1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
|
package log
import (
"time"
"github.com/go-stack/stack"
)
// A Valuer generates a log value. When passed to With or WithPrefix in a
// value element (odd indexes), it represents a dynamic value which is re-
// evaluated with each log event.
type Valuer func() interface{}
// bindValues replaces all value elements (odd indexes) containing a Valuer
// with their generated value.
func bindValues(keyvals []interface{}) {
for i := 1; i < len(keyvals); i += 2 {
if v, ok := keyvals[i].(Valuer); ok {
keyvals[i] = v()
}
}
}
// containsValuer returns true if any of the value elements (odd indexes)
// contain a Valuer.
func containsValuer(keyvals []interface{}) bool {
for i := 1; i < len(keyvals); i += 2 {
if _, ok := keyvals[i].(Valuer); ok {
return true
}
}
return false
}
// Timestamp returns a timestamp Valuer. It invokes the t function to get the
// time; unless you are doing something tricky, pass time.Now.
//
// Most users will want to use DefaultTimestamp or DefaultTimestampUTC, which
// are TimestampFormats that use the RFC3339Nano format.
func Timestamp(t func() time.Time) Valuer {
return func() interface{} { return t() }
}
// TimestampFormat returns a timestamp Valuer with a custom time format. It
// invokes the t function to get the time to format; unless you are doing
// something tricky, pass time.Now. The layout string is passed to
// Time.Format.
//
// Most users will want to use DefaultTimestamp or DefaultTimestampUTC, which
// are TimestampFormats that use the RFC3339Nano format.
func TimestampFormat(t func() time.Time, layout string) Valuer {
return func() interface{} {
return timeFormat{
time: t(),
layout: layout,
}
}
}
// A timeFormat represents an instant in time and a layout used when
// marshaling to a text format.
type timeFormat struct {
time time.Time
layout string
}
func (tf timeFormat) String() string {
return tf.time.Format(tf.layout)
}
// MarshalText implements encoding.TextMarshaller.
func (tf timeFormat) MarshalText() (text []byte, err error) {
// The following code adapted from the standard library time.Time.Format
// method. Using the same undocumented magic constant to extend the size
// of the buffer as seen there.
b := make([]byte, 0, len(tf.layout)+10)
b = tf.time.AppendFormat(b, tf.layout)
return b, nil
}
// Caller returns a Valuer that returns a file and line from a specified depth
// in the callstack. Users will probably want to use DefaultCaller.
func Caller(depth int) Valuer {
return func() interface{} { return stack.Caller(depth) }
}
var (
// DefaultTimestamp is a Valuer that returns the current wallclock time,
// respecting time zones, when bound.
DefaultTimestamp = TimestampFormat(time.Now, time.RFC3339Nano)
// DefaultTimestampUTC is a Valuer that returns the current time in UTC
// when bound.
DefaultTimestampUTC = TimestampFormat(
func() time.Time { return time.Now().UTC() },
time.RFC3339Nano,
)
// DefaultCaller is a Valuer that returns the file and line where the Log
// method was invoked. It can only be used with log.With.
DefaultCaller = Caller(3)
)
|
