Mercurial > hg
view mercurial/lsprof.py @ 40626:87a872555e90
revlog: detect incomplete revlog reads
_readsegment() is supposed to return N bytes of revlog revision
data starting at a file offset. Surprisingly, its behavior before
this patch never verified that it actually read and returned N
bytes! Instead, it would perform the read(), then return whatever
data was available. And even more surprisingly, nothing in the
call chain appears to have been validating that it received all
the data it was expecting.
This behavior could lead to partial or incomplete revision chunks
being operated on. This could result in e.g. cached deltas being
applied against incomplete base revisions. The delta application
process would happily perform this operation. Only hash
verification would detect the corruption and save us.
This commit changes the behavior of raw revlog reading to validate
that we actually read() the number of bytes that were requested.
We will raise a more specific error faster, rather than possibly
have it go undetected or manifest later in the call stack, at
delta application or hash verification.
Differential Revision: https://phab.mercurial-scm.org/D5266
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Tue, 13 Nov 2018 12:30:59 -0800 |
parents | 56ea22fa55f0 |
children | 2372284d9457 |
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from __future__ import absolute_import, print_function import _lsprof import sys Profiler = _lsprof.Profiler # PyPy doesn't expose profiler_entry from the module. profiler_entry = getattr(_lsprof, 'profiler_entry', None) __all__ = ['profile', '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=r"inlinetime"): """XXX docstring""" # profiler_entries isn't defined when running under PyPy. if profiler_entry: if crit not in profiler_entry.__dict__: raise ValueError("Can't sort by %s" % crit) elif self.data and not getattr(self.data[0], crit, None): raise ValueError("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 = "% 12d %12d %11.4f %11.4f %s\n" hcols = "% 12s %12s %12s %12s %s\n" file.write(hcols % ("CallCount", "Recursive", "Total(s)", "Inline(s)", "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, " %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(sys.modules.iteritems()): 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] = r'<%s>' % code.co_filename res = r'%s:%d(%s)' % (mname, code.co_firstlineno, code.co_name) if sys.version_info.major >= 3: res = res.encode('latin-1') return res if __name__ == '__main__': import os sys.argv = sys.argv[1:] if not sys.argv: print("usage: lsprof.py <script> <arguments...>", file=sys.stderr) sys.exit(2) sys.path.insert(0, os.path.abspath(os.path.dirname(sys.argv[0]))) stats = profile(execfile, sys.argv[0], globals(), locals()) stats.sort() stats.pprint()