1 // Copyright (c) 2016-2022 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 "go.uber.org/multierr"
24 25 type multiCore []Core
26 27 var (
28 _ leveledEnabler = multiCore(nil)
29 _ Core = multiCore(nil)
30 )
31 32 // NewTee creates a Core that duplicates log entries into two or more
33 // underlying Cores.
34 //
35 // Calling it with a single Core returns the input unchanged, and calling
36 // it with no input returns a no-op Core.
37 func NewTee(cores ...Core) Core {
38 switch len(cores) {
39 case 0:
40 return NewNopCore()
41 case 1:
42 return cores[0]
43 default:
44 return multiCore(cores)
45 }
46 }
47 48 func (mc multiCore) With(fields []Field) Core {
49 clone := make(multiCore, len(mc))
50 for i := range mc {
51 clone[i] = mc[i].With(fields)
52 }
53 return clone
54 }
55 56 func (mc multiCore) Level() Level {
57 minLvl := _maxLevel // mc is never empty
58 for i := range mc {
59 if lvl := LevelOf(mc[i]); lvl < minLvl {
60 minLvl = lvl
61 }
62 }
63 return minLvl
64 }
65 66 func (mc multiCore) Enabled(lvl Level) bool {
67 for i := range mc {
68 if mc[i].Enabled(lvl) {
69 return true
70 }
71 }
72 return false
73 }
74 75 func (mc multiCore) Check(ent Entry, ce *CheckedEntry) *CheckedEntry {
76 for i := range mc {
77 ce = mc[i].Check(ent, ce)
78 }
79 return ce
80 }
81 82 func (mc multiCore) Write(ent Entry, fields []Field) error {
83 var err error
84 for i := range mc {
85 err = multierr.Append(err, mc[i].Write(ent, fields))
86 }
87 return err
88 }
89 90 func (mc multiCore) Sync() error {
91 var err error
92 for i := range mc {
93 err = multierr.Append(err, mc[i].Sync())
94 }
95 return err
96 }
97