,0 +1,1 @@
+mq1
$ cat .hg/patches/f.patch
# HG changeset patch
# User test
# Date 4 0
# Thu Jan 01 00:00:04 1970 +0000
# Node ID c77a2661c64c60d82f63c4f7aefd95b3a948a557
# Parent 12d9f6a3bbe560dee50c7c454d434add7fb8e837
P1
diff -r 12d9f6a3bbe5 -r c77a2661c64c p
--- a/p Thu Jan 01 00:00:03 1970 +0000
+++ b/p Thu Jan 01 00:00:04 1970 +0000
@@ -1,1 +1,1 @@
-mq1
+mq2
$ cd ..
Rebase with guards
$ hg init foo
$ cd foo
$ echo a > a
$ hg ci -Am a
adding a
Create mq repo with guarded patches foo and bar and empty patch:
$ hg qinit
$ echo guarded > guarded
$ hg add guarded
$ hg qnew guarded
$ hg qnew empty-important -m 'important commit message' -d '1 0'
$ echo bar > bar
$ hg add bar
$ hg qnew bar -d '2 0'
$ echo foo > foo
$ hg add foo
$ hg qnew foo
$ hg qpop -a
popping foo
popping bar
popping empty-important
popping guarded
patch queue now empty
$ hg qguard guarded +guarded
$ hg qguard bar +baz
$ hg qguard foo +baz
$ hg qselect baz
number of unguarded, unapplied patches has changed from 1 to 3
$ hg qpush bar
applying empty-important
patch empty-important is empty
applying bar
now at: bar
$ hg qguard -l
guarded: +guarded
empty-important: unguarded
bar: +baz
foo: +baz
$ hg tglog
@ 2: 4f44b861d38c 'imported patch bar' tags: bar qtip tip
|
o 1: 0aaf4c3af7eb 'important commit message' tags: empty-important qbase
|
o 0: cb9a9f314b8b 'a' tags: qparent
Create new head to rebase bar onto:
$ hg up -C 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo b > b
$ hg add b
$ hg ci -m b
created new head
$ hg up -C 2
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo a >> a
$ hg qref
$ hg tglog
@ 3: d526d4536ed6 '[mq]: bar' tags: bar qtip tip
|
| o 2: d2ae7f538514 'b' tags:
| |
o | 1: 0aaf4c3af7eb 'important commit message' tags: empty-important qbase
|/
o 0: cb9a9f314b8b 'a' tags: qparent
Rebase bar (make sure series order is preserved and empty-important also is
removed from the series):
$ hg qseries
guarded
empty-important
bar
foo
$ [ -f .hg/patches/empty-important ]
$ hg -q rebase -d 2
note: not rebasing 1:0aaf4c3af7eb empty-important qbase "important commit message", its destination already has all its changes
$ hg qseries
guarded
bar
foo
$ [ -f .hg/patches/empty-important ]
[1]
$ hg qguard -l
guarded: +guarded
bar: +baz
foo: +baz
$ hg tglog
@ 2: 477d948bb2af '[mq]: bar' tags: bar qbase qtip tip
|
o 1: d2ae7f538514 'b' tags: qparent
|
o 0: cb9a9f314b8b 'a' tags:
$ cd ..