Mercurial > hg
view mercurial/txnutil.py @ 34306:bd50aa1aa035
alias: make alias command lazily resolved
With many aliases, resolving them could have some visible overhead. Below is
part of traceprof [1] output of `hg bookmark --hidden`:
(time unit: ms)
37 \ addaliases dispatch.py:526
37 | __init__ (60 times) dispatch.py:402
33 | findcmd (108 times) cmdutil.py:721
16 | findpossible (49 times) cmdutil.py:683
It may get better by optimizing `findcmd` to do a bisect, but we don't
really need to resolve an alias if it's not used, so let's make those
command entries lazy.
After this patch, `addalias` takes less than 1ms.
.. perf:: improved performance when many aliases are defined
[1]: https://bitbucket.org/facebook/hg-experimental/src/9aca0dbdbdfc48457e5d2581ca2d6e662fced2e6/hgext3rd/traceprof.pyx
Differential Revision: https://phab.mercurial-scm.org/D805
author | Jun Wu <quark@fb.com> |
---|---|
date | Sat, 23 Sep 2017 13:46:12 -0700 |
parents | 206532700213 |
children | 2372284d9457 |
line wrap: on
line source
# txnutil.py - transaction related utilities # # Copyright FUJIWARA Katsunori <foozy@lares.dti.ne.jp> and others # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import import errno from . import ( encoding, ) def mayhavepending(root): '''return whether 'root' may have pending changes, which are visible to this process. ''' return root == encoding.environ.get('HG_PENDING') def trypending(root, vfs, filename, **kwargs): '''Open file to be read according to HG_PENDING environment variable This opens '.pending' of specified 'filename' only when HG_PENDING is equal to 'root'. This returns '(fp, is_pending_opened)' tuple. ''' if mayhavepending(root): try: return (vfs('%s.pending' % filename, **kwargs), True) except IOError as inst: if inst.errno != errno.ENOENT: raise return (vfs(filename, **kwargs), False)