1 // Copyright (c) 2017 Uber Technologies, Inc. 2 // 3 // Permission is hereby granted, free of charge, to any person obtaining a copy 4 // of this software and associated documentation files (the "Software"), to deal 5 // in the Software without restriction, including without limitation the rights 6 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 7 // copies of the Software, and to permit persons to whom the Software is 8 // furnished to do so, subject to the following conditions: 9 // 10 // The above copyright notice and this permission notice shall be included in 11 // all copies or substantial portions of the Software. 12 // 13 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 14 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 15 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 16 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 17 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 18 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 19 // THE SOFTWARE. 20 21 package zapcore 22 23 import ( 24 "fmt" 25 "reflect" 26 27 "go.uber.org/zap/internal/pool" 28 ) 29 30 // Encodes the given error into fields of an object. A field with the given 31 // name is added for the error message. 32 // 33 // If the error implements fmt.Formatter, a field with the name ${key}Verbose 34 // is also added with the full verbose error message. 35 // 36 // Finally, if the error implements errorGroup (from go.uber.org/multierr) or 37 // causer (from github.com/pkg/errors), a ${key}Causes field is added with an 38 // array of objects containing the errors this error was comprised of. 39 // 40 // { 41 // "error": err.Error(), 42 // "errorVerbose": fmt.Sprintf("%+v", err), 43 // "errorCauses": [ 44 // ... 45 // ], 46 // } 47 func encodeError(key string, err error, enc ObjectEncoder) (retErr error) { 48 // Try to capture panics (from nil references or otherwise) when calling 49 // the Error() method 50 defer func() { 51 if rerr := recover(); rerr != nil { 52 // If it's a nil pointer, just say "<nil>". The likeliest causes are a 53 // error that fails to guard against nil or a nil pointer for a 54 // value receiver, and in either case, "<nil>" is a nice result. 55 if v := reflect.ValueOf(err); v.Kind() == reflect.Ptr && v.IsNil() { 56 enc.AddString(key, "<nil>") 57 return 58 } 59 60 retErr = fmt.Errorf("PANIC=%v", rerr) 61 } 62 }() 63 64 basic := err.Error() 65 enc.AddString(key, basic) 66 67 switch e := err.(type) { 68 case errorGroup: 69 return enc.AddArray(key+"Causes", errArray(e.Errors())) 70 case fmt.Formatter: 71 verbose := fmt.Sprintf("%+v", e) 72 if verbose != basic { 73 // This is a rich error type, like those produced by 74 // github.com/pkg/errors. 75 enc.AddString(key+"Verbose", verbose) 76 } 77 } 78 return nil 79 } 80 81 type errorGroup interface { 82 // Provides read-only access to the underlying list of errors, preferably 83 // without causing any allocs. 84 Errors() []error 85 } 86 87 // Note that errArray and errArrayElem are very similar to the version 88 // implemented in the top-level error.go file. We can't re-use this because 89 // that would require exporting errArray as part of the zapcore API. 90 91 // Encodes a list of errors using the standard error encoding logic. 92 type errArray []error 93 94 func (errs errArray) MarshalLogArray(arr ArrayEncoder) error { 95 for i := range errs { 96 if errs[i] == nil { 97 continue 98 } 99 100 el := newErrArrayElem(errs[i]) 101 err := arr.AppendObject(el) 102 el.Free() 103 if err != nil { 104 return err 105 } 106 } 107 return nil 108 } 109 110 var _errArrayElemPool = pool.New(func() *errArrayElem { 111 return &errArrayElem{} 112 }) 113 114 // Encodes any error into a {"error": ...} re-using the same errors logic. 115 // 116 // May be passed in place of an array to build a single-element array. 117 type errArrayElem struct{ err error } 118 119 func newErrArrayElem(err error) *errArrayElem { 120 e := _errArrayElemPool.Get() 121 e.err = err 122 return e 123 } 124 125 func (e *errArrayElem) MarshalLogArray(arr ArrayEncoder) error { 126 return arr.AppendObject(e) 127 } 128 129 func (e *errArrayElem) MarshalLogObject(enc ObjectEncoder) error { 130 return encodeError("error", e.err, enc) 131 } 132 133 func (e *errArrayElem) Free() { 134 e.err = nil 135 _errArrayElemPool.Put(e) 136 } 137