utils.go

Documentation: github.com/chaos-mesh/chaos-mesh/pkg/chaosdaemon/netem

     1  // Copyright 2021 Chaos Mesh Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  // http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  //
    15  
    16  package netem
    17  
    18  import (
    19  	"math"
    20  	"strconv"
    21  	"strings"
    22  
    23  	chaosdaemon "github.com/chaos-mesh/chaos-mesh/pkg/chaosdaemon/pb"
    24  )
    25  
    26  // MergeNetem merges two Netem protos into a new one.
    27  // REMEMBER to assign the return value, i.e. merged = utils.MergeNetm(merged, em)
    28  // For each field it takes the bigger value of the two.
    29  // Its main use case is merging netem of different types, e.g. delay and loss.
    30  // It returns nil if both inputs are nil.
    31  // Otherwise it returns a new Netem with merged values.
    32  func MergeNetem(a, b *chaosdaemon.Netem) *chaosdaemon.Netem {
    33  	if a == nil && b == nil {
    34  		return nil
    35  	}
    36  	// NOTE: because proto getters check nil, we are good here even if one of them is nil.
    37  	// But we just assign empty value to make IDE and linters happy.
    38  	if a == nil {
    39  		a = &chaosdaemon.Netem{}
    40  	}
    41  	if b == nil {
    42  		b = &chaosdaemon.Netem{}
    43  	}
    44  	return &chaosdaemon.Netem{
    45  		Time:          maxu32(a.GetTime(), b.GetTime()),
    46  		Jitter:        maxu32(a.GetJitter(), b.GetJitter()),
    47  		DelayCorr:     maxf32(a.GetDelayCorr(), b.GetDelayCorr()),
    48  		Limit:         maxu32(a.GetLimit(), b.GetLimit()),
    49  		Loss:          maxf32(a.GetLoss(), b.GetLoss()),
    50  		LossCorr:      maxf32(a.GetLossCorr(), b.GetLossCorr()),
    51  		Gap:           maxu32(a.GetGap(), b.GetGap()),
    52  		Duplicate:     maxf32(a.GetDuplicate(), b.GetDuplicate()),
    53  		DuplicateCorr: maxf32(a.GetDuplicateCorr(), b.GetDuplicateCorr()),
    54  		Reorder:       maxf32(a.GetReorder(), b.GetReorder()),
    55  		ReorderCorr:   maxf32(a.GetReorderCorr(), b.GetReorderCorr()),
    56  		Corrupt:       maxf32(a.GetCorrupt(), b.GetCorrupt()),
    57  		CorruptCorr:   maxf32(a.GetCorruptCorr(), b.GetCorruptCorr()),
    58  		Rate:          maxRateString(a.GetRate(), b.GetRate()),
    59  	}
    60  }
    61  
    62  func maxu32(a, b uint32) uint32 {
    63  	if a > b {
    64  		return a
    65  	}
    66  	return b
    67  }
    68  
    69  func maxf32(a, b float32) float32 {
    70  	return float32(math.Max(float64(a), float64(b)))
    71  }
    72  
    73  func parseRate(nu string) uint64 {
    74  	// normalize input
    75  	s := strings.ToLower(strings.TrimSpace(nu))
    76  
    77  	for i, u := range []string{"tbps", "gbps", "mbps", "kbps", "bps"} {
    78  		if strings.HasSuffix(s, u) {
    79  			ts := strings.TrimSuffix(s, u)
    80  			s := strings.TrimSpace(ts)
    81  
    82  			n, err := strconv.ParseUint(s, 10, 64)
    83  
    84  			if err != nil {
    85  				return 0
    86  			}
    87  
    88  			// convert unit to bytes
    89  			for j := 4 - i; j > 0; j-- {
    90  				n = n * 1024
    91  			}
    92  
    93  			return n
    94  		}
    95  	}
    96  
    97  	for i, u := range []string{"tbit", "gbit", "mbit", "kbit", "bit"} {
    98  		if strings.HasSuffix(s, u) {
    99  			ts := strings.TrimSuffix(s, u)
   100  			s := strings.TrimSpace(ts)
   101  
   102  			n, err := strconv.ParseUint(s, 10, 64)
   103  
   104  			if err != nil {
   105  				return 0
   106  			}
   107  
   108  			// convert unit to bytes
   109  			for j := 4 - i; j > 0; j-- {
   110  				n = n * 1000
   111  			}
   112  			n = n / 8
   113  
   114  			return n
   115  		}
   116  	}
   117  
   118  	return 0
   119  }
   120  
   121  func maxRateString(a, b string) string {
   122  	if parseRate(a) > parseRate(b) {
   123  		return a
   124  	}
   125  	return b
   126  }
   127