Mercurial > hg
view contrib/hgperf @ 43658:0796e266d26b
dirs: resolve fuzzer OOM situation by disallowing deep directory hierarchies
It seems like 2048 directories ought to be enough for any reasonable
use of Mercurial?
A previous version of this patch scanned for slashes before any allocations
occurred. That approach is slower than this in the happy path, but much faster
than this in the case that too many slashes are encountered. We may want to
revisit it in the future using memchr() so it'll be well-optimized by the libc
we're using.
.. bc:
Mercurial will now defend against OOMs by refusing to operate on
paths with 2048 or more components. This means that _extremely_
deep path hierarchies will be rejected, but we anticipate nobody
is using hierarchies this deep.
Differential Revision: https://phab.mercurial-scm.org/D7411
author | Augie Fackler <augie@google.com> |
---|---|
date | Tue, 12 Nov 2019 10:17:59 -0500 |
parents | 163fa0aea71e |
children | 99e231afc29c |
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#!/usr/bin/env python # # hgperf - measure performance of Mercurial commands # # Copyright 2014 Matt Mackall <mpm@selenic.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. '''measure performance of Mercurial commands Using ``hgperf`` instead of ``hg`` measures performance of the target Mercurial command. For example, the execution below measures performance of :hg:`heads --topo`:: $ hgperf heads --topo All command output via ``ui`` is suppressed, and just measurement result is displayed: see also "perf" extension in "contrib". Costs of processing before dispatching to the command function like below are not measured:: - parsing command line (e.g. option validity check) - reading configuration files in But ``pre-`` and ``post-`` hook invocation for the target command is measured, even though these are invoked before or after dispatching to the command function, because these may be required to repeat execution of the target command correctly. ''' import os import sys libdir = '@LIBDIR@' if libdir != '@' 'LIBDIR' '@': if not os.path.isabs(libdir): libdir = os.path.join(os.path.dirname(os.path.realpath(__file__)), libdir) libdir = os.path.abspath(libdir) sys.path.insert(0, libdir) # enable importing on demand to reduce startup time try: from mercurial import demandimport; demandimport.enable() except ImportError: import sys sys.stderr.write("abort: couldn't find mercurial libraries in [%s]\n" % ' '.join(sys.path)) sys.stderr.write("(check your install and PYTHONPATH)\n") sys.exit(-1) from mercurial import ( dispatch, util, ) def timer(func, title=None): results = [] begin = util.timer() count = 0 while True: ostart = os.times() cstart = util.timer() r = func() cstop = util.timer() ostop = os.times() count += 1 a, b = ostart, ostop results.append((cstop - cstart, b[0] - a[0], b[1]-a[1])) if cstop - begin > 3 and count >= 100: break if cstop - begin > 10 and count >= 3: break if title: sys.stderr.write("! %s\n" % title) if r: sys.stderr.write("! result: %s\n" % r) m = min(results) sys.stderr.write("! wall %f comb %f user %f sys %f (best of %d)\n" % (m[0], m[1] + m[2], m[1], m[2], count)) orgruncommand = dispatch.runcommand def runcommand(lui, repo, cmd, fullargs, ui, options, d, cmdpats, cmdoptions): ui.pushbuffer() lui.pushbuffer() timer(lambda : orgruncommand(lui, repo, cmd, fullargs, ui, options, d, cmdpats, cmdoptions)) ui.popbuffer() lui.popbuffer() dispatch.runcommand = runcommand dispatch.run()