/// <summary>
/// Decode the provided byte array received from the user with unique
/// identity <c>userId</c>.
/// </summary>
/// <param name="userId">the unique identity for the user</param>
/// <param name="encodedBytes">the encoded message received</param>
/// <returns></returns>
public byte[] Decode(int userId, byte[] encodedBytes)
{
log.Trace("\n>>>> DECODING <<<<<");
Stream input = TryInflating(encodedBytes);
CompressedMessagePackage cmp = new CompressedMessagePackage();
cmp.TemplateId = (short)ByteUtils.DecodeLength(input);
log.Trace(String.Format("==> Decoding with template {0}", cmp.TemplateId));
int inputValue;
while((inputValue = input.ReadByte()) != -1) {
switch ((GMCMessageKey)inputValue)
{
case GMCMessageKey.Huffed: cmp.Huffed = true; break;
case GMCMessageKey.NotHuffed: cmp.Huffed = false; break;
case GMCMessageKey.Template:
cmp.Template = DecodeTemplate(input);
if (log.IsTraceEnabled)
{
log.Trace(String.Format("TID={0}: Decoded template: {1}",
cmp.TemplateId, ByteUtils.DumpBytes(cmp.Template)));
}
break;
case GMCMessageKey.HuffmanFrequencyTable:
cmp.FrequencyTable = DecodeFrequencies(input);
log.Trace(String.Format("TID={0}: Decoded huffman frequencies", cmp.TemplateId));
break;
case GMCMessageKey.Announcements:
cmp.Announcements = DecodeAnnouncements(input);
if (log.IsTraceEnabled)
{
StringBuilder message = new StringBuilder();
message.Append(String.Format("TID={0}: Decoded {1} dictionary announcements:",
cmp.TemplateId, cmp.Announcements.Count));
foreach(KeyValuePair<uint, byte> kvp in cmp.Announcements)
{
message.Append(' ');
message.Append(kvp.Key);
message.Append("->");
message.Append(kvp.Value);
}
log.Trace(message);
}
break;
case GMCMessageKey.Message:
uint len = ByteUtils.DecodeLength(input);
cmp.Message = new byte[len];
input.Read(cmp.Message, 0, (int)len);
if (log.IsTraceEnabled)
{
log.Trace(String.Format("Decoded message: {0}",
ByteUtils.DumpBytes(cmp.Message)));
}
break;
default:
log.Trace("Invalid GMC message");
throw new MarshallingException("invalid GMC message");
}
}
GeneralMessageCompressor handler;
if (!decompressors.TryGetValue(userId, out handler))
{
if (cmp.Template == null)
{
//we haven't received any templates whatsoever from this person.
MissingInformationException mte = new MissingInformationException();
mte.Template = 0;
mte.UserID = userId;
mte.ExceptionType = EnumExceptionType.MissingTemplate;
throw mte;
}
handler = decompressors[userId] = new GeneralMessageCompressor();
}
return handler.Decode(cmp, userId);
}
/// <summary>Creates a new instance of GMC.
/// Typically GMC will function as a singleton for each client,
/// however, there are cases where the designer may wish to have a variety of GMCS.</summary>
/// <param name="subMrshlr">the submarshaller to use for marshalling objects to bytes.</param>
public GMCMarshaller(IMarshaller subMrshlr)
{
log = LogManager.GetLogger(GetType());
subMarshaller = subMrshlr;
compressor = new GeneralMessageCompressor();
decompressors = new Dictionary<int, GeneralMessageCompressor>();
}