public unsafe IList <ArraySegment <byte> > CreateBuffer(IList <ArraySegment <byte> > appendTo = null) { // key size var keyData = BinaryConverter.EncodeKey(this.Key); var keyLength = keyData == null ? 0 : keyData.Length; if (keyLength > 0xffff) { throw new InvalidOperationException("KeyTooLong"); } // extra size var extras = this.Extra; var extraLength = extras.Array == null ? 0 : extras.Count; if (extraLength > 0xff) { throw new InvalidOperationException("ExtraTooLong"); } // body size var body = this.Data; var bodyLength = body.Array == null ? 0 : body.Count; // total payload size var totalLength = extraLength + keyLength + bodyLength; //build the header var header = new byte[24]; fixed(byte *buffer = header) { buffer[0x00] = 0x80; // magic buffer[0x01] = this.Operation; // key length buffer[0x02] = (byte)(keyLength >> 8); buffer[0x03] = (byte)(keyLength & 255); // extra length buffer[0x04] = (byte)(extraLength); // 5 -- data type, 0 (RAW) // 6,7 -- reserved, always 0 buffer[0x06] = (byte)(this.Reserved >> 8); buffer[0x07] = (byte)(this.Reserved & 255); // body length buffer[0x08] = (byte)(totalLength >> 24); buffer[0x09] = (byte)(totalLength >> 16); buffer[0x0a] = (byte)(totalLength >> 8); buffer[0x0b] = (byte)(totalLength & 255); buffer[0x0c] = (byte)(this.CorrelationID >> 24); buffer[0x0d] = (byte)(this.CorrelationID >> 16); buffer[0x0e] = (byte)(this.CorrelationID >> 8); buffer[0x0f] = (byte)(this.CorrelationID & 255); // CAS ulong cas = this.Cas; if (cas > 0) { // skip this if no cas is specfied buffer[0x10] = (byte)(cas >> 56); buffer[0x11] = (byte)(cas >> 48); buffer[0x12] = (byte)(cas >> 40); buffer[0x13] = (byte)(cas >> 32); buffer[0x14] = (byte)(cas >> 24); buffer[0x15] = (byte)(cas >> 16); buffer[0x16] = (byte)(cas >> 8); buffer[0x17] = (byte)(cas & 255); } } var result = appendTo ?? new List <ArraySegment <byte> >(4); result.Add(new ArraySegment <byte>(header)); if (extraLength > 0) { result.Add(extras); } // key must be already encoded and should not contain any invalid characters which are not allowed by the protocol if (keyLength > 0) { result.Add(new ArraySegment <byte>(keyData)); } if (bodyLength > 0) { result.Add(body); } return(result); }