Mercurial > hg
view mercurial/lsprof.py @ 47799:3fffb48539ee stable
rust-nodemap: falling back to C impl as mitigation
This is a mitigation for https://bz.mercurial-scm.org/show_bug.cgi?id=6554
We see sometimes almost all data except the most recent revisions
removed from the persistent nodemap, but we don't know how to
reproduce yet.
This has sadly repercussions beyond just needing to reconstruct the
persistent nodemap: for instance, this automatically filters out
all bookmarks pointing to revisions that the nodemap cannot resolve.
If such filtering happens in a transaction, the update of the
bookmarks file that happens at the end of transaction loses all
bookmarks that have been affected. There may be similar consequences
for other data.
So this is a data loss, something that we have to prevent as soon as
possible.
As a mitigation measure, we will now fallback to the C implementation
in case nodemap lookups failed. This will add some latency, e.g., in
discovery, yet less than disabling the persistent nodemap entirely.
We considered implementing the fallback directly on the Python
side, but `revlog.get_rev()` is not systematically used, there are
also several direct calls to the index method (`self.index.rev()` for
a `revlog` instance). It is therefore more direct to implement the
mitigation in the rust-cpython wrapper.
Differential Revision: https://phab.mercurial-scm.org/D11238
author | Georges Racinet <georges.racinet@octobus.net> |
---|---|
date | Sun, 01 Aug 2021 14:39:38 +0200 |
parents | 9f70512ae2cf |
children | 6000f5b25c9b |
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from __future__ import absolute_import, print_function import _lsprof import sys from .pycompat import getattr from . import pycompat Profiler = _lsprof.Profiler # PyPy doesn't expose profiler_entry from the module. profiler_entry = getattr(_lsprof, 'profiler_entry', None) __all__ = [b'profile', b'Stats'] def profile(f, *args, **kwds): """XXX docstring""" p = Profiler() p.enable(subcalls=True, builtins=True) try: f(*args, **kwds) finally: p.disable() return Stats(p.getstats()) class Stats(object): """XXX docstring""" def __init__(self, data): self.data = data def sort(self, crit="inlinetime"): """XXX docstring""" # profiler_entries isn't defined when running under PyPy. if profiler_entry: if crit not in profiler_entry.__dict__: raise ValueError(b"Can't sort by %s" % crit) elif self.data and not getattr(self.data[0], crit, None): raise ValueError(b"Can't sort by %s" % crit) self.data.sort(key=lambda x: getattr(x, crit), reverse=True) for e in self.data: if e.calls: e.calls.sort(key=lambda x: getattr(x, crit), reverse=True) def pprint(self, top=None, file=None, limit=None, climit=None): """XXX docstring""" if file is None: file = sys.stdout d = self.data if top is not None: d = d[:top] cols = b"% 12d %12d %11.4f %11.4f %s\n" hcols = b"% 12s %12s %12s %12s %s\n" file.write( hcols % ( b"CallCount", b"Recursive", b"Total(s)", b"Inline(s)", b"module:lineno(function)", ) ) count = 0 for e in d: file.write( cols % ( e.callcount, e.reccallcount, e.totaltime, e.inlinetime, label(e.code), ) ) count += 1 if limit is not None and count == limit: return ccount = 0 if climit and e.calls: for se in e.calls: file.write( cols % ( se.callcount, se.reccallcount, se.totaltime, se.inlinetime, b" %s" % label(se.code), ) ) count += 1 ccount += 1 if limit is not None and count == limit: return if climit is not None and ccount == climit: break def freeze(self): """Replace all references to code objects with string descriptions; this makes it possible to pickle the instance.""" # this code is probably rather ickier than it needs to be! for i in range(len(self.data)): e = self.data[i] if not isinstance(e.code, str): self.data[i] = type(e)((label(e.code),) + e[1:]) if e.calls: for j in range(len(e.calls)): se = e.calls[j] if not isinstance(se.code, str): e.calls[j] = type(se)((label(se.code),) + se[1:]) _fn2mod = {} def label(code): if isinstance(code, str): if sys.version_info.major >= 3: code = code.encode('latin-1') return code try: mname = _fn2mod[code.co_filename] except KeyError: for k, v in list(pycompat.iteritems(sys.modules)): if v is None: continue if not isinstance(getattr(v, '__file__', None), str): continue if v.__file__.startswith(code.co_filename): mname = _fn2mod[code.co_filename] = k break else: mname = _fn2mod[code.co_filename] = '<%s>' % code.co_filename res = '%s:%d(%s)' % (mname, code.co_firstlineno, code.co_name) if sys.version_info.major >= 3: res = res.encode('latin-1') return res