optimize(orbyte): use manual destroy

gold/head/box.go

@@ -47,6 +47,7 @@ func (p *Packet) PreCRC64() (crc uint64) {
 			)
 		}
 	})
+	w.Destroy()
 	return
 }
 
@@ -58,11 +59,13 @@ func (p *Packet) WriteHeaderTo(buf *bytes.Buffer) {
 		buf.Write((*[PacketHeadNoCRCLen]byte)(
 			(unsafe.Pointer)(p),
 		)[:])
-		pbuf.NewBytes(buf.Len()).V(func(b []byte) {
+		b := pbuf.NewBytes(buf.Len())
+		b.V(func(b []byte) {
 			copy(b, buf.Bytes())
 			ClearTTL(b)
 			p.md5h8 = algo.MD5Hash8(b)
 		})
+		b.ManualDestroy()
 		_ = binary.Write(buf, binary.LittleEndian, p.md5h8)
 		return
 	}
@@ -76,14 +79,17 @@ func (p *Packet) WriteHeaderTo(buf *bytes.Buffer) {
 	w.Write(p.src[:])
 	w.Write(p.dst[:])
 	w.P(func(buf *pbuf.Buffer) {
-		pbuf.NewBytes(buf.Len()).V(func(b []byte) {
+		b := pbuf.NewBytes(buf.Len())
+		b.V(func(b []byte) {
 			copy(b, buf.Bytes())
 			ClearTTL(b)
 			p.md5h8 = algo.MD5Hash8(b)
 		})
+		b.ManualDestroy()
 	})
 	w.WriteUInt64(p.md5h8)
 	w.P(func(b *pbuf.Buffer) {
 		_, _ = buf.ReadFrom(b)
 	})
+	w.Destroy()
 }