Mercurial > hg
view mercurial/progress.py @ 49000:dd6b67d5c256 stable
rust: fix unsound `OwningDirstateMap`
As per the previous patch, `OwningDirstateMap` is unsound. Self-referential
structs are difficult to implement correctly in Rust since the compiler is
free to move structs around as much as it wants to. They are also very rarely
needed in practice, so the state-of-the-art on how they should be done within
the Rust rules is still a bit new.
The crate `ouroboros` is an attempt at providing a safe way (in the Rust sense)
of declaring self-referential structs. It is getting a lot attention and was
improved very quickly when soundness issues were found in the past: rather than
relying on our own (limited) review circle, we might as well use the de-facto
common crate to fix this problem. This will give us a much better chance of
finding issues should any new ones be discovered as well as the benefit of
fewer `unsafe` APIs of our own.
I was starting to think about how I would present a safe API to the old struct
but soon realized that the callback-based approach was already done in
`ouroboros`, along with a lot more care towards refusing incorrect structs.
In short: we don't return a mutable reference to the `DirstateMap` anymore, we
expect users of its API to pass a `FnOnce` that takes the map as an argument.
This allows our `OwningDirstateMap` to control the input and output lifetimes
of the code that modifies it to prevent such issues.
Changing to `ouroboros` meant changing every API with it, but it is relatively
low churn in the end. It correctly identified the example buggy modification of
`copy_map_insert` outlined in the previous patch as violating the borrow rules.
Differential Revision: https://phab.mercurial-scm.org/D12429
author | Raphaël Gomès <rgomes@octobus.net> |
---|---|
date | Tue, 05 Apr 2022 10:55:28 +0200 |
parents | 89a2afe31e82 |
children | 6000f5b25c9b |
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# progress.py progress bars related code # # Copyright (C) 2010 Augie Fackler <durin42@gmail.com> # # 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