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