view mercurial/progress.py @ 29847:9a9629b9416c stable

bundle2: fail faster when interrupted

Before this patch, bundle2 application attempted to consume remaining
bundle2 part data when the process is interrupted (SIGINT) or when
sys.exit is called (translated into a SystemExit exception). This
meant that if one of these occurred when applying a say 1 GB
changegroup bundle2 part being downloaded over a network, it may take
Mercurial *several minutes* to terminate after a SIGINT because the
process is waiting on the network to stream megabytes of data. This is
not a great user experience and a regression from bundle1. Furthermore,
many process supervisors tend to only give processes a finite amount of
time to exit after delivering SIGINT: if processes take too long to
self-terminate, a SIGKILL is issued and Mercurial has no opportunity to
clean up. This would mean orphaned locks and transactions. Not good.

This patch changes the bundle2 application behavior to fail faster
when an interrupt or system exit is requested. It does so by not
catching BaseException (which includes KeyboardInterrupt and
SystemExit) and by explicitly checking for these conditions in
yet another handler which would also seek to the end of the current
bundle2 part on failure.

The end result of this patch is that SIGINT is now reacted to
significantly faster: the active transaction is rolled back
immediately without waiting for incoming bundle2 data to be consumed.
This restores the pre-bundle2 behavior and makes Mercurial treat
signals with the urgency they deserve.

# progress.py progress bars related code
#
# Copyright (C) 2010 Augie Fackler <[e-mail]>
#
# 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

import sys
import threading
import time

from .i18n import _
from . import encoding

def spacejoin(*args):
    return ' '.join(s for s in args if s)

def shouldprint(ui):
    return not (ui.quiet or ui.plain('progress')) and (
        ui._isatty(sys.stderr) or ui.configbool('progress', 'assume-tty'))

def fmtremaining(seconds):
    """format a number of remaining seconds in human readable way

    This will properly display seconds, minutes, hours, days if needed"""
    if seconds < 60:
        # i18n: format XX seconds as "XXs"
        return _("%02ds") % (seconds)
    minutes = seconds // 60
    if minutes < 60:
        seconds -= minutes * 60
        # i18n: format X minutes and YY seconds as "XmYYs"
        return _("%dm%02ds") % (minutes, seconds)
    # we're going to ignore seconds in this case
    minutes += 1
    hours = minutes // 60
    minutes -= hours * 60
    if hours < 30:
        # i18n: format X hours and YY minutes as "XhYYm"
        return _("%dh%02dm") % (hours, minutes)
    # we're going to ignore minutes in this case
    hours += 1
    days = hours // 24
    hours -= days * 24
    if days < 15:
        # i18n: format X days and YY hours as "XdYYh"
        return _("%dd%02dh") % (days, hours)
    # we're going to ignore hours in this case
    days += 1
    weeks = days // 7
    days -= weeks * 7
    if weeks < 55:
        # i18n: format X weeks and YY days as "XwYYd"
        return _("%dw%02dd") % (weeks, days)
    # we're going to ignore days and treat a year as 52 weeks
    weeks += 1
    years = weeks // 52
    weeks -= years * 52
    # i18n: format X years and YY weeks as "XyYYw"
    return _("%dy%02dw") % (years, weeks)

class progbar(object):
    def __init__(self, ui):
        self.ui = ui
        self._refreshlock = threading.Lock()
        self.resetstate()

    def resetstate(self):
        self.topics = []
        self.topicstates = {}
        self.starttimes = {}
        self.startvals = {}
        self.printed = False
        self.lastprint = time.time() + float(self.ui.config(
            'progress', 'delay', default=3))
        self.curtopic = None
        self.lasttopic = None
        self.indetcount = 0
        self.refresh = float(self.ui.config(
            'progress', 'refresh', default=0.1))
        self.changedelay = max(3 * self.refresh,
                               float(self.ui.config(
                                   'progress', 'changedelay', default=1)))
        self.order = self.ui.configlist(
            'progress', 'format',
            default=['topic', 'bar', 'number', 'estimate'])

    def show(self, now, topic, pos, item, unit, total):
        if not shouldprint(self.ui):
            return
        termwidth = self.width()
        self.printed = True
        head = ''
        needprogress = False
        tail = ''
        for indicator in self.order:
            add = ''
            if indicator == 'topic':
                add = topic
            elif indicator == 'number':
                if total:
                    add = ('% ' + str(len(str(total))) +
                           's/%s') % (pos, total)
                else:
                    add = str(pos)
            elif indicator.startswith('item') and item:
                slice = 'end'
                if '-' in indicator:
                    wid = int(indicator.split('-')[1])
                elif '+' in indicator:
                    slice = 'beginning'
                    wid = int(indicator.split('+')[1])
                else:
                    wid = 20
                if slice == 'end':
                    add = encoding.trim(item, wid, leftside=True)
                else:
                    add = encoding.trim(item, wid)
                add += (wid - encoding.colwidth(add)) * ' '
            elif indicator == 'bar':
                add = ''
                needprogress = True
            elif indicator == 'unit' and unit:
                add = unit
            elif indicator == 'estimate':
                add = self.estimate(topic, pos, total, now)
            elif indicator == 'speed':
                add = self.speed(topic, pos, unit, now)
            if not needprogress:
                head = spacejoin(head, add)
            else:
                tail = spacejoin(tail, add)
        if needprogress:
            used = 0
            if head:
                used += encoding.colwidth(head) + 1
            if tail:
                used += encoding.colwidth(tail) + 1
            progwidth = termwidth - used - 3
            if total and pos <= total:
                amt = pos * progwidth // total
                bar = '=' * (amt - 1)
                if amt > 0:
                    bar += '>'
                bar += ' ' * (progwidth - amt)
            else:
                progwidth -= 3
                self.indetcount += 1
                # mod the count by twice the width so we can make the
                # cursor bounce between the right and left sides
                amt = self.indetcount % (2 * progwidth)
                amt -= progwidth
                bar = (' ' * int(progwidth - abs(amt)) + '<=>' +
                       ' ' * int(abs(amt)))
            prog = ''.join(('[', bar , ']'))
            out = spacejoin(head, prog, tail)
        else:
            out = spacejoin(head, tail)
        sys.stderr.write('\r' + encoding.trim(out, termwidth))
        self.lasttopic = topic
        sys.stderr.flush()

    def clear(self):
        if not self.printed or not self.lastprint or not shouldprint(self.ui):
            return
        sys.stderr.write('\r%s\r' % (' ' * self.width()))
        if self.printed:
            # force immediate re-paint of progress bar
            self.lastprint = 0

    def complete(self):
        if not shouldprint(self.ui):
            return
        if self.ui.configbool('progress', 'clear-complete', default=True):
            self.clear()
        else:
            sys.stderr.write('\n')
        sys.stderr.flush()

    def width(self):
        tw = self.ui.termwidth()
        return min(int(self.ui.config('progress', 'width', default=tw)), tw)

    def estimate(self, topic, pos, total, now):
        if total is None:
            return ''
        initialpos = self.startvals[topic]
        target = total - initialpos
        delta = pos - initialpos
        if delta > 0:
            elapsed = now - self.starttimes[topic]
            # experimental config: progress.estimate
            if elapsed > float(
                self.ui.config('progress', 'estimate', default=2)):
                seconds = (elapsed * (target - delta)) // delta + 1
                return fmtremaining(seconds)
        return ''

    def speed(self, topic, pos, unit, now):
        initialpos = self.startvals[topic]
        delta = pos - initialpos
        elapsed = now - self.starttimes[topic]
        if elapsed > float(
            self.ui.config('progress', 'estimate', default=2)):
            return _('%d %s/sec') % (delta / elapsed, unit)
        return ''

    def _oktoprint(self, now):
        '''Check if conditions are met to print - e.g. changedelay elapsed'''
        if (self.lasttopic is None # first time we printed
            # not a topic change
            or self.curtopic == self.lasttopic
            # it's been long enough we should print anyway
            or now - self.lastprint >= self.changedelay):
            return True
        else:
            return False

    def progress(self, topic, pos, item='', unit='', total=None):
        now = time.time()
        self._refreshlock.acquire()
        try:
            if pos is None:
                self.starttimes.pop(topic, None)
                self.startvals.pop(topic, None)
                self.topicstates.pop(topic, None)
                # reset the progress bar if this is the outermost topic
                if self.topics and self.topics[0] == topic and self.printed:
                    self.complete()
                    self.resetstate()
                # truncate the list of topics assuming all topics within
                # this one are also closed
                if topic in self.topics:
                    self.topics = self.topics[:self.topics.index(topic)]
                    # reset the last topic to the one we just unwound to,
                    # so that higher-level topics will be stickier than
                    # lower-level topics
                    if self.topics:
                        self.lasttopic = self.topics[-1]
                    else:
                        self.lasttopic = None
            else:
                if topic not in self.topics:
                    self.starttimes[topic] = now
                    self.startvals[topic] = pos
                    self.topics.append(topic)
                self.topicstates[topic] = pos, item, unit, total
                self.curtopic = topic
                if now - self.lastprint >= self.refresh and self.topics:
                    if self._oktoprint(now):
                        self.lastprint = now
                        self.show(now, topic, *self.topicstates[topic])
        finally:
            self._refreshlock.release()