msgpackの練習

msgpack.go

package main

import (
	"log"
	"math"

	"github.com/vmihailenco/msgpack"
)

func main() {
	for i := 0; i < 10000; i = int(float32(i+1) * 1.7) {
		var b string
		for j := 0; j < i; j++ {
			b = b + "a"
		}
		f(b)
	}
}

func f(s string) {
	b, _ := msgpack.Marshal(s)
	log.Printf("%#v, %d, %d", b[:int32(math.Min(10, float64(len(b))))], len(b), len(s))
}

$ go run main.go 
2019/07/27 05:30:37 []byte{0xa0}, 1, 0
2019/07/27 05:30:37 []byte{0xa1, 0x61}, 2, 1
2019/07/27 05:30:37 []byte{0xa3, 0x61, 0x61, 0x61}, 4, 3
2019/07/27 05:30:37 []byte{0xa6, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61}, 7, 6
2019/07/27 05:30:37 []byte{0xab, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61}, 12, 11
2019/07/27 05:30:37 []byte{0xb4, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61}, 21, 20
2019/07/27 05:30:37 []byte{0xd9, 0x23, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61}, 37, 35
2019/07/27 05:30:37 []byte{0xd9, 0x3d, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61}, 63, 61
2019/07/27 05:30:37 []byte{0xd9, 0x69, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61}, 107, 105
2019/07/27 05:30:37 []byte{0xd9, 0xb4, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61}, 182, 180
2019/07/27 05:30:37 []byte{0xda, 0x1, 0x33, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61}, 310, 307
2019/07/27 05:30:37 []byte{0xda, 0x2, 0xb, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61}, 526, 523
2019/07/27 05:30:37 []byte{0xda, 0x3, 0x7a, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61}, 893, 890
2019/07/27 05:30:37 []byte{0xda, 0x5, 0xea, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61}, 1517, 1514
2019/07/27 05:30:37 []byte{0xda, 0xa, 0xf, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61}, 2578, 2575
2019/07/27 05:30:37 []byte{0xda, 0x11, 0x1b, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61}, 4382, 4379
2019/07/27 05:30:37 []byte{0xda, 0x1d, 0x16, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61}, 7449, 7446

https://github.com/msgpack/msgpack/blob/master/spec.md