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
21package zap
22
23import (
24	"sync"
25
26	"go.uber.org/zap/zapcore"
27)
28
29var _errArrayElemPool = sync.Pool{New: func() interface{} {
30	return &errArrayElem{}
31}}
32
33// Error is shorthand for the common idiom NamedError("error", err).
34func Error(err error) Field {
35	return NamedError("error", err)
36}
37
38// NamedError constructs a field that lazily stores err.Error() under the
39// provided key. Errors which also implement fmt.Formatter (like those produced
40// by github.com/pkg/errors) will also have their verbose representation stored
41// under key+"Verbose". If passed a nil error, the field is a no-op.
42//
43// For the common case in which the key is simply "error", the Error function
44// is shorter and less repetitive.
45func NamedError(key string, err error) Field {
46	if err == nil {
47		return Skip()
48	}
49	return Field{Key: key, Type: zapcore.ErrorType, Interface: err}
50}
51
52type errArray []error
53
54func (errs errArray) MarshalLogArray(arr zapcore.ArrayEncoder) error {
55	for i := range errs {
56		if errs[i] == nil {
57			continue
58		}
59		// To represent each error as an object with an "error" attribute and
60		// potentially an "errorVerbose" attribute, we need to wrap it in a
61		// type that implements LogObjectMarshaler. To prevent this from
62		// allocating, pool the wrapper type.
63		elem := _errArrayElemPool.Get().(*errArrayElem)
64		elem.error = errs[i]
65		arr.AppendObject(elem)
66		elem.error = nil
67		_errArrayElemPool.Put(elem)
68	}
69	return nil
70}
71
72type errArrayElem struct {
73	error
74}
75
76func (e *errArrayElem) MarshalLogObject(enc zapcore.ObjectEncoder) error {
77	// Re-use the error field's logic, which supports non-standard error types.
78	Error(e.error).AddTo(enc)
79	return nil
80}
81