/// <summary>
/// We can read a string from the StringSocket by doing
///
/// ss.BeginReceive(callback, payload)
///
/// where callback is a ReceiveCallback (see below) and payload is an arbitrary object.
/// This is non-blocking, asynchronous operation. When the StringSocket has read a
/// string of text terminated by a newline character from the underlying Socket, or
/// failed in the attempt, it invokes the callback. The parameters to the callback are
/// a (possibly null) string, a (possibly null) Exception, and the payload. Either the
/// string or the Exception will be non-null, but nor both. If the string is non-null,
/// it is the requested string (with the newline removed). If the Exception is non-null,
/// it is the Exception that caused the send attempt to fail.
///
/// This method is non-blocking. This means that it does not wait until a line of text
/// has been received before returning. Instead, it arranges for a line to be received
/// and then returns. When the line is actually received (at some time in the future), the
/// callback is called on another thread.
///
/// This method is thread safe. This means that multiple threads can call BeginReceive
/// on a shared socket without worrying around synchronization. The implementation of
/// BeginReceive must take care of synchronization instead. On a given StringSocket, each
/// arriving line of text must be passed to callbacks in the order in which the corresponding
/// BeginReceive call arrived.
///
/// Note that it is possible for there to be incoming bytes arriving at the underlying Socket
/// even when there are no pending callbacks. StringSocket implementations should refrain
/// from buffering an unbounded number of incoming bytes beyond what is required to service
/// the pending callbacks.
///
/// <param name="callback"> The function to call upon receiving the data</param>
/// <param name="payload">
/// The payload is "remembered" so that when the callback is invoked, it can be associated
/// with a specific Begin Receiver....
/// </param>
///
/// <example>
/// Here is how you might use this code:
/// <code>
/// client = new TcpClient("localhost", port);
/// Socket clientSocket = client.Client;
/// StringSocket receiveSocket = new StringSocket(clientSocket, new UTF8Encoding());
/// receiveSocket.BeginReceive(CompletedReceive1, 1);
///
/// </code>
/// </example>
/// </summary>
public void BeginReceive(ReceiveCallback callback, object payload)
{
// Store the receive request, with its specified callback and payload.
ReceiveRequest receiveRequest = new ReceiveRequest(callback, payload);
ReceiveQueue.Enqueue(receiveRequest);
// Ask the socket to call MessageReceive as soon as up to 1024 bytes arrive.
byte[] buffer = new byte[1024];//this should work when this is set to a small number
socket.BeginReceive(buffer, 0, buffer.Length,
SocketFlags.None, MessageReceived, buffer);
}
/// <summary>
/// We can read a string from the StringSocket by doing
///
/// ss.BeginReceive(callback, payload)
///
/// where callback is a ReceiveCallback (see below) and payload is an arbitrary object.
/// This is non-blocking, asynchronous operation. When the StringSocket has read a
/// string of text terminated by a newline character from the underlying Socket, or
/// failed in the attempt, it invokes the callback. The parameters to the callback are
/// a (possibly null) string, a (possibly null) Exception, and the payload. Either the
/// string or the Exception will be non-null, but nor both. If the string is non-null,
/// it is the requested string (with the newline removed). If the Exception is non-null,
/// it is the Exception that caused the send attempt to fail.
///
/// This method is non-blocking. This means that it does not wait until a line of text
/// has been received before returning. Instead, it arranges for a line to be received
/// and then returns. When the line is actually received (at some time in the future), the
/// callback is called on another thread.
///
/// This method is thread safe. This means that multiple threads can call BeginReceive
/// on a shared socket without worrying around synchronization. The implementation of
/// BeginReceive must take care of synchronization instead. On a given StringSocket, each
/// arriving line of text must be passed to callbacks in the order in which the corresponding
/// BeginReceive call arrived.
///
/// Note that it is possible for there to be incoming bytes arriving at the underlying Socket
/// even when there are no pending callbacks. StringSocket implementations should refrain
/// from buffering an unbounded number of incoming bytes beyond what is required to service
/// the pending callbacks.
///
/// <param name="callback"> The function to call upon receiving the data</param>
/// <param name="payload">
/// The payload is "remembered" so that when the callback is invoked, it can be associated
/// with a specific Begin Receiver....
/// </param>
///
/// <example>
/// Here is how you might use this code:
/// <code>
/// client = new TcpClient("localhost", port);
/// Socket clientSocket = client.Client;
/// StringSocket receiveSocket = new StringSocket(clientSocket, new UTF8Encoding());
/// receiveSocket.BeginReceive(CompletedReceive1, 1);
///
/// </code>
/// </example>
/// </summary>
public void BeginReceive(ReceiveCallback callback, object payload)
{
// Protect the ReceiveQueue
lock (ReceiveQueue)
{
// Create and store the receive request.
ReceiveRequest receiveRequest = new ReceiveRequest(callback, payload);
ReceiveQueue.Enqueue(receiveRequest);
// If there is no receive ongoing, start receiving.
if (ReceiveQueue.Count == 1)
{
ProcessReceivedMessage();
}
}
}
/// <summary>
/// This private method is the callback for the receive attempts.
/// </summary>
private void BytesReceived(IAsyncResult ar)
{
// Get the number of bytes received.
int count;
try
{
count = socket.EndReceive(ar);
}
catch (Exception e)
{
ReceiveRequest req = receiveRequests.Dequeue();
ThreadPool.QueueUserWorkItem(x => req.Callback(null, e, req.Payload));
ProcessReceiveQueue();
incompleteLine = "";
return;
}
// If no bytes were received, this means that the remote socket has
// shut down. Send a null to the callback to signal this.
if (count == 0)
{
receivedLines.Enqueue(null);
ProcessReceiveQueue();
}
// If bytes were received, save them.
else
{
//incompleteLine += encoding.GetString(receiveBytes, 0, count);
int charsRead = decoder.GetChars(receiveBytes, 0, count, receiveChars, 0, false);
incompleteLine += new String(receiveChars, 0, charsRead);
// Extract all complete lines of text and put into the ReceivedLines queue
int lineEnd, lineStart = 0;
while ((lineEnd = incompleteLine.IndexOf('\n', lineStart)) >= 0)
{
receivedLines.Enqueue(incompleteLine.Substring(lineStart, lineEnd - lineStart));
lineStart = lineEnd + 1;
}
incompleteLine = incompleteLine.Substring(lineStart);
// Try to fill requests with the new data
ProcessReceiveQueue();
}
}
