oslo.i18n/oslo_i18n/_gettextutils.py

128 lines
4.1 KiB
Python

# Copyright 2012 Red Hat, Inc.
# Copyright 2013 IBM Corp.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""gettextutils provides a wrapper around gettext for OpenStack projects
"""
import copy
import gettext
import os
from babel import localedata
from oslo_i18n import _factory
from oslo_i18n import _locale
__all__ = [
'install',
'get_available_languages',
]
def install(domain):
"""Install a _() function using the given translation domain.
Given a translation domain, install a _() function using gettext's
install() function.
The main difference from gettext.install() is that we allow
overriding the default localedir (e.g. /usr/share/locale) using
a translation-domain-specific environment variable (e.g.
NOVA_LOCALEDIR).
:param domain: the translation domain
"""
from six import moves
tf = _factory.TranslatorFactory(domain)
moves.builtins.__dict__['_'] = tf.primary
_AVAILABLE_LANGUAGES = {}
def get_available_languages(domain):
"""Lists the available languages for the given translation domain.
:param domain: the domain to get languages for
"""
if domain in _AVAILABLE_LANGUAGES:
return copy.copy(_AVAILABLE_LANGUAGES[domain])
localedir = os.environ.get(_locale.get_locale_dir_variable_name(domain))
find = lambda x: gettext.find(domain,
localedir=localedir,
languages=[x])
# NOTE(mrodden): en_US should always be available (and first in case
# order matters) since our in-line message strings are en_US
language_list = ['en_US']
locale_identifiers = localedata.locale_identifiers()
language_list.extend(language for language in locale_identifiers
if find(language))
# In Babel 1.3, locale_identifiers() doesn't list some OpenStack supported
# locales (e.g. 'zh_CN', and 'zh_TW') so we add the locales explicitly if
# necessary so that they are listed as supported.
aliases = {'zh': 'zh_CN',
'zh_Hant_HK': 'zh_HK',
'zh_Hant': 'zh_TW',
'fil': 'tl_PH'}
language_list.extend(alias for locale, alias in aliases.items()
if (locale in language_list and
alias not in language_list))
language_list.extend(alias for locale, alias in aliases.items()
if (locale not in language_list and
find(alias)))
# In webob.acceptparse, the best_match is just match the first element in
# the language_list, so make the precise element in front
result = ['en_US']
for i in language_list[1:]:
if '_' in i:
result.insert(1, i)
else:
result.append(i)
_AVAILABLE_LANGUAGES[domain] = result
return copy.copy(result)
_original_find = gettext.find
_FIND_CACHE = {}
def cached_find(domain, localedir=None, languages=None, all=0):
"""A version of gettext.find using a cache.
gettext.find looks for mo files on the disk using os.path.exists. Those
don't tend to change over time, but the system calls pile up with a
long-running service. This caches the result so that we return the same mo
files, and only call find once per domain.
"""
key = (domain,
localedir,
tuple(languages) if languages is not None else None,
all)
if key in _FIND_CACHE:
return _FIND_CACHE[key]
result = _original_find(domain, localedir, languages, all)
_FIND_CACHE[key] = result
return result
gettext.find = cached_find