view hgext/progress.py @ 25561:50a6c3c55db1 stable

parsers: do not cache RevlogError type (issue4451)

Index lookups raise RevlogError when the lookup fails. The previous
implementation was caching a reference to the RevlogError type in a
static variable. This assumed that the "mercurial.error" module was
only loaded once and there was only a single copy of it floating
around in memory. Unfortunately, in some situations - including
certain mod_wsgi configurations - this was not the case: the
"mercurial.error" module could be reloaded. It was possible for a
"RevlogError" reference from the first interpreter to be used by
a second interpreter. While the underlying thing was a
"mercurial.error.RevlogError," the object IDs were different, so
the Python code in revlog.py was failing to catch the exception! This
error has existed since the C index lookup code was implemented in
changeset e8d37b78acfb, which was first released in Mercurial 2.2 in
2012.
http://emptysqua.re/blog/python-c-extensions-and-mod-wsgi/#static-variables-are-shared
contains more details.

This patch removes the caching of the RevlogError type from the
function.

Since pretty much the entire function was refactored and the return
value of the function wasn't used, I changed the function signature
to not return anything.

For reasons unknown to me, we were calling PyErr_SetObject()
with the type of RevlogError and an instance of RevlogError. This
was equivalent to the Python code "raise RevlogError(RevlogError)".
This seemed wonky and completely unnecessary. The Python code only
cares about the type of the exception, not its contents. So I got
rid of this complexity.

This is my first Python C extension patch. Please give extra scrutiny
to it during review.

# progress.py show progress bars for some actions
#
# 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.

"""show progress bars for some actions

This extension uses the progress information logged by hg commands
to draw progress bars that are as informative as possible. Some progress
bars only offer indeterminate information, while others have a definite
end point.

The following settings are available::

  [progress]
  delay = 3 # number of seconds (float) before showing the progress bar
  changedelay = 1 # changedelay: minimum delay before showing a new topic.
                  # If set to less than 3 * refresh, that value will
                  # be used instead.
  refresh = 0.1 # time in seconds between refreshes of the progress bar
  format = topic bar number estimate # format of the progress bar
  width = <none> # if set, the maximum width of the progress information
                 # (that is, min(width, term width) will be used)
  clear-complete = True # clear the progress bar after it's done
  disable = False # if true, don't show a progress bar
  assume-tty = False # if true, ALWAYS show a progress bar, unless
                     # disable is given

Valid entries for the format field are topic, bar, number, unit,
estimate, speed, and item. item defaults to the last 20 characters of
the item, but this can be changed by adding either ``-<num>`` which
would take the last num characters, or ``+<num>`` for the first num
characters.
"""

import sys
import time
import threading

from mercurial.i18n import _
testedwith = 'internal'

from mercurial import encoding

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

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

def fmtremaining(seconds):
    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 shouldprint(self.ui):
            return
        sys.stderr.write('\r%s\r' % (' ' * self.width()))

    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]
            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()

_singleton = None

def uisetup(ui):
    global _singleton
    class progressui(ui.__class__):
        _progbar = None

        def _quiet(self):
            return self.debugflag or self.quiet

        def progress(self, *args, **opts):
            if not self._quiet():
                self._progbar.progress(*args, **opts)
            return super(progressui, self).progress(*args, **opts)

        def write(self, *args, **opts):
            if not self._quiet() and self._progbar.printed:
                self._progbar.clear()
            return super(progressui, self).write(*args, **opts)

        def write_err(self, *args, **opts):
            if not self._quiet() and self._progbar.printed:
                self._progbar.clear()
            return super(progressui, self).write_err(*args, **opts)

    # Apps that derive a class from ui.ui() can use
    # setconfig('progress', 'disable', 'True') to disable this extension
    if ui.configbool('progress', 'disable'):
        return
    if shouldprint(ui) and not ui.debugflag and not ui.quiet:
        ui.__class__ = progressui
        # we instantiate one globally shared progress bar to avoid
        # competing progress bars when multiple UI objects get created
        if not progressui._progbar:
            if _singleton is None:
                _singleton = progbar(ui)
            progressui._progbar = _singleton

def reposetup(ui, repo):
    uisetup(repo.ui)