hgext/graphlog.py

i18n: cache the result of every gettext call

In looking at profiler output for 'hg log' on mozilla-central, I
noticed we spent a _huge_ amount of time in gettext relative to what
it's doing. Caching provides a roughly 15% performance improvement
even on repositories as small as hg.

== hg repo on linux ==

Before:
  %   cumulative      self
 time    seconds   seconds  name
  5.05      0.19      0.19  i18n.py:62:gettext
  4.84      0.18      0.18  revlog.py:88:decompress
  2.95      0.17      0.11  changelog.py:201:node
  2.32      0.09      0.09  ui.py:577:write
  2.11      0.08      0.08  i18n.py:72:gettext
  2.11      0.08      0.08  obsolete.py:196:_fm0readmarkers
  1.89      0.07      0.07  obsolete.py:569:_load
  1.68      0.63      0.06  localrepo.py:29:__get__

real	0m4.026s
user	0m3.993s
sys	0m0.034s

After:
  %   cumulative      self
 time    seconds   seconds  name
  8.05      0.26      0.26  revlog.py:88:decompress
  2.68      0.22      0.09  color.py:395:write
  2.20      0.07      0.07  obsolete.py:196:_fm0readmarkers
  1.95      0.06      0.06  obsolete.py:174:_fm0readmarkers
  1.95      0.06      0.06  ui.py:577:write
  1.95      0.06      0.06  util.py:1228:datestr
  1.71      0.06      0.06  utf_8.py:16:decode
  1.71      0.06      0.06  revlog.py:273:__len__

real	0m3.519s
user	0m3.447s
sys	0m0.073s


== mozilla-central repo on linux ==
Before:
  %   cumulative      self
 time    seconds   seconds  name
  7.72      2.35      2.35  revlog.py:88:decompress
  4.46      1.36      1.36  i18n.py:62:gettext
  2.22      0.67      0.67  i18n.py:72:gettext
  2.19      1.14      0.67  changelog.py:201:node
  2.16      0.66      0.66  ui.py:577:write
  1.96      0.60      0.60  utf_8.py:16:decode
  1.93      1.97      0.59  color.py:395:write
  1.85      0.81      0.56  changelog.py:136:tip

real	0m30.822s
user	0m30.660s
sys	0m0.149s

After:
  %   cumulative      self
 time    seconds   seconds  name
  9.82      2.49      2.49  revlog.py:88:decompress
  2.67      1.31      0.68  localrepo.py:29:__get__
  2.57      0.65      0.65  utf_8.py:16:decode
  2.48      1.01      0.63  changelog.py:201:node
  2.10      0.82      0.53  changelog.py:136:tip
  2.01      0.51      0.51  ui.py:577:write
  1.91      0.49      0.49  util.py:1232:datestr
  1.85      1.65      0.47  color.py:395:write

real	0m25.619s
user	0m25.446s
sys	0m0.166s

== cpython repo on os x =
Before:
  %   cumulative      self
 time    seconds   seconds  name
  5.05      1.35      1.35  cmdutil.py:982:_show
  4.59      1.22      1.22  revlog.py:274:__len__
  3.98      1.06      1.06  i18n.py:62:gettext
  3.91      1.04      1.04  revlog.py:1016:revision
  3.68      0.98      0.98  revlog.py:337:parents
  3.45      0.92      0.92  revlog.py:88:decompress
  2.91      0.78      0.78  revlog.py:309:rev
  2.62      0.70      0.70  revlog.py:1033:revision

real	0m30.414s
user	0m28.145s
sys	0m0.541s



After:
  %   cumulative      self
 time    seconds   seconds  name
  7.98      1.66      1.66  cmdutil.py:982:_show
  6.83      1.42      1.42  changelog.py:46:decodeextra
  5.18      1.08      1.08  revlog.py:274:__len__
  3.94      0.82      0.82  revlog.py:1016:revision
  3.41      0.71      0.71  revlog.py:309:rev
  3.32      0.69      0.69  revlog.py:88:decompress
  2.99      0.63      0.62  revlog.py:1033:revision
  2.69      0.56      0.56  revlog.py:341:start

real	0m22.811s
user	0m21.883s
sys	0m0.397s

# ASCII graph log extension for Mercurial
#
# Copyright 2007 Joel Rosdahl <[e-mail]>
#
# 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 range'), _('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.
    """
    return cmdutil.graphlog(ui, repo, *pats, **opts)