Mercurial > hg
view hgext/blackbox.py @ 27430:e240e914d226 stable
revlog: seek to end of file before writing (issue4943)
Revlogs were recently refactored to open file handles in "a+" and use a
persistent file handle for reading and writing. This drastically
reduced the number of file handles being opened.
Unfortunately, it appears that some versions of Solaris lose the file
offset when performing a write after the handle has been seeked.
The simplest workaround is to seek to EOF on files opened in a+ mode
before writing to them, which is what this patch does.
Ideally, this code would exist in the vfs layer. However, this would
require creating a proxy class for file objects in order to provide a
custom implementation of write(). This would add overhead. Since
revlogs are the only files we open in a+ mode, the one-off workaround
in revlog.py should be sufficient.
This patch appears to have little to no impact on performance on my
Linux machine.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Thu, 17 Dec 2015 17:16:02 -0800 |
parents | e8f9dffca36f |
children | ab6468270b83 |
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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 = * [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 mercurial import util, cmdutil from mercurial.i18n import _ import errno, os, re cmdtable = {} command = cmdutil.command(cmdtable) # Note for extension authors: ONLY specify testedwith = 'internal' 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 = 'internal' lastblackbox = None def wrapui(ui): class blackboxui(ui.__class__): @util.propertycache def track(self): return self.configlist('blackbox', 'track', ['*']) def _openlogfile(self): def rotate(oldpath, newpath): try: os.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: os.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 = self._bbopener('blackbox.log', 'a') maxsize = self.configbytes('blackbox', 'maxsize', 1048576) if maxsize > 0: st = os.fstat(fp.fileno()) if st.st_size >= maxsize: path = fp.name fp.close() 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 = self._bbopener('blackbox.log', 'a') return fp def log(self, event, *msg, **opts): global lastblackbox super(blackboxui, self).log(event, *msg, **opts) if not '*' in self.track and not event in self.track: return if util.safehasattr(self, '_blackbox'): blackbox = self._blackbox elif util.safehasattr(self, '_bbopener'): try: self._blackbox = self._openlogfile() except (IOError, OSError) as err: self.debug('warning: cannot write to blackbox.log: %s\n' % err.strerror) del self._bbopener self._blackbox = None blackbox = self._blackbox else: # certain ui instances exist outside the context of # a repo, so just default to the last blackbox that # was seen. blackbox = lastblackbox if blackbox: date = util.datestr(None, '%Y/%m/%d %H:%M:%S') user = util.getuser() pid = str(os.getpid()) formattedmsg = msg[0] % msg[1:] try: blackbox.write('%s %s (%s)> %s' % (date, user, pid, formattedmsg)) except IOError as err: self.debug('warning: cannot write to blackbox.log: %s\n' % err.strerror) lastblackbox = blackbox def setrepo(self, repo): self._bbopener = repo.vfs ui.__class__ = 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 os.path.exists(repo.join('blackbox.log')): return limit = opts.get('limit') blackbox = repo.vfs('blackbox.log', 'r') lines = blackbox.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)))