progress: flush stderr after clearing

On python3, ui.stderr is buffered, it seems, so we need to flush it to actually
get the progress bar off the screen. This is important since ui.write() will
call into progbar.clear() if it thinks there's a progress bar on the screen,
with the intent that the next thing it outputs is at the beginning of the line
(instead of at the end of the progress bar line). Without the flush, we buffer
up the clearing of the screen, and we get some really weird/corrupt output.

Differential Revision: https://phab.mercurial-scm.org/D7784

mercurial/progress.py

@@ -1,315 +1,316 b''
 # 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 errno
 import threading
 import time
 
 from .i18n import _
 from . import encoding
 
 
 def spacejoin(*args):
     return b' '.join(s for s in args if s)
 
 
 def shouldprint(ui):
     return not (ui.quiet or ui.plain(b'progress')) and (
         ui._isatty(ui.ferr) or ui.configbool(b'progress', b'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 _(b"%02ds") % seconds
     minutes = seconds // 60
     if minutes < 60:
         seconds -= minutes * 60
         # i18n: format X minutes and YY seconds as "XmYYs"
         return _(b"%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 _(b"%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 _(b"%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 _(b"%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 _(b"%dy%02dw") % (years, weeks)
 
 
 # file_write() and file_flush() of Python 2 do not restart on EINTR if
 # the file is attached to a "slow" device (e.g. a terminal) and raise
 # IOError. We cannot know how many bytes would be written by file_write(),
 # but a progress text is known to be short enough to be written by a
 # single write() syscall, so we can just retry file_write() with the whole
 # text. (issue5532)
 #
 # This should be a short-term workaround. We'll need to fix every occurrence
 # of write() to a terminal or pipe.
 def _eintrretry(func, *args):
     while True:
         try:
             return func(*args)
         except IOError as err:
             if err.errno == errno.EINTR:
                 continue
             raise
 
 
 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(b'progress', b'delay')
         )
         self.curtopic = None
         self.lasttopic = None
         self.indetcount = 0
         self.refresh = float(self.ui.config(b'progress', b'refresh'))
         self.changedelay = max(
             3 * self.refresh, float(self.ui.config(b'progress', b'changedelay'))
         )
         self.order = self.ui.configlist(b'progress', b'format')
         self.estimateinterval = self.ui.configwith(
             float, b'progress', b'estimateinterval'
         )
 
     def show(self, now, topic, pos, item, unit, total):
         if not shouldprint(self.ui):
             return
         termwidth = self.width()
         self.printed = True
         head = b''
         needprogress = False
         tail = b''
         for indicator in self.order:
             add = b''
             if indicator == b'topic':
                 add = topic
             elif indicator == b'number':
                 if total:
                     add = b'%*d/%d' % (len(str(total)), pos, total)
                 else:
                     add = b'%d' % pos
             elif indicator.startswith(b'item') and item:
                 slice = b'end'
                 if b'-' in indicator:
                     wid = int(indicator.split(b'-')[1])
                 elif b'+' in indicator:
                     slice = b'beginning'
                     wid = int(indicator.split(b'+')[1])
                 else:
                     wid = 20
                 if slice == b'end':
                     add = encoding.trim(item, wid, leftside=True)
                 else:
                     add = encoding.trim(item, wid)
                 add += (wid - encoding.colwidth(add)) * b' '
             elif indicator == b'bar':
                 add = b''
                 needprogress = True
             elif indicator == b'unit' and unit:
                 add = unit
             elif indicator == b'estimate':
                 add = self.estimate(topic, pos, total, now)
             elif indicator == b'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 = b'=' * (amt - 1)
                 if amt > 0:
                     bar += b'>'
                 bar += b' ' * (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 = (
                     b' ' * int(progwidth - abs(amt))
                     + b'<=>'
                     + b' ' * int(abs(amt))
                 )
             prog = b''.join((b'[', bar, b']'))
             out = spacejoin(head, prog, tail)
         else:
             out = spacejoin(head, tail)
         self._writeerr(b'\r' + encoding.trim(out, termwidth))
         self.lasttopic = topic
         self._flusherr()
 
     def clear(self):
         if not self.printed or not self.lastprint or not shouldprint(self.ui):
             return
         self._writeerr(b'\r%s\r' % (b' ' * self.width()))
+        self._flusherr()
         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(b'progress', b'clear-complete'):
             self.clear()
         else:
             self._writeerr(b'\n')
         self._flusherr()
 
     def _flusherr(self):
         _eintrretry(self.ui.ferr.flush)
 
     def _writeerr(self, msg):
         _eintrretry(self.ui.ferr.write, msg)
 
     def width(self):
         tw = self.ui.termwidth()
         return min(int(self.ui.config(b'progress', b'width', default=tw)), tw)
 
     def estimate(self, topic, pos, total, now):
         if total is None:
             return b''
         initialpos = self.startvals[topic]
         target = total - initialpos
         delta = pos - initialpos
         if delta > 0:
             elapsed = now - self.starttimes[topic]
             seconds = (elapsed * (target - delta)) // delta + 1
             return fmtremaining(seconds)
         return b''
 
     def speed(self, topic, pos, unit, now):
         initialpos = self.startvals[topic]
         delta = pos - initialpos
         elapsed = now - self.starttimes[topic]
         if elapsed > 0:
             return _(b'%d %s/sec') % (delta / elapsed, unit)
         return b''
 
     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 _calibrateestimate(self, topic, now, pos):
         '''Adjust starttimes and startvals for topic so ETA works better
 
         If progress is non-linear (ex. get much slower in the last minute),
         it's more friendly to only use a recent time span for ETA and speed
         calculation.
 
             [======================================>       ]
                                              ^^^^^^^
                            estimateinterval, only use this for estimation
         '''
         interval = self.estimateinterval
         if interval <= 0:
             return
         elapsed = now - self.starttimes[topic]
         if elapsed > interval:
             delta = pos - self.startvals[topic]
             newdelta = delta * interval / elapsed
             # If a stall happens temporarily, ETA could change dramatically
             # frequently. This is to avoid such dramatical change and make ETA
             # smoother.
             if newdelta < 0.1:
                 return
             self.startvals[topic] = pos - newdelta
             self.starttimes[topic] = now - interval
 
     def progress(self, topic, pos, item=b'', unit=b'', total=None):
         if pos is None:
             self.closetopic(topic)
             return
         now = time.time()
         with self._refreshlock:
             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
             self._calibrateestimate(topic, now, pos)
             if now - self.lastprint >= self.refresh and self.topics:
                 if self._oktoprint(now):
                     self.lastprint = now
                     self.show(now, topic, *self.topicstates[topic])
 
     def closetopic(self, topic):
         with self._refreshlock:
             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