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
When Mercurial accepts more than one revision, they may be specified
individually, or provided as a topologically continuous range,
separated by the ":" character.
The syntax of range notation is [BEGIN]:[END], where BEGIN and END are
revision identifiers. Both BEGIN and END are optional. If BEGIN is not
specified, it defaults to revision number 0. If END is not specified,
it defaults to the tip. The range ":" thus means "all revisions".
If BEGIN is greater than END, revisions are treated in reverse order.
A range acts as a closed interval. This means that a range of 3:5
gives 3, 4 and 5. Similarly, a range of 9:6 gives 9, 8, 7, and 6.