revlog: don't flush data file after every added revision
The current behavior of revlogs is to flush the data file when writing
data to it. Tracing system calls revealed that changegroup processing
incurred numerous write(2) calls for values much smaller than the
default buffer size (Python defaults to 4096, but it can be adjusted
based on detected block size at run time by CPython).
The reason we flush revlogs is so readers have all data available.
For example, the current code in revlog.py will re-open the revlog
file (instead of seeking an existing file handle) to read the text
of a revision. This happens when starting a new delta chain when
adding several revisions from changegroups, for example. Yes, this
is likely sub-optimal (we should probably be sharing file descriptors
between readers and writers to avoid the flushing and associated
overhead of re-opening files).
While flushing revlogs is necessary, it appears all callers are
diligent about flushing files before a read is performed (see
buildtext() in _addrevision()), making the flush in
_writeentry() redundant and unncessary. So, we remove it. In practice,
this means we incur a write(2) a) when the buffer is full (typically
4096 bytes) b) when a new delta chain is created rather than after
every added revision. This applies to every revlog, but by volume
it mostly impacts filelogs.
Removing the redundant flush from _writeentry() significantly
reduces the number of write(2) calls during changegroup processing on
my Linux machine. When applying a changegroup of the hg repo based on
my local repo, the total number of write(2) calls during application
of the mercurial/localrepo.py revlogs dropped from 1,320 to 217 with
this patch applied. Total I/O related system calls dropped from 1,577
to 474.
When unbundling a mozilla-central gzipped bundle (264,403 changesets
with 1,492,215 changes to 222,507 files), total write(2) calls
dropped from 1,252,881 to 827,106 and total system calls dropped from
3,601,259 to 3,178,636 - a reduction of 425,775!
While the system call reduction is significant, it appears
to have no impact on wall time on my Linux and Windows machines. Still,
fewer syscalls is fewer syscalls. Surely this can't hurt. If nothing
else, it makes examining remaining system call usage simpler and opens
the door to experimenting with the performance impact of different
buffer sizes.
#
# This is the mercurial setup script.
#
# 'python setup.py install', or
# 'python setup.py --help' for more options
import sys, platform
if getattr(sys, 'version_info', (0, 0, 0)) < (2, 6, 0, 'final'):
raise SystemExit("Mercurial requires Python 2.6 or later.")
if sys.version_info[0] >= 3:
def b(s):
'''A helper function to emulate 2.6+ bytes literals using string
literals.'''
return s.encode('latin1')
printf = eval('print')
libdir_escape = 'unicode_escape'
else:
libdir_escape = 'string_escape'
def b(s):
'''A helper function to emulate 2.6+ bytes literals using string
literals.'''
return s
def printf(*args, **kwargs):
f = kwargs.get('file', sys.stdout)
end = kwargs.get('end', '\n')
f.write(b(' ').join(args) + end)
# Solaris Python packaging brain damage
try:
import hashlib
sha = hashlib.sha1()
except ImportError:
try:
import sha
sha.sha # silence unused import warning
except ImportError:
raise SystemExit(
"Couldn't import standard hashlib (incomplete Python install).")
try:
import zlib
zlib.compressobj # silence unused import warning
except ImportError:
raise SystemExit(
"Couldn't import standard zlib (incomplete Python install).")
# The base IronPython distribution (as of 2.7.1) doesn't support bz2
isironpython = False
try:
isironpython = (platform.python_implementation()
.lower().find("ironpython") != -1)
except AttributeError:
pass
if isironpython:
sys.stderr.write("warning: IronPython detected (no bz2 support)\n")
else:
try:
import bz2
bz2.BZ2Compressor # silence unused import warning
except ImportError:
raise SystemExit(
"Couldn't import standard bz2 (incomplete Python install).")
ispypy = "PyPy" in sys.version
import os, stat, subprocess, time
import re
import shutil
import tempfile
from distutils import log
from distutils.core import setup, Command, Extension
from distutils.dist import Distribution
from distutils.command.build import build
from distutils.command.build_ext import build_ext
from distutils.command.build_py import build_py
from distutils.command.install_lib import install_lib
from distutils.command.install_scripts import install_scripts
from distutils.spawn import spawn, find_executable
from distutils import file_util
from distutils.errors import CCompilerError, DistutilsExecError
from distutils.sysconfig import get_python_inc, get_config_var
from distutils.version import StrictVersion
convert2to3 = '--c2to3' in sys.argv
if convert2to3:
try:
from distutils.command.build_py import build_py_2to3 as build_py
from lib2to3.refactor import get_fixers_from_package as getfixers
except ImportError:
if sys.version_info[0] < 3:
raise SystemExit("--c2to3 is only compatible with python3.")
raise
sys.path.append('contrib')
elif sys.version_info[0] >= 3:
raise SystemExit("setup.py with python3 needs --c2to3 (experimental)")
scripts = ['hg']
if os.name == 'nt':
scripts.append('contrib/win32/hg.bat')
# simplified version of distutils.ccompiler.CCompiler.has_function
# that actually removes its temporary files.
def hasfunction(cc, funcname):
tmpdir = tempfile.mkdtemp(prefix='hg-install-')
devnull = oldstderr = None
try:
fname = os.path.join(tmpdir, 'funcname.c')
f = open(fname, 'w')
f.write('int main(void) {\n')
f.write(' %s();\n' % funcname)
f.write('}\n')
f.close()
# Redirect stderr to /dev/null to hide any error messages
# from the compiler.
# This will have to be changed if we ever have to check
# for a function on Windows.
devnull = open('/dev/null', 'w')
oldstderr = os.dup(sys.stderr.fileno())
os.dup2(devnull.fileno(), sys.stderr.fileno())
objects = cc.compile([fname], output_dir=tmpdir)
cc.link_executable(objects, os.path.join(tmpdir, "a.out"))
return True
except Exception:
return False
finally:
if oldstderr is not None:
os.dup2(oldstderr, sys.stderr.fileno())
if devnull is not None:
devnull.close()
shutil.rmtree(tmpdir)
# py2exe needs to be installed to work
try:
import py2exe
py2exe.Distribution # silence unused import warning
py2exeloaded = True
# import py2exe's patched Distribution class
from distutils.core import Distribution
except ImportError:
py2exeloaded = False
def runcmd(cmd, env):
if (sys.platform == 'plan9'
and (sys.version_info[0] == 2 and sys.version_info[1] < 7)):
# subprocess kludge to work around issues in half-baked Python
# ports, notably bichued/python:
_, out, err = os.popen3(cmd)
return str(out), str(err)
else:
p = subprocess.Popen(cmd, stdout=subprocess.PIPE,
stderr=subprocess.PIPE, env=env)
out, err = p.communicate()
return out, err
def runhg(cmd, env):
out, err = runcmd(cmd, env)
# If root is executing setup.py, but the repository is owned by
# another user (as in "sudo python setup.py install") we will get
# trust warnings since the .hg/hgrc file is untrusted. That is
# fine, we don't want to load it anyway. Python may warn about
# a missing __init__.py in mercurial/locale, we also ignore that.
err = [e for e in err.splitlines()
if not e.startswith(b('not trusting file')) \
and not e.startswith(b('warning: Not importing')) \
and not e.startswith(b('obsolete feature not enabled'))]
if err:
printf("stderr from '%s':" % (' '.join(cmd)), file=sys.stderr)
printf(b('\n').join([b(' ') + e for e in err]), file=sys.stderr)
return ''
return out
version = ''
# Execute hg out of this directory with a custom environment which
# includes the pure Python modules in mercurial/pure. We also take
# care to not use any hgrc files and do no localization.
pypath = ['mercurial', os.path.join('mercurial', 'pure')]
env = {'PYTHONPATH': os.pathsep.join(pypath),
'HGRCPATH': '',
'LANGUAGE': 'C'}
if 'LD_LIBRARY_PATH' in os.environ:
env['LD_LIBRARY_PATH'] = os.environ['LD_LIBRARY_PATH']
if 'SystemRoot' in os.environ:
# Copy SystemRoot into the custom environment for Python 2.6
# under Windows. Otherwise, the subprocess will fail with
# error 0xc0150004. See: http://bugs.python.org/issue3440
env['SystemRoot'] = os.environ['SystemRoot']
if os.path.isdir('.hg'):
cmd = [sys.executable, 'hg', 'log', '-r', '.', '--template', '{tags}\n']
numerictags = [t for t in runhg(cmd, env).split() if t[0].isdigit()]
hgid = runhg([sys.executable, 'hg', 'id', '-i'], env).strip()
if numerictags: # tag(s) found
version = numerictags[-1]
if hgid.endswith('+'): # propagate the dirty status to the tag
version += '+'
else: # no tag found
ltagcmd = [sys.executable, 'hg', 'parents', '--template',
'{latesttag}']
ltag = runhg(ltagcmd, env)
changessincecmd = [sys.executable, 'hg', 'log', '-T', 'x\n', '-r',
"only(.,'%s')" % ltag]
changessince = len(runhg(changessincecmd, env).splitlines())
version = '%s+%s-%s' % (ltag, changessince, hgid)
if version.endswith('+'):
version += time.strftime('%Y%m%d')
elif os.path.exists('.hg_archival.txt'):
kw = dict([[t.strip() for t in l.split(':', 1)]
for l in open('.hg_archival.txt')])
if 'tag' in kw:
version = kw['tag']
elif 'latesttag' in kw:
if 'changessincelatesttag' in kw:
version = '%(latesttag)s+%(changessincelatesttag)s-%(node).12s' % kw
else:
version = '%(latesttag)s+%(latesttagdistance)s-%(node).12s' % kw
else:
version = kw.get('node', '')[:12]
if version:
f = open("mercurial/__version__.py", "w")
f.write('# this file is autogenerated by setup.py\n')
f.write('version = "%s"\n' % version)
f.close()
try:
from mercurial import __version__
version = __version__.version
except ImportError:
version = 'unknown'
class hgbuild(build):
# Insert hgbuildmo first so that files in mercurial/locale/ are found
# when build_py is run next.
sub_commands = [('build_mo', None),
# We also need build_ext before build_py. Otherwise, when 2to3 is
# called (in build_py), it will not find osutil & friends,
# thinking that those modules are global and, consequently, making
# a mess, now that all module imports are global.
('build_ext', build.has_ext_modules),
] + build.sub_commands
class hgbuildmo(build):
description = "build translations (.mo files)"
def run(self):
if not find_executable('msgfmt'):
self.warn("could not find msgfmt executable, no translations "
"will be built")
return
podir = 'i18n'
if not os.path.isdir(podir):
self.warn("could not find %s/ directory" % podir)
return
join = os.path.join
for po in os.listdir(podir):
if not po.endswith('.po'):
continue
pofile = join(podir, po)
modir = join('locale', po[:-3], 'LC_MESSAGES')
mofile = join(modir, 'hg.mo')
mobuildfile = join('mercurial', mofile)
cmd = ['msgfmt', '-v', '-o', mobuildfile, pofile]
if sys.platform != 'sunos5':
# msgfmt on Solaris does not know about -c
cmd.append('-c')
self.mkpath(join('mercurial', modir))
self.make_file([pofile], mobuildfile, spawn, (cmd,))
class hgdist(Distribution):
pure = ispypy
global_options = Distribution.global_options + \
[('pure', None, "use pure (slow) Python "
"code instead of C extensions"),
('c2to3', None, "(experimental!) convert "
"code with 2to3"),
]
def has_ext_modules(self):
# self.ext_modules is emptied in hgbuildpy.finalize_options which is
# too late for some cases
return not self.pure and Distribution.has_ext_modules(self)
class hgbuildext(build_ext):
def build_extension(self, ext):
try:
build_ext.build_extension(self, ext)
except CCompilerError:
if not getattr(ext, 'optional', False):
raise
log.warn("Failed to build optional extension '%s' (skipping)",
ext.name)
class hgbuildpy(build_py):
if convert2to3:
fixer_names = sorted(set(getfixers("lib2to3.fixes") +
getfixers("hgfixes")))
def finalize_options(self):
build_py.finalize_options(self)
if self.distribution.pure:
if self.py_modules is None:
self.py_modules = []
for ext in self.distribution.ext_modules:
if ext.name.startswith("mercurial."):
self.py_modules.append("mercurial.pure.%s" % ext.name[10:])
self.distribution.ext_modules = []
else:
h = os.path.join(get_python_inc(), 'Python.h')
if not os.path.exists(h):
raise SystemExit('Python headers are required to build '
'Mercurial but weren\'t found in %s' % h)
def find_modules(self):
modules = build_py.find_modules(self)
for module in modules:
if module[0] == "mercurial.pure":
if module[1] != "__init__":
yield ("mercurial", module[1], module[2])
else:
yield module
class buildhgextindex(Command):
description = 'generate prebuilt index of hgext (for frozen package)'
user_options = []
_indexfilename = 'hgext/__index__.py'
def initialize_options(self):
pass
def finalize_options(self):
pass
def run(self):
if os.path.exists(self._indexfilename):
f = open(self._indexfilename, 'w')
f.write('# empty\n')
f.close()
# here no extension enabled, disabled() lists up everything
code = ('import pprint; from mercurial import extensions; '
'pprint.pprint(extensions.disabled())')
out, err = runcmd([sys.executable, '-c', code], env)
if err:
raise DistutilsExecError(err)
f = open(self._indexfilename, 'w')
f.write('# this file is autogenerated by setup.py\n')
f.write('docs = ')
f.write(out)
f.close()
class buildhgexe(build_ext):
description = 'compile hg.exe from mercurial/exewrapper.c'
def build_extensions(self):
if os.name != 'nt':
return
if isinstance(self.compiler, HackedMingw32CCompiler):
self.compiler.compiler_so = self.compiler.compiler # no -mdll
self.compiler.dll_libraries = [] # no -lmsrvc90
hv = sys.hexversion
pythonlib = 'python%d%d' % (hv >> 24, (hv >> 16) & 0xff)
f = open('mercurial/hgpythonlib.h', 'wb')
f.write('/* this file is autogenerated by setup.py */\n')
f.write('#define HGPYTHONLIB "%s"\n' % pythonlib)
f.close()
objects = self.compiler.compile(['mercurial/exewrapper.c'],
output_dir=self.build_temp)
dir = os.path.dirname(self.get_ext_fullpath('dummy'))
target = os.path.join(dir, 'hg')
self.compiler.link_executable(objects, target,
libraries=[],
output_dir=self.build_temp)
class hginstalllib(install_lib):
'''
This is a specialization of install_lib that replaces the copy_file used
there so that it supports setting the mode of files after copying them,
instead of just preserving the mode that the files originally had. If your
system has a umask of something like 027, preserving the permissions when
copying will lead to a broken install.
Note that just passing keep_permissions=False to copy_file would be
insufficient, as it might still be applying a umask.
'''
def run(self):
realcopyfile = file_util.copy_file
def copyfileandsetmode(*args, **kwargs):
src, dst = args[0], args[1]
dst, copied = realcopyfile(*args, **kwargs)
if copied:
st = os.stat(src)
# Persist executable bit (apply it to group and other if user
# has it)
if st[stat.ST_MODE] & stat.S_IXUSR:
setmode = int('0755', 8)
else:
setmode = int('0644', 8)
m = stat.S_IMODE(st[stat.ST_MODE])
m = (m & ~int('0777', 8)) | setmode
os.chmod(dst, m)
file_util.copy_file = copyfileandsetmode
try:
install_lib.run(self)
finally:
file_util.copy_file = realcopyfile
class hginstallscripts(install_scripts):
'''
This is a specialization of install_scripts that replaces the @LIBDIR@ with
the configured directory for modules. If possible, the path is made relative
to the directory for scripts.
'''
def initialize_options(self):
install_scripts.initialize_options(self)
self.install_lib = None
def finalize_options(self):
install_scripts.finalize_options(self)
self.set_undefined_options('install',
('install_lib', 'install_lib'))
def run(self):
install_scripts.run(self)
if (os.path.splitdrive(self.install_dir)[0] !=
os.path.splitdrive(self.install_lib)[0]):
# can't make relative paths from one drive to another, so use an
# absolute path instead
libdir = self.install_lib
else:
common = os.path.commonprefix((self.install_dir, self.install_lib))
rest = self.install_dir[len(common):]
uplevel = len([n for n in os.path.split(rest) if n])
libdir = uplevel * ('..' + os.sep) + self.install_lib[len(common):]
for outfile in self.outfiles:
fp = open(outfile, 'rb')
data = fp.read()
fp.close()
# skip binary files
if b('\0') in data:
continue
data = data.replace(b('@LIBDIR@'), libdir.encode(libdir_escape))
fp = open(outfile, 'wb')
fp.write(data)
fp.close()
cmdclass = {'build': hgbuild,
'build_mo': hgbuildmo,
'build_ext': hgbuildext,
'build_py': hgbuildpy,
'build_hgextindex': buildhgextindex,
'install_lib': hginstalllib,
'install_scripts': hginstallscripts,
'build_hgexe': buildhgexe,
}
packages = ['mercurial', 'mercurial.hgweb', 'mercurial.httpclient',
'hgext', 'hgext.convert', 'hgext.highlight', 'hgext.zeroconf',
'hgext.largefiles']
pymodules = []
common_depends = ['mercurial/util.h']
osutil_ldflags = []
if sys.platform == 'darwin':
osutil_ldflags += ['-framework', 'ApplicationServices']
extmodules = [
Extension('mercurial.base85', ['mercurial/base85.c'],
depends=common_depends),
Extension('mercurial.bdiff', ['mercurial/bdiff.c'],
depends=common_depends),
Extension('mercurial.diffhelpers', ['mercurial/diffhelpers.c'],
depends=common_depends),
Extension('mercurial.mpatch', ['mercurial/mpatch.c'],
depends=common_depends),
Extension('mercurial.parsers', ['mercurial/dirs.c',
'mercurial/manifest.c',
'mercurial/parsers.c',
'mercurial/pathencode.c'],
depends=common_depends),
Extension('mercurial.osutil', ['mercurial/osutil.c'],
extra_link_args=osutil_ldflags,
depends=common_depends),
]
try:
from distutils import cygwinccompiler
# the -mno-cygwin option has been deprecated for years
compiler = cygwinccompiler.Mingw32CCompiler
class HackedMingw32CCompiler(cygwinccompiler.Mingw32CCompiler):
def __init__(self, *args, **kwargs):
compiler.__init__(self, *args, **kwargs)
for i in 'compiler compiler_so linker_exe linker_so'.split():
try:
getattr(self, i).remove('-mno-cygwin')
except ValueError:
pass
cygwinccompiler.Mingw32CCompiler = HackedMingw32CCompiler
except ImportError:
# the cygwinccompiler package is not available on some Python
# distributions like the ones from the optware project for Synology
# DiskStation boxes
class HackedMingw32CCompiler(object):
pass
packagedata = {'mercurial': ['locale/*/LC_MESSAGES/hg.mo',
'help/*.txt',
'default.d/*.rc',
'dummycert.pem']}
def ordinarypath(p):
return p and p[0] != '.' and p[-1] != '~'
for root in ('templates',):
for curdir, dirs, files in os.walk(os.path.join('mercurial', root)):
curdir = curdir.split(os.sep, 1)[1]
dirs[:] = filter(ordinarypath, dirs)
for f in filter(ordinarypath, files):
f = os.path.join(curdir, f)
packagedata['mercurial'].append(f)
datafiles = []
setupversion = version
extra = {}
if py2exeloaded:
extra['console'] = [
{'script':'hg',
'copyright':'Copyright (C) 2005-2015 Matt Mackall and others',
'product_version':version}]
# sub command of 'build' because 'py2exe' does not handle sub_commands
build.sub_commands.insert(0, ('build_hgextindex', None))
# put dlls in sub directory so that they won't pollute PATH
extra['zipfile'] = 'lib/library.zip'
if os.name == 'nt':
# Windows binary file versions for exe/dll files must have the
# form W.X.Y.Z, where W,X,Y,Z are numbers in the range 0..65535
setupversion = version.split('+', 1)[0]
if sys.platform == 'darwin' and os.path.exists('/usr/bin/xcodebuild'):
version = runcmd(['/usr/bin/xcodebuild', '-version'], {})[0].splitlines()
if version:
version = version[0]
if sys.version_info[0] == 3:
version = version.decode('utf-8')
xcode4 = (version.startswith('Xcode') and
StrictVersion(version.split()[1]) >= StrictVersion('4.0'))
xcode51 = re.match(r'^Xcode\s+5\.1', version) is not None
else:
# xcodebuild returns empty on OS X Lion with XCode 4.3 not
# installed, but instead with only command-line tools. Assume
# that only happens on >= Lion, thus no PPC support.
xcode4 = True
xcode51 = False
# XCode 4.0 dropped support for ppc architecture, which is hardcoded in
# distutils.sysconfig
if xcode4:
os.environ['ARCHFLAGS'] = ''
# XCode 5.1 changes clang such that it now fails to compile if the
# -mno-fused-madd flag is passed, but the version of Python shipped with
# OS X 10.9 Mavericks includes this flag. This causes problems in all
# C extension modules, and a bug has been filed upstream at
# http://bugs.python.org/issue21244. We also need to patch this here
# so Mercurial can continue to compile in the meantime.
if xcode51:
cflags = get_config_var('CFLAGS')
if cflags and re.search(r'-mno-fused-madd\b', cflags) is not None:
os.environ['CFLAGS'] = (
os.environ.get('CFLAGS', '') + ' -Qunused-arguments')
setup(name='mercurial',
version=setupversion,
author='Matt Mackall and many others',
author_email='mercurial@selenic.com',
url='http://mercurial.selenic.com/',
download_url='http://mercurial.selenic.com/release/',
description=('Fast scalable distributed SCM (revision control, version '
'control) system'),
long_description=('Mercurial is a distributed SCM tool written in Python.'
' It is used by a number of large projects that require'
' fast, reliable distributed revision control, such as '
'Mozilla.'),
license='GNU GPLv2 or any later version',
classifiers=[
'Development Status :: 6 - Mature',
'Environment :: Console',
'Intended Audience :: Developers',
'Intended Audience :: System Administrators',
'License :: OSI Approved :: GNU General Public License (GPL)',
'Natural Language :: Danish',
'Natural Language :: English',
'Natural Language :: German',
'Natural Language :: Italian',
'Natural Language :: Japanese',
'Natural Language :: Portuguese (Brazilian)',
'Operating System :: Microsoft :: Windows',
'Operating System :: OS Independent',
'Operating System :: POSIX',
'Programming Language :: C',
'Programming Language :: Python',
'Topic :: Software Development :: Version Control',
],
scripts=scripts,
packages=packages,
py_modules=pymodules,
ext_modules=extmodules,
data_files=datafiles,
package_data=packagedata,
cmdclass=cmdclass,
distclass=hgdist,
options={'py2exe': {'packages': ['hgext', 'email']},
'bdist_mpkg': {'zipdist': False,
'license': 'COPYING',
'readme': 'contrib/macosx/Readme.html',
'welcome': 'contrib/macosx/Welcome.html',
},
},
**extra)