1 files changed, 4 insertions, 63 deletions

diff --git a/lib/btrfs/btrfssum/shortsum.go b/lib/btrfs/btrfssum/shortsum.go
index 754a79d..490c40a 100644
--- a/lib/btrfs/btrfssum/shortsum.go
+++ b/lib/btrfs/btrfssum/shortsum.go
@@ -5,12 +5,12 @@
 package btrfssum
 
 import (
-	"fmt"
 	"io"
-	"math"
 	"strings"
 
 	"git.lukeshu.com/go/lowmemjson"
+
+	"git.lukeshu.com/btrfs-progs-ng/lib/jsonutil"
 )
 
 type ShortSum string
@@ -27,72 +27,13 @@ func (sum ShortSum) ToFullSum() CSum {
 }
 
 func (sum ShortSum) EncodeJSON(w io.Writer) error {
-	const hextable = "0123456789abcdef"
-	var buf [2]byte
-	buf[0] = '"'
-	if _, err := w.Write(buf[:1]); err != nil {
-		return err
-	}
-	for i := 0; i < len(sum); i++ {
-		buf[0] = hextable[sum[i]>>4]
-		buf[1] = hextable[sum[i]&0x0f]
-		if _, err := w.Write(buf[:]); err != nil {
-			return err
-		}
-	}
-	buf[0] = '"'
-	if _, err := w.Write(buf[:1]); err != nil {
-		return err
-	}
-	return nil
-}
-
-func deHex(r rune) (byte, bool) {
-	if r > math.MaxUint8 {
-		return 0, false
-	}
-	c := byte(r)
-	//nolint:gomnd // Hex conversion.
-	switch {
-	case '0' <= c && c <= '9':
-		return c - '0', true
-	case 'a' <= c && c <= 'f':
-		return c - 'a' + 10, true
-	case 'A' <= c && c <= 'F':
-		return c - 'A' + 10, true
-	default:
-		return 0, false
-	}
+	return jsonutil.EncodeHexString(w, sum)
 }
 
 func (sum *ShortSum) DecodeJSON(r io.RuneScanner) error {
 	var out strings.Builder
-	if c, _, err := r.ReadRune(); err != nil {
+	if err := jsonutil.DecodeHexString(r, &out); err != nil {
 		return err
-	} else if c != '"' {
-		return fmt.Errorf("expected %q, got %q", '"', c)
-	}
-	for {
-		a, _, err := r.ReadRune()
-		if err != nil {
-			return err
-		}
-		if a == '"' {
-			break
-		}
-		aN, ok := deHex(a)
-		if !ok {
-			return fmt.Errorf("expected a hex digit, got %q", a)
-		}
-		b, _, err := r.ReadRune()
-		if err != nil {
-			return err
-		}
-		bN, ok := deHex(b)
-		if !ok {
-			return fmt.Errorf("expected a hex digit, got %q", b)
-		}
-		out.WriteByte(aN<<4 | bN)
 	}
 	*sum = ShortSum(out.String())
 	return nil