Added functions for calculating and fixing message sizes

source/styx2000/extrautil/styxmessage.d

@@ -398,3 +398,31 @@ auto createRmsgWalk(ushort tag = STYX_NOTAG, Qid[] nwqid = [])
 		new Nwqid(nwqid)
 	];
 }
+
+/// Calculate real (!) message size
+auto calculateMessageSize(StyxMessage msg)
+{
+	ulong realSize = 0;
+
+	foreach (e; msg)
+	{
+		realSize += e.pack.length;
+	}
+
+	return realSize;
+}
+
+
+/// Fix incorrect size in some messages which generated by helpers (fix zero sizes)
+auto fixMessageSize(StyxMessage msg)
+{
+	StyxMessage newMsg = msg[1..$];
+	uint realSize = 4; // Size field has length = 4 bytes
+
+	foreach (e; newMsg)
+	{
+		realSize += e.pack.length;
+	}
+
+	return cast(StyxMessage) [new Size(realSize)] ~ newMsg;
+}