# Profiling: Times operations and provides the user with statistical information

import sys

import datetime

import dates

import format

class Profiler:

    def __init__(self, start_now=False):

        self.total = datetime.timedelta()

        if start_now: self.start()

    def add_time(self, time): self.total += time

    def start(self): self.start_ = dates.now()

    def stop(self):

        assert self.start_ != None

        self.add_time(dates.now() - self.start_)

    def msg(self): return 'Took '+str(self.total)+' sec'

    def add_subprofiler(self, profiler):

        '''for use with cumulative profilers'''

        self.add_time(profiler.total)

class ItersProfiler(Profiler):

    def __init__(self, iter_text='iteration', **settings):

        Profiler.__init__(self, **settings)

        self.iter_text = iter_text

        self.iter_ct = None

    def add_iters(self, iter_ct):

        if self.iter_ct == None: self.iter_ct = 0

        self.iter_ct += iter_ct

    def stop(self, iter_ct=None):

        Profiler.stop(self)

        if iter_ct != None: self.add_iters(iter_ct)

    def msg(self):

        msg = Profiler.msg(self)

        if self.iter_ct != None and self.iter_ct > 0:

            msg += ('/'+format.int2str(self.iter_ct)+' '+self.iter_text+'(s) = '

            +format.to_si(float(dates.total_seconds(self.total))/self.iter_ct)

            +'s/'+self.iter_text)

        return msg

    def add_subprofiler(self, profiler):

        Profiler.add_subprofiler(self, profiler)

        self.add_iters(profiler.iter_ct)