public ReadOnlyMemory<byte> SetKey(IKeyFormatter formatter, string key)
{
#if DEBUG
Debug.Assert(!didKey, "Key can only be set once");
Debug.Assert(!didBody, "Key must be set before accessing the body");
didKey = true;
#endif
AllocateExtras();
var start = bodyBuilder.Mark();
var preKey = bodyBuilder.Length;
Debug.Assert(preKey == extra.Length, "unexpected data was written between extra & key");
formatter.Serialize(bodyBuilder, key);
var end = bodyBuilder.Mark();
var tmpLength = bodyBuilder.Length - preKey;
if (tmpLength > Protocol.MaxKeyLength)
throw new ArgumentException($"Key is too long; was {tmpLength}, maximum is {Protocol.MaxKeyLength}");
keyLength = (ushort)tmpLength;
var seq = bodyBuilder.Slice(start, end);
if (seq.IsSingleSegment)
{
Debug.Assert(seq.First.Length == keyLength);
return seq.First;
}
return seq.ToArray();
}
