From 3e1474324568a277bd3d8e493d26021ec3f3767c Mon Sep 17 00:00:00 2001 From: Dan Prince Date: Mon, 9 Jun 2014 17:13:57 -0400 Subject: Import processutils from oslo-incubator. --- os_net_config/openstack/common/gettextutils.py | 498 +++++++++++++++++++++++++ 1 file changed, 498 insertions(+) create mode 100644 os_net_config/openstack/common/gettextutils.py (limited to 'os_net_config/openstack/common/gettextutils.py') diff --git a/os_net_config/openstack/common/gettextutils.py b/os_net_config/openstack/common/gettextutils.py new file mode 100644 index 0000000..8e0081f --- /dev/null +++ b/os_net_config/openstack/common/gettextutils.py @@ -0,0 +1,498 @@ +# 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. + +""" +gettext for openstack-common modules. + +Usual usage in an openstack.common module: + + from os_net_config.openstack.common.gettextutils import _ +""" + +import copy +import functools +import gettext +import locale +from logging import handlers +import os + +from babel import localedata +import six + +_AVAILABLE_LANGUAGES = {} + +# FIXME(dhellmann): Remove this when moving to oslo.i18n. +USE_LAZY = False + + +class TranslatorFactory(object): + """Create translator functions + """ + + def __init__(self, domain, lazy=False, localedir=None): + """Establish a set of translation functions for the domain. + + :param domain: Name of translation domain, + specifying a message catalog. + :type domain: str + :param lazy: Delays translation until a message is emitted. + Defaults to False. + :type lazy: Boolean + :param localedir: Directory with translation catalogs. + :type localedir: str + """ + self.domain = domain + self.lazy = lazy + if localedir is None: + localedir = os.environ.get(domain.upper() + '_LOCALEDIR') + self.localedir = localedir + + def _make_translation_func(self, domain=None): + """Return a new translation function ready for use. + + Takes into account whether or not lazy translation is being + done. + + The domain can be specified to override the default from the + factory, but the localedir from the factory is always used + because we assume the log-level translation catalogs are + installed in the same directory as the main application + catalog. + + """ + if domain is None: + domain = self.domain + if self.lazy: + return functools.partial(Message, domain=domain) + t = gettext.translation( + domain, + localedir=self.localedir, + fallback=True, + ) + if six.PY3: + return t.gettext + return t.ugettext + + @property + def primary(self): + "The default translation function." + return self._make_translation_func() + + def _make_log_translation_func(self, level): + return self._make_translation_func(self.domain + '-log-' + level) + + @property + def log_info(self): + "Translate info-level log messages." + return self._make_log_translation_func('info') + + @property + def log_warning(self): + "Translate warning-level log messages." + return self._make_log_translation_func('warning') + + @property + def log_error(self): + "Translate error-level log messages." + return self._make_log_translation_func('error') + + @property + def log_critical(self): + "Translate critical-level log messages." + return self._make_log_translation_func('critical') + + +# NOTE(dhellmann): When this module moves out of the incubator into +# oslo.i18n, these global variables can be moved to an integration +# module within each application. + +# Create the global translation functions. +_translators = TranslatorFactory('os_net_config') + +# The primary translation function using the well-known name "_" +_ = _translators.primary + +# Translators for log levels. +# +# The abbreviated names are meant to reflect the usual use of a short +# name like '_'. The "L" is for "log" and the other letter comes from +# the level. +_LI = _translators.log_info +_LW = _translators.log_warning +_LE = _translators.log_error +_LC = _translators.log_critical + +# NOTE(dhellmann): End of globals that will move to the application's +# integration module. + + +def enable_lazy(): + """Convenience function for configuring _() to use lazy gettext + + Call this at the start of execution to enable the gettextutils._ + function to use lazy gettext functionality. This is useful if + your project is importing _ directly instead of using the + gettextutils.install() way of importing the _ function. + """ + # FIXME(dhellmann): This function will be removed in oslo.i18n, + # because the TranslatorFactory makes it superfluous. + global _, _LI, _LW, _LE, _LC, USE_LAZY + tf = TranslatorFactory('os_net_config', lazy=True) + _ = tf.primary + _LI = tf.log_info + _LW = tf.log_warning + _LE = tf.log_error + _LC = tf.log_critical + USE_LAZY = True + + +def install(domain, lazy=False): + """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 + :param lazy: indicates whether or not to install the lazy _() function. + The lazy _() introduces a way to do deferred translation + of messages by installing a _ that builds Message objects, + instead of strings, which can then be lazily translated into + any available locale. + """ + if lazy: + from six import moves + tf = TranslatorFactory(domain, lazy=True) + moves.builtins.__dict__['_'] = tf.primary + else: + localedir = '%s_LOCALEDIR' % domain.upper() + if six.PY3: + gettext.install(domain, + localedir=os.environ.get(localedir)) + else: + gettext.install(domain, + localedir=os.environ.get(localedir), + unicode=True) + + +class Message(six.text_type): + """A Message object is a unicode object that can be translated. + + Translation of Message is done explicitly using the translate() method. + For all non-translation intents and purposes, a Message is simply unicode, + and can be treated as such. + """ + + def __new__(cls, msgid, msgtext=None, params=None, + domain='os_net_config', *args): + """Create a new Message object. + + In order for translation to work gettext requires a message ID, this + msgid will be used as the base unicode text. It is also possible + for the msgid and the base unicode text to be different by passing + the msgtext parameter. + """ + # If the base msgtext is not given, we use the default translation + # of the msgid (which is in English) just in case the system locale is + # not English, so that the base text will be in that locale by default. + if not msgtext: + msgtext = Message._translate_msgid(msgid, domain) + # We want to initialize the parent unicode with the actual object that + # would have been plain unicode if 'Message' was not enabled. + msg = super(Message, cls).__new__(cls, msgtext) + msg.msgid = msgid + msg.domain = domain + msg.params = params + return msg + + def translate(self, desired_locale=None): + """Translate this message to the desired locale. + + :param desired_locale: The desired locale to translate the message to, + if no locale is provided the message will be + translated to the system's default locale. + + :returns: the translated message in unicode + """ + + translated_message = Message._translate_msgid(self.msgid, + self.domain, + desired_locale) + if self.params is None: + # No need for more translation + return translated_message + + # This Message object may have been formatted with one or more + # Message objects as substitution arguments, given either as a single + # argument, part of a tuple, or as one or more values in a dictionary. + # When translating this Message we need to translate those Messages too + translated_params = _translate_args(self.params, desired_locale) + + translated_message = translated_message % translated_params + + return translated_message + + @staticmethod + def _translate_msgid(msgid, domain, desired_locale=None): + if not desired_locale: + system_locale = locale.getdefaultlocale() + # If the system locale is not available to the runtime use English + if not system_locale[0]: + desired_locale = 'en_US' + else: + desired_locale = system_locale[0] + + locale_dir = os.environ.get(domain.upper() + '_LOCALEDIR') + lang = gettext.translation(domain, + localedir=locale_dir, + languages=[desired_locale], + fallback=True) + if six.PY3: + translator = lang.gettext + else: + translator = lang.ugettext + + translated_message = translator(msgid) + return translated_message + + def __mod__(self, other): + # When we mod a Message we want the actual operation to be performed + # by the parent class (i.e. unicode()), the only thing we do here is + # save the original msgid and the parameters in case of a translation + params = self._sanitize_mod_params(other) + unicode_mod = super(Message, self).__mod__(params) + modded = Message(self.msgid, + msgtext=unicode_mod, + params=params, + domain=self.domain) + return modded + + def _sanitize_mod_params(self, other): + """Sanitize the object being modded with this Message. + + - Add support for modding 'None' so translation supports it + - Trim the modded object, which can be a large dictionary, to only + those keys that would actually be used in a translation + - Snapshot the object being modded, in case the message is + translated, it will be used as it was when the Message was created + """ + if other is None: + params = (other,) + elif isinstance(other, dict): + # Merge the dictionaries + # Copy each item in case one does not support deep copy. + params = {} + if isinstance(self.params, dict): + for key, val in self.params.items(): + params[key] = self._copy_param(val) + for key, val in other.items(): + params[key] = self._copy_param(val) + else: + params = self._copy_param(other) + return params + + def _copy_param(self, param): + try: + return copy.deepcopy(param) + except Exception: + # Fallback to casting to unicode this will handle the + # python code-like objects that can't be deep-copied + return six.text_type(param) + + def __add__(self, other): + msg = _('Message objects do not support addition.') + raise TypeError(msg) + + def __radd__(self, other): + return self.__add__(other) + + if six.PY2: + def __str__(self): + # NOTE(luisg): Logging in python 2.6 tries to str() log records, + # and it expects specifically a UnicodeError in order to proceed. + msg = _('Message objects do not support str() because they may ' + 'contain non-ascii characters. ' + 'Please use unicode() or translate() instead.') + raise UnicodeError(msg) + + +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 = '%s_LOCALEDIR' % domain.upper() + find = lambda x: gettext.find(domain, + localedir=os.environ.get(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'] + # NOTE(luisg): Babel <1.0 used a function called list(), which was + # renamed to locale_identifiers() in >=1.0, the requirements master list + # requires >=0.9.6, uncapped, so defensively work with both. We can remove + # this check when the master list updates to >=1.0, and update all projects + list_identifiers = (getattr(localedata, 'list', None) or + getattr(localedata, 'locale_identifiers')) + locale_identifiers = list_identifiers() + + for i in locale_identifiers: + if find(i) is not None: + language_list.append(i) + + # NOTE(luisg): Babel>=1.0,<1.3 has a bug where some OpenStack supported + # locales (e.g. 'zh_CN', and 'zh_TW') aren't supported even though they + # are perfectly legitimate locales: + # https://github.com/mitsuhiko/babel/issues/37 + # In Babel 1.3 they fixed the bug and they support these locales, but + # they are still not explicitly "listed" by locale_identifiers(). + # That is why we add the locales here 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'} + for (locale, alias) in six.iteritems(aliases): + if locale in language_list and alias not in language_list: + language_list.append(alias) + + _AVAILABLE_LANGUAGES[domain] = language_list + return copy.copy(language_list) + + +def translate(obj, desired_locale=None): + """Gets the translated unicode representation of the given object. + + If the object is not translatable it is returned as-is. + If the locale is None the object is translated to the system locale. + + :param obj: the object to translate + :param desired_locale: the locale to translate the message to, if None the + default system locale will be used + :returns: the translated object in unicode, or the original object if + it could not be translated + """ + message = obj + if not isinstance(message, Message): + # If the object to translate is not already translatable, + # let's first get its unicode representation + message = six.text_type(obj) + if isinstance(message, Message): + # Even after unicoding() we still need to check if we are + # running with translatable unicode before translating + return message.translate(desired_locale) + return obj + + +def _translate_args(args, desired_locale=None): + """Translates all the translatable elements of the given arguments object. + + This method is used for translating the translatable values in method + arguments which include values of tuples or dictionaries. + If the object is not a tuple or a dictionary the object itself is + translated if it is translatable. + + If the locale is None the object is translated to the system locale. + + :param args: the args to translate + :param desired_locale: the locale to translate the args to, if None the + default system locale will be used + :returns: a new args object with the translated contents of the original + """ + if isinstance(args, tuple): + return tuple(translate(v, desired_locale) for v in args) + if isinstance(args, dict): + translated_dict = {} + for (k, v) in six.iteritems(args): + translated_v = translate(v, desired_locale) + translated_dict[k] = translated_v + return translated_dict + return translate(args, desired_locale) + + +class TranslationHandler(handlers.MemoryHandler): + """Handler that translates records before logging them. + + The TranslationHandler takes a locale and a target logging.Handler object + to forward LogRecord objects to after translating them. This handler + depends on Message objects being logged, instead of regular strings. + + The handler can be configured declaratively in the logging.conf as follows: + + [handlers] + keys = translatedlog, translator + + [handler_translatedlog] + class = handlers.WatchedFileHandler + args = ('/var/log/api-localized.log',) + formatter = context + + [handler_translator] + class = openstack.common.log.TranslationHandler + target = translatedlog + args = ('zh_CN',) + + If the specified locale is not available in the system, the handler will + log in the default locale. + """ + + def __init__(self, locale=None, target=None): + """Initialize a TranslationHandler + + :param locale: locale to use for translating messages + :param target: logging.Handler object to forward + LogRecord objects to after translation + """ + # NOTE(luisg): In order to allow this handler to be a wrapper for + # other handlers, such as a FileHandler, and still be able to + # configure it using logging.conf, this handler has to extend + # MemoryHandler because only the MemoryHandlers' logging.conf + # parsing is implemented such that it accepts a target handler. + handlers.MemoryHandler.__init__(self, capacity=0, target=target) + self.locale = locale + + def setFormatter(self, fmt): + self.target.setFormatter(fmt) + + def emit(self, record): + # We save the message from the original record to restore it + # after translation, so other handlers are not affected by this + original_msg = record.msg + original_args = record.args + + try: + self._translate_and_log_record(record) + finally: + record.msg = original_msg + record.args = original_args + + def _translate_and_log_record(self, record): + record.msg = translate(record.msg, self.locale) + + # In addition to translating the message, we also need to translate + # arguments that were passed to the log method that were not part + # of the main message e.g., log.info(_('Some message %s'), this_one)) + record.args = _translate_args(record.args, self.locale) + + self.target.emit(record) -- cgit 1.2.3-korg