localrepo: stop doing special dirstate backup at transaction open
Since the dirstate writes are already managed by the transaction, we already do
a backup of the dirstate when necessary (and even trigger one to keep `hg
rollback` happy).
We needs some special code to deal with the initial empty checkout, but it is
not too complicated.
Managing variable filename (as dirstate-v2 uses) at the "journalfile" level, is
complex and fragile (which is consistent with the fact these files are not
journal…). If we no longer do it, our life is significantly simpler.
In some sense, we apply the xkcd-1134¹ solution to our savebackup/restorebackup
problem.
[1] https://xkcd.com/1134/
(the change to test-hardlink are expect as decreasing the number of duplicated
backup drive the hardlink count down)
test --time
$ hg --time help -q help 2>&1 | grep time > /dev/null
$ hg init a
$ cd a
Function to check that statprof ran
$ statprofran () {
> egrep 'Sample count:|No samples recorded' > /dev/null
> }
test --profile
$ hg st --profile 2>&1 | statprofran
Abreviated version
$ hg st --prof 2>&1 | statprofran
In alias
$ hg --config "alias.profst=status --profile" profst 2>&1 | statprofran
#if lsprof
$ prof () {
> hg --config profiling.type=ls --profile $@
> }
$ prof st 2>../out
$ grep CallCount ../out > /dev/null || cat ../out
$ prof --config profiling.output=../out st
$ grep CallCount ../out > /dev/null || cat ../out
$ prof --config profiling.output=blackbox --config extensions.blackbox= st
$ grep CallCount .hg/blackbox.log > /dev/null || cat .hg/blackbox.log
$ prof --config profiling.format=text st 2>../out
$ grep CallCount ../out > /dev/null || cat ../out
$ echo "[profiling]" >> $HGRCPATH
$ echo "format=kcachegrind" >> $HGRCPATH
$ prof st 2>../out
$ grep 'events: Ticks' ../out > /dev/null || cat ../out
$ prof --config profiling.output=../out st
$ grep 'events: Ticks' ../out > /dev/null || cat ../out
#endif
#if lsprof serve
Profiling of HTTP requests works
$ prof --config profiling.format=text --config profiling.output=../profile.log serve -d -p $HGPORT --pid-file ../hg.pid -A ../access.log
$ cat ../hg.pid >> $DAEMON_PIDS
$ hg -q clone -U http://localhost:$HGPORT ../clone
A single profile is logged because file logging doesn't append
$ grep CallCount ../profile.log | wc -l
\s*1 (re)
#endif
Install an extension that can sleep and guarantee a profiler has time to run
$ cat >> sleepext_with_a_long_filename.py << EOF
> import time
> from mercurial import registrar
> cmdtable = {}
> command = registrar.command(cmdtable)
> @command(b'sleep', [], b'hg sleep')
> def sleep_for_at_least_one_stat_cycle(ui, *args, **kwargs):
> t = time.time() # don't use time.sleep because we need CPU time
> while time.time() - t < 0.5:
> pass
> EOF
$ cat >> $HGRCPATH << EOF
> [extensions]
> sleep = `pwd`/sleepext_with_a_long_filename.py
> EOF
statistical profiler works
$ hg --profile sleep 2>../out
$ cat ../out | statprofran
Various statprof formatters work
$ hg --profile --config profiling.statformat=byline sleep 2>../out || cat ../out
$ grep -v _path_stat ../out | head -n 3
% cumulative self
time seconds seconds name
* sleepext_with_a_long_filename.py:*:sleep_for_at_least_one_stat_cycle (glob)
$ cat ../out | statprofran
$ hg --profile --config profiling.statformat=bymethod sleep 2>../out || cat ../out
$ head -n 1 ../out
% cumulative self
$ cat ../out | statprofran
Windows real time tracking is broken, only use CPU
#if no-windows
$ hg --profile --config profiling.time-track=real --config profiling.statformat=hotpath sleep 2>../out || cat ../out
$ cat ../out | statprofran
$ grep sleepext_with_a_long_filename.py ../out | head -n 1
.* [0-9.]+% [0-9.]+s sleepext_with_a_long_filename.py:\s*sleep_for_at_least_one_stat_cycle, line \d+:\s+(while|pass).* (re)
#endif
$ hg --profile --config profiling.time-track=cpu --config profiling.statformat=hotpath sleep 2>../out || cat ../out
$ cat ../out | statprofran
$ grep sleepext_with_a_long_filename.py ../out | head -n 1
.* [0-9.]+% [0-9.]+s sleepext_with_a_long_filename.py:\s*sleep_for_at_least_one_stat_cycle, line \d+:\s+(while|pass).* (re)
$ hg --profile --config profiling.statformat=json sleep 2>../out || cat ../out
$ cat ../out
\[\[-?\d+.* (re)
statprof can be used as a standalone module
$ "$PYTHON" -m mercurial.statprof hotpath
must specify --file to load
[1]
$ cd ..
#if no-chg
profiler extension could be loaded before other extensions
$ cat > fooprof.py <<EOF
> import contextlib
> import sys
> @contextlib.contextmanager
> def profile(ui, fp):
> print('fooprof: start profile')
> sys.stdout.flush()
> yield
> print('fooprof: end profile')
> sys.stdout.flush()
> def extsetup(ui):
> ui.write(b'fooprof: loaded\n')
> EOF
$ cat > otherextension.py <<EOF
> def extsetup(ui):
> ui.write(b'otherextension: loaded\n')
> EOF
$ hg init b
$ cd b
$ cat >> .hg/hgrc <<EOF
> [extensions]
> other = $TESTTMP/otherextension.py
> fooprof = $TESTTMP/fooprof.py
> EOF
$ hg root
otherextension: loaded
fooprof: loaded
$TESTTMP/b
$ HGPROF=fooprof hg root --profile
fooprof: loaded
fooprof: start profile
otherextension: loaded
$TESTTMP/b
fooprof: end profile
$ HGPROF=other hg root --profile 2>&1 | head -n 2
otherextension: loaded
unrecognized profiler 'other' - ignored
$ HGPROF=unknown hg root --profile 2>&1 | head -n 1
unrecognized profiler 'unknown' - ignored
$ cd ..
#endif