/// <summary>
/// Decodes the message.
/// </summary>
/// <param name="buffer">The buffer.</param>
/// <param name="offset">The offset.</param>
/// <param name="message">The message.</param>
/// <returns>
/// True if decoding was successful; false otherwise.
/// </returns>
public static bool TryDecode(byte[] buffer, int offset, out ScrapeMessage message)
{
long connectionId;
int action;
int transactionId;
List <string> infoHashes = new List <string>();
message = null;
if (buffer != null &&
buffer.Length >= offset + ConnectionIdLength + ActionLength + TransactionIdLength &&
offset >= 0)
{
connectionId = Message.ReadLong(buffer, ref offset);
action = Message.ReadInt(buffer, ref offset);
transactionId = Message.ReadInt(buffer, ref offset);
if (connectionId >= 0 &&
action == (int)TrackingAction.Scrape &&
transactionId >= 0)
{
while (offset <= buffer.Length - InfoHashLength)
{
infoHashes.Add(Message.ReadBytes(buffer, ref offset, InfoHashLength).ToHexaDecimalString());
}
message = new ScrapeMessage(connectionId, transactionId, infoHashes);
}
}
return(message != null);
}
/// <summary>
/// Tries to decode the message.
/// </summary>
/// <param name="buffer">The buffer.</param>
/// <param name="offset">The offset.</param>
/// <param name="messageType">Type of the message.</param>
/// <param name="message">The decoded message.</param>
/// <returns>
/// True if message was successfully decoded; false otherwise.
/// </returns>
public static bool TryDecode(byte[] buffer, int offset, MessageType messageType, out TrackerMessage message)
{
int action;
message = null;
if (buffer.IsNotNullOrEmpty())
{
action = messageType == MessageType.Request ? Message.ReadInt(buffer, ref offset) : Message.ReadInt(buffer, ref offset);
offset = 0;
if (action == (int)TrackingAction.Connect)
{
if (messageType == MessageType.Request)
{
ConnectMessage message2;
ConnectMessage.TryDecode(buffer, offset, out message2);
message = message2;
}
else
{
ConnectResponseMessage message2;
ConnectResponseMessage.TryDecode(buffer, offset, out message2);
message = message2;
}
}
else if (action == (int)TrackingAction.Announce)
{
if (messageType == MessageType.Request)
{
AnnounceMessage message2;
AnnounceMessage.TryDecode(buffer, offset, out message2);
message = message2;
}
else
{
AnnounceResponseMessage message2;
AnnounceResponseMessage.TryDecode(buffer, offset, out message2);
message = message2;
}
}
else if (action == (int)TrackingAction.Scrape)
{
if (messageType == MessageType.Request)
{
ScrapeMessage message2;
ScrapeMessage.TryDecode(buffer, offset, out message2);
message = message2;
}
else
{
ScrapeResponseMessage message2;
ScrapeResponseMessage.TryDecode(buffer, offset, out message2);
message = message2;
}
}
else if (action == (int)TrackingAction.Error)
{
ErrorMessage message2;
ErrorMessage.TryDecode(buffer, offset, out message2);
message = message2;
}
else
{
// could not decode UDP message
}
}
return(message != null);
}
