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ntool/nrandom/id.go

67 lines
1.4 KiB
Go

package nrandom
import (
"hash/crc32"
"math/rand"
"os"
"strconv"
"time"
)
// global id:
//
// https://github.com/rs/xid
// https://github.com/satori/go.uuid
var (
DefMinInt = 1000
DefMaxInt = 9999
)
// MicroTimeID generate.
// return like: 16074145697981929446(len: 20) 9446:RandInt
func MicroTimeID() string {
ms := time.Now().UnixNano() / 1000
ri := RandInt(DefMinInt, DefMaxInt)
return strconv.FormatInt(ms, 10) + strconv.FormatInt(int64(ri), 10)
}
// MicroTimeHexID generate.
// return like: 5b5f0588af1761ad3(len: 16-17)
func MicroTimeHexID() string {
ms := time.Now().UnixNano() / 1000
ri := RandInt(DefMinInt, DefMaxInt)
return strconv.FormatInt(ms, 16) + strconv.FormatInt(int64(ri), 16)
}
// DatetimeNo generate. can use for order-no.
//
// No prefix, return like: 2023041410484904074285478388(len: 28)
func DatetimeNo(prefix string) string {
nt := time.Now()
pl := len(prefix)
bs := make([]byte, 0, 28+pl)
if pl > 0 {
bs = append(bs, prefix...)
}
// micro datatime
bs = nt.AppendFormat(bs, "20060102150405.000000")
bs[14+pl] = '0'
// host
name, err := os.Hostname()
if err != nil {
name = "default"
}
c32 := crc32.ChecksumIEEE([]byte(name)) // eg: 4006367001
bs = strconv.AppendUint(bs, uint64(c32%99), 10)
// rand 10000 - 99999
rs := rand.New(rand.NewSource(nt.UnixNano()))
bs = strconv.AppendInt(bs, 10000+rs.Int63n(89999), 10)
return string(bs)
}