Filesystem benchmark in Go

write_test.go

package main

import (
	"fmt"
	"os"
	"testing"
)

func BenchmarkWrite(b *testing.B) {
	for cnt, cntP := 10, 1; cntP <= 3; cnt, cntP = cnt*10, cntP+1 {
		for bts, btsP := 10, 1; btsP <= 3; bts, btsP = bts*10, btsP+1 {
			content := make([]byte, bts)
			for i := 0; i < bts; i++ {
				content[i] = byte('a' + (i % 26))
			}
			os.Remove("testfile.txt")
			b.Run(fmt.Sprintf("Write_%d_Bytes_%d_times", bts, cnt), func(b *testing.B) {
				// Create test file
				f, err := os.OpenFile("testfile.txt", os.O_CREATE, 0644)
				if err != nil {
					b.Error(err)
				}
				if err := f.Close(); err != nil {
					b.Error(err)
				}

				// Perform repeated writes to file
				b.ResetTimer()
				for i := 0; i < cnt*b.N; i++ {
					f, err := os.OpenFile("testfile.txt", os.O_WRONLY, 0644)
					if err != nil {
						b.Error(err)
					}
					if _, err := f.Write(content); err != nil {
						b.Error(err)
					}
					if err := f.Sync(); err != nil {
						b.Error(err)
					}
					if err := f.Close(); err != nil {
						b.Error(err)
					}
				}
			})
		}
	}
}

func BenchmarkAppend(b *testing.B) {
	for cnt, cntP := 10, 1; cntP <= 3; cnt, cntP = cnt*10, cntP+1 {
		for bts, btsP := 10, 1; btsP <= 3; bts, btsP = bts*10, btsP+1 {
			content := make([]byte, bts)
			for i := 0; i < bts; i++ {
				content[i] = byte('a' + (i % 26))
			}
			os.Remove("testfile.txt")
			b.Run(fmt.Sprintf("Append_%d_Bytes_%d_times", bts, cnt), func(b *testing.B) {
				// Create file and immediately close it
				f, err := os.OpenFile("testfile.txt", os.O_CREATE, 0644)
				if err != nil {
					b.Error(err)
				}
				if err := f.Close(); err != nil {
					b.Error(err)
				}

				// Append bytes to file
				b.ResetTimer()
				for i := 0; i < cnt*b.N; i++ {
					f, err := os.OpenFile("testfile.txt", os.O_WRONLY|os.O_APPEND, 0644)
					if err != nil {
						b.Error(err)
					}
					if _, err := f.Write(content); err != nil {
						b.Error(err)
					}
					if err := f.Sync(); err != nil {
						b.Error(err)
					}
					if err := f.Close(); err != nil {
						b.Error(err)
					}
				}
			})
		}
	}
}