1 # Copyright (c) 2021 Cisco and/or its affiliates.
2 # Licensed under the Apache License, Version 2.0 (the "License");
3 # you may not use this file except in compliance with the License.
4 # You may obtain a copy of the License at:
6 # http://www.apache.org/licenses/LICENSE-2.0
8 # Unless required by applicable law or agreed to in writing, software
9 # distributed under the License is distributed on an "AS IS" BASIS,
10 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11 # See the License for the specific language governing permissions and
12 # limitations under the License.
14 """Module defining ReceiveRateMeasurement class."""
17 class ReceiveRateMeasurement:
18 """Structure defining the result of single Rr measurement."""
21 self, duration, target_tr, transmit_count, loss_count,
22 approximated_duration=0.0, partial_transmit_count=0,
23 effective_loss_ratio=None):
24 """Constructor, normalize primary and compute secondary quantities.
26 If approximated_duration is nonzero, it is stored.
27 If approximated_duration is zero, duration value is stored.
28 Either way, additional secondary quantities are computed
31 If there is zero transmit_count, ratios are set to zero.
33 In some cases, traffic generator does not attempt all the needed
34 transactions. In that case, nonzero partial_transmit_count
35 holds (an estimate of) count of the actually attempted transactions.
36 This is used to populate some secondary quantities.
38 TODO: Use None instead of zero?
40 Field effective_loss_ratio is specific for use in MLRsearch,
41 where measurements with lower loss ratio at higher target_tr
42 cannot be relied upon if there is a measurement with higher loss ratio
43 at lower target_tr. In this case, the higher loss ratio from
44 other measurement is stored as effective loss ratio in this measurement.
45 If None, the computed loss ratio of this measurement is used.
46 If not None, the computed ratio can still be apllied if it is larger.
48 :param duration: Measurement duration [s].
49 :param target_tr: Target transmit rate [pps].
50 If bidirectional traffic is measured, this is bidirectional rate.
51 :param transmit_count: Number of packets transmitted [1].
52 :param loss_count: Number of packets transmitted but not received [1].
53 :param approximated_duration: Estimate of the actual time of the trial.
54 :param partial_transmit_count: Estimate count of actually attempted
56 :param effective_loss_ratio: None or highest loss ratio so far.
58 :type target_tr: float
59 :type transmit_count: int
61 :type approximated_duration: float
62 :type partial_transmit_count: int
64 self.duration = float(duration)
65 self.target_tr = float(target_tr)
66 self.transmit_count = int(transmit_count)
67 self.loss_count = int(loss_count)
68 self.receive_count = transmit_count - loss_count
69 self.transmit_rate = transmit_count / self.duration
70 self.loss_rate = loss_count / self.duration
71 self.receive_rate = self.receive_count / self.duration
73 float(self.loss_count) / self.transmit_count
74 if self.transmit_count > 0 else 1.0
76 self.effective_loss_ratio = self.loss_ratio
77 if effective_loss_ratio is not None:
78 if effective_loss_ratio > self.loss_ratio:
79 self.effective_loss_ratio = float(effective_loss_ratio)
80 self.receive_ratio = (
81 float(self.receive_count) / self.transmit_count
82 if self.transmit_count > 0 else 0.0
84 self.approximated_duration = (
85 float(approximated_duration) if approximated_duration
88 self.approximated_receive_rate = (
89 self.receive_count / self.approximated_duration
90 if self.approximated_duration > 0.0 else 0.0
92 # If the traffic generator is unreliable and sends less packets,
93 # the absolute receive rate might be too low for next target.
94 self.partial_transmit_count = (
95 int(partial_transmit_count) if partial_transmit_count
96 else self.transmit_count
98 self.partial_receive_ratio = (
99 float(self.receive_count) / self.partial_transmit_count
100 if self.partial_transmit_count > 0 else 0.0
102 self.partial_receive_rate = (
103 self.target_tr * self.partial_receive_ratio
105 # We use relative packet ratios in order to support cases
106 # where target_tr is in transactions per second,
107 # but there are multiple packets per transaction.
108 self.relative_receive_rate = (
109 self.target_tr * self.receive_count / self.transmit_count
113 """Return string reporting input and loss ratio."""
114 return f"d={self.duration!s},Tr={self.target_tr!s}," \
115 f"Df={self.loss_ratio!s}"
118 """Return string evaluable as a constructor call."""
119 return f"ReceiveRateMeasurement(duration={self.duration!r}," \
120 f"target_tr={self.target_tr!r}," \
121 f"transmit_count={self.transmit_count!r}," \
122 f"loss_count={self.loss_count!r}," \
123 f"approximated_duration={self.approximated_duration!r}," \
124 f"partial_transmit_count={self.partial_transmit_count!r}," \
125 f"effective_loss_ratio={self.effective_loss_ratio!r})"