go - Instagram 媒体 ID 到时间戳的转换

Question

Instagram 在这篇博文中解释了他们如何创建媒体 ID

https://instagram-engineering.com/sharding-ids-at-instagram-1cf5a71e5a5c

Each of our IDs consists of: 41 bits for time in milliseconds (gives us 41 years of IDs with a custom epoch) 13 bits that represent the logical shard ID 10 bits that represent an auto-incrementing sequence, modulus 1024. This means we can generate 1024 IDs, per shard, per millisecond.

our ‘epoch’ begins on January 1st, 2011 not sure if that's the actual production value or only for the example

如何从媒体 ID 取回时间戳？

我有这两个媒体 ID，我知道时间戳，但我需要从其他媒体中提取它

2384288897814875714 2020-08-26T13:43:27Z

2383568809444681765 2020-08-25T13:52:46Z

Answer 1

playground

package main

import (
    "fmt"
    "time"
)

const (
    instaEpoch int64 = 1314220021721
    mediaID int64 = 2384288897814875714
)

func main()  {
    extractedTimestamp := mediaID >> (64-41)
    timeFromMediaID := extractedTimestamp + instaEpoch
    fmt.Println(time.Unix(timeFromMediaID/1000,0).UTC())
}

输出:

2020-08-26 13:43:27 +0000 UTC

您只需右移 id 即可取回时间戳。然后你必须将毫秒添加到 instagram 正在使用的时代。