push: rework the computation of fallbackheads to be correct
The previous computation tried to be smart but ended up being wrong. This was
caught by phase movement test while reworking the phase discovery logic to be
faster.
The previous logic was failing to catch case where the pushed set was not based
on a common heads (i.e. when the discovery seemed to have "over discovered"
content, outside the pushed set)
In the following graph, `e` is a common head and we `hg push -r f`. We need to
detect `c` as a fallback heads and we previous failed to do so::
e
|
d f
|/
c
|
b
|
a
The performance impact of the change seems minimal. On the most impacted
repository at hand (mozilla-try), the slowdown seems mostly mixed in the
overall noise `hg push` but seems to be in the hundred of milliseconds order of
magnitude. When using rust, we seems to be a bit faster, probably because we
leverage more accelaratd internals.
I added a couple of performance related common for further investigation later
on.
# profiling.py - profiling functions
#
# Copyright 2016 Gregory Szorc <gregory.szorc@gmail.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
import contextlib
from .i18n import _
from .pycompat import (
open,
)
from . import (
encoding,
error,
extensions,
pycompat,
util,
)
def _loadprofiler(ui, profiler):
"""load profiler extension. return profile method, or None on failure"""
extname = profiler
extensions.loadall(ui, whitelist=[extname])
try:
mod = extensions.find(extname)
except KeyError:
return None
else:
return getattr(mod, 'profile', None)
@contextlib.contextmanager
def lsprofile(ui, fp):
format = ui.config(b'profiling', b'format')
field = ui.config(b'profiling', b'sort')
limit = ui.configint(b'profiling', b'limit')
climit = ui.configint(b'profiling', b'nested')
if format not in [b'text', b'kcachegrind']:
ui.warn(_(b"unrecognized profiling format '%s' - Ignored\n") % format)
format = b'text'
try:
from . import lsprof
except ImportError:
raise error.Abort(
_(
b'lsprof not available - install from '
b'http://codespeak.net/svn/user/arigo/hack/misc/lsprof/'
)
)
p = lsprof.Profiler()
p.enable(subcalls=True)
try:
yield
finally:
p.disable()
if format == b'kcachegrind':
from . import lsprofcalltree
calltree = lsprofcalltree.KCacheGrind(p)
calltree.output(fp)
else:
# format == 'text'
stats = lsprof.Stats(p.getstats())
stats.sort(pycompat.sysstr(field))
stats.pprint(limit=limit, file=fp, climit=climit)
@contextlib.contextmanager
def flameprofile(ui, fp):
try:
from flamegraph import flamegraph # pytype: disable=import-error
except ImportError:
raise error.Abort(
_(
b'flamegraph not available - install from '
b'https://github.com/evanhempel/python-flamegraph'
)
)
# developer config: profiling.freq
freq = ui.configint(b'profiling', b'freq')
filter_ = None
collapse_recursion = True
thread = flamegraph.ProfileThread(
fp, 1.0 / freq, filter_, collapse_recursion
)
start_time = util.timer()
try:
thread.start()
yield
finally:
thread.stop()
thread.join()
print(
b'Collected %d stack frames (%d unique) in %2.2f seconds.'
% (
util.timer() - start_time,
thread.num_frames(),
thread.num_frames(unique=True),
)
)
@contextlib.contextmanager
def statprofile(ui, fp):
from . import statprof
freq = ui.configint(b'profiling', b'freq')
if freq > 0:
# Cannot reset when profiler is already active. So silently no-op.
if statprof.state.profile_level == 0:
statprof.reset(freq)
else:
ui.warn(_(b"invalid sampling frequency '%s' - ignoring\n") % freq)
track = ui.config(
b'profiling', b'time-track', pycompat.iswindows and b'cpu' or b'real'
)
statprof.start(mechanism=b'thread', track=track)
try:
yield
finally:
data = statprof.stop()
profformat = ui.config(b'profiling', b'statformat')
formats = {
b'byline': statprof.DisplayFormats.ByLine,
b'bymethod': statprof.DisplayFormats.ByMethod,
b'hotpath': statprof.DisplayFormats.Hotpath,
b'json': statprof.DisplayFormats.Json,
b'chrome': statprof.DisplayFormats.Chrome,
}
if profformat in formats:
displayformat = formats[profformat]
else:
ui.warn(_(b'unknown profiler output format: %s\n') % profformat)
displayformat = statprof.DisplayFormats.Hotpath
kwargs = {}
def fraction(s):
if isinstance(s, (float, int)):
return float(s)
if s.endswith(b'%'):
v = float(s[:-1]) / 100
else:
v = float(s)
if 0 <= v <= 1:
return v
raise ValueError(s)
if profformat == b'chrome':
showmin = ui.configwith(fraction, b'profiling', b'showmin', 0.005)
showmax = ui.configwith(fraction, b'profiling', b'showmax')
kwargs.update(minthreshold=showmin, maxthreshold=showmax)
elif profformat == b'hotpath':
# inconsistent config: profiling.showmin
limit = ui.configwith(fraction, b'profiling', b'showmin', 0.05)
kwargs['limit'] = limit
showtime = ui.configbool(b'profiling', b'showtime')
kwargs['showtime'] = showtime
statprof.display(fp, data=data, format=displayformat, **kwargs)
class profile:
"""Start profiling.
Profiling is active when the context manager is active. When the context
manager exits, profiling results will be written to the configured output.
"""
def __init__(self, ui, enabled=True):
self._ui = ui
self._output = None
self._fp = None
self._fpdoclose = True
self._flushfp = None
self._profiler = None
self._enabled = enabled
self._entered = False
self._started = False
def __enter__(self):
self._entered = True
if self._enabled:
self.start()
return self
def start(self):
"""Start profiling.
The profiling will stop at the context exit.
If the profiler was already started, this has no effect."""
if not self._entered:
raise error.ProgrammingError(b'use a context manager to start')
if self._started:
return
self._started = True
profiler = encoding.environ.get(b'HGPROF')
proffn = None
if profiler is None:
profiler = self._ui.config(b'profiling', b'type')
if profiler not in (b'ls', b'stat', b'flame'):
# try load profiler from extension with the same name
proffn = _loadprofiler(self._ui, profiler)
if proffn is None:
self._ui.warn(
_(b"unrecognized profiler '%s' - ignored\n") % profiler
)
profiler = b'stat'
self._output = self._ui.config(b'profiling', b'output')
try:
if self._output == b'blackbox':
self._fp = util.stringio()
elif self._output:
path = util.expandpath(self._output)
self._fp = open(path, b'wb')
elif pycompat.iswindows:
# parse escape sequence by win32print()
class uifp:
def __init__(self, ui):
self._ui = ui
def write(self, data):
self._ui.write_err(data)
def flush(self):
self._ui.flush()
self._fpdoclose = False
self._fp = uifp(self._ui)
else:
self._fpdoclose = False
self._fp = self._ui.ferr
# Ensure we've flushed fout before writing to ferr.
self._flushfp = self._ui.fout
if proffn is not None:
pass
elif profiler == b'ls':
proffn = lsprofile
elif profiler == b'flame':
proffn = flameprofile
else:
proffn = statprofile
self._profiler = proffn(self._ui, self._fp)
self._profiler.__enter__()
except: # re-raises
self._closefp()
raise
def __exit__(self, exception_type, exception_value, traceback):
propagate = None
if self._profiler is not None:
self._uiflush()
propagate = self._profiler.__exit__(
exception_type, exception_value, traceback
)
if self._output == b'blackbox':
val = b'Profile:\n%s' % self._fp.getvalue()
# ui.log treats the input as a format string,
# so we need to escape any % signs.
val = val.replace(b'%', b'%%')
self._ui.log(b'profile', val)
self._closefp()
return propagate
def _closefp(self):
if self._fpdoclose and self._fp is not None:
self._fp.close()
def _uiflush(self):
if self._flushfp:
self._flushfp.flush()