Mercurial > hg
view mercurial/i18n.py @ 29304:5e32852fa4bd
revset: make filteredset.__nonzero__ respect the order of the filteredset
This fix allows __nonzero__ to respect the direction of iteration of the
whole filteredset. Here's the case when it matters. Imagine that we have a
very large repository and we want to execute a command like:
$ hg log --rev '(tip:0) and user(ikostia)' --limit 1
(we want to get the latest commit by me).
Mercurial will evaluate a filteredset lazy data structure, an
instance of the filteredset class, which will know that it has to iterate
in a descending order (isdescending() will return True if called). This
means that when some code iterates over the instance of this filteredset,
the 'and user(ikostia)' condition will be first checked on the latest
revision, then on the second latest and so on, allowing Mercurial to
print matches as it founds them. However, cmdutil.getgraphlogrevs
contains the following code:
revs = _logrevs(repo, opts)
if not revs:
return revset.baseset(), None, None
The "not revs" expression is evaluated by calling filteredset.__nonzero__,
which in its current implementation will try to iterate the filteredset
in ascending order until it finds a revision that matches the 'and user(..'
condition. If the condition is only true on late revisions, a lot of
useless iterations will be done. These iterations could be avoided if
__nonzero__ followed the order of the filteredset, which in my opinion
is a sensible thing to do here.
The problem gets even worse when instead of 'user(ikostia)' some more
expensive check is performed, like grepping the commit diff.
I tested this fix on a very large repo where tip is my commit and my very
first commit comes fairly late in the revision history. Results of timing
of the above command on that very large repo.
-with my fix:
real 0m1.795s
user 0m1.657s
sys 0m0.135s
-without my fix:
real 1m29.245s
user 1m28.223s
sys 0m0.929s
I understand that this is a very specific kind of problem that presents
itself very rarely, only on very big repositories and with expensive
checks and so on. But I don't see any disadvantages to this kind of fix
either.
author | Kostia Balytskyi <ikostia@fb.com> |
---|---|
date | Thu, 02 Jun 2016 22:39:01 +0100 |
parents | 03d1ecbbd81e |
children | 47fb4beb992b |
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# i18n.py - internationalization support for mercurial # # Copyright 2005, 2006 Matt Mackall <mpm@selenic.com> # # 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 gettext as gettextmod import locale import os import sys from . import encoding # modelled after templater.templatepath: if getattr(sys, 'frozen', None) is not None: module = sys.executable else: module = __file__ try: unicode except NameError: unicode = str _languages = None if (os.name == 'nt' and 'LANGUAGE' not in os.environ and 'LC_ALL' not in os.environ and 'LC_MESSAGES' not in os.environ and 'LANG' not in os.environ): # Try to detect UI language by "User Interface Language Management" API # if no locale variables are set. Note that locale.getdefaultlocale() # uses GetLocaleInfo(), which may be different from UI language. # (See http://msdn.microsoft.com/en-us/library/dd374098(v=VS.85).aspx ) try: import ctypes langid = ctypes.windll.kernel32.GetUserDefaultUILanguage() _languages = [locale.windows_locale[langid]] except (ImportError, AttributeError, KeyError): # ctypes not found or unknown langid pass _ugettext = None def setdatapath(datapath): localedir = os.path.join(datapath, 'locale') t = gettextmod.translation('hg', localedir, _languages, fallback=True) global _ugettext try: _ugettext = t.ugettext except AttributeError: _ugettext = t.gettext _msgcache = {} def gettext(message): """Translate message. The message is looked up in the catalog to get a Unicode string, which is encoded in the local encoding before being returned. Important: message is restricted to characters in the encoding given by sys.getdefaultencoding() which is most likely 'ascii'. """ # If message is None, t.ugettext will return u'None' as the # translation whereas our callers expect us to return None. if message is None or not _ugettext: 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: return False exceptions = os.environ.get('HGPLAINEXCEPT', '').strip().split(',') return 'i18n' not in exceptions if _plain(): _ = lambda message: message else: _ = gettext