3f9a902198
the variable '_class_prefixes' of stringify.StringifyMixin is used to help the method 'from_jsondict()' to create the class instance.
'_class_prefixes' requires a list of the class names.
some classes have another list of the class names already.
this patch adds a method which makes '_class_prefixes' by using the existing list.
before applying this patch:
(e.g. ryu.lib.packet.ipv6)
# append the name to another list
@ipv6.register_header_type(inet.IPPROTO_HOPOPTS)
class hop_opts(opt_header):
...
@ipv6.register_header_type(inet.IPPROTO_DSTOPTS)
class dst_opts(opt_header):
....
# append the name again
ipv6._class_prefixes = ['hop_opts', 'dst_opts', ...]
after applying this patch:
(e.g. ryu.lib.packet.ipv6)
# append the name to another list
@ipv6.register_header_type(inet.IPPROTO_HOPOPTS)
class hop_opts(opt_header):
...
@ipv6.register_header_type(inet.IPPROTO_DSTOPTS)
class dst_opts(opt_header):
....
# create the new list from another list
ipv6.set_classes(ipv6._IPV6_EXT_HEADER_TYPE)
Signed-off-by: Yuichi Ito <ito.yuichi0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
345 lines
11 KiB
Python
345 lines
11 KiB
Python
#!/usr/bin/env python
|
|
#
|
|
# Copyright (C) 2013 Nippon Telegraph and Telephone Corporation.
|
|
# Copyright (C) 2013 YAMAMOTO Takashi <yamamoto at valinux co jp>
|
|
#
|
|
# 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.
|
|
|
|
import base64
|
|
import collections
|
|
import inspect
|
|
|
|
|
|
# Some arguments to __init__ is mungled in order to avoid name conflicts
|
|
# with builtin names.
|
|
# The standard mangling is to append '_' in order to avoid name clashes
|
|
# with reserved keywords.
|
|
#
|
|
# PEP8:
|
|
# Function and method arguments
|
|
# If a function argument's name clashes with a reserved keyword,
|
|
# it is generally better to append a single trailing underscore
|
|
# rather than use an abbreviation or spelling corruption. Thus
|
|
# class_ is better than clss. (Perhaps better is to avoid such
|
|
# clashes by using a synonym.)
|
|
#
|
|
# grep __init__ *.py | grep '[^_]_\>' showed that
|
|
# 'len', 'property', 'set', 'type'
|
|
# A bit more generic way is adopted
|
|
import __builtin__
|
|
_RESERVED_KEYWORD = dir(__builtin__)
|
|
|
|
|
|
_mapdict = lambda f, d: dict([(k, f(v)) for k, v in d.items()])
|
|
_mapdict_key = lambda f, d: dict([(f(k), v) for k, v in d.items()])
|
|
_mapdict_kv = lambda f, d: dict([(k, f(k, v)) for k, v in d.items()])
|
|
|
|
|
|
class TypeDescr(object):
|
|
pass
|
|
|
|
|
|
class AsciiStringType(TypeDescr):
|
|
@staticmethod
|
|
def encode(v):
|
|
return unicode(v, 'ascii')
|
|
|
|
@staticmethod
|
|
def decode(v):
|
|
return v.encode('ascii')
|
|
|
|
|
|
class Utf8StringType(TypeDescr):
|
|
@staticmethod
|
|
def encode(v):
|
|
return unicode(v, 'utf-8')
|
|
|
|
@staticmethod
|
|
def decode(v):
|
|
return v.encode('utf-8')
|
|
|
|
|
|
_types = {
|
|
'ascii': AsciiStringType,
|
|
'utf-8': Utf8StringType,
|
|
}
|
|
|
|
|
|
class StringifyMixin(object):
|
|
|
|
_TYPE = {}
|
|
"""_TYPE class attribute is used to annotate types of attributes.
|
|
|
|
This type information is used to find an appropriate conversion for
|
|
a JSON style dictionary.
|
|
|
|
Currently the following types are implemented.
|
|
|
|
===== ==========
|
|
Type Descrption
|
|
===== ==========
|
|
ascii US-ASCII
|
|
utf-8 UTF-8
|
|
===== ==========
|
|
|
|
Example::
|
|
_TYPE = {
|
|
'ascii': [
|
|
'hw_addr',
|
|
],
|
|
'utf-8': [
|
|
'name',
|
|
]
|
|
}
|
|
"""
|
|
|
|
_class_prefixes = []
|
|
|
|
def stringify_attrs(self):
|
|
"""an override point for sub classes"""
|
|
return obj_python_attrs(self)
|
|
|
|
def __str__(self):
|
|
# repr() to escape binaries
|
|
return self.__class__.__name__ + '(' + \
|
|
','.join("%s=%s" % (k, repr(v)) for k, v in
|
|
self.stringify_attrs()) + ')'
|
|
__repr__ = __str__ # note: str(list) uses __repr__ for elements
|
|
|
|
@classmethod
|
|
def _is_class(cls, dict_):
|
|
# we distinguish a dict like OFPSwitchFeatures.ports
|
|
# from OFPxxx classes using heuristics.
|
|
# exmples of OFP classes:
|
|
# {"OFPMatch": { ... }}
|
|
# {"MTIPv6SRC": { ... }}
|
|
assert isinstance(dict_, dict)
|
|
if len(dict_) != 1:
|
|
return False
|
|
k = dict_.keys()[0]
|
|
if not isinstance(k, (bytes, unicode)):
|
|
return False
|
|
for p in cls._class_prefixes:
|
|
if k.startswith(p):
|
|
return True
|
|
return False
|
|
|
|
@classmethod
|
|
def _get_type(cls, k):
|
|
if hasattr(cls, '_TYPE'):
|
|
for t, attrs in cls._TYPE.iteritems():
|
|
if k in attrs:
|
|
return _types[t]
|
|
return None
|
|
|
|
@classmethod
|
|
def _get_encoder(cls, k, encode_string):
|
|
t = cls._get_type(k)
|
|
if t:
|
|
return t.encode
|
|
return cls._get_default_encoder(encode_string)
|
|
|
|
@classmethod
|
|
def _encode_value(cls, k, v, encode_string=base64.b64encode):
|
|
return cls._get_encoder(k, encode_string)(v)
|
|
|
|
@classmethod
|
|
def _get_default_encoder(cls, encode_string):
|
|
def _encode(v):
|
|
if isinstance(v, (bytes, unicode)):
|
|
json_value = encode_string(v)
|
|
elif isinstance(v, list):
|
|
json_value = map(_encode, v)
|
|
elif isinstance(v, dict):
|
|
json_value = _mapdict(_encode, v)
|
|
# while a python dict key can be any hashable object,
|
|
# a JSON object key should be a string.
|
|
json_value = _mapdict_key(str, json_value)
|
|
assert not cls._is_class(json_value)
|
|
else:
|
|
try:
|
|
json_value = v.to_jsondict()
|
|
except:
|
|
json_value = v
|
|
return json_value
|
|
return _encode
|
|
|
|
def to_jsondict(self, encode_string=base64.b64encode):
|
|
"""
|
|
This method returns a JSON style dict to describe this object.
|
|
|
|
The returned dict is compatible with json.dumps() and json.loads().
|
|
|
|
Suppose ClassName object inherits StringifyMixin.
|
|
For an object like the following::
|
|
|
|
ClassName(Param1=100, Param2=200)
|
|
|
|
this method would produce::
|
|
|
|
{ "ClassName": {"Param1": 100, "Param2": 200} }
|
|
|
|
This method takes the following arguments.
|
|
|
|
============= =====================================================
|
|
Argument Description
|
|
============= =====================================================
|
|
encode_string (Optional) specify how to encode attributes which has
|
|
python 'str' type.
|
|
The default is base64.
|
|
This argument is used only for attributes which don't
|
|
have explicit type annotations in _TYPE class attribute.
|
|
============= =====================================================
|
|
"""
|
|
dict_ = {}
|
|
encode = lambda k, x: self._encode_value(k, x, encode_string)
|
|
for k, v in obj_attrs(self):
|
|
dict_[k] = encode(k, v)
|
|
return {self.__class__.__name__: dict_}
|
|
|
|
@classmethod
|
|
def cls_from_jsondict_key(cls, k):
|
|
# find a class with the given name from our class' module.
|
|
import sys
|
|
mod = sys.modules[cls.__module__]
|
|
return getattr(mod, k)
|
|
|
|
@classmethod
|
|
def obj_from_jsondict(cls, jsondict):
|
|
assert len(jsondict) == 1
|
|
for k, v in jsondict.iteritems():
|
|
obj_cls = cls.cls_from_jsondict_key(k)
|
|
return obj_cls.from_jsondict(v)
|
|
|
|
@classmethod
|
|
def _get_decoder(cls, k, decode_string):
|
|
t = cls._get_type(k)
|
|
if t:
|
|
return t.decode
|
|
return cls._get_default_decoder(decode_string)
|
|
|
|
@classmethod
|
|
def _decode_value(cls, k, json_value, decode_string=base64.b64decode):
|
|
return cls._get_decoder(k, decode_string)(json_value)
|
|
|
|
@classmethod
|
|
def _get_default_decoder(cls, decode_string):
|
|
def _decode(json_value):
|
|
if isinstance(json_value, (bytes, unicode)):
|
|
v = decode_string(json_value)
|
|
elif isinstance(json_value, list):
|
|
v = map(_decode, json_value)
|
|
elif isinstance(json_value, dict):
|
|
if cls._is_class(json_value):
|
|
v = cls.obj_from_jsondict(json_value)
|
|
else:
|
|
v = _mapdict(_decode, json_value)
|
|
# XXXhack
|
|
# try to restore integer keys used by
|
|
# OFPSwitchFeatures.ports.
|
|
try:
|
|
v = _mapdict_key(int, v)
|
|
except ValueError:
|
|
pass
|
|
else:
|
|
v = json_value
|
|
return v
|
|
return _decode
|
|
|
|
@staticmethod
|
|
def _restore_args(dict_):
|
|
def restore(k):
|
|
if k in _RESERVED_KEYWORD:
|
|
return k + '_'
|
|
return k
|
|
return _mapdict_key(restore, dict_)
|
|
|
|
@classmethod
|
|
def from_jsondict(cls, dict_, decode_string=base64.b64decode,
|
|
**additional_args):
|
|
"""Create an instance from a JSON style dict.
|
|
|
|
Instantiate this class with parameters specified by the dict.
|
|
|
|
This method takes the following arguments.
|
|
|
|
=============== =====================================================
|
|
Argument Descrpition
|
|
=============== =====================================================
|
|
dict\_ A dictionary which describes the parameters.
|
|
For example, {"Param1": 100, "Param2": 200}
|
|
decode_string (Optional) specify how to decode strings.
|
|
The default is base64.
|
|
This argument is used only for attributes which don't
|
|
have explicit type annotations in _TYPE class
|
|
attribute.
|
|
additional_args (Optional) Additional kwargs for constructor.
|
|
=============== =====================================================
|
|
"""
|
|
decode = lambda k, x: cls._decode_value(k, x, decode_string)
|
|
kwargs = cls._restore_args(_mapdict_kv(decode, dict_))
|
|
try:
|
|
return cls(**dict(kwargs, **additional_args))
|
|
except TypeError:
|
|
#debug
|
|
print "CLS", cls
|
|
print "ARG", dict_
|
|
print "KWARG", kwargs
|
|
raise
|
|
|
|
@classmethod
|
|
def set_classes(cls, registered_dict):
|
|
cls._class_prefixes.extend([v.__name__ for v in
|
|
registered_dict.values()])
|
|
|
|
|
|
def obj_python_attrs(msg_):
|
|
"""iterate object attributes for stringify purposes
|
|
"""
|
|
|
|
# a special case for namedtuple which seems widely used in
|
|
# ofp parser implementations.
|
|
if hasattr(msg_, '_fields'):
|
|
for k in msg_._fields:
|
|
yield(k, getattr(msg_, k))
|
|
return
|
|
base = getattr(msg_, '_base_attributes', [])
|
|
for k, v in inspect.getmembers(msg_):
|
|
if k.startswith('_'):
|
|
continue
|
|
if callable(v):
|
|
continue
|
|
if k in base:
|
|
continue
|
|
if hasattr(msg_.__class__, k):
|
|
continue
|
|
yield (k, v)
|
|
|
|
|
|
def obj_attrs(msg_):
|
|
"""similar to obj_python_attrs() but deals with python reserved keywords
|
|
"""
|
|
|
|
if isinstance(msg_, StringifyMixin):
|
|
iter = msg_.stringify_attrs()
|
|
else:
|
|
# probably called by msg_str_attr
|
|
iter = obj_python_attrs(msg_)
|
|
for k, v in iter:
|
|
if k.endswith('_') and k[:-1] in _RESERVED_KEYWORD:
|
|
# XXX currently only StringifyMixin has restoring logic
|
|
assert isinstance(msg_, StringifyMixin)
|
|
k = k[:-1]
|
|
yield (k, v)
|