如何在Go中压缩int（数字）

Question

is there any way to compress int and decompress it use Go?

For example this number 10 char 4251658154

I want to compress (make size small, for example my 10 char int to 5 char bytes) int or any kind of data type accept number than decompress it

Answer 1

If you just want to compress arbitrary number at different magniturdes, What you're looking for is varint encoding. If the number is small (<127) it can be encoded in one byte, and so forth. Example from the docs:

package main

import (
    "encoding/binary"
    "fmt"
)

func main() {
    buf := make([]byte, binary.MaxVarintLen64)

    for _, x := range []int64{-65, -64, -2, -1, 0, 1, 2, 63, 64} {
        n := binary.PutVarint(buf, x)
        fmt.Printf("%x
", buf[:n])
    }
}

// Prints:
// 8101
// 7f
// 03
// 01
// 00
// 02
// 04
// 7e
// 8001

If however you want to represent IPV4 addresses in an efficient manner, just encode them as unsigned int32 numbers.

import (
    "bytes"
    "encoding/binary"
    "fmt"
    "net"
)

func IPToNumber(addr string) (uint32, error) {
    var n uint32
    err := binary.Read(bytes.NewBuffer(net.ParseIP(addr).To4()), binary.BigEndian, &n)
    return n, err
}

func main() {
    if n, err := IPToNumber("255.255.255.255"); err == nil {
        fmt.Printf("%x", n)
    }
}