pierventre | 8520818 | 2021-09-02 19:16:32 +0200 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2021-present Open Networking Foundation |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package org.onosproject.drivers.barefoot; |
| 18 | |
| 19 | import org.onosproject.drivers.p4runtime.P4RuntimeMeterProgrammable; |
| 20 | import org.onosproject.net.meter.MeterProgrammable; |
| 21 | import org.onosproject.net.pi.runtime.PiMeterBand; |
| 22 | import org.onosproject.net.pi.runtime.PiMeterCellConfig; |
| 23 | |
| 24 | /** |
| 25 | * Implementation of the MeterProgrammable behaviour for a Tofino-based switch. |
| 26 | */ |
| 27 | public class TofinoMeterProgrammable extends P4RuntimeMeterProgrammable implements MeterProgrammable { |
| 28 | // More insights for these magic numbers can be found in this doc |
| 29 | // https://docs.google.com/document/d/1Vuf_2RaO0BJPTj_weE9h2spUBCMsiBX-iIMb4OoEIB0/edit?usp=sharing |
| 30 | private static final double RATE_ERROR = 0.02; |
| 31 | private static final long BURST_LOWER_DIVIDER = 126; |
| 32 | private static final long BURST_UPPER_DIVIDER = 125; |
| 33 | private static final long BURST_MULTIPLIER = 125; |
| 34 | |
| 35 | @Override |
| 36 | public boolean isSimilar(PiMeterCellConfig onosMeter, PiMeterCellConfig deviceMeter) { |
| 37 | final PiMeterBand onosCommittedBand = onosMeter.committedBand(); |
| 38 | final PiMeterBand onosPeakBand = onosMeter.peakBand(); |
| 39 | final PiMeterBand deviceCommittedBand = deviceMeter.committedBand(); |
| 40 | final PiMeterBand devicePeakBand = deviceMeter.peakBand(); |
| 41 | final long onosCir = onosCommittedBand.rate(); |
| 42 | final long onosCburst = onosCommittedBand.burst(); |
| 43 | final long onosPir = onosPeakBand.rate(); |
| 44 | final long onosPburst = onosPeakBand.burst(); |
| 45 | final long deviceCir = deviceCommittedBand.rate(); |
| 46 | final long deviceCburst = deviceCommittedBand.burst(); |
| 47 | final long devicePir = devicePeakBand.rate(); |
| 48 | final long devicePburst = devicePeakBand.burst(); |
| 49 | |
| 50 | return isRateSimilar(onosCir, deviceCir) && isRateSimilar(onosPir, devicePir) && |
| 51 | isBurstSimilar(onosCburst, deviceCburst) && isBurstSimilar(onosPburst, devicePburst); |
| 52 | } |
| 53 | |
| 54 | // Verify if device rate is included in the confidence interval |
| 55 | // derived from the rate stored in ONOS |
| 56 | private boolean isRateSimilar(long onosRate, long deviceRate) { |
| 57 | double lowerEnd = (double) onosRate * (1.0 - RATE_ERROR); |
| 58 | double upperEnd = (double) onosRate * (1.0 + RATE_ERROR); |
| 59 | |
| 60 | if (log.isDebugEnabled()) { |
| 61 | log.debug("isRateSimilar {} in [{}, {}]", deviceRate, lowerEnd, upperEnd); |
| 62 | } |
| 63 | |
| 64 | return deviceRate >= lowerEnd && deviceRate <= upperEnd; |
| 65 | } |
| 66 | |
| 67 | // Verify if device burst is included in the confidence interval |
| 68 | // derived from the burst stored in ONOS |
| 69 | private boolean isBurstSimilar(long onosBurst, long deviceBurst) { |
| 70 | // Rundown removing the decimal part |
| 71 | long lowerEnd = (onosBurst / BURST_LOWER_DIVIDER) * BURST_MULTIPLIER; |
| 72 | long upperEnd = (onosBurst / BURST_UPPER_DIVIDER) * BURST_MULTIPLIER; |
| 73 | |
| 74 | if (log.isDebugEnabled()) { |
| 75 | log.debug("isBurstSimilar {} in [{}, {}]", deviceBurst, lowerEnd, upperEnd); |
| 76 | } |
| 77 | |
| 78 | return deviceBurst >= lowerEnd && deviceBurst <= upperEnd; |
| 79 | } |
| 80 | |
| 81 | } |