# 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.

from __future__ import absolute_import, print_function

import contextlib

from .i18n import _

from . import (

    encoding,

    error,

    extensions,

    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('profiling', 'format', default='text')

    field = ui.config('profiling', 'sort', default='inlinetime')

    limit = ui.configint('profiling', 'limit', default=30)

    climit = ui.configint('profiling', 'nested', default=0)

    if format not in ['text', 'kcachegrind']:

        ui.warn(_("unrecognized profiling format '%s'"

                    " - Ignored\n") % format)

        format = 'text'

    try:

        from . import lsprof

    except ImportError:

        raise error.Abort(_(

            'lsprof not available - install from '

            'http://codespeak.net/svn/user/arigo/hack/misc/lsprof/'))

    p = lsprof.Profiler()

    p.enable(subcalls=True)

    try:

        yield

    finally:

        p.disable()

        if format == 'kcachegrind':

            from . import lsprofcalltree

            calltree = lsprofcalltree.KCacheGrind(p)

            calltree.output(fp)

        else:

            # format == 'text'

            stats = lsprof.Stats(p.getstats())

            stats.sort(field)

            stats.pprint(limit=limit, file=fp, climit=climit)

@contextlib.contextmanager

def flameprofile(ui, fp):

    try:

        from flamegraph import flamegraph

    except ImportError:

        raise error.Abort(_(

            'flamegraph not available - install from '

            'https://github.com/evanhempel/python-flamegraph'))

    # developer config: profiling.freq

    freq = ui.configint('profiling', 'freq', default=1000)

    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('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('profiling', 'freq', default=1000)

    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(_("invalid sampling frequency '%s' - ignoring\n") % freq)

    statprof.start(mechanism='thread')

    try:

        yield

    finally:

        data = statprof.stop()

        profformat = ui.config('profiling', 'statformat', 'hotpath')

        formats = {

            'byline': statprof.DisplayFormats.ByLine,

            'bymethod': statprof.DisplayFormats.ByMethod,

            'hotpath': statprof.DisplayFormats.Hotpath,

            'json': statprof.DisplayFormats.Json,

            'chrome': statprof.DisplayFormats.Chrome,

        }

        if profformat in formats:

            displayformat = formats[profformat]

        else:

            ui.warn(_('unknown profiler output format: %s\n') % profformat)

            displayformat = statprof.DisplayFormats.Hotpath

        kwargs = {}

        def fraction(s):

            if s.endswith('%'):

                v = float(s[:-1]) / 100

            else:

                v = float(s)

            if 0 <= v <= 1:

                return v

            raise ValueError(s)

        if profformat == 'chrome':

            showmin = ui.configwith(fraction, 'profiling', 'showmin', 0.005)

            showmax = ui.configwith(fraction, 'profiling', 'showmax', 0.999)

            kwargs.update(minthreshold=showmin, maxthreshold=showmax)

        statprof.display(fp, data=data, format=displayformat, **kwargs)

class profile(object):

    """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._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()

        if self._started:

            return

        self._started = True

        profiler = encoding.environ.get('HGPROF')

        proffn = None

        if profiler is None:

            profiler = self._ui.config('profiling', 'type', default='stat')

        if profiler not in ('ls', 'stat', 'flame'):

            # try load profiler from extension with the same name

            proffn = _loadprofiler(self._ui, profiler)

            if proffn is None:

                self._ui.warn(_("unrecognized profiler '%s' - ignored\n")

                              % profiler)

                profiler = 'stat'

        self._output = self._ui.config('profiling', 'output')

    def __exit__(self, exception_type, exception_value, traceback):

        if self._profiler is None:

            return

        self._profiler.__exit__(exception_type, exception_value, traceback)

        if self._output == 'blackbox':

            val = '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('%', '%%')

            self._ui.log('profile', val)

        self._closefp()

    def _closefp(self):

        if self._fpdoclose and self._fp is not None:

            self._fp.close()