1 // Copyright (c) 2023 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 "sync"
24 25 type lazyWithCore struct {
26 Core
27 sync.Once
28 fields []Field
29 }
30 31 // NewLazyWith wraps a Core with a "lazy" Core that will only encode fields if
32 // the logger is written to (or is further chained in a lon-lazy manner).
33 func NewLazyWith(core Core, fields []Field) Core {
34 return &lazyWithCore{
35 Core: core,
36 fields: fields,
37 }
38 }
39 40 func (d *lazyWithCore) initOnce() {
41 d.Once.Do(func() {
42 d.Core = d.Core.With(d.fields)
43 })
44 }
45 46 func (d *lazyWithCore) With(fields []Field) Core {
47 d.initOnce()
48 return d.Core.With(fields)
49 }
50 51 func (d *lazyWithCore) Check(e Entry, ce *CheckedEntry) *CheckedEntry {
52 d.initOnce()
53 return d.Core.Check(e, ce)
54 }
55