tests/test-profile.t

bundle2: implement consume() API on unbundlepart

We want bundle parts to not be seekable by default. That means
eliminating the generic seek() method.

A common pattern in bundle2.py is to seek to the end of the part
data. This is mainly used by the part iteration code to ensure
the underlying stream is advanced to the next bundle part.

In this commit, we establish a dedicated API for consuming a
bundle2 part data. We switch users of seek() to it.

The old implementation of seek(0, os.SEEK_END) would effectively
call self.read(). The new implementation calls self.read(32768)
in a loop. The old implementation would therefore assemble a
buffer to hold all remaining data being seeked over. For seeking
over large bundle parts, this would involve a large allocation and
a lot of overhead to collect intermediate data! This overhead can
be seen in the results for `hg perfbundleread`:

! bundle2 iterparts()
! wall 10.891305 comb 10.820000 user 7.990000 sys 2.830000 (best of 3)
! wall 8.070791 comb 8.060000 user 7.180000 sys 0.880000 (best of 3)
! bundle2 part seek()
! wall 12.991478 comb 10.390000 user 7.720000 sys 2.670000 (best of 3)
! wall 10.370142 comb 10.350000 user 7.430000 sys 2.920000 (best of 3)

Of course, skipping over large payload data isn't likely very common.
So I doubt the performance wins will be observed in the wild.

Differential Revision: https://phab.mercurial-scm.org/D1388

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.py << EOF
  > import time
  > from mercurial import registrar, commands
  > cmdtable = {}
  > command = registrar.command(cmdtable)
  > @command(b'sleep', [], 'hg sleep')
  > def sleep(ui, *args, **kwargs):
  >     time.sleep(0.1)
  > EOF

  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > sleep = `pwd`/sleepext.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
  $ head -n 1 ../out
    %   cumulative      self          
  $ cat ../out | statprofran

  $ hg --profile --config profiling.statformat=bymethod sleep 2>../out
  $ head -n 1 ../out
    %   cumulative      self          
  $ cat ../out | statprofran

  $ hg --profile --config profiling.statformat=hotpath sleep 2>../out
  $ cat ../out | statprofran

  $ hg --profile --config profiling.statformat=json sleep 2>../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
  > from __future__ import absolute_import
  > import contextlib
  > @contextlib.contextmanager
  > def profile(ui, fp):
  >     print('fooprof: start profile')
  >     yield
  >     print('fooprof: end profile')
  > def extsetup(ui):
  >     ui.write('fooprof: loaded\n')
  > EOF

  $ cat > otherextension.py <<EOF
  > from __future__ import absolute_import
  > def extsetup(ui):
  >     ui.write('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 (glob)
  $ HGPROF=fooprof hg root --profile
  fooprof: loaded
  fooprof: start profile
  otherextension: loaded
  $TESTTMP/b (glob)
  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