Test Failed
Pull Request — master (#102)
by Carlos
02:20
created

build.flow.MatchBase.__init__()   B

Complexity

Conditions 1

Size

Total Lines 54
Code Lines 51

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 43
CRAP Score 1

Importance

Changes 0
Metric Value
eloc 51
dl 0
loc 54
ccs 43
cts 43
cp 1
rs 8.6036
c 0
b 0
f 0
cc 1
nop 41
crap 1

How to fix   Long Method    Many Parameters   

Long Method

Small methods make your code easier to understand, in particular if combined with a good name. Besides, if your method is small, finding a good name is usually much easier.

For example, if you find yourself adding comments to a method's body, this is usually a good sign to extract the commented part to a new method, and use the comment as a starting point when coming up with a good name for this new method.

Commonly applied refactorings include:

Many Parameters

Methods with many parameters are not only hard to understand, but their parameters also often become inconsistent when you need more, or different data.

There are several approaches to avoid long parameter lists:

1
"""High-level abstraction for Flows of multiple OpenFlow versions.
2
3
Use common fields of FlowStats/FlowMod of supported OF versions. ``match`` and
4
``actions`` fields are different, so Flow, Action and Match related classes are
5
inherited in v0x01 and v0x04 modules.
6
"""
7 1
import json
8 1
from abc import ABC, abstractmethod
9 1
from hashlib import md5
10
11
# Note: FlowModCommand is the same in both v0x01 and v0x04
12 1
from pyof.v0x04.controller2switch.flow_mod import FlowModCommand
13
14 1
from napps.kytos.of_core import v0x01, v0x04
15
16
17 1
class FlowFactory(ABC):  # pylint: disable=too-few-public-methods
18
    """Choose the correct Flow according to OpenFlow version."""
19
20 1
    @classmethod
21
    def from_of_flow_stats(cls, of_flow_stats, switch):
22
        """Return a Flow for the switch OpenFlow version."""
23 1
        flow_class = cls.get_class(switch)
24 1
        return flow_class.from_of_flow_stats(of_flow_stats, switch)
25
26 1
    @staticmethod
27
    def get_class(switch):
28
        """Return the Flow class for the switch OF version."""
29 1
        of_version = switch.connection.protocol.version
30 1
        if of_version == 0x01:
31 1
            return v0x01.flow.Flow
32 1
        if of_version == 0x04:
33 1
            return v0x04.flow.Flow
34
        raise NotImplementedError(f'Unsupported OpenFlow version {of_version}')
35
36
37 1
class FlowBase(ABC):  # pylint: disable=too-many-instance-attributes
38
    """Class to abstract a Flow to switches.
39
40
    This class represents a Flow installed or to be installed inside the
41
    switch. A flow, in this case is represented by a Match object and a set of
42
    actions that should occur in case any match happen.
43
    """
44
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    # of_version number: 0x01, 0x04
46 1
    of_version = None
47
48
    # Subclasses must set their version-specific classes
49 1
    _action_factory = None
50 1
    _flow_mod_class = None
51 1
    _match_class = None
52
53 1
    def __init__(self, switch, table_id=0xff, match=None, priority=0x8000,
54
                 idle_timeout=0, hard_timeout=0, cookie=0, actions=None,
55
                 stats=None):
56
        """Assign parameters to attributes.
57
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        Args:
59
            switch (kytos.core.switch.Switch): Switch ID is used to uniquely
60
                identify a flow.
61
            table_id (int): The index of a single table or 0xff for all tables.
62
            match (|match|): Match object.
63
            priority (int): Priority level of flow entry.
64
            idle_timeout (int): Idle time before discarding, in seconds.
65
            hard_timeout (int): Max time before discarding, in seconds.
66
            cookie (int): Opaque controller-issued identifier.
67
            actions (|list_of_actions|): List of actions to apply.
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            stats (Stats): Latest flow statistics.
69
        """
70
        # pylint: disable=too-many-arguments,too-many-locals
71 1
        self.switch = switch
72 1
        self.table_id = table_id
73
        # Disable not-callable error as subclasses set a class
74 1
        self.match = match or self._match_class()  # pylint: disable=E1102
75 1
        self.priority = priority
76 1
        self.idle_timeout = idle_timeout
77 1
        self.hard_timeout = hard_timeout
78 1
        self.cookie = cookie
79 1
        self.actions = actions or []
80 1
        self.stats = stats or FlowStats()  # pylint: disable=E1102
81
82 1
    @property
83
    def id(self):  # pylint: disable=invalid-name
84
        """Return this flow unique identifier.
85
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        Calculate an md5 hash based on this object's modified json string. The
87
        json for ID calculation excludes ``stats`` attribute that changes over
88
        time.
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        Returns:
91
            str: Flow unique identifier (md5sum).
92
93
        """
94 1
        flow_str = self.as_json(sort_keys=True, include_id=False)
95 1
        md5sum = md5()
96 1
        md5sum.update(flow_str.encode('utf-8'))
97 1
        return md5sum.hexdigest()
98
99 1
    def as_dict(self, include_id=True):
100
        """Return the Flow as a serializable Python dictionary.
101
102
        Args:
103
            include_id (bool): Default is ``True``. Internally, it is set to
104
                ``False`` when calculating the flow ID that is based in this
105
                dictionary's JSON string.
106
107
        Returns:
108
            dict: Serializable dictionary.
109
110
        """
111 1
        flow_dict = {
112
            'switch': self.switch.id,
113
            'table_id': self.table_id,
114
            'match': self.match.as_dict(),
115
            'priority': self.priority,
116
            'idle_timeout': self.idle_timeout,
117
            'hard_timeout': self.hard_timeout,
118
            'cookie': self.cookie,
119
            'actions': [action.as_dict() for action in self.actions]}
120 1
        if include_id:
121
            # Avoid infinite recursion
122 1
            flow_dict['id'] = self.id
123
            # Remove statistics that change over time
124 1
            flow_dict['stats'] = self.stats.as_dict()
125
126 1
        return flow_dict
127
128 1
    @classmethod
129
    def from_dict(cls, flow_dict, switch):
130
        """Return an instance with values from ``flow_dict``."""
131 1
        flow = cls(switch)
132
133
        # Set attributes found in ``flow_dict``
134 1
        for attr_name, attr_value in flow_dict.items():
135 1
            if attr_name in vars(flow):
136 1
                setattr(flow, attr_name, attr_value)
137
138 1
        flow.switch = switch
139 1
        if 'stats' in flow_dict:
140 1
            flow.stats = FlowStats.from_dict(flow_dict['stats'])
141
142
        # Version-specific attributes
143 1
        if 'match' in flow_dict:
144 1
            flow.match = cls._match_class.from_dict(flow_dict['match'])
145 1
        if 'actions' in flow_dict:
146 1
            flow.actions = []
147 1
            for action_dict in flow_dict['actions']:
148 1
                action = cls._action_factory.from_dict(action_dict)
149 1
                if action:
150 1
                    flow.actions.append(action)
151
152 1
        return flow
153
154 1
    def as_json(self, sort_keys=False, include_id=True):
155
        """Return the representation of a flow in JSON format.
156
157
        Args:
158
            sort_keys (bool): ``False`` by default (Python's default). Sorting
159
                is used, for example, to calculate the flow ID.
160
            include_id (bool): ``True`` by default. Internally, the ID is not
161
                included while calculating it.
162
163
        Returns:
164
            string: Flow JSON string representation.
165
166
        """
167 1
        return json.dumps(self.as_dict(include_id), sort_keys=sort_keys)
168
169 1
    def as_of_add_flow_mod(self):
170
        """Return an OpenFlow add FlowMod."""
171 1
        return self._as_of_flow_mod(FlowModCommand.OFPFC_ADD)
172
173 1
    def as_of_delete_flow_mod(self):
174
        """Return an OpenFlow delete FlowMod."""
175 1
        return self._as_of_flow_mod(FlowModCommand.OFPFC_DELETE)
176
177 1
    @abstractmethod
178
    def _as_of_flow_mod(self, command):
179
        """Return a pyof FlowMod with given ``command``."""
180
        # Disable not-callable error as subclasses will set a class
181 1
        flow_mod = self._flow_mod_class()  # pylint: disable=E1102
182 1
        flow_mod.match = self.match.as_of_match()
183 1
        flow_mod.cookie = self.cookie
184 1
        flow_mod.command = command
185 1
        flow_mod.idle_timeout = self.idle_timeout
186 1
        flow_mod.hard_timeout = self.hard_timeout
187 1
        flow_mod.priority = self.priority
188 1
        return flow_mod
189
190 1
    @staticmethod
191 1
    @abstractmethod
192
    def _get_of_actions(of_flow_stats):
193
        """Return pyof actions from pyof FlowStats."""
194
195 1
    @classmethod
196
    def from_of_flow_stats(cls, of_flow_stats, switch):
197
        """Create a flow with latest stats based on pyof FlowStats."""
198
        of_actions = cls._get_of_actions(of_flow_stats)
199
        actions = (cls._action_factory.from_of_action(of_action)
0 ignored issues
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Comprehensibility Best Practice introduced by
The variable of_action does not seem to be defined.
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200
                   for of_action in of_actions)
201
        non_none_actions = [action for action in actions if action]
202
        return cls(switch,
203
                   table_id=of_flow_stats.table_id.value,
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                   match=cls._match_class.from_of_match(of_flow_stats.match),
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                   priority=of_flow_stats.priority.value,
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                   idle_timeout=of_flow_stats.idle_timeout.value,
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                   hard_timeout=of_flow_stats.hard_timeout.value,
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                   cookie=of_flow_stats.cookie.value,
209
                   actions=non_none_actions,
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                   stats=FlowStats.from_of_flow_stats(of_flow_stats))
211
212
    def __eq__(self, other):
213 1
        if not isinstance(other, self.__class__):
214
            raise ValueError(f'Error comparing flows: {other} is not '
215
                             f'an instance of {self.__class__}')
216 1
217
        return self.as_dict(include_id=False) == other.as_dict(include_id=False)
218 1
219
220 1
class ActionBase(ABC):
221
    """Base class for a flow action."""
222
223 1
    def as_dict(self):
224 1
        """Return a dict that can be dumped as JSON."""
225 1
        return vars(self)
226 1
227 1
    @classmethod
228
    def from_dict(cls, action_dict):
229 1
        """Return an action instance from attributes in a dictionary."""
230
        action = cls(None)
231
        for attr_name, value in action_dict.items():
232
            if hasattr(action, attr_name):
233 1
                setattr(action, attr_name, value)
234 1
        return action
235
236
    @abstractmethod
237
    def as_of_action(self):
238
        """Return a pyof action to be used by a FlowMod."""
239 1
240
    @classmethod
241
    @abstractmethod
242
    def from_of_action(cls, of_action):
243 1
        """Return an action from a pyof action."""
244
245
246
class ActionFactoryBase(ABC):
247
    """Deal with different implementations of ActionBase."""
248
249 1
    # key: action_type or pyof class, value: ActionBase child
250
    _action_class = {
251
        'output': None,
252
        'set_vlan': None,
253
        # pyof class: ActionBase child
254
    }
255
256 1
    @classmethod
257 1
    def from_dict(cls, action_dict):
258 1
        """Build the proper Action from a dictionary.
259
260 1
        Args:
261
            action_dict (dict): Action attributes.
262
        """
263
        action_type = action_dict.get('action_type')
264
        action_class = cls._action_class[action_type]
265
        return action_class.from_dict(action_dict) if action_class else None
266
267
    @classmethod
268
    def from_of_action(cls, of_action):
269
        """Build the proper Action from a pyof action.
270
271
        Args:
272 1
            of_action (pyof action): Action from python-openflow.
273
        """
274
        of_class = type(of_action)
275 1
        action_class = cls._action_class.get(of_class)
276
        return action_class.from_of_action(of_action) if action_class else None
277
278
279
class MatchBase:  # pylint: disable=too-many-instance-attributes
280
    """Base class with common high-level Match fields."""
281
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    def __init__(self, in_port=None, dl_src=None, dl_dst=None, dl_vlan=None,
283
                 dl_vlan_pcp=None, dl_type=None, nw_proto=None, nw_src=None,
284
                 nw_dst=None, tp_src=None, tp_dst=None, in_phy_port=None,
285
                 ip_dscp=None, ip_ecn=None, udp_src=None, udp_dst=None,
286
                 sctp_src=None, sctp_dst=None, icmpv4_type=None,
287
                 icmpv4_code=None, arp_op=None, arp_spa=None, arp_tpa=None,
288
                 arp_sha=None, arp_tha=None, ipv6_src=None, ipv6_dst=None,
289 1
                 ipv6_flabel=None, icmpv6_type=None, icmpv6_code=None,
290 1
                 nd_tar=None, nd_sll=None, nd_tll=None, mpls_lab=None,
291 1
                 mpls_tc=None, mpls_bos=None, pbb_isid=None, v6_hdr=None,
292 1
                 metadata=None, tun_id=None):
293 1
        """Make it possible to set all attributes from the constructor."""
294 1
        # pylint: disable=too-many-arguments
295 1
        # pylint: disable=too-many-locals
296 1
        self.in_port = in_port
297 1
        self.dl_src = dl_src
298 1
        self.dl_dst = dl_dst
299 1
        self.dl_vlan = dl_vlan
300 1
        self.dl_vlan_pcp = dl_vlan_pcp
301 1
        self.dl_type = dl_type
302 1
        self.nw_proto = nw_proto
303 1
        self.nw_src = nw_src
304 1
        self.nw_dst = nw_dst
305 1
        self.tp_src = tp_src
306 1
        self.tp_dst = tp_dst
307 1
        self.in_phy_port = in_phy_port
308 1
        self.ip_dscp = ip_dscp
309 1
        self.ip_ecn = ip_ecn
310 1
        self.udp_src = udp_src
311 1
        self.udp_dst = udp_dst
312 1
        self.sctp_src = sctp_src
313 1
        self.sctp_dst = sctp_dst
314 1
        self.icmpv4_type = icmpv4_type
315 1
        self.icmpv4_code = icmpv4_code
316 1
        self.arp_op = arp_op
317 1
        self.arp_spa = arp_spa
318 1
        self.arp_tpa = arp_tpa
319 1
        self.arp_sha = arp_sha
320 1
        self.arp_tha = arp_tha
321 1
        self.ipv6_src = ipv6_src
322 1
        self.ipv6_dst = ipv6_dst
323 1
        self.ipv6_flabel = ipv6_flabel
324 1
        self.icmpv6_type = icmpv6_type
325 1
        self.icmpv6_code = icmpv6_code
326 1
        self.nd_tar = nd_tar
327 1
        self.nd_sll = nd_sll
328 1
        self.nd_tll = nd_tll
329
        self.mpls_lab = mpls_lab
330 1
        self.mpls_tc = mpls_tc
331
        self.mpls_bos = mpls_bos
332 1
        self.pbb_isid = pbb_isid
333
        self.v6_hdr = v6_hdr
334 1
        self.metadata = metadata
335
        self.tun_id = tun_id
336
337 1
    def as_dict(self):
338 1
        """Return a dictionary excluding ``None`` values."""
339 1
        return {k: v for k, v in self.__dict__.items() if v is not None}
340 1
341 1
    @classmethod
342
    def from_dict(cls, match_dict):
343 1
        """Return a Match instance from a dictionary."""
344 1
        match = cls()
345
        for key, value in match_dict.items():
346
            if key in match.__dict__:
347
                setattr(match, key, value)
348 1
        return match
349
350
    @classmethod
351
    @abstractmethod
352
    def from_of_match(cls, of_match):
353 1
        """Return a Match instance from a pyof Match."""
354
355
    @abstractmethod
356 1
    def as_of_match(self):
357
        """Return a python-openflow Match."""
358 1
359
360
class Stats:
361
    """Simple class to store statistics as attributes and values."""
362 1
363
    def as_dict(self):
364
        """Return a dict excluding attributes with ``None`` value."""
365 1
        return {attribute: value
366 1
                for attribute, value in vars(self).items()
367 1
                if value is not None}
368
369 1
    @classmethod
370
    def from_dict(cls, stats_dict):
371
        """Return a statistics object from a dictionary."""
372
        stats = cls()
373
        cls._update(stats, stats_dict.items())
374
        return stats
375
376 1
    @classmethod
377
    def from_of_flow_stats(cls, of_stats):
378
        """Create an instance from a pyof FlowStats."""
379
        stats = cls()
380
        stats.update(of_stats)
381
        return stats
382
383
    def update(self, of_stats):
384
        """Given a pyof stats object, update attributes' values.
385
386
        Avoid object creation and memory leak. pyof values are GenericType
387
        instances whose native values can be accessed by `.value`.
388 1
        """
389
        # Generator for GenericType values
390
        attr_name_value = ((attr_name, gen_type.value)
0 ignored issues
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Comprehensibility Best Practice introduced by
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Comprehensibility Best Practice introduced by
The variable attr_name does not seem to be defined.
Loading history...
391 1
                           for attr_name, gen_type in vars(of_stats).items()
392
                           if attr_name in vars(self))
393
        self._update(self, attr_name_value)
394
395
    @staticmethod
396 1
    def _update(obj, iterable):
397
        """From attribute name and value pairs, update ``obj``."""
398
        for attr_name, value in iterable:
399 1
            if hasattr(obj, attr_name):
400
                setattr(obj, attr_name, value)
401 1
402 1
403 1
class FlowStats(Stats):
404 1
    """Common fields for 1.0 and 1.3 FlowStats."""
405
406
    def __init__(self):
407 1
        """Initialize all statistics as ``None``."""
408
        self.byte_count = None
409
        self.duration_sec = None
410 1
        self.duration_nsec = None
411
        self.packet_count = None
412
413
414
class PortStats(Stats):  # pylint: disable=too-many-instance-attributes
415
    """Common fields for 1.0 and 1.3 PortStats."""
416
417
    def __init__(self):
418
        """Initialize all statistics as ``None``."""
419
        self.rx_packets = None
420
        self.tx_packets = None
421
        self.rx_bytes = None
422
        self.tx_bytes = None
423
        self.rx_dropped = None
424
        self.tx_dropped = None
425
        self.rx_errors = None
426
        self.tx_errors = None
427
        self.rx_frame_err = None
428
        self.rx_over_err = None
429
        self.rx_crc_err = None
430
        self.collisions = None
431