view mercurial/progress.py @ 48068:bf8837e3d7ce

dirstate: Remove the flat Rust DirstateMap implementation Before this changeset we had two Rust implementations of `DirstateMap`. This removes the "flat" DirstateMap so that the "tree" DirstateMap is always used when Rust enabled. This simplifies the code a lot, and will enable (in the next changeset) further removal of a trait abstraction. This is a performance regression when: * Rust is enabled, and * The repository uses the legacy dirstate-v1 file format, and * For `hg status`, unknown files are not listed (such as with `-mard`) The regression is about 100 milliseconds for `hg status -mard` on a semi-large repository (mozilla-central), from ~320ms to ~420ms. We deem this to be small enough to be worth it. The new dirstate-v2 is still experimental at this point, but we aim to stabilize it (though not yet enable it by default for new repositories) in Mercurial 6.0. Eventually, upgrating repositories to dirsate-v2 will eliminate this regression (and enable other performance improvements). # Background The flat DirstateMap was introduced with the first Rust implementation of the status algorithm. It works similarly to the previous Python + C one, with a single `HashMap` that associates file paths to a `DirstateEntry` (where Python has a dict). We later added the tree DirstateMap where the root of the tree contains nodes for files and directories that are directly at the root of the repository, and nodes for directories can contain child nodes representing the files and directly that *they* contain directly. The shape of this tree mirrors that of the working directory in the filesystem. This enables the status algorithm to traverse this tree in tandem with traversing the filesystem tree, which in turns enables a more efficient algorithm. Furthermore, the new dirstate-v2 file format is also based on a tree of the same shape. The tree DirstateMap can access a dirstate-v2 file without parsing it: binary data in a single large (possibly memory-mapped) bytes buffer is traversed on demand. This allows `DirstateMap` creation to take `O(1)` time. (Mutation works by creating new in-memory nodes with copy-on-write semantics, and serialization is append-mostly.) The tradeoff is that for "legacy" repositories that use the dirstate-v1 file format, parsing that file into a tree DirstateMap takes more time. Profiling shows that this time is dominated by `HashMap`. For a dirstate containing `F` files with an average `D` directory depth, the flat DirstateMap does parsing in `O(F)` number of HashMap operations but the tree DirstateMap in `O(F × D)` operations, since each node has its own HashMap containing its child nodes. This slower costs ~140ms on an old snapshot of mozilla-central, and ~80ms on an old snapshot of the Netbeans repository. The status algorithm is faster, but with `-mard` (when not listing unknown files) it is typically not faster *enough* to compensate the slower parsing. Both Rust implementations are always faster than the Python + C implementation # Benchmark results All benchmarks are run on changeset 98c0408324e6, with repositories that use the dirstate-v1 file format, on a server with 4 CPU cores and 4 CPU threads (no HyperThreading). `hg status` benchmarks show wall clock times of the entire command as the average and standard deviation of serveral runs, collected by https://github.com/sharkdp/hyperfine and reformated. Parsing benchmarks are wall clock time of the Rust function that converts a bytes buffer of the dirstate file into the `DirstateMap` data structure as used by the status algorithm. A single run each, collected by running `hg status` this environment variable: RUST_LOG=hg::dirstate::dirstate_map=trace,hg::dirstate_tree::dirstate_map=trace Benchmark 1: Rust flat DirstateMap → Rust tree DirstateMap hg status mozilla-clean 562.3 ms ± 2.0 ms → 462.5 ms ± 0.6 ms 1.22 ± 0.00 times faster mozilla-dirty 859.6 ms ± 2.2 ms → 719.5 ms ± 3.2 ms 1.19 ± 0.01 times faster mozilla-ignored 558.2 ms ± 3.0 ms → 457.9 ms ± 2.9 ms 1.22 ± 0.01 times faster mozilla-unknowns 859.4 ms ± 5.7 ms → 716.0 ms ± 4.7 ms 1.20 ± 0.01 times faster netbeans-clean 336.5 ms ± 0.9 ms → 339.5 ms ± 0.4 ms 0.99 ± 0.00 times faster netbeans-dirty 491.4 ms ± 1.6 ms → 475.1 ms ± 1.2 ms 1.03 ± 0.00 times faster netbeans-ignored 343.7 ms ± 1.0 ms → 347.8 ms ± 0.4 ms 0.99 ± 0.00 times faster netbeans-unknowns 484.3 ms ± 1.0 ms → 466.0 ms ± 1.2 ms 1.04 ± 0.00 times faster hg status -mard mozilla-clean 317.3 ms ± 0.6 ms → 422.5 ms ± 1.2 ms 0.75 ± 0.00 times faster mozilla-dirty 315.4 ms ± 0.6 ms → 417.7 ms ± 1.1 ms 0.76 ± 0.00 times faster mozilla-ignored 314.6 ms ± 0.6 ms → 417.4 ms ± 1.0 ms 0.75 ± 0.00 times faster mozilla-unknowns 312.9 ms ± 0.9 ms → 417.3 ms ± 1.6 ms 0.75 ± 0.00 times faster netbeans-clean 212.0 ms ± 0.6 ms → 283.6 ms ± 0.8 ms 0.75 ± 0.00 times faster netbeans-dirty 211.4 ms ± 1.0 ms → 283.4 ms ± 1.6 ms 0.75 ± 0.01 times faster netbeans-ignored 211.4 ms ± 0.9 ms → 283.9 ms ± 0.8 ms 0.74 ± 0.01 times faster netbeans-unknowns 211.1 ms ± 0.6 ms → 283.4 ms ± 1.0 ms 0.74 ± 0.00 times faster Parsing mozilla-clean 38.4ms → 177.6ms mozilla-dirty 38.8ms → 177.0ms mozilla-ignored 38.8ms → 178.0ms mozilla-unknowns 38.7ms → 176.9ms netbeans-clean 16.5ms → 97.3ms netbeans-dirty 16.5ms → 98.4ms netbeans-ignored 16.9ms → 97.4ms netbeans-unknowns 16.9ms → 96.3ms Benchmark 2: Python + C dirstatemap → Rust tree DirstateMap hg status mozilla-clean 1261.0 ms ± 3.6 ms → 461.1 ms ± 0.5 ms 2.73 ± 0.00 times faster mozilla-dirty 2293.4 ms ± 9.1 ms → 719.6 ms ± 3.6 ms 3.19 ± 0.01 times faster mozilla-ignored 1240.4 ms ± 2.3 ms → 457.7 ms ± 1.9 ms 2.71 ± 0.00 times faster mozilla-unknowns 2283.3 ms ± 9.0 ms → 719.7 ms ± 3.8 ms 3.17 ± 0.01 times faster netbeans-clean 879.7 ms ± 3.5 ms → 339.9 ms ± 0.5 ms 2.59 ± 0.00 times faster netbeans-dirty 1257.3 ms ± 4.7 ms → 474.6 ms ± 1.6 ms 2.65 ± 0.01 times faster netbeans-ignored 943.9 ms ± 1.9 ms → 347.3 ms ± 1.1 ms 2.72 ± 0.00 times faster netbeans-unknowns 1188.1 ms ± 5.0 ms → 465.2 ms ± 2.3 ms 2.55 ± 0.01 times faster hg status -mard mozilla-clean 903.2 ms ± 3.6 ms → 423.4 ms ± 2.2 ms 2.13 ± 0.01 times faster mozilla-dirty 884.6 ms ± 4.5 ms → 417.3 ms ± 1.4 ms 2.12 ± 0.01 times faster mozilla-ignored 881.9 ms ± 1.3 ms → 417.3 ms ± 0.8 ms 2.11 ± 0.00 times faster mozilla-unknowns 878.5 ms ± 1.9 ms → 416.4 ms ± 0.9 ms 2.11 ± 0.00 times faster netbeans-clean 434.9 ms ± 1.8 ms → 284.0 ms ± 0.8 ms 1.53 ± 0.01 times faster netbeans-dirty 434.1 ms ± 0.8 ms → 283.1 ms ± 0.8 ms 1.53 ± 0.00 times faster netbeans-ignored 431.7 ms ± 1.1 ms → 283.6 ms ± 1.8 ms 1.52 ± 0.01 times faster netbeans-unknowns 433.0 ms ± 1.3 ms → 283.5 ms ± 0.7 ms 1.53 ± 0.00 times faster Differential Revision: https://phab.mercurial-scm.org/D11516
author Simon Sapin <simon.sapin@octobus.net>
date Mon, 27 Sep 2021 12:09:15 +0200
parents 89a2afe31e82
children 6000f5b25c9b
line wrap: on
line source

# 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