lib/discover, lib/protocol: Buffer allocation

2021-09-06 15:30:56 +02:00
parent 4e2a9bb139
commit eafb40460d
2 changed files with 7 additions and 8 deletions
@@ -114,19 +114,18 @@ func (c *localClient) announcementPkt(instanceID int64, msg []byte) ([]byte, boo
 		return msg, false
 	}

-	if cap(msg) >= 4 {
-		msg = msg[:4]
-	} else {
-		msg = make([]byte, 4)
-	}
-	binary.BigEndian.PutUint32(msg, Magic)
-
 	pkt := Announce{
 		ID:         c.myID,
 		Addresses:  addrs,
 		InstanceID: instanceID,
 	}
 	bs, _ := pkt.Marshal()
+
+	if pktLen := 4 + len(bs); cap(msg) < pktLen {
+		msg = make([]byte, 0, pktLen)
+	}
+	msg = msg[:4]
+	binary.BigEndian.PutUint32(msg, Magic)
 	msg = append(msg, bs...)

 	return msg, true