bundle2: implement consume() API on unbundlepart
We want bundle parts to not be seekable by default. That means
eliminating the generic seek() method.
A common pattern in bundle2.py is to seek to the end of the part
data. This is mainly used by the part iteration code to ensure
the underlying stream is advanced to the next bundle part.
In this commit, we establish a dedicated API for consuming a
bundle2 part data. We switch users of seek() to it.
The old implementation of seek(0, os.SEEK_END) would effectively
call self.read(). The new implementation calls self.read(32768)
in a loop. The old implementation would therefore assemble a
buffer to hold all remaining data being seeked over. For seeking
over large bundle parts, this would involve a large allocation and
a lot of overhead to collect intermediate data! This overhead can
be seen in the results for `hg perfbundleread`:
! bundle2 iterparts()
! wall 10.891305 comb 10.820000 user 7.990000 sys 2.830000 (best of 3)
! wall 8.070791 comb 8.060000 user 7.180000 sys 0.880000 (best of 3)
! bundle2 part seek()
! wall 12.991478 comb 10.390000 user 7.720000 sys 2.670000 (best of 3)
! wall 10.370142 comb 10.350000 user 7.430000 sys 2.920000 (best of 3)
Of course, skipping over large payload data isn't likely very common.
So I doubt the performance wins will be observed in the wild.
Differential Revision: https://phab.mercurial-scm.org/D1388
# win32text.py - LF <-> CRLF/CR translation utilities for Windows/Mac users
#
# Copyright 2005, 2007-2009 Matt Mackall <mpm@selenic.com> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''perform automatic newline conversion (DEPRECATED)
Deprecation: The win32text extension requires each user to configure
the extension again and again for each clone since the configuration
is not copied when cloning.
We have therefore made the ``eol`` as an alternative. The ``eol``
uses a version controlled file for its configuration and each clone
will therefore use the right settings from the start.
To perform automatic newline conversion, use::
[extensions]
win32text =
[encode]
** = cleverencode:
# or ** = macencode:
[decode]
** = cleverdecode:
# or ** = macdecode:
If not doing conversion, to make sure you do not commit CRLF/CR by accident::
[hooks]
pretxncommit.crlf = python:hgext.win32text.forbidcrlf
# or pretxncommit.cr = python:hgext.win32text.forbidcr
To do the same check on a server to prevent CRLF/CR from being
pushed or pulled::
[hooks]
pretxnchangegroup.crlf = python:hgext.win32text.forbidcrlf
# or pretxnchangegroup.cr = python:hgext.win32text.forbidcr
'''
from __future__ import absolute_import
import re
from mercurial.i18n import _
from mercurial.node import (
short,
)
from mercurial import (
registrar,
util,
)
# 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 = 'ships-with-hg-core'
configtable = {}
configitem = registrar.configitem(configtable)
configitem('win32text', 'warn',
default=True,
)
# regexp for single LF without CR preceding.
re_single_lf = re.compile('(^|[^\r])\n', re.MULTILINE)
newlinestr = {'\r\n': 'CRLF', '\r': 'CR'}
filterstr = {'\r\n': 'clever', '\r': 'mac'}
def checknewline(s, newline, ui=None, repo=None, filename=None):
# warn if already has 'newline' in repository.
# it might cause unexpected eol conversion.
# see issue 302:
# https://bz.mercurial-scm.org/302
if newline in s and ui and filename and repo:
ui.warn(_('WARNING: %s already has %s line endings\n'
'and does not need EOL conversion by the win32text plugin.\n'
'Before your next commit, please reconsider your '
'encode/decode settings in \nMercurial.ini or %s.\n') %
(filename, newlinestr[newline], repo.vfs.join('hgrc')))
def dumbdecode(s, cmd, **kwargs):
checknewline(s, '\r\n', **kwargs)
# replace single LF to CRLF
return re_single_lf.sub('\\1\r\n', s)
def dumbencode(s, cmd):
return s.replace('\r\n', '\n')
def macdumbdecode(s, cmd, **kwargs):
checknewline(s, '\r', **kwargs)
return s.replace('\n', '\r')
def macdumbencode(s, cmd):
return s.replace('\r', '\n')
def cleverdecode(s, cmd, **kwargs):
if not util.binary(s):
return dumbdecode(s, cmd, **kwargs)
return s
def cleverencode(s, cmd):
if not util.binary(s):
return dumbencode(s, cmd)
return s
def macdecode(s, cmd, **kwargs):
if not util.binary(s):
return macdumbdecode(s, cmd, **kwargs)
return s
def macencode(s, cmd):
if not util.binary(s):
return macdumbencode(s, cmd)
return s
_filters = {
'dumbdecode:': dumbdecode,
'dumbencode:': dumbencode,
'cleverdecode:': cleverdecode,
'cleverencode:': cleverencode,
'macdumbdecode:': macdumbdecode,
'macdumbencode:': macdumbencode,
'macdecode:': macdecode,
'macencode:': macencode,
}
def forbidnewline(ui, repo, hooktype, node, newline, **kwargs):
halt = False
seen = set()
# we try to walk changesets in reverse order from newest to
# oldest, so that if we see a file multiple times, we take the
# newest version as canonical. this prevents us from blocking a
# changegroup that contains an unacceptable commit followed later
# by a commit that fixes the problem.
tip = repo['tip']
for rev in xrange(len(repo) - 1, repo[node].rev() - 1, -1):
c = repo[rev]
for f in c.files():
if f in seen or f not in tip or f not in c:
continue
seen.add(f)
data = c[f].data()
if not util.binary(data) and newline in data:
if not halt:
ui.warn(_('attempt to commit or push text file(s) '
'using %s line endings\n') %
newlinestr[newline])
ui.warn(_('in %s: %s\n') % (short(c.node()), f))
halt = True
if halt and hooktype == 'pretxnchangegroup':
crlf = newlinestr[newline].lower()
filter = filterstr[newline]
ui.warn(_('\nTo prevent this mistake in your local repository,\n'
'add to Mercurial.ini or .hg/hgrc:\n'
'\n'
'[hooks]\n'
'pretxncommit.%s = python:hgext.win32text.forbid%s\n'
'\n'
'and also consider adding:\n'
'\n'
'[extensions]\n'
'win32text =\n'
'[encode]\n'
'** = %sencode:\n'
'[decode]\n'
'** = %sdecode:\n') % (crlf, crlf, filter, filter))
return halt
def forbidcrlf(ui, repo, hooktype, node, **kwargs):
return forbidnewline(ui, repo, hooktype, node, '\r\n', **kwargs)
def forbidcr(ui, repo, hooktype, node, **kwargs):
return forbidnewline(ui, repo, hooktype, node, '\r', **kwargs)
def reposetup(ui, repo):
if not repo.local():
return
for name, fn in _filters.iteritems():
repo.adddatafilter(name, fn)
def extsetup(ui):
# deprecated config: win32text.warn
if ui.configbool('win32text', 'warn'):
ui.warn(_("win32text is deprecated: "
"https://mercurial-scm.org/wiki/Win32TextExtension\n"))