changeset 23031:3c0983cc279e

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
author Augie Fackler <raf@durin42.com>
date Fri, 17 Oct 2014 13:52:10 -0400
parents a0e0aa12b672
children f484be02bd35
files mercurial/i18n.py
diffstat 1 files changed, 22 insertions(+), 18 deletions(-) [+]
line wrap: on
line diff
--- a/mercurial/i18n.py	Sat Aug 30 17:38:14 2014 +0200
+++ b/mercurial/i18n.py	Fri Oct 17 13:52:10 2014 -0400
@@ -41,6 +41,8 @@
     global _ugettext
     _ugettext = t.ugettext
 
+_msgcache = {}
+
 def gettext(message):
     """Translate message.
 
@@ -55,24 +57,26 @@
     if message is None or not _ugettext:
         return message
 
-    if type(message) is unicode:
-        # goofy unicode docstrings in test
-        paragraphs = message.split(u'\n\n')
-    else:
-        paragraphs = [p.decode("ascii") for p in message.split('\n\n')]
-    # Be careful not to translate the empty string -- it holds the
-    # meta data of the .po file.
-    u = u'\n\n'.join([p and _ugettext(p) or '' for p in paragraphs])
-    try:
-        # encoding.tolocal cannot be used since it will first try to
-        # decode the Unicode string. Calling u.decode(enc) really
-        # means u.encode(sys.getdefaultencoding()).decode(enc). Since
-        # the Python encoding defaults to 'ascii', this fails if the
-        # translated string use non-ASCII characters.
-        return u.encode(encoding.encoding, "replace")
-    except LookupError:
-        # An unknown encoding results in a LookupError.
-        return message
+    if message not in _msgcache:
+        if type(message) is unicode:
+            # goofy unicode docstrings in test
+            paragraphs = message.split(u'\n\n')
+        else:
+            paragraphs = [p.decode("ascii") for p in message.split('\n\n')]
+        # Be careful not to translate the empty string -- it holds the
+        # meta data of the .po file.
+        u = u'\n\n'.join([p and _ugettext(p) or '' for p in paragraphs])
+        try:
+            # encoding.tolocal cannot be used since it will first try to
+            # decode the Unicode string. Calling u.decode(enc) really
+            # means u.encode(sys.getdefaultencoding()).decode(enc). Since
+            # the Python encoding defaults to 'ascii', this fails if the
+            # translated string use non-ASCII characters.
+            _msgcache[message] = u.encode(encoding.encoding, "replace")
+        except LookupError:
+            # An unknown encoding results in a LookupError.
+            _msgcache[message] = message
+    return _msgcache[message]
 
 def _plain():
     if 'HGPLAIN' not in os.environ and 'HGPLAINEXCEPT' not in os.environ: