##// END OF EJS Templates
compression: introduce a `storage.revlog.zlib.level` configuration...
compression: introduce a `storage.revlog.zlib.level` configuration This option control the zlib compression level used when compression revlog chunk. This is also a good excuse to pave the way for a similar configuration option for the zstd compression engine. Having a dedicated option for each compression algorithm is useful because they don't support the same range of values. Using a higher zlib compression impact CPU consumption at compression time, but does not directly affected decompression time. However dealing with small compressed chunk can directly help decompression and indirectly help other revlog logic. I ran some basic test on repositories using different level. I am using the mercurial, pypy, netbeans and mozilla-central clone from our benchmark suite. All tested repository use sparse-revlog and got all their delta recomputed. The different compression level has a small effect on the repository size (about 10% variation in the total range). My quick analysis is that revlog mostly store small delta, that are not affected by the compression level much. So the variation probably mostly comes from better compression of the snapshots revisions, and snapshot revision only represent a small portion of the repository content. I also made some basic timings measurements. The "read" timings are gathered using simple run of `hg perfrevlogrevisions`, the "write" timings using `hg perfrevlogwrite` (restricted to the last 5000 revisions for netbeans and mozilla central). The timings are gathered on a generic machine, (not one of our performance locked machine), so small variation might not be meaningful. However large trend remains relevant. Keep in mind that these numbers are not pure compression/decompression time. They also involve the full revlog logic. In particular the difference in chunk size has an impact on the delta chain structure, affecting performance when writing or reading them. On read/write performance, the compression level has a bigger impact. Counter-intuitively, the higher compression levels improve "write" performance for the large repositories in our tested setting. Maybe because the last 5000 delta chain end up having a very different shape in this specific spot? Or maybe because of a more general trend of better delta chains thanks to the smaller chunk and snapshot. This series does not intend to change the default compression level. However, these result call for a deeper analysis of this performance difference in the future. Full data ========= repo level .hg/store size 00manifest.d read write ---------------------------------------------------------------- mercurial 1 49,402,813 5,963,475 0.170159 53.250304 mercurial 6 47,197,397 5,875,730 0.182820 56.264320 mercurial 9 47,121,596 5,849,781 0.189219 56.293612 pypy 1 370,830,572 28,462,425 2.679217 460.721984 pypy 6 340,112,317 27,648,747 2.768691 467.537158 pypy 9 338,360,736 27,639,003 2.763495 476.589918 netbeans 1 1,281,847,810 165,495,457 122.477027 520.560316 netbeans 6 1,205,284,353 159,161,207 139.876147 715.930400 netbeans 9 1,197,135,671 155,034,586 141.620281 678.297064 mozilla 1 2,775,497,186 298,527,987 147.867662 751.263721 mozilla 6 2,596,856,420 286,597,671 170.572118 987.056093 mozilla 9 2,587,542,494 287,018,264 163.622338 739.803002

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gnuarch.py
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# gnuarch.py - GNU Arch support for the convert extension
#
# Copyright 2008, 2009 Aleix Conchillo Flaque <aleix@member.fsf.org>
# 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.
from __future__ import absolute_import
import email.parser as emailparser
import os
import shutil
import stat
import tempfile
from mercurial.i18n import _
from mercurial import (
encoding,
error,
pycompat,
util,
)
from mercurial.utils import (
dateutil,
procutil,
)
from . import common
class gnuarch_source(common.converter_source, common.commandline):
class gnuarch_rev(object):
def __init__(self, rev):
self.rev = rev
self.summary = ''
self.date = None
self.author = ''
self.continuationof = None
self.add_files = []
self.mod_files = []
self.del_files = []
self.ren_files = {}
self.ren_dirs = {}
def __init__(self, ui, repotype, path, revs=None):
super(gnuarch_source, self).__init__(ui, repotype, path, revs=revs)
if not os.path.exists(os.path.join(path, '{arch}')):
raise common.NoRepo(_("%s does not look like a GNU Arch repository")
% path)
# Could use checktool, but we want to check for baz or tla.
self.execmd = None
if procutil.findexe('baz'):
self.execmd = 'baz'
else:
if procutil.findexe('tla'):
self.execmd = 'tla'
else:
raise error.Abort(_('cannot find a GNU Arch tool'))
common.commandline.__init__(self, ui, self.execmd)
self.path = os.path.realpath(path)
self.tmppath = None
self.treeversion = None
self.lastrev = None
self.changes = {}
self.parents = {}
self.tags = {}
self.catlogparser = emailparser.Parser()
self.encoding = encoding.encoding
self.archives = []
def before(self):
# Get registered archives
self.archives = [i.rstrip('\n')
for i in self.runlines0('archives', '-n')]
if self.execmd == 'tla':
output = self.run0('tree-version', self.path)
else:
output = self.run0('tree-version', '-d', self.path)
self.treeversion = output.strip()
# Get name of temporary directory
version = self.treeversion.split('/')
self.tmppath = os.path.join(tempfile.gettempdir(),
'hg-%s' % version[1])
# Generate parents dictionary
self.parents[None] = []
treeversion = self.treeversion
child = None
while treeversion:
self.ui.status(_('analyzing tree version %s...\n') % treeversion)
archive = treeversion.split('/')[0]
if archive not in self.archives:
self.ui.status(_('tree analysis stopped because it points to '
'an unregistered archive %s...\n') % archive)
break
# Get the complete list of revisions for that tree version
output, status = self.runlines('revisions', '-r', '-f', treeversion)
self.checkexit(status, 'failed retrieving revisions for %s'
% treeversion)
# No new iteration unless a revision has a continuation-of header
treeversion = None
for l in output:
rev = l.strip()
self.changes[rev] = self.gnuarch_rev(rev)
self.parents[rev] = []
# Read author, date and summary
catlog, status = self.run('cat-log', '-d', self.path, rev)
if status:
catlog = self.run0('cat-archive-log', rev)
self._parsecatlog(catlog, rev)
# Populate the parents map
self.parents[child].append(rev)
# Keep track of the current revision as the child of the next
# revision scanned
child = rev
# Check if we have to follow the usual incremental history
# or if we have to 'jump' to a different treeversion given
# by the continuation-of header.
if self.changes[rev].continuationof:
treeversion = '--'.join(
self.changes[rev].continuationof.split('--')[:-1])
break
# If we reached a base-0 revision w/o any continuation-of
# header, it means the tree history ends here.
if rev[-6:] == 'base-0':
break
def after(self):
self.ui.debug('cleaning up %s\n' % self.tmppath)
shutil.rmtree(self.tmppath, ignore_errors=True)
def getheads(self):
return self.parents[None]
def getfile(self, name, rev):
if rev != self.lastrev:
raise error.Abort(_('internal calling inconsistency'))
if not os.path.lexists(os.path.join(self.tmppath, name)):
return None, None
return self._getfile(name, rev)
def getchanges(self, rev, full):
if full:
raise error.Abort(_("convert from arch does not support --full"))
self._update(rev)
changes = []
copies = {}
for f in self.changes[rev].add_files:
changes.append((f, rev))
for f in self.changes[rev].mod_files:
changes.append((f, rev))
for f in self.changes[rev].del_files:
changes.append((f, rev))
for src in self.changes[rev].ren_files:
to = self.changes[rev].ren_files[src]
changes.append((src, rev))
changes.append((to, rev))
copies[to] = src
for src in self.changes[rev].ren_dirs:
to = self.changes[rev].ren_dirs[src]
chgs, cps = self._rendirchanges(src, to)
changes += [(f, rev) for f in chgs]
copies.update(cps)
self.lastrev = rev
return sorted(set(changes)), copies, set()
def getcommit(self, rev):
changes = self.changes[rev]
return common.commit(author=changes.author, date=changes.date,
desc=changes.summary, parents=self.parents[rev],
rev=rev)
def gettags(self):
return self.tags
def _execute(self, cmd, *args, **kwargs):
cmdline = [self.execmd, cmd]
cmdline += args
cmdline = [procutil.shellquote(arg) for arg in cmdline]
cmdline += ['>', os.devnull, '2>', os.devnull]
cmdline = procutil.quotecommand(' '.join(cmdline))
self.ui.debug(cmdline, '\n')
return os.system(pycompat.rapply(procutil.tonativestr, cmdline))
def _update(self, rev):
self.ui.debug('applying revision %s...\n' % rev)
changeset, status = self.runlines('replay', '-d', self.tmppath,
rev)
if status:
# Something went wrong while merging (baz or tla
# issue?), get latest revision and try from there
shutil.rmtree(self.tmppath, ignore_errors=True)
self._obtainrevision(rev)
else:
old_rev = self.parents[rev][0]
self.ui.debug('computing changeset between %s and %s...\n'
% (old_rev, rev))
self._parsechangeset(changeset, rev)
def _getfile(self, name, rev):
mode = os.lstat(os.path.join(self.tmppath, name)).st_mode
if stat.S_ISLNK(mode):
data = util.readlink(os.path.join(self.tmppath, name))
if mode:
mode = 'l'
else:
mode = ''
else:
data = util.readfile(os.path.join(self.tmppath, name))
mode = (mode & 0o111) and 'x' or ''
return data, mode
def _exclude(self, name):
exclude = ['{arch}', '.arch-ids', '.arch-inventory']
for exc in exclude:
if name.find(exc) != -1:
return True
return False
def _readcontents(self, path):
files = []
contents = os.listdir(path)
while len(contents) > 0:
c = contents.pop()
p = os.path.join(path, c)
# os.walk could be used, but here we avoid internal GNU
# Arch files and directories, thus saving a lot time.
if not self._exclude(p):
if os.path.isdir(p):
contents += [os.path.join(c, f) for f in os.listdir(p)]
else:
files.append(c)
return files
def _rendirchanges(self, src, dest):
changes = []
copies = {}
files = self._readcontents(os.path.join(self.tmppath, dest))
for f in files:
s = os.path.join(src, f)
d = os.path.join(dest, f)
changes.append(s)
changes.append(d)
copies[d] = s
return changes, copies
def _obtainrevision(self, rev):
self.ui.debug('obtaining revision %s...\n' % rev)
output = self._execute('get', rev, self.tmppath)
self.checkexit(output)
self.ui.debug('analyzing revision %s...\n' % rev)
files = self._readcontents(self.tmppath)
self.changes[rev].add_files += files
def _stripbasepath(self, path):
if path.startswith('./'):
return path[2:]
return path
def _parsecatlog(self, data, rev):
try:
catlog = self.catlogparser.parsestr(data)
# Commit date
self.changes[rev].date = dateutil.datestr(
dateutil.strdate(catlog['Standard-date'],
'%Y-%m-%d %H:%M:%S'))
# Commit author
self.changes[rev].author = self.recode(catlog['Creator'])
# Commit description
self.changes[rev].summary = '\n\n'.join((catlog['Summary'],
catlog.get_payload()))
self.changes[rev].summary = self.recode(self.changes[rev].summary)
# Commit revision origin when dealing with a branch or tag
if 'Continuation-of' in catlog:
self.changes[rev].continuationof = self.recode(
catlog['Continuation-of'])
except Exception:
raise error.Abort(_('could not parse cat-log of %s') % rev)
def _parsechangeset(self, data, rev):
for l in data:
l = l.strip()
# Added file (ignore added directory)
if l.startswith('A') and not l.startswith('A/'):
file = self._stripbasepath(l[1:].strip())
if not self._exclude(file):
self.changes[rev].add_files.append(file)
# Deleted file (ignore deleted directory)
elif l.startswith('D') and not l.startswith('D/'):
file = self._stripbasepath(l[1:].strip())
if not self._exclude(file):
self.changes[rev].del_files.append(file)
# Modified binary file
elif l.startswith('Mb'):
file = self._stripbasepath(l[2:].strip())
if not self._exclude(file):
self.changes[rev].mod_files.append(file)
# Modified link
elif l.startswith('M->'):
file = self._stripbasepath(l[3:].strip())
if not self._exclude(file):
self.changes[rev].mod_files.append(file)
# Modified file
elif l.startswith('M'):
file = self._stripbasepath(l[1:].strip())
if not self._exclude(file):
self.changes[rev].mod_files.append(file)
# Renamed file (or link)
elif l.startswith('=>'):
files = l[2:].strip().split(' ')
if len(files) == 1:
files = l[2:].strip().split('\t')
src = self._stripbasepath(files[0])
dst = self._stripbasepath(files[1])
if not self._exclude(src) and not self._exclude(dst):
self.changes[rev].ren_files[src] = dst
# Conversion from file to link or from link to file (modified)
elif l.startswith('ch'):
file = self._stripbasepath(l[2:].strip())
if not self._exclude(file):
self.changes[rev].mod_files.append(file)
# Renamed directory
elif l.startswith('/>'):
dirs = l[2:].strip().split(' ')
if len(dirs) == 1:
dirs = l[2:].strip().split('\t')
src = self._stripbasepath(dirs[0])
dst = self._stripbasepath(dirs[1])
if not self._exclude(src) and not self._exclude(dst):
self.changes[rev].ren_dirs[src] = dst