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 netutils 17 18 import ( 19 "crypto/sha256" 20 "fmt" 21 "log" 22 ) 23 24 // CompressName compresses name to targetLength with specified postfix 25 // targetLength < 7 or targetLength-7-len(namePostFix) < 0 are not allowed 26 func CompressName(originalName string, targetLength int, namePostFix string) (name string) { 27 if targetLength < 7 { 28 log.Fatal("targetLength shouldn't be less than 7") 29 } 30 if targetLength-7-len(namePostFix) < 0 { 31 log.Fatalf("namePostFix longer than (targetLength-7) = %d: %s", targetLength-7, namePostFix) 32 } 33 34 if len(originalName) < 6 { 35 // len(originalName) < 6 && 7 + len(namePostFix) < targetlength 36 // => 1 + len(originalName) + len(namePostFix) < targetLength 37 name = originalName + "_" + namePostFix 38 return 39 } 40 41 namePrefix := originalName[0:5] 42 nameRest := originalName[5:] 43 44 hasher := sha256.New() 45 hasher.Write([]byte(nameRest)) 46 hashValue := fmt.Sprintf("%x", hasher.Sum(nil)) 47 48 // keep the length does not exceed targetLength 49 name = namePrefix + "_" + hashValue[0:targetLength-7-len(namePostFix)] + "_" + namePostFix 50 51 return 52 } 53