Refactor debug into debug module

cmd/gentestdata/main.go

@@ -0,0 +1,69 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"math/rand"
+	"os"
+	"path/filepath"
+)
+
+const (
+	MaxFiles = 23
+	MaxDepth = 3
+)
+
+var urnd *os.File
+
+func init() {
+	f, err := os.Open("/dev/urandom")
+	if err != nil {
+		panic(err)
+	}
+
+	urnd = f
+}
+
+func rndRd(bytes int) io.Reader {
+	return io.LimitReader(urnd, int64(bytes))
+}
+
+func create_dir(target string, depth int) {
+	fmt.Printf("create_dir %s, depth %d\n", target, depth)
+	err := os.Mkdir(target, 0755)
+	if err != nil && !os.IsExist(err) {
+		panic(err)
+	}
+
+	for i := 0; i < MaxFiles; i++ {
+		if depth == 0 {
+			filename := filepath.Join(target, fmt.Sprintf("file%d", i))
+			fmt.Printf("create file %v\n", filename)
+			f, err := os.Create(filename)
+			if err != nil {
+				panic(err)
+			}
+
+			_, err = io.Copy(f, rndRd(rand.Intn(1024)))
+			if err != nil {
+				panic(err)
+			}
+
+			err = f.Close()
+			if err != nil {
+				panic(err)
+			}
+		} else {
+			create_dir(filepath.Join(target, fmt.Sprintf("dir%d", i)), depth-1)
+		}
+	}
+}
+
+func main() {
+	if len(os.Args) != 2 {
+		fmt.Fprintf(os.Stderr, "USAGE: %s TARGETDIR\n", os.Args[0])
+		os.Exit(1)
+	}
+
+	create_dir(os.Args[1], MaxDepth)
+}