exchangev2: fetch file revisions
Now that the server has an API for fetching file data, we can call into
it to fetch file revisions.
The implementation is relatively straightforward: we examine the
manifests that we fetched and find all new file revisions referenced
by them. We build up a mapping from file path to file nodes to
manifest node. (The mapping to first manifest node allows us to
map back to first changelog node/revision, which is used for the
linkrev.)
Once that map is built up, we iterate over it in a deterministic
manner and fetch and store file data. The code is very similar
to manifest fetching. So similar that we could probably extract the
common bits into a generic function.
With file data retrieval implemented, `hg clone` and `hg pull` are
effectively feature complete, at least as far as the completeness
of data transfer for essential repository data (changesets, manifests,
files, phases, and bookmarks). We're still missing support for
obsolescence markers, the hgtags fnodes cache, and the branchmap
cache. But these are non-essential for the moment (and will be
implemented later).
This is a good point to assess the state of exchangev2 in terms of
performance. I ran a local `hg clone` for the mozilla-unified
repository using both version 1 and version 2 of the wire protocols
and exchange methods. This is effectively comparing the performance
of the wire protocol overhead and "getbundle" versus domain-specific
commands. Wire protocol version 2 doesn't have compression implemented
yet. So I tested version 1 with `server.compressionengines=none` to
remove compression overhead from the equation.
server
before: user 220.420+0.000 sys 14.420+0.000
after: user 321.980+0.000 sys 18.990+0.000
client
before: real 561.650 secs (user 497.670+0.000 sys 28.160+0.000)
after: real 1226.260 secs (user 944.240+0.000 sys 354.150+0.000)
We have substantial regressions on both client and server. This
is obviously not desirable. I'm aware of some reasons:
* Lack of hgtagsfnodes transfer (contributes significant CPU to
client).
* Lack of branch cache transfer (contributes significant CPU to
client).
* Little to no profiling / optimization performed on wire protocol
version 2 code.
* There appears to be a memory leak on the client and that is likely
causing swapping on my machine.
* Using multiple threads on the client may be counter-productive because
Python.
* We're not compressing on the server.
* We're tracking file nodes on the client via manifest diffing
rather than using linkrev shortcuts on the server.
I'm pretty confident that most of these issues are addressable.
But even if we can't get wire protocol version 2 on performance parity
with "getbundle," I still think it is important to have the set of low
level data-specific retrieval commands that we have implemented so
far. This is because the existence of such commands allows flexibility
in how clients access server data.
Differential Revision: https://phab.mercurial-scm.org/D4491
# 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 ' '.join(s for s in args if s)
def shouldprint(ui):
return not (ui.quiet or ui.plain('progress')) and (
ui._isatty(ui.ferr) 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)
# 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(
'progress', 'delay'))
self.curtopic = None
self.lasttopic = None
self.indetcount = 0
self.refresh = float(self.ui.config(
'progress', 'refresh'))
self.changedelay = max(3 * self.refresh,
float(self.ui.config(
'progress', 'changedelay')))
self.order = self.ui.configlist('progress', 'format')
self.estimateinterval = self.ui.configwith(
float, 'progress', 'estimateinterval')
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 = b'%*d/%d' % (len(str(total)), pos, total)
else:
add = b'%d' % 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)
self._writeerr('\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('\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'):
self.clear()
else:
self._writeerr('\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('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]
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 > 0:
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 _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='', unit='', 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