initial commit

main.go

@@ -0,0 +1,111 @@
+package main
+
+import (
+	"bytes"
+	"flag"
+	"go/format"
+	"io"
+	"io/ioutil"
+	"log"
+	"os"
+	"text/template"
+)
+
+const chunkSize = 0x10
+
+const tmpl = `
+package {{.Pkg}}
+
+var {{.Name}} = []byte{
+    // {{ len .Value }} bytes from {{ .InputPath }}
+	{{ range .Chunks -}}
+		{{ range . }} {{ printf "0x%02x" . }}, {{ end }}
+	{{ end }}
+}
+`
+
+var t *template.Template
+
+func init() {
+	t = template.Must(template.New("constfile").Parse(tmpl))
+}
+
+type file struct {
+	Pkg, Name, InputPath string
+	Value                []byte
+}
+
+func (f *file) Chunks() [][]byte {
+	return chunks(f.Value, chunkSize)
+}
+
+func chunks(b []byte, n int) [][]byte {
+	var c [][]byte
+
+	nChks := len(b) / n
+
+	for i := 0; i < nChks; i++ {
+		m := i * n
+		c = append(c, b[m:m+n])
+	}
+
+	if r := len(b) % n; r > 0 {
+		m := n * nChks
+		c = append(c, b[m:m+r])
+	}
+
+	return c
+}
+
+func (f *file) Read() (err error) {
+	f.Value, err = ioutil.ReadFile(f.InputPath)
+	return
+}
+
+func (f *file) Render(w io.Writer) error {
+	outputPath := f.InputPath + ".go"
+	var buf bytes.Buffer
+	if err := t.Execute(&buf, &f); err != nil {
+		return err
+	}
+
+	b, err := format.Source(buf.Bytes())
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	if err := ioutil.WriteFile(outputPath, b, os.ModePerm); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func main() {
+
+	var f file
+	flag.StringVar(&f.Pkg, "pkg", "", "package")
+	flag.StringVar(&f.Name, "name", "", "const name")
+	flag.StringVar(&f.InputPath, "input", "", "input file")
+	flag.Parse()
+
+	if f.Pkg == "" {
+		log.Fatal("pkg required")
+	}
+
+	if f.Name == "" {
+		log.Fatal("name required")
+	}
+
+	if f.InputPath == "" {
+		log.Fatal("input file required")
+	}
+
+	if err := f.Read(); err != nil {
+		log.Fatal(err)
+	}
+
+	if err := f.Render(os.Stdout); err != nil {
+		log.Fatal(err)
+	}
+}