log15 库将纪元时间从纳秒到秒进行记录

Question

我想在我的 golang 项目中记录毫秒精度，目前使用 log15 库

问题是当我将它附加到上下文时，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，我得到 "2018-09-25 15:07:45.25801232 -0500 PDT"，但当我不这样做时，小数消失，我得到 2018-09-25 15:07:45 -0700 PDT。

虽然我想保持时间格式并且不使用字符串，但有人对为什么会发生这种情况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 以您想要的精度显示您的time.Time 值。除非您修改它的值，否则它不会失去其精度，您看到差异的原因仅仅是因为在打印您的时间时调用 time.Format 时使用了 layout。

当您使用mytime.String() 时，所使用的布局与打印您的时间的其他布局不同。

这就是为什么您需要使用 time.Time 值但操纵它的打印方式，或者将其存储为格式化字符串。

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"

自己试试here