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Diffstat (limited to 'os_net_config/openstack/common/jsonutils.py')
| -rw-r--r-- | os_net_config/openstack/common/jsonutils.py | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/os_net_config/openstack/common/jsonutils.py b/os_net_config/openstack/common/jsonutils.py new file mode 100644 index 0000000..809659f --- /dev/null +++ b/os_net_config/openstack/common/jsonutils.py @@ -0,0 +1,186 @@ +# Copyright 2010 United States Government as represented by the +# Administrator of the National Aeronautics and Space Administration. +# Copyright 2011 Justin Santa Barbara +# 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. + +''' +JSON related utilities. + +This module provides a few things: + + 1) A handy function for getting an object down to something that can be + JSON serialized. See to_primitive(). + + 2) Wrappers around loads() and dumps(). The dumps() wrapper will + automatically use to_primitive() for you if needed. + + 3) This sets up anyjson to use the loads() and dumps() wrappers if anyjson + is available. +''' + + +import codecs +import datetime +import functools +import inspect +import itertools +import sys + +if sys.version_info < (2, 7): + # On Python <= 2.6, json module is not C boosted, so try to use + # simplejson module if available + try: + import simplejson as json + except ImportError: + import json +else: + import json + +import six +import six.moves.xmlrpc_client as xmlrpclib + +from os_net_config.openstack.common import gettextutils +from os_net_config.openstack.common import importutils +from os_net_config.openstack.common import strutils +from os_net_config.openstack.common import timeutils + +netaddr = importutils.try_import("netaddr") + +_nasty_type_tests = [inspect.ismodule, inspect.isclass, inspect.ismethod, + inspect.isfunction, inspect.isgeneratorfunction, + inspect.isgenerator, inspect.istraceback, inspect.isframe, + inspect.iscode, inspect.isbuiltin, inspect.isroutine, + inspect.isabstract] + +_simple_types = (six.string_types + six.integer_types + + (type(None), bool, float)) + + +def to_primitive(value, convert_instances=False, convert_datetime=True, + level=0, max_depth=3): + """Convert a complex object into primitives. + + Handy for JSON serialization. We can optionally handle instances, + but since this is a recursive function, we could have cyclical + data structures. + + To handle cyclical data structures we could track the actual objects + visited in a set, but not all objects are hashable. Instead we just + track the depth of the object inspections and don't go too deep. + + Therefore, convert_instances=True is lossy ... be aware. + + """ + # handle obvious types first - order of basic types determined by running + # full tests on nova project, resulting in the following counts: + # 572754 <type 'NoneType'> + # 460353 <type 'int'> + # 379632 <type 'unicode'> + # 274610 <type 'str'> + # 199918 <type 'dict'> + # 114200 <type 'datetime.datetime'> + # 51817 <type 'bool'> + # 26164 <type 'list'> + # 6491 <type 'float'> + # 283 <type 'tuple'> + # 19 <type 'long'> + if isinstance(value, _simple_types): + return value + + if isinstance(value, datetime.datetime): + if convert_datetime: + return timeutils.strtime(value) + else: + return value + + # value of itertools.count doesn't get caught by nasty_type_tests + # and results in infinite loop when list(value) is called. + if type(value) == itertools.count: + return six.text_type(value) + + # FIXME(vish): Workaround for LP bug 852095. Without this workaround, + # tests that raise an exception in a mocked method that + # has a @wrap_exception with a notifier will fail. If + # we up the dependency to 0.5.4 (when it is released) we + # can remove this workaround. + if getattr(value, '__module__', None) == 'mox': + return 'mock' + + if level > max_depth: + return '?' + + # The try block may not be necessary after the class check above, + # but just in case ... + try: + recursive = functools.partial(to_primitive, + convert_instances=convert_instances, + convert_datetime=convert_datetime, + level=level, + max_depth=max_depth) + if isinstance(value, dict): + return dict((k, recursive(v)) for k, v in six.iteritems(value)) + elif isinstance(value, (list, tuple)): + return [recursive(lv) for lv in value] + + # It's not clear why xmlrpclib created their own DateTime type, but + # for our purposes, make it a datetime type which is explicitly + # handled + if isinstance(value, xmlrpclib.DateTime): + value = datetime.datetime(*tuple(value.timetuple())[:6]) + + if convert_datetime and isinstance(value, datetime.datetime): + return timeutils.strtime(value) + elif isinstance(value, gettextutils.Message): + return value.data + elif hasattr(value, 'iteritems'): + return recursive(dict(value.iteritems()), level=level + 1) + elif hasattr(value, '__iter__'): + return recursive(list(value)) + elif convert_instances and hasattr(value, '__dict__'): + # Likely an instance of something. Watch for cycles. + # Ignore class member vars. + return recursive(value.__dict__, level=level + 1) + elif netaddr and isinstance(value, netaddr.IPAddress): + return six.text_type(value) + else: + if any(test(value) for test in _nasty_type_tests): + return six.text_type(value) + return value + except TypeError: + # Class objects are tricky since they may define something like + # __iter__ defined but it isn't callable as list(). + return six.text_type(value) + + +def dumps(value, default=to_primitive, **kwargs): + return json.dumps(value, default=default, **kwargs) + + +def loads(s, encoding='utf-8', **kwargs): + return json.loads(strutils.safe_decode(s, encoding), **kwargs) + + +def load(fp, encoding='utf-8', **kwargs): + return json.load(codecs.getreader(encoding)(fp), **kwargs) + + +try: + import anyjson +except ImportError: + pass +else: + anyjson._modules.append((__name__, 'dumps', TypeError, + 'loads', ValueError, 'load')) + anyjson.force_implementation(__name__) |