Mercurial > hg
view hgext/blackbox.py @ 25561:50a6c3c55db1 stable
parsers: do not cache RevlogError type (issue4451)
Index lookups raise RevlogError when the lookup fails. The previous
implementation was caching a reference to the RevlogError type in a
static variable. This assumed that the "mercurial.error" module was
only loaded once and there was only a single copy of it floating
around in memory. Unfortunately, in some situations - including
certain mod_wsgi configurations - this was not the case: the
"mercurial.error" module could be reloaded. It was possible for a
"RevlogError" reference from the first interpreter to be used by
a second interpreter. While the underlying thing was a
"mercurial.error.RevlogError," the object IDs were different, so
the Python code in revlog.py was failing to catch the exception! This
error has existed since the C index lookup code was implemented in
changeset e8d37b78acfb, which was first released in Mercurial 2.2 in
2012.
http://emptysqua.re/blog/python-c-extensions-and-mod-wsgi/#static-variables-are-shared
contains more details.
This patch removes the caching of the RevlogError type from the
function.
Since pretty much the entire function was refactored and the return
value of the function wasn't used, I changed the function signature
to not return anything.
For reasons unknown to me, we were calling PyErr_SetObject()
with the type of RevlogError and an instance of RevlogError. This
was equivalent to the Python code "raise RevlogError(RevlogError)".
This seemed wonky and completely unnecessary. The Python code only
cares about the type of the exception, not its contents. So I got
rid of this complexity.
This is my first Python C extension patch. Please give extra scrutiny
to it during review.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 12 Jun 2015 14:43:59 -0700 |
parents | 7cc77030c557 |
children | 80c5b2666a96 |
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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) 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, 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, 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), 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() formattedmsg = msg[0] % msg[1:] try: blackbox.write('%s %s> %s' % (date, user, formattedmsg)) except IOError, 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)))