Mercurial > hg
view hgext/blackbox.py @ 30561:7c0c722d568d
bdiff: early pruning of common prefix before doing expensive computations
It seems quite common that files don't change completely. New lines are often
pretty much appended, and modifications will often only change a small section
of the file which on average will be in the middle.
There can thus be a big win by pruning a common prefix before starting the more
expensive search for longest common substrings.
Worst case, it will scan through a long sequence of similar bytes without
encountering a newline. Splitlines will then have to do the same again ...
twice for each side. If similar lines are found, splitlines will save the
double iteration and hashing of the lines ... plus there will be less lines to
find common substrings in.
This change might in some cases make the algorith pick shorter or less optimal
common substrings. We can't have the cake and eat it.
This make hg --time bundle --base null -r 4.0 go from 14.5 to 15 s - a 3%
increase.
On mozilla-unified:
perfbdiff -m 3041e4d59df2
! wall 0.053088 comb 0.060000 user 0.060000 sys 0.000000 (best of 100) to
! wall 0.024618 comb 0.020000 user 0.020000 sys 0.000000 (best of 116)
perfbdiff 0e9928989e9c --alldata --count 10
! wall 0.702075 comb 0.700000 user 0.700000 sys 0.000000 (best of 15) to
! wall 0.579235 comb 0.580000 user 0.580000 sys 0.000000 (best of 18)
author | Mads Kiilerich <madski@unity3d.com> |
---|---|
date | Wed, 16 Nov 2016 19:45:35 +0100 |
parents | d5883fd055c6 |
children | 055cca8e167b |
line wrap: on
line source
# 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)))