/// <summary>
/// Reads the Frame portion of the message header.
/// See http://lan.developer.lifx.com/docs/header-description for more details.
/// </summary>
/// <param name="buffer">The buffer to read from.</param>
private void ReadFrame(MemoryStream buffer)
{
Debug.Assert(buffer != null);
// Read the message size (2B) and verify it matches the expected size.
//
_messageSizeRead = buffer.LittleEndianReadUInt16();
if (_messageSizeRead != MessageSizeInBytes)
{
throw new LifXNetException(
"Size of received message does not match expected size! Expect {0}B for messages of type {1}, but received {2}",
MessageSizeInBytes,
MessageType,
_messageSizeRead);
}
// The next 2 bytes contain some flags we don't care about, and the protocol number
// (the last 12 bits.) We need to verify the protocol number matches what we expect.
//
const UInt16 ProtocolMask = 0xFFF;
UInt16 temp = buffer.LittleEndianReadUInt16();
_protocolVersionRead = (UInt16)(temp & ProtocolMask);
if (_protocolVersionRead != Constants.LifXProtocolNumber)
{
throw new LifXNetException(
"Received message using unsupported protocol version '{0}'",
_protocolVersionRead);
}
// The last 4 bytes of the Frame are the message Source.
//
Source = buffer.LittleEndianReadUInt32();
}
/// <summary>
/// Reads the Protocol Header portion of the message header.
/// See http://lan.developer.lifx.com/docs/header-description for more details.
/// </summary>
/// <param name="buffer">The buffer to read from.</param>
private void ReadProtocolHeader(MemoryStream buffer)
{
Debug.Assert(buffer != null);
// The first 8 bytes are unused and marked "Reserved".
//
byte[] oblivion = buffer.ReadBytes(8);
// The next 2 bytes are the MessageType. Verify that the type in the buffer
// matches this type. This is the expected case, since a mismatch here would
// indicate a bug in the library (possibly in the ResponseFactory.)
//
UInt16 messageTypeRead = buffer.LittleEndianReadUInt16();
if (messageTypeRead != (UInt16)MessageType)
{
throw new LifXNetException(
"Type of the message being deserialized does not match what was expected. This is likely a bug in the library!");
}
// The last 2 bytes are also unused and marked "Reserved".
//
oblivion = buffer.ReadBytes(2);
}
