Mercurial > hg
view mercurial/i18n.py @ 29375:fcaf20175b1b
demandimport: delay loading for "from a import b" with absolute_import
Before this patch, "from a import b" doesn't delay loading module "b",
if absolute_import is enabled, even though "from . import b" does.
For example:
- it is assumed that extension X has "from P import M" for module M
under package P with absolute_import feature
- if importing module M is already delayed before loading extension
X, loading module M in extension X is delayed until actually
referring
util, cmdutil, scmutil or so of Mercurial itself should be
imported by "from . import M" style before loading extension X
- otherwise, module M is loaded immediately at loading extension X,
even if extension X itself isn't used at that "hg" command invocation
Some minor modules (e.g. filemerge or so) of Mercurial itself
aren't imported by "from . import M" style before loading
extension X. And of course, external libraries aren't, too.
This might cause startup performance problem of hg command, because
many bundled extensions already enable absolute_import feature.
To delay loading module for "from a import b" with absolute_import
feature, this patch does below in "from a (or .a) import b" with
absolute_import case:
1. import root module of "name" by system built-in __import__
(referred as _origimport)
2. recurse down the module chain for hierarchical "name"
This logic can be shared with non absolute_import
case. Therefore, this patch also centralizes it into chainmodules().
3. and fall through to process elements in "fromlist" for the leaf
module of "name"
Processing elements in "fromlist" is executed in the code path
after "if _pypy: .... else: ..." clause. Therefore, this patch
replaces "if _pypy:" with "elif _pypy:" to share it.
At 4f1144c3c72b introducing original "work around" for "from a import
b" case, elements in "fromlist" were imported with "level=level". But
"level" might be grater than 1 (e.g. level=2 in "from .. import b"
case) at demandimport() invocation, and importing direct sub-module in
"fromlist" with level grater than 1 causes unexpected result.
IMHO, this seems main reason of "errors for unknown reason" described
in 4f1144c3c72b, and we don't have to worry about it, because this
issue was already fixed by 78d05778907b.
This is reason why this patch removes "errors for unknown reasons"
comment.
author | FUJIWARA Katsunori <foozy@lares.dti.ne.jp> |
---|---|
date | Sun, 19 Jun 2016 02:17:33 +0900 |
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