bundle2: inline changegroup.readexactly()
Profiling reveals this loop is pretty tight. Literally any
function call elimination can make a big difference.
This commit inlines the relatively trivial changegroup.readexactly()
method inside the loop.
The results with `hg perfbundleread` on a bundle of the Firefox repo
speak for themselves:
! read(8k)
! wall 0.679730 comb 0.680000 user 0.140000 sys 0.540000 (best of 15)
! read(16k)
! wall 0.577228 comb 0.570000 user 0.080000 sys 0.490000 (best of 17)
! read(32k)
! wall 0.516060 comb 0.520000 user 0.040000 sys 0.480000 (best of 20)
! read(128k)
! wall 0.496378 comb 0.490000 user 0.010000 sys 0.480000 (best of 20)
! bundle2 iterparts()
! wall 3.460903 comb 3.460000 user 2.760000 sys 0.700000 (best of 3)
! wall 3.056811 comb 3.050000 user 2.340000 sys 0.710000 (best of 4)
! bundle2 iterparts() seekable
! wall 4.312722 comb 4.310000 user 3.480000 sys 0.830000 (best of 3)
! wall 4.007676 comb 4.000000 user 3.170000 sys 0.830000 (best of 3)
! bundle2 part seek()
! wall 6.754764 comb 6.740000 user 3.970000 sys 2.770000 (best of 3)
! wall 6.267110 comb 6.250000 user 3.480000 sys 2.770000 (best of 3)
! bundle2 part read(8k)
! wall 3.668004 comb 3.660000 user 2.960000 sys 0.700000 (best of 3)
! wall 3.404164 comb 3.400000 user 2.650000 sys 0.750000 (best of 3)
! bundle2 part read(16k)
! wall 3.489196 comb 3.480000 user 2.750000 sys 0.730000 (best of 3)
! wall 3.197972 comb 3.200000 user 2.490000 sys 0.710000 (best of 4)
! bundle2 part read(32k)
! wall 3.388569 comb 3.380000 user 2.640000 sys 0.740000 (best of 3)
! wall 3.060557 comb 3.060000 user 2.340000 sys 0.720000 (best of 4)
! bundle2 part read(128k)
! wall 3.276415 comb 3.270000 user 2.560000 sys 0.710000 (best of 4)
! wall 2.952209 comb 2.950000 user 2.230000 sys 0.720000 (best of 4)
Differential Revision: https://phab.mercurial-scm.org/D1392
$ hg init repo
$ cd repo
$ echo a > a
$ hg add a
$ hg commit -m test
Do we ever miss a sub-second change?:
$ for i in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20; do
> hg co -qC 0
> echo b > a
> hg st
> done
M a
M a
M a
M a
M a
M a
M a
M a
M a
M a
M a
M a
M a
M a
M a
M a
M a
M a
M a
M a
$ echo test > b
$ mkdir dir1
$ echo test > dir1/c
$ echo test > d
$ echo test > e
#if execbit
A directory will typically have the execute bit -- make sure it doesn't get
confused with a file with the exec bit set
$ chmod +x e
#endif
$ hg add b dir1 d e
adding dir1/c (glob)
$ hg commit -m test2
$ cat >> $TESTTMP/dirstaterace.py << EOF
> from mercurial import (
> context,
> extensions,
> )
> def extsetup():
> extensions.wrapfunction(context.workingctx, '_checklookup', overridechecklookup)
> def overridechecklookup(orig, self, files):
> # make an update that changes the dirstate from underneath
> self._repo.ui.system(r"sh '$TESTTMP/dirstaterace.sh'",
> cwd=self._repo.root)
> return orig(self, files)
> EOF
$ hg debugrebuilddirstate
$ hg debugdirstate
n 0 -1 unset a
n 0 -1 unset b
n 0 -1 unset d
n 0 -1 unset dir1/c
n 0 -1 unset e
XXX Note that this returns M for files that got replaced by directories. This is
definitely a bug, but the fix for that is hard and the next status run is fine
anyway.
$ cat > $TESTTMP/dirstaterace.sh <<EOF
> rm b && rm -r dir1 && rm d && mkdir d && rm e && mkdir e
> EOF
$ hg status --config extensions.dirstaterace=$TESTTMP/dirstaterace.py
M d
M e
! b
! dir1/c
$ hg debugdirstate
n 644 2 * a (glob)
n 0 -1 unset b
n 0 -1 unset d
n 0 -1 unset dir1/c
n 0 -1 unset e
$ hg status
! b
! d
! dir1/c
! e
$ rmdir d e
$ hg update -C -q .
Test that dirstate changes aren't written out at the end of "hg
status", if .hg/dirstate is already changed simultaneously before
acquisition of wlock in workingctx._poststatusfixup().
This avoidance is important to keep consistency of dirstate in race
condition (see issue5584 for detail).
$ hg parents -q
1:* (glob)
$ hg debugrebuilddirstate
$ hg debugdirstate
n 0 -1 unset a
n 0 -1 unset b
n 0 -1 unset d
n 0 -1 unset dir1/c
n 0 -1 unset e
$ cat > $TESTTMP/dirstaterace.sh <<EOF
> # This script assumes timetable of typical issue5584 case below:
> #
> # 1. "hg status" loads .hg/dirstate
> # 2. "hg status" confirms clean-ness of FILE
> # 3. "hg update -C 0" updates the working directory simultaneously
> # (FILE is removed, and FILE is dropped from .hg/dirstate)
> # 4. "hg status" acquires wlock
> # (.hg/dirstate is re-loaded = no FILE entry in dirstate)
> # 5. "hg status" marks FILE in dirstate as clean
> # (FILE entry is added to in-memory dirstate)
> # 6. "hg status" writes dirstate changes into .hg/dirstate
> # (FILE entry is written into .hg/dirstate)
> #
> # To reproduce similar situation easily and certainly, #2 and #3
> # are swapped. "hg cat" below ensures #2 on "hg status" side.
>
> hg update -q -C 0
> hg cat -r 1 b > b
> EOF
"hg status" below should excludes "e", of which exec flag is set, for
portability of test scenario, because unsure but missing "e" is
treated differently in _checklookup() according to runtime platform.
- "missing(!)" on POSIX, "pctx[f].cmp(self[f])" raises ENOENT
- "modified(M)" on Windows, "self.flags(f) != pctx.flags(f)" is True
$ hg status --config extensions.dirstaterace=$TESTTMP/dirstaterace.py --debug -X path:e
skip updating dirstate: identity mismatch
M a
! d
! dir1/c
$ hg parents -q
0:* (glob)
$ hg files
a
$ hg debugdirstate
n * * * a (glob)
$ rm b
#if fsmonitor
Create fsmonitor state.
$ hg status
$ f --type .hg/fsmonitor.state
.hg/fsmonitor.state: file
Test that invalidating fsmonitor state in the middle (which doesn't require the
wlock) causes the fsmonitor update to be skipped.
hg debugrebuilddirstate ensures that the dirstaterace hook will be called, but
it also invalidates the fsmonitor state. So back it up and restore it.
$ mv .hg/fsmonitor.state .hg/fsmonitor.state.tmp
$ hg debugrebuilddirstate
$ mv .hg/fsmonitor.state.tmp .hg/fsmonitor.state
$ cat > $TESTTMP/dirstaterace.sh <<EOF
> rm .hg/fsmonitor.state
> EOF
$ hg status --config extensions.dirstaterace=$TESTTMP/dirstaterace.py --debug
skip updating fsmonitor.state: identity mismatch
$ f .hg/fsmonitor.state
.hg/fsmonitor.state: file not found
#endif
Set up a rebase situation for issue5581.
$ echo c2 > a
$ echo c2 > b
$ hg add b
$ hg commit -m c2
created new head
$ echo c3 >> a
$ hg commit -m c3
$ hg update 2
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo c4 >> a
$ echo c4 >> b
$ hg commit -m c4
created new head
Configure a merge tool that runs status in the middle of the rebase. The goal of
the status call is to trigger a potential bug if fsmonitor's state is written
even though the wlock is held by another process. The output of 'hg status' in
the merge tool goes to /dev/null because we're more interested in the results of
'hg status' run after the rebase.
$ cat >> $TESTTMP/mergetool-race.sh << EOF
> echo "custom merge tool"
> printf "c2\nc3\nc4\n" > \$1
> hg --cwd "$TESTTMP/repo" status > /dev/null
> echo "custom merge tool end"
> EOF
$ cat >> $HGRCPATH << EOF
> [extensions]
> rebase =
> [merge-tools]
> test.executable=sh
> test.args=$TESTTMP/mergetool-race.sh \$output
> EOF
$ hg rebase -s . -d 3 --tool test
rebasing 4:b08445fd6b2a "c4" (tip)
merging a
custom merge tool
custom merge tool end
saved backup bundle to $TESTTMP/repo/.hg/strip-backup/* (glob)
This hg status should be empty, whether or not fsmonitor is enabled (issue5581).
$ hg status