# Copyright (C) 2007 Canonical Ltd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
"""Library API versioning support.
Added in bzrlib 0.18 this allows export of compatibility information about
bzrlib. Please see doc/developers/api-versioning.txt for design details and
examples.
"""
import bzrlib
from bzrlib.lazy_import import lazy_import
lazy_import(globals(), """
from bzrlib.errors import IncompatibleAPI
""")
def get_current_api_version(object_with_api):
"""Return the API version tuple for object_with_api.
:param object_with_api: An object to look for an API version on. If the
object has a api_current_version attribute, that is used. Otherwise if
there is a version_info attribute, its first three elements are used.
Finally if there was no version_info attribute, the current api version
of bzrlib itself is used.
Added in bzrlib 0.18.
"""
try:
return object_with_api.api_current_version
except AttributeError:
try:
return object_with_api.version_info[0:3]
except AttributeError:
return get_current_api_version(bzrlib)
def get_minimum_api_version(object_with_api):
"""Return the minimum API version supported by object_with_api.
:param object_with_api: An object to look for an API version on. If the
object has a api_minimum_version attribute, that is used. Otherwise the
minimum api version of bzrlib itself is used.
Added in bzrlib 0.18.
"""
try:
return object_with_api.api_minimum_version
except AttributeError:
return get_minimum_api_version(bzrlib)
def require_api(object_with_api, wanted_api):
"""Check if object_with_api supports the api version wanted_api.
:param object_with_api: An object which exports an API minimum and current
version. See get_minimum_api_version and get_current_api_version for
details.
:param wanted_api: The API version for which support is required.
:return: None
:raises IncompatibleAPI: When the wanted_api is not supported by
object_with_api.
Added in bzrlib 0.18.
"""
current = get_current_api_version(object_with_api)
minimum = get_minimum_api_version(object_with_api)
if wanted_api < minimum or wanted_api > current:
raise IncompatibleAPI(object_with_api, wanted_api, minimum, current)
def require_any_api(object_with_api, wanted_api_list):
"""Check if object_with_api supports the api version wanted_api.
:param object_with_api: An object which exports an API minimum and current
version. See get_minimum_api_version and get_current_api_version for
details.
:param wanted_api: A list of API versions, any of which being available is
sufficent.
:return: None
:raises IncompatibleAPI: When the wanted_api is not supported by
object_with_api.
Added in bzrlib 1.9.
"""
for api in wanted_api_list[:-1]:
try:
return require_api(object_with_api, api)
except IncompatibleAPI:
pass
require_api(object_with_api, wanted_api_list[-1])
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