procutil: make stream detection in make_line_buffered more correct and strict
In make_line_buffered(), we don’t want to wrap the stream if we know that lines
get flushed to the underlying raw stream already.
Previously, the heuristic was too optimistic. It assumed that any stream which
is not an instance of io.BufferedIOBase doesn’t need wrapping. However, there
are buffered streams that aren’t instances of io.BufferedIOBase, like
Mercurial’s own winstdout.
The new logic is different in two ways:
First, only for the check, if unwraps any combination of WriteAllWrapper and
winstdout.
Second, it skips wrapping the stream only if it is an instance of io.RawIOBase
(or already wrapped). If it is an instance of io.BufferedIOBase, it gets
wrapped. In any other case, the function raises an exception. This ensures
that, if an unknown stream is passed or we add another wrapper in the future,
we don’t wrap the stream if it’s already line buffered or not wrap the stream
if it’s not line buffered. In fact, this was already helpful during development
of this change. Without it, I possibly would have forgot that WriteAllWrapper
needs to be ignored for the check, leading to unnecessary wrapping if stdout is
unbuffered.
The alternative would have been to always wrap unknown streams. However, I
don’t think that anyone would benefit from being less strict. We can expect
streams from the standard library to be subclassing either io.RawIOBase or
io.BufferedIOBase, so running Mercurial in the standard way should not regress
by this change. Py2exe might replace sys.stdout and sys.stderr, but that
currently breaks Mercurial anyway and also these streams don’t claim to be
interactive, so this function is not called for them.
# 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 (
getattr,
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()