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Diffstat (limited to 'keystone-moon/keystone/openstack/common/versionutils.py')
| -rw-r--r-- | keystone-moon/keystone/openstack/common/versionutils.py | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/keystone-moon/keystone/openstack/common/versionutils.py b/keystone-moon/keystone/openstack/common/versionutils.py new file mode 100644 index 00000000..111bfd6f --- /dev/null +++ b/keystone-moon/keystone/openstack/common/versionutils.py @@ -0,0 +1,262 @@ +# Copyright (c) 2013 OpenStack Foundation +# 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. + +""" +Helpers for comparing version strings. +""" + +import copy +import functools +import inspect +import logging + +from oslo_config import cfg +import pkg_resources +import six + +from keystone.openstack.common._i18n import _ + + +LOG = logging.getLogger(__name__) +CONF = cfg.CONF + + +deprecated_opts = [ + cfg.BoolOpt('fatal_deprecations', + default=False, + help='Enables or disables fatal status of deprecations.'), +] + + +def list_opts(): + """Entry point for oslo.config-generator. + """ + return [(None, copy.deepcopy(deprecated_opts))] + + +class deprecated(object): + """A decorator to mark callables as deprecated. + + This decorator logs a deprecation message when the callable it decorates is + used. The message will include the release where the callable was + deprecated, the release where it may be removed and possibly an optional + replacement. + + Examples: + + 1. Specifying the required deprecated release + + >>> @deprecated(as_of=deprecated.ICEHOUSE) + ... def a(): pass + + 2. Specifying a replacement: + + >>> @deprecated(as_of=deprecated.ICEHOUSE, in_favor_of='f()') + ... def b(): pass + + 3. Specifying the release where the functionality may be removed: + + >>> @deprecated(as_of=deprecated.ICEHOUSE, remove_in=+1) + ... def c(): pass + + 4. Specifying the deprecated functionality will not be removed: + >>> @deprecated(as_of=deprecated.ICEHOUSE, remove_in=0) + ... def d(): pass + + 5. Specifying a replacement, deprecated functionality will not be removed: + >>> @deprecated(as_of=deprecated.ICEHOUSE, in_favor_of='f()', remove_in=0) + ... def e(): pass + + """ + + # NOTE(morganfainberg): Bexar is used for unit test purposes, it is + # expected we maintain a gap between Bexar and Folsom in this list. + BEXAR = 'B' + FOLSOM = 'F' + GRIZZLY = 'G' + HAVANA = 'H' + ICEHOUSE = 'I' + JUNO = 'J' + KILO = 'K' + LIBERTY = 'L' + + _RELEASES = { + # NOTE(morganfainberg): Bexar is used for unit test purposes, it is + # expected we maintain a gap between Bexar and Folsom in this list. + 'B': 'Bexar', + 'F': 'Folsom', + 'G': 'Grizzly', + 'H': 'Havana', + 'I': 'Icehouse', + 'J': 'Juno', + 'K': 'Kilo', + 'L': 'Liberty', + } + + _deprecated_msg_with_alternative = _( + '%(what)s is deprecated as of %(as_of)s in favor of ' + '%(in_favor_of)s and may be removed in %(remove_in)s.') + + _deprecated_msg_no_alternative = _( + '%(what)s is deprecated as of %(as_of)s and may be ' + 'removed in %(remove_in)s. It will not be superseded.') + + _deprecated_msg_with_alternative_no_removal = _( + '%(what)s is deprecated as of %(as_of)s in favor of %(in_favor_of)s.') + + _deprecated_msg_with_no_alternative_no_removal = _( + '%(what)s is deprecated as of %(as_of)s. It will not be superseded.') + + def __init__(self, as_of, in_favor_of=None, remove_in=2, what=None): + """Initialize decorator + + :param as_of: the release deprecating the callable. Constants + are define in this class for convenience. + :param in_favor_of: the replacement for the callable (optional) + :param remove_in: an integer specifying how many releases to wait + before removing (default: 2) + :param what: name of the thing being deprecated (default: the + callable's name) + + """ + self.as_of = as_of + self.in_favor_of = in_favor_of + self.remove_in = remove_in + self.what = what + + def __call__(self, func_or_cls): + if not self.what: + self.what = func_or_cls.__name__ + '()' + msg, details = self._build_message() + + if inspect.isfunction(func_or_cls): + + @six.wraps(func_or_cls) + def wrapped(*args, **kwargs): + report_deprecated_feature(LOG, msg, details) + return func_or_cls(*args, **kwargs) + return wrapped + elif inspect.isclass(func_or_cls): + orig_init = func_or_cls.__init__ + + # TODO(tsufiev): change `functools` module to `six` as + # soon as six 1.7.4 (with fix for passing `assigned` + # argument to underlying `functools.wraps`) is released + # and added to the oslo-incubator requrements + @functools.wraps(orig_init, assigned=('__name__', '__doc__')) + def new_init(self, *args, **kwargs): + report_deprecated_feature(LOG, msg, details) + orig_init(self, *args, **kwargs) + func_or_cls.__init__ = new_init + return func_or_cls + else: + raise TypeError('deprecated can be used only with functions or ' + 'classes') + + def _get_safe_to_remove_release(self, release): + # TODO(dstanek): this method will have to be reimplemented once + # when we get to the X release because once we get to the Y + # release, what is Y+2? + new_release = chr(ord(release) + self.remove_in) + if new_release in self._RELEASES: + return self._RELEASES[new_release] + else: + return new_release + + def _build_message(self): + details = dict(what=self.what, + as_of=self._RELEASES[self.as_of], + remove_in=self._get_safe_to_remove_release(self.as_of)) + + if self.in_favor_of: + details['in_favor_of'] = self.in_favor_of + if self.remove_in > 0: + msg = self._deprecated_msg_with_alternative + else: + # There are no plans to remove this function, but it is + # now deprecated. + msg = self._deprecated_msg_with_alternative_no_removal + else: + if self.remove_in > 0: + msg = self._deprecated_msg_no_alternative + else: + # There are no plans to remove this function, but it is + # now deprecated. + msg = self._deprecated_msg_with_no_alternative_no_removal + return msg, details + + +def is_compatible(requested_version, current_version, same_major=True): + """Determine whether `requested_version` is satisfied by + `current_version`; in other words, `current_version` is >= + `requested_version`. + + :param requested_version: version to check for compatibility + :param current_version: version to check against + :param same_major: if True, the major version must be identical between + `requested_version` and `current_version`. This is used when a + major-version difference indicates incompatibility between the two + versions. Since this is the common-case in practice, the default is + True. + :returns: True if compatible, False if not + """ + requested_parts = pkg_resources.parse_version(requested_version) + current_parts = pkg_resources.parse_version(current_version) + + if same_major and (requested_parts[0] != current_parts[0]): + return False + + return current_parts >= requested_parts + + +# Track the messages we have sent already. See +# report_deprecated_feature(). +_deprecated_messages_sent = {} + + +def report_deprecated_feature(logger, msg, *args, **kwargs): + """Call this function when a deprecated feature is used. + + If the system is configured for fatal deprecations then the message + is logged at the 'critical' level and :class:`DeprecatedConfig` will + be raised. + + Otherwise, the message will be logged (once) at the 'warn' level. + + :raises: :class:`DeprecatedConfig` if the system is configured for + fatal deprecations. + """ + stdmsg = _("Deprecated: %s") % msg + CONF.register_opts(deprecated_opts) + if CONF.fatal_deprecations: + logger.critical(stdmsg, *args, **kwargs) + raise DeprecatedConfig(msg=stdmsg) + + # Using a list because a tuple with dict can't be stored in a set. + sent_args = _deprecated_messages_sent.setdefault(msg, list()) + + if args in sent_args: + # Already logged this message, so don't log it again. + return + + sent_args.append(args) + logger.warn(stdmsg, *args, **kwargs) + + +class DeprecatedConfig(Exception): + message = _("Fatal call to deprecated config: %(msg)s") + + def __init__(self, msg): + super(Exception, self).__init__(self.message % dict(msg=msg)) |