osutil: use getdirentriesattr on OS X if possible
This is a significant win for large repositories on OS X, especially with a
cold cache. Unfortunately we need to keep the lstat-based implementation around
for two reasons:
- Not all filesystems support this call.
- There's an edge case in which it's best to fall back to avoid a retry loop.
More about this in the comments.
The below tests are all performed on a Mac with an SSD running OS X 10.9, on a
repository with over 200k files. The results are best of 5 with simulated
best-effort conditions.
The gains with a hot cache are pretty impressive: 'hg status' goes from 5.18
seconds to 3.79 seconds.
However, a repository that large will probably already be using something like
hgwatchman [1], which helps much more (for this repo, 'hg status' with
hgwatchman is approximately 1 second). Where this really helps is when the
cache is cold [2]: hg status goes from 31.0 seconds to 9.66.
See http://lists.apple.com/archives/filesystem-dev/2014/Dec/msg00002.html for
some more discussion about this function.
This is based on a patch by Sean Farley <sean@farley.io>.
[1] https://bitbucket.org/facebook/hgwatchman
[2] There appears to be no easy way to clear the file cache (aka "vnodes") on
OS X short of rebooting. purge(8) purportedly does that but in my testing had
little effect. The workaround I came up with was to assume that vnode eviction
was LRU, make sure the kern.maxvnodes sysctl is smaller than the size of the
repository, then make sure we'd always miss the cache by running 'hg status' in
another clone of the repository before running it in the test repository.
# ASCII graph log extension for Mercurial
#
# Copyright 2007 Joel Rosdahl <joel@rosdahl.net>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''command to view revision graphs from a shell (DEPRECATED)
The functionality of this extension has been include in core Mercurial
since version 2.3.
This extension adds a --graph option to the incoming, outgoing and log
commands. When this options is given, an ASCII representation of the
revision graph is also shown.
'''
from mercurial.i18n import _
from mercurial import cmdutil, commands
cmdtable = {}
command = cmdutil.command(cmdtable)
testedwith = 'internal'
@command('glog',
[('f', 'follow', None,
_('follow changeset history, or file history across copies and renames')),
('', 'follow-first', None,
_('only follow the first parent of merge changesets (DEPRECATED)')),
('d', 'date', '', _('show revisions matching date spec'), _('DATE')),
('C', 'copies', None, _('show copied files')),
('k', 'keyword', [],
_('do case-insensitive search for a given text'), _('TEXT')),
('r', 'rev', [], _('show the specified revision or revset'), _('REV')),
('', 'removed', None, _('include revisions where files were removed')),
('m', 'only-merges', None, _('show only merges (DEPRECATED)')),
('u', 'user', [], _('revisions committed by user'), _('USER')),
('', 'only-branch', [],
_('show only changesets within the given named branch (DEPRECATED)'),
_('BRANCH')),
('b', 'branch', [],
_('show changesets within the given named branch'), _('BRANCH')),
('P', 'prune', [],
_('do not display revision or any of its ancestors'), _('REV')),
] + commands.logopts + commands.walkopts,
_('[OPTION]... [FILE]'),
inferrepo=True)
def graphlog(ui, repo, *pats, **opts):
"""show revision history alongside an ASCII revision graph
Print a revision history alongside a revision graph drawn with
ASCII characters.
Nodes printed as an @ character are parents of the working
directory.
"""
opts['graph'] = True
return commands.log(ui, repo, *pats, **opts)