| 1 | // SPDX-License-Identifier: GPL-3.0-or-later |
| 2 | |
| 3 | package pinger |
| 4 | |
| 5 | import ( |
| 6 | "time" |
| 7 | |
| 8 | probing "github.com/prometheus-community/pro-bing" |
| 9 | ) |
| 10 | |
| 11 | func deriveSample(host string, stats *probing.Statistics, track bool, states *stateStore, cfg AnalysisConfig) Sample { |
| 12 | sample := Sample{ |
| 13 | Host: host, |
| 14 | PacketsSent: int64(stats.PacketsSent), |
| 15 | PacketsRecv: int64(stats.PacketsRecv), |
| 16 | PacketLossPct: stats.PacketLoss, |
| 17 | RTT: deriveRTT(stats), |
| 18 | } |
| 19 | |
| 20 | sample.Jitter = deriveJitter(host, stats, track, states, cfg) |
| 21 | |
| 22 | return sample |
| 23 | } |
| 24 | |
| 25 | func deriveRTT(stats *probing.Statistics) RTTSummary { |
| 26 | if stats.PacketsRecv == 0 { |
| 27 | return RTTSummary{} |
| 28 | } |
| 29 | |
| 30 | return RTTSummary{ |
| 31 | Valid: true, |
| 32 | Min: stats.MinRtt, |
| 33 | Max: stats.MaxRtt, |
| 34 | Avg: stats.AvgRtt, |
| 35 | StdDev: stats.StdDevRtt, |
| 36 | } |
| 37 | } |
| 38 | |
| 39 | func deriveJitter(host string, stats *probing.Statistics, track bool, states *stateStore, cfg AnalysisConfig) JitterSummary { |
| 40 | if len(stats.Rtts) < 2 { |
| 41 | return JitterSummary{} |
| 42 | } |
| 43 | |
| 44 | mean := calcMeanJitter(stats.Rtts) |
| 45 | js := JitterSummary{ |
| 46 | InstantValid: true, |
| 47 | Mean: mean, |
| 48 | } |
| 49 | |
| 50 | if !track { |
| 51 | return js |
| 52 | } |
| 53 | |
| 54 | ewma, sma := states.update(host, mean, cfg) |
| 55 | js.SmoothedValid = true |
| 56 | js.EWMA = ewma |
| 57 | js.SMA = sma |
| 58 | |
| 59 | return js |
| 60 | } |
| 61 | |
| 62 | func calcMeanJitter(rtts []time.Duration) time.Duration { |
| 63 | if len(rtts) < 2 { |
| 64 | return 0 |
| 65 | } |
| 66 | |
| 67 | var sum int64 |
| 68 | for i := 1; i < len(rtts); i++ { |
| 69 | diff := rtts[i] - rtts[i-1] |
| 70 | if diff < 0 { |
| 71 | diff = -diff |
| 72 | } |
| 73 | sum += int64(diff) |
| 74 | } |
| 75 | |
| 76 | return time.Duration(sum / int64(len(rtts)-1)) |
| 77 | } |