Mercurial > hg
view hgext/blackbox.py @ 30212:260af19891f2
changegroup: increase write buffer size to 128k
By default, Python defers to the operating system for choosing the
default buffer size on opened files. On my Linux machine, the default
is 4k, which is really small for 2016.
This patch bumps the write buffer size when writing
changegroups/bundles to 128k. This matches the 128k read buffer
we already use on revlogs.
It's worth noting that this only impacts when writing to an explicit
file (such as during `hg bundle`). Buffers when writing to bundle
files via the repo vfs or to a temporary file are not impacted.
When producing a none-v2 bundle file of the mozilla-unified repository,
this change caused the number of write() system calls to drop from
952,449 to 29,788. After this change, the most frequent system
calls are fstat(), read(), lseek(), and open(). There were
2,523,672 system calls after this patch (so a net decrease of
~950k is statistically significant).
This change shows no performance change on my system. But I have a
high-end system with a fast SSD. It is quite possible this change
will have a significant impact on network file systems, where
extra network round trips due to excessive I/O system calls could
introduce significant latency.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sun, 16 Oct 2016 13:35:23 -0700 |
parents | d5883fd055c6 |
children | 055cca8e167b |
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# blackbox.py - log repository events to a file for post-mortem debugging # # Copyright 2010 Nicolas Dumazet # Copyright 2013 Facebook, Inc. # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. """log repository events to a blackbox for debugging Logs event information to .hg/blackbox.log to help debug and diagnose problems. The events that get logged can be configured via the blackbox.track config key. Examples:: [blackbox] track = * # dirty is *EXPENSIVE* (slow); # each log entry indicates `+` if the repository is dirty, like :hg:`id`. dirty = True # record the source of log messages logsource = True [blackbox] track = command, commandfinish, commandexception, exthook, pythonhook [blackbox] track = incoming [blackbox] # limit the size of a log file maxsize = 1.5 MB # rotate up to N log files when the current one gets too big maxfiles = 3 """ from __future__ import absolute_import import errno import re from mercurial.i18n import _ from mercurial.node import hex from mercurial import ( cmdutil, ui as uimod, util, ) cmdtable = {} command = cmdutil.command(cmdtable) # 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' lastui = None filehandles = {} def _openlog(vfs): path = vfs.join('blackbox.log') if path in filehandles: return filehandles[path] filehandles[path] = fp = vfs('blackbox.log', 'a') return fp def _closelog(vfs): path = vfs.join('blackbox.log') fp = filehandles[path] del filehandles[path] fp.close() def wrapui(ui): class blackboxui(ui.__class__): def __init__(self, src=None): super(blackboxui, self).__init__(src) if src is None: self._partialinit() else: self._bbfp = getattr(src, '_bbfp', None) self._bbinlog = False self._bbrepo = getattr(src, '_bbrepo', None) self._bbvfs = getattr(src, '_bbvfs', None) def _partialinit(self): if util.safehasattr(self, '_bbvfs'): return self._bbfp = None self._bbinlog = False self._bbrepo = None self._bbvfs = None def copy(self): self._partialinit() return self.__class__(self) @util.propertycache def track(self): return self.configlist('blackbox', 'track', ['*']) def _openlogfile(self): def rotate(oldpath, newpath): try: self._bbvfs.unlink(newpath) except OSError as err: if err.errno != errno.ENOENT: self.debug("warning: cannot remove '%s': %s\n" % (newpath, err.strerror)) try: if newpath: self._bbvfs.rename(oldpath, newpath) except OSError as err: if err.errno != errno.ENOENT: self.debug("warning: cannot rename '%s' to '%s': %s\n" % (newpath, oldpath, err.strerror)) fp = _openlog(self._bbvfs) maxsize = self.configbytes('blackbox', 'maxsize', 1048576) if maxsize > 0: st = self._bbvfs.fstat(fp) if st.st_size >= maxsize: path = fp.name _closelog(self._bbvfs) maxfiles = self.configint('blackbox', 'maxfiles', 7) for i in xrange(maxfiles - 1, 1, -1): rotate(oldpath='%s.%d' % (path, i - 1), newpath='%s.%d' % (path, i)) rotate(oldpath=path, newpath=maxfiles > 0 and path + '.1') fp = _openlog(self._bbvfs) return fp def _bbwrite(self, fmt, *args): self._bbfp.write(fmt % args) self._bbfp.flush() def log(self, event, *msg, **opts): global lastui super(blackboxui, self).log(event, *msg, **opts) self._partialinit() if not '*' in self.track and not event in self.track: return if self._bbfp: ui = self elif self._bbvfs: try: self._bbfp = self._openlogfile() except (IOError, OSError) as err: self.debug('warning: cannot write to blackbox.log: %s\n' % err.strerror) del self._bbvfs self._bbfp = None ui = self else: # certain ui instances exist outside the context of # a repo, so just default to the last blackbox that # was seen. ui = lastui if not ui or not ui._bbfp: return if not lastui or ui._bbrepo: lastui = ui if ui._bbinlog: # recursion guard return try: ui._bbinlog = True date = util.datestr(None, '%Y/%m/%d %H:%M:%S') user = util.getuser() pid = str(util.getpid()) formattedmsg = msg[0] % msg[1:] rev = '(unknown)' changed = '' if ui._bbrepo: ctx = ui._bbrepo[None] parents = ctx.parents() rev = ('+'.join([hex(p.node()) for p in parents])) if (ui.configbool('blackbox', 'dirty', False) and ( any(ui._bbrepo.status()) or any(ctx.sub(s).dirty() for s in ctx.substate) )): changed = '+' if ui.configbool('blackbox', 'logsource', False): src = ' [%s]' % event else: src = '' try: ui._bbwrite('%s %s @%s%s (%s)%s> %s', date, user, rev, changed, pid, src, formattedmsg) except IOError as err: self.debug('warning: cannot write to blackbox.log: %s\n' % err.strerror) finally: ui._bbinlog = False def setrepo(self, repo): self._bbfp = None self._bbinlog = False self._bbrepo = repo self._bbvfs = repo.vfs ui.__class__ = blackboxui uimod.ui = blackboxui def uisetup(ui): wrapui(ui) def reposetup(ui, repo): # During 'hg pull' a httppeer repo is created to represent the remote repo. # It doesn't have a .hg directory to put a blackbox in, so we don't do # the blackbox setup for it. if not repo.local(): return if util.safehasattr(ui, 'setrepo'): ui.setrepo(repo) @command('^blackbox', [('l', 'limit', 10, _('the number of events to show')), ], _('hg blackbox [OPTION]...')) def blackbox(ui, repo, *revs, **opts): '''view the recent repository events ''' if not repo.vfs.exists('blackbox.log'): return limit = opts.get('limit') fp = repo.vfs('blackbox.log', 'r') lines = fp.read().split('\n') count = 0 output = [] for line in reversed(lines): if count >= limit: break # count the commands by matching lines like: 2013/01/23 19:13:36 root> if re.match('^\d{4}/\d{2}/\d{2} \d{2}:\d{2}:\d{2} .*> .*', line): count += 1 output.append(line) ui.status('\n'.join(reversed(output)))