write_ip.go

package main

import (
	"compress/zlib"
	"fmt"
	"math/rand"
	"os"
	"time"
	"unsafe"
)

const LENGTH = 1e9

func generateRandomUint32() []uint32 {
	buf := make([]uint32, LENGTH)
	for i := 0; i < LENGTH; i++ {
		buf = append(buf, rand.Uint32())
	}
	return buf
}

func WriteToFileRaw(data []byte) {
	f, err := os.Create("data-raw")
	if err != nil {
		panic(err)
	}

	start := time.Now()
	_, err = f.Write(data)
	if err != nil {
		panic(err)
	}
	f.Close()

	elapsed := time.Since(start)
	fmt.Println("WriteToFileRaw", elapsed)
}

func WriteToFileZlib(data []byte) {
	start := time.Now()
	f, err := os.Create("data-zlib")
	if err != nil {
		panic(err)
	}

	w, err := zlib.NewWriterLevel(f, zlib.BestSpeed)
	if err != nil {
		panic(err)
	}

	_, err = w.Write(data)
	if err != nil {
		panic(err)
	}

	w.Close()
	f.Close()

	elapsed := time.Since(start)
	fmt.Println("WriteToFileZlib", elapsed)
}

func main() {
	data := generateRandomUint32()
	bdata := (*[LENGTH * 4]byte)(unsafe.Pointer(&data[0]))[:]

	for i := 0; i < 5; i++ {
		WriteToFileRaw(bdata)
		WriteToFileZlib(bdata)
	}
}