Question

我想在使用当前的log15库的golang项目中记录毫秒级精度

问题是当我将其附加到Context时，它会四舍五入到秒

newTimeWithMilliseconds := time.Unix(0, time.Now().UnixNano())

return log.FuncHandler(func(r *log.Record) {
     r.Ctx = append(r.Ctx, "time", newTimeWithMilliseconds)
     nextHandler.Log(r)
})

当我将其转换为字符串newTimeWithMilliseconds.String()时，它可以工作，并且得到"2018-09-25 15:07:45.25801232 -0500 PDT"，但是当我不这样做时，小数点消失，而我得到2018-09-25 15:07:45 -0700 PDT。

虽然我想保持时间格式，而不要使用字符串，但是有人对为什么会发生以及如何解决这个问题有任何想法吗？

Answer 1

您需要使用time.Format以所需的精度显示time.Time的值。除非您修改其值，否则它不会丧失其精度，之所以会看到差异，仅是由于layout的调用所使用的time.Format会消耗您的时间。

使用mytime.String()时，所使用的布局与其他人所用的布局不同，否则会打印您的时间。

这就是为什么您需要使用time.Time值但要控制其打印方式，或者将其存储为格式化字符串。

请参见Go by example

// Go supports time formatting and parsing via
// pattern-based layouts.

package main

import "fmt"
import "time"

func main() {
    p := fmt.Println

    // Here's a basic example of formatting a time
    // according to RFC3339, using the corresponding layout
    // constant.
    t := time.Now()
    p(t.Format(time.RFC3339))

    // Time parsing uses the same layout values as `Format`.
    t1, e := time.Parse(
        time.RFC3339,
        "2012-11-01T22:08:41+00:00")
    p(t1)

    // `Format` and `Parse` use example-based layouts. Usually
    // you'll use a constant from `time` for these layouts, but
    // you can also supply custom layouts. Layouts must use the
    // reference time `Mon Jan 2 15:04:05 MST 2006` to show the
    // pattern with which to format/parse a given time/string.
    // The example time must be exactly as shown: the year 2006,
    // 15 for the hour, Monday for the day of the week, etc.
    p(t.Format("3:04PM"))
    p(t.Format("Mon Jan _2 15:04:05 2006"))
    p(t.Format("2006-01-02T15:04:05.999999-07:00"))
    form := "3 04 PM"
    t2, e := time.Parse(form, "8 41 PM")
    p(t2)

    // For purely numeric representations you can also
    // use standard string formatting with the extracted
    // components of the time value.
    fmt.Printf("%d-%02d-%02dT%02d:%02d:%02d-00:00\n",
        t.Year(), t.Month(), t.Day(),
        t.Hour(), t.Minute(), t.Second())

    // `Parse` will return an error on malformed input
    // explaining the parsing problem.
    ansic := "Mon Jan _2 15:04:05 2006"
    _, e = time.Parse(ansic, "8:41PM")
    p(e)
}

输出

2009-11-10T23:00:00Z
2012-11-01 22:08:41 +0000 UTC
11:00PM
Tue Nov 10 23:00:00 2009
2009-11-10T23:00:00+00:00
0000-01-01 20:41:00 +0000 UTC
2009-11-10T23:00:00-00:00
parsing time "8:41PM" as "Mon Jan _2 15:04:05 2006": cannot parse "8:41PM" as "Mon"

亲自尝试here

log15库将纪元时间从纳秒舍入到秒以进行记录

1 个答案: