Add native Go ext4 filesystem image creator

pkg/ext4/bench_test.go

@@ -0,0 +1,136 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package ext4
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+)
+
+func diskUsage(t testing.TB, path string) (apparent, actual int64) {
+	t.Helper()
+	info, err := os.Stat(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	apparent = info.Size()
+
+	out, err := exec.Command("du", "--block-size=1", path).CombinedOutput()
+	if err == nil {
+		fmt.Sscanf(string(out), "%d", &actual)
+	} else {
+		actual = apparent
+	}
+	return apparent, actual
+}
+
+var benchSizes = []struct {
+	name string
+	size int64
+}{
+	{"64MiB", 64 * 1024 * 1024},
+	{"256MiB", 256 * 1024 * 1024},
+	{"1GiB", 1024 * 1024 * 1024},
+}
+
+// BenchmarkCreate benchmarks the native Go Create function.
+func BenchmarkCreate(b *testing.B) {
+	for _, sz := range benchSizes {
+		b.Run(sz.name, func(b *testing.B) {
+			outDir := b.TempDir()
+			b.ResetTimer()
+			for i := 0; i < b.N; i++ {
+				imgPath := filepath.Join(outDir, fmt.Sprintf("test_%d.ext4", i))
+				if err := Create(imgPath, sz.size); err != nil {
+					b.Fatal(err)
+				}
+				if i == b.N-1 {
+					apparent, actual := diskUsage(b, imgPath)
+					b.ReportMetric(float64(apparent), "apparent-bytes")
+					b.ReportMetric(float64(actual), "disk-bytes")
+				}
+			}
+		})
+	}
+}
+
+// BenchmarkMkfsOptimized benchmarks mkfs.ext4 with the same optimized flags.
+func BenchmarkMkfsOptimized(b *testing.B) {
+	checkTools(b)
+
+	for _, sz := range benchSizes {
+		b.Run(sz.name, func(b *testing.B) {
+			outDir := b.TempDir()
+			b.ResetTimer()
+			for i := 0; i < b.N; i++ {
+				imgPath := filepath.Join(outDir, fmt.Sprintf("test_%d.ext4", i))
+				f, err := os.Create(imgPath)
+				if err != nil {
+					b.Fatal(err)
+				}
+				f.Truncate(sz.size)
+				f.Close()
+				cmd := exec.Command("mkfs.ext4",
+					"-b", "4096", "-m", "0",
+					"-O", "^has_journal,sparse_super2,^resize_inode",
+					"-E", "lazy_itable_init=1,lazy_journal_init=1,nodiscard,assume_storage_prezeroed=1",
+					"-F", "-q", imgPath)
+				if out, err := cmd.CombinedOutput(); err != nil {
+					b.Fatalf("mkfs.ext4 failed: %v\n%s", err, out)
+				}
+				if i == b.N-1 {
+					apparent, actual := diskUsage(b, imgPath)
+					b.ReportMetric(float64(apparent), "apparent-bytes")
+					b.ReportMetric(float64(actual), "disk-bytes")
+				}
+			}
+		})
+	}
+}
+
+// BenchmarkMkfsDefaults benchmarks mkfs.ext4 with default options.
+func BenchmarkMkfsDefaults(b *testing.B) {
+	checkTools(b)
+
+	for _, sz := range benchSizes {
+		b.Run(sz.name, func(b *testing.B) {
+			outDir := b.TempDir()
+			b.ResetTimer()
+			for i := 0; i < b.N; i++ {
+				imgPath := filepath.Join(outDir, fmt.Sprintf("test_%d.ext4", i))
+				f, err := os.Create(imgPath)
+				if err != nil {
+					b.Fatal(err)
+				}
+				f.Truncate(sz.size)
+				f.Close()
+				cmd := exec.Command("mkfs.ext4", "-F", "-q", imgPath)
+				if out, err := cmd.CombinedOutput(); err != nil {
+					b.Fatalf("mkfs.ext4 failed: %v\n%s", err, out)
+				}
+				if i == b.N-1 {
+					apparent, actual := diskUsage(b, imgPath)
+					b.ReportMetric(float64(apparent), "apparent-bytes")
+					b.ReportMetric(float64(actual), "disk-bytes")
+				}
+			}
+		})
+	}
+}