~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005 Aaron Bentley <aaron.bentley@utoronto.ca>

# Copyright (C) 2005 Canonical <canonical.com>

#

#    This program is free software; you can redistribute it and/or modify

#    it under the terms of the GNU General Public License as published by

#    the Free Software Foundation; either version 2 of the License, or

#    (at your option) any later version.

#

#    This program is distributed in the hope that it will be useful,

#    but WITHOUT ANY WARRANTY; without even the implied warranty of

#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

#    GNU General Public License for more details.

#

#    You should have received a copy of the GNU General Public License

#    along with this program; if not, write to the Free Software

#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

"""

Simple text-mode progress indicator.

Everyone loves ascii art!

To display an indicator, create a ProgressBar object.  Call it,

passing Progress objects indicating the current state.  When done,

call clear().

Progress is suppressed when output is not sent to a terminal, so as

not to clutter log files.

"""

# TODO: remove functions in favour of keeping everything in one class

# TODO: should be a global option e.g. --silent that disables progress

# indicators, preferably without needing to adjust all code that

# potentially calls them.

# TODO: Perhaps don't write updates faster than a certain rate, say

# 5/second.

import sys

import time

def _width():

    """Return estimated terminal width.

    TODO: Do something smart on Windows?

    TODO: Is there anything that gets a better update when the window

          is resized while the program is running?

    """

    import os

    try:

        return int(os.environ['COLUMNS'])

    except (IndexError, KeyError, ValueError):

        return 80

def _supports_progress(f):

    return hasattr(f, 'isatty') and f.isatty()

class ProgressBar(object):

    """Progress bar display object.

    Several options are available to control the display.  These can

    be passed as parameters to the constructor or assigned at any time:

    show_pct

        Show percentage complete.

    show_spinner

        Show rotating baton.  This ticks over on every update even

        if the values don't change.

    show_eta

        Show predicted time-to-completion.

    show_bar

        Show bar graph.

    show_count

        Show numerical counts.

    The output file should be in line-buffered or unbuffered mode.

    """

    SPIN_CHARS = r'/-\|'

    MIN_PAUSE = 0.1 # seconds

    start_time = None

    last_update = None

    def __init__(self,

                 to_file=sys.stderr,

                 show_pct=False,

                 show_spinner=False,

                 show_eta=True,

                 show_bar=True,

                 show_count=True):

        object.__init__(self)

        self.to_file = to_file

        self.suppressed = not _supports_progress(self.to_file)

        self.spin_pos = 0

        self.show_pct = show_pct

        self.show_spinner = show_spinner

        self.show_eta = show_eta

        self.show_bar = show_bar

        self.show_count = show_count

    def tick(self):

        self.update(self.last_msg, self.last_cnt, self.last_total)

    def update(self, msg, current_cnt=None, total_cnt=None):

        """Update and redraw progress bar."""

        if self.suppressed:

            return

        # save these for the tick() function

        self.last_msg = msg

        self.last_cnt = current_cnt

        self.last_total = total_cnt

        now = time.time()

        if self.start_time is None:

            self.start_time = now

        else:

            interval = now - self.last_update

            if interval > 0 and interval < self.MIN_PAUSE:

                return

        self.last_update = now

        width = _width()

        if total_cnt:

            assert current_cnt <= total_cnt

        if current_cnt:

            assert current_cnt >= 0

        if self.show_eta and self.start_time and total_cnt:

            eta = get_eta(self.start_time, current_cnt, total_cnt)

            eta_str = " " + str_tdelta(eta)

        else:

            eta_str = ""

        if self.show_spinner:

            spin_str = self.SPIN_CHARS[self.spin_pos % 4] + ' '            

        else:

            spin_str = ''

        # always update this; it's also used for the bar

        self.spin_pos += 1

        if self.show_pct and total_cnt and current_cnt:

            pct = 100.0 * current_cnt / total_cnt

            pct_str = ' (%5.1f%%)' % pct

        else:

            pct_str = ''

        if not self.show_count:

            count_str = ''

        elif current_cnt is None:

            count_str = ''

        elif total_cnt is None:

            count_str = ' %i' % (current_cnt)

        else:

            # make both fields the same size

            t = '%i' % (total_cnt)

            c = '%*i' % (len(t), current_cnt)

            count_str = ' ' + c + '/' + t 

        if self.show_bar:

            # progress bar, if present, soaks up all remaining space

            cols = width - 1 - len(msg) - len(spin_str) - len(pct_str) \

                   - len(eta_str) - len(count_str) - 3

            if total_cnt:

                # number of markers highlighted in bar

                markers = int(round(float(cols) * current_cnt / total_cnt))

                bar_str = '[' + ('=' * markers).ljust(cols) + '] '

            elif False:

                # don't know total, so can't show completion.

                # so just show an expanded spinning thingy

                m = self.spin_pos % cols

                ms = (' ' * m + '*').ljust(cols)

                bar_str = '[' + ms + '] '

            else:

                bar_str = ''

        else:

            bar_str = ''

        m = spin_str + bar_str + msg + count_str + pct_str + eta_str

        assert len(m) < width

        self.to_file.write('\r' + m.ljust(width - 1))

        #self.to_file.flush()

    def clear(self):

        if self.suppressed:

            return

        self.to_file.write('\r%s\r' % (' ' * (_width() - 1)))

        #self.to_file.flush()        

def str_tdelta(delt):

    if delt is None:

        return "-:--:--"

    delt = int(round(delt))

    return '%d:%02d:%02d' % (delt/3600,

                             (delt/60) % 60,

                             delt % 60)

def get_eta(start_time, current, total, enough_samples=3):

    if start_time is None:

        return None

    if not total:

        return None

    if current < enough_samples:

        return None

    if current > total:

        return None                     # wtf?

    elapsed = time.time() - start_time

    if elapsed < 2.0:                   # not enough time to estimate

        return None

    total_duration = float(elapsed) * float(total) / float(current)

    assert total_duration >= elapsed

    return total_duration - elapsed

def run_tests():

    import doctest

    result = doctest.testmod()

    if result[1] > 0:

        if result[0] == 0:

            print "All tests passed"

    else:

        print "No tests to run"

def demo():

    from time import sleep

    pb = ProgressBar(show_pct=True, show_bar=True, show_spinner=False)

    for i in range(100):

        pb.update('Elephanten', i, 99)

        sleep(0.1)

    sleep(2)

    pb.clear()

    sleep(1)

    print 'done!'

if __name__ == "__main__":

    demo()