diff: do not concatenate immutable bytes while building a/b bodies (
issue6445)
Use bytearray instead. I don't know what's changed since Python 2, but bytes
concatenation is 100x slow on Python 3.
% python2.7 -m timeit -s "s = b''" "for i in range(10000): s += b'line'"
1000 loops, best of 3: 321 usec per loop
% python3.9 -m timeit -s "s = b''" "for i in range(10000): s += b'line'"
5 loops, best of 5: 39.2 msec per loop
Benchmark using tailwind.css (measuring the fast path, a is empty):
% HGRCPATH=/dev/null python2.7 ./hg log -R /tmp/
issue6445 -p --time \
--color=always --config diff.word-diff=true >/dev/null
(prev) time: real 1.580 secs (user 1.560+0.000 sys 0.020+0.000)
(this) time: real 1.610 secs (user 1.570+0.000 sys 0.030+0.000)
% HGRCPATH=/dev/null python3.9 ./hg log -R /tmp/
issue6445 -p --time \
--color=always --config diff.word-diff=true >/dev/null
(prev) time: real 114.500 secs (user 114.460+0.000 sys 0.030+0.000)
(this) time: real 2.180 secs (user 2.140+0.000 sys 0.040+0.000)
Benchmark using random tabular text data (not the fast path):
% dd if=/dev/urandom bs=1k count=1000 | hexdump -v -e '16/1 "%3u," "\n"' > ttf
% hg ci -ma
% dd if=/dev/urandom bs=1k count=1000 | hexdump -v -e '16/1 "%3u," "\n"' > ttf
% hg ci -mb
% HGRCPATH=/dev/null python2.7 ./hg log -R /tmp/
issue6445 -p --time \
--color=always --config diff.word-diff=true >/dev/null
(prev) time: real 3.240 secs (user 3.040+0.000 sys 0.200+0.000
(this) time: real 3.230 secs (user 3.070+0.000 sys 0.160+0.000)
% HGRCPATH=/dev/null python3.9 ./hg log -R /tmp/
issue6445 -p --time \
--color=always --config diff.word-diff=true >/dev/null
(prev) time: real 44.130 secs (user 43.850+0.000 sys 0.270+0.000)
(this) time: real 4.170 secs (user 3.850+0.000 sys 0.310+0.000)
# pager.py - display output using a pager
#
# Copyright 2008 David Soria Parra <dsp@php.net>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
#
# To load the extension, add it to your configuration file:
#
# [extension]
# pager =
#
# Run 'hg help pager' to get info on configuration.
'''browse command output with an external pager (DEPRECATED)
Forcibly enable paging for individual commands that don't typically
request pagination with the attend-<command> option. This setting
takes precedence over ignore options and defaults::
[pager]
attend-cat = false
'''
from __future__ import absolute_import
from mercurial import (
cmdutil,
commands,
dispatch,
extensions,
registrar,
)
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = b'ships-with-hg-core'
configtable = {}
configitem = registrar.configitem(configtable)
configitem(
b'pager', b'attend', default=lambda: attended,
)
def uisetup(ui):
def pagecmd(orig, ui, options, cmd, cmdfunc):
auto = options[b'pager'] == b'auto'
if auto and not ui.pageractive:
usepager = False
attend = ui.configlist(b'pager', b'attend')
ignore = ui.configlist(b'pager', b'ignore')
cmds, _ = cmdutil.findcmd(cmd, commands.table)
for cmd in cmds:
var = b'attend-%s' % cmd
if ui.config(b'pager', var, None):
usepager = ui.configbool(b'pager', var, True)
break
if cmd in attend or (cmd not in ignore and not attend):
usepager = True
break
if usepager:
# Slight hack: the attend list is supposed to override
# the ignore list for the pager extension, but the
# core code doesn't know about attend, so we have to
# lobotomize the ignore list so that the extension's
# behavior is preserved.
ui.setconfig(b'pager', b'ignore', b'', b'pager')
ui.pager(b'extension-via-attend-' + cmd)
else:
ui.disablepager()
return orig(ui, options, cmd, cmdfunc)
extensions.wrapfunction(dispatch, b'_runcommand', pagecmd)
attended = [b'annotate', b'cat', b'diff', b'export', b'glog', b'log', b'qdiff']