/// <summary>
/// Read and return the next IPacket from the stream
/// </summary>
public IPacket Read()
{
#if ADD_GUARD_BYTES
byte[] preamble = new byte[4];
m_Stream.Read(preamble, 0, 4);
//now compare it against the preamble.
CompareArrays(preamble, PacketWriter.s_PreambleGuardPattern);
#endif
int packetSize = (int)m_Reader.ReadUInt64();
//if the packet size is less than one, that's obviously wrong
if (packetSize < 1)
{
throw new GibraltarSerializationException("The size of the next packet is smaller than 1 byte or negative, which can't be correct. The packet stream is corrupted.", true);
}
// TODO: There's got to be a more efficient way to get this done
byte[] buffer = new byte[packetSize];
m_Stream.Read(buffer, 0, packetSize);
IFieldReader bufferReader = new FieldReader(new MemoryStream(buffer), m_Reader.Strings, m_MajorVersion, m_MinorVersion);
PacketDefinition definition;
int typeIndex = (int)bufferReader.ReadUInt32();
if (typeIndex >= m_cachedTypes.Count)
{
definition = PacketDefinition.ReadPacketDefinition(bufferReader);
if (string.IsNullOrEmpty(definition.TypeName))
{
//we're hosed... we won't be able to parse this packet.
throw new GibraltarSerializationException("The type name of the definition is null, which can't be correct. The packet stream is corrupted.", true);
}
m_cachedTypes.Add(definition);
m_cachedTypes.Commit();
}
else
{
definition = m_cachedTypes[typeIndex];
}
IPacketFactory factory = m_PacketFactory.GetPacketFactory(definition.TypeName);
IPacket packet = factory.CreatePacket(definition, bufferReader);
//we used to populate a packet cache here, but a cached packet should be read just once - it shouldn't be in the stream
//(and I changed PacketWriter to enforce that)
#if ADD_GUARD_BYTES
byte[] postamble = new byte[4];
m_Stream.Read(postamble, 0, 4);
//now compare it against the preamble.
CompareArrays(postamble, PacketWriter.s_PostambleGuardPattern);
#endif
return(packet);
}
/// <summary>
/// Initialize a PacketReader to read the specified stream using
/// the provided encoding for strings.
/// </summary>
/// <param name="stream">Data to be read</param>
/// <param name="inputIsReadOnly">Indicates if the input can be assumed fixed in length</param>
/// <param name="majorVersion">Major version of the serialization protocol</param>
/// <param name="minorVersion">Minor version of the serialization protocol</param>
public PacketReader(Stream stream, bool inputIsReadOnly, int majorVersion, int minorVersion)
{
m_Stream = stream;
m_InputIsReadOnly = inputIsReadOnly;
m_MajorVersion = majorVersion;
m_MinorVersion = minorVersion;
// m_ReleaseStream = false; // m_Stream was passed in to us, don't release it upon Dispose()!
// (false by default) If we were invoked from another constructor, they will overwrite m_ReleaseStream correctly
m_Reader = new FieldReader(stream, new UniqueStringList(), majorVersion, minorVersion);
m_cachedTypes = new PacketDefinitionList();
m_PacketFactory = new PacketFactory();
if ((inputIsReadOnly) && (m_Stream != null))
{
m_StreamLength = m_Stream.Length;
}
}
