istio.io/istio@v0.0.0-20240520182934-d79c90f27776/operator/pkg/util/errs.go (about) 1 // Copyright Istio 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 package util 16 17 import ( 18 "fmt" 19 ) 20 21 const ( 22 defaultSeparator = ", " 23 ) 24 25 // Errors is a slice of error. 26 type Errors []error 27 28 // Error implements the error#Error method. 29 func (e Errors) Error() string { 30 return ToString(e, defaultSeparator) 31 } 32 33 // String implements the stringer#String method. 34 func (e Errors) String() string { 35 return e.Error() 36 } 37 38 // ToError returns an error from Errors. 39 func (e Errors) ToError() error { 40 if len(e) == 0 { 41 return nil 42 } 43 return fmt.Errorf("%s", e) 44 } 45 46 // Dedup removes any duplicated errors. 47 func (e Errors) Dedup() Errors { 48 logCountMap := make(map[string]int) 49 for _, ee := range e { 50 if ee == nil { 51 continue 52 } 53 item := ee.Error() 54 _, exist := logCountMap[item] 55 if exist { 56 logCountMap[item]++ 57 } else { 58 logCountMap[item] = 1 59 } 60 } 61 var out Errors 62 for _, ee := range e { 63 item := ee.Error() 64 count := logCountMap[item] 65 if count == 0 { 66 continue 67 } 68 times := "" 69 if count > 1 { 70 times = fmt.Sprintf(" (repeated %d times)", count) 71 } 72 out = AppendErr(out, fmt.Errorf("%s%s", ee, times)) 73 // reset seen log count 74 logCountMap[item] = 0 75 } 76 return out 77 } 78 79 // NewErrs returns a slice of error with a single element err. 80 // If err is nil, returns nil. 81 func NewErrs(err error) Errors { 82 if err == nil { 83 return nil 84 } 85 return []error{err} 86 } 87 88 // AppendErr appends err to errors if it is not nil and returns the result. 89 // If err is nil, it is not appended. 90 func AppendErr(errors []error, err error) Errors { 91 if err == nil { 92 if len(errors) == 0 { 93 return nil 94 } 95 return errors 96 } 97 return append(errors, err) 98 } 99 100 // AppendErrs appends newErrs to errors and returns the result. 101 // If newErrs is empty, nothing is appended. 102 func AppendErrs(errors []error, newErrs []error) Errors { 103 if len(newErrs) == 0 { 104 return errors 105 } 106 for _, e := range newErrs { 107 errors = AppendErr(errors, e) 108 } 109 if len(errors) == 0 { 110 return nil 111 } 112 return errors 113 } 114 115 // ToString returns a string representation of errors, with elements separated by separator string. Any nil errors in the 116 // slice are skipped. 117 func ToString(errors []error, separator string) string { 118 var out string 119 for i, e := range errors { 120 if e == nil { 121 continue 122 } 123 if i != 0 { 124 out += separator 125 } 126 out += e.Error() 127 } 128 return out 129 } 130 131 // EqualErrors reports whether a and b are equal, regardless of ordering. 132 func EqualErrors(a, b Errors) bool { 133 if len(a) != len(b) { 134 return false 135 } 136 m := make(map[string]bool) 137 for _, e := range b { 138 m[e.Error()] = true 139 } 140 for _, ea := range a { 141 if !m[ea.Error()] { 142 return false 143 } 144 } 145 return true 146 }