void ProcessReceived(SocketAsyncEventArgs e)
{
//..
if (e.BytesTransferred > 0 && e.SocketError == SocketError.Success)
{
AsyncUserToken token = (AsyncUserToken)e.UserToken;
int offset = 0; // token.BytesReceivedStatic;
int bytesExpected = 0; // token.BytesExpected;
token.BytesReceivedDynamic = e.BytesTransferred; // bytes received this time
token.BytesReceivedStatic += e.BytesTransferred; // bytes accumulated in the buffer
if (ReportReceivedProgress != null)
{
ReportReceivedProgress(e, token);
}
bool hasCompletedMessage = true;
while (hasCompletedMessage)
{
if (token.IsHead) // is head, read the prefix length
{
// incomplete prefix bytes
if (token.BytesReceivedStatic < 4)
{
break;
}
token.BytesExpected = BitConverter.ToInt32(e.Buffer, 0);
if (token.BytesExpected == 0)
{
// heartbeat message
// remove 4 bytes at head
Buffer.BlockCopy(e.Buffer, 4, e.Buffer, 0, token.BytesReceivedStatic - 4);
// continue to receive
break;
}
// expand the buffer size when the buffer is not large enough
if (token.BytesExpected > receiveBuffer.Length)
{
byte[] temp = new byte[token.BytesExpected * 2];
Buffer.BlockCopy(e.Buffer, 0, temp, 0, e.Buffer.Length);
receiveBuffer = temp;
e.SetBuffer(temp, 0, temp.Length);
}
token.IsHead = false;
}
// if bytes accumulated in the buffer is greater than or equals to bytes expected
hasCompletedMessage = token.BytesReceivedStatic >= token.BytesExpected;
//
if (hasCompletedMessage) // at least one complete message
{
// deliver the first message in the buffer
byte[] receivedData = new byte[token.BytesExpected - 4];
Buffer.BlockCopy(receiveBuffer, 4, receivedData, 0, receivedData.Length);
OnDataReceivedCompleted(this, receivedData);
token.IsHead = true; // reset the head flag
// valid bytes left in the buffer
int bytesLeftInBuffer = token.BytesReceivedStatic - token.BytesExpected;
// shift the incomplete data to the head of the buffer
// TODO:
// FIXME: only do shift the last incomplete data
Buffer.BlockCopy(e.Buffer, token.BytesExpected, e.Buffer, 0, bytesLeftInBuffer);
// reset the bytes of valid data in the buffer
token.BytesReceivedStatic = bytesLeftInBuffer;
}
}
// append the following data to the buffer from offset position
offset = token.BytesReceivedStatic; // start position of the buffer
bytesExpected =
//// only expected message length bytes
//token.BytesExpected - token.BytesReceivedStatic;
//// expected bytes as much as the buffer can hold
e.Buffer.Length - token.BytesReceivedStatic;
e.SetBuffer(offset, bytesExpected);
e.UserToken = token;
if (!clientSocket.ReceiveAsync(e))
{
ProcessReceived(e);
}
}
else
{
CloseConnection();
}
}
void a_conn_ReportSendProgress(SocketAsyncEventArgs e, AsyncUserToken token)
{
if (this.ReportSendProgress != null)
this.ReportSendProgress(e, token);
}