/// <summary>
/// Handles the HTTP response.
/// </summary>
/// <param name="iEvent">Socket event arguments object.</param>
private void ProcessHttp(SocketAsyncEventArgs iEvent)
{
// resize response buffer if not enough
if ((_RspLength + iEvent.BytesTransferred) < _RspBfr.Length)
{
Array.Resize(ref _RspBfr, _RspLength + iEvent.BytesTransferred);
}
// append new data to response buffer
Array.Copy(iEvent.Buffer, 0, _RspBfr, _RspLength, iEvent.BytesTransferred);
// update new response length
_RspLength += iEvent.BytesTransferred;
Int32 aBeg = 0;
Int32 aB = 0;
Int32 aEnd = _RspLength;
String aTemp = String.Empty;
Int32 aMsgLength = 0;
byte[] aCookie = null;
bool aClear = true;
// process response buffer loop
while (aBeg < aEnd)
{ // skip whitespaces
while ((Char.IsWhiteSpace((char)_RspBfr[aBeg])) && (aBeg < aEnd))
{
aBeg++;
}
// buffer overflow protection
if (aBeg == aEnd)
{
aClear = false;
break; // not enough bytes
}
// make sure we can read the protocol header
if (aBeg + HTTP_HDR.Length > aEnd)
{
aClear = false;
break; // not enough bytes
}
// read the protocol header
aTemp = System.Text.Encoding.ASCII.GetString(_RspBfr, aBeg, HTTP_HDR.Length);
if (aTemp != HTTP_HDR)
{ // EMIT PROTOCOL ERROR
SocketErrorEventArgs aSocketError = new SocketErrorEventArgs();
aSocketError.Error = "Unknown Procotol";
SocketErrorEvent(this, aSocketError);
break;
}
aB = aBeg;
// extract Set-Cookie and Content-Length loop
do
{ // scan past next newline
while (aB < aEnd && ((char)_RspBfr[aB++]) != '\n')
{
;
}
if (aB + SET_COOKIE.Length < aEnd &&
_RspBfr[aB] == 'S' &&
_RspBfr[aB + 1] == 'e' &&
_RspBfr[aB + 2] == 't' &&
_RspBfr[aB + 3] == '-' &&
_RspBfr[aB + 4] == 'C' &&
_RspBfr[aB + 5] == 'o' &&
_RspBfr[aB + 6] == 'o' &&
_RspBfr[aB + 7] == 'k' &&
_RspBfr[aB + 8] == 'i' &&
_RspBfr[aB + 9] == 'e')
{ // scan past the colon (:)
while ((aB < aEnd) && (_RspBfr[aB++] != ':'))
{
;
}
if (aB < aEnd)
{
Int32 aEol = 0;
if (_RspBfr[aB] == ' ')
{
aB++;
}
for (aEol = aB; (aEol < aEnd) && (_RspBfr[aEol] != '\r') &&
(_RspBfr[aEol] != '\n'); aEol++)
{
;
}
aCookie = new byte[aEol - aB];
Array.Copy(_RspBfr, aB, aCookie, 0, aEol - aB);
}
}
else if (aB + CONTENT_LENGTH.Length < aEnd &&
_RspBfr[aB] == 'C' &&
_RspBfr[aB + 1] == 'o' &&
_RspBfr[aB + 2] == 'n' &&
_RspBfr[aB + 3] == 't' &&
_RspBfr[aB + 4] == 'e' &&
_RspBfr[aB + 5] == 'n' &&
_RspBfr[aB + 6] == 't' &&
_RspBfr[aB + 7] == '-' &&
_RspBfr[aB + 8] == 'L' &&
_RspBfr[aB + 9] == 'e' &&
_RspBfr[aB + 10] == 'g' &&
_RspBfr[aB + 11] == 'n' &&
_RspBfr[aB + 12] == 't' &&
_RspBfr[aB + 13] == 'h')
{
while ((aB < aEnd) && _RspBfr[aB] < '0' || _RspBfr[aB] > '9')
{
aB++;
}
// get the content-length
if (aB < aEnd)
{
Int32 aEol = 0;
for (aEol = aB; (aEol < aEnd) && (_RspBfr[aEol] != '\r') &&
(_RspBfr[aEol] != '\n'); aEol++)
{
;
}
aTemp = Encoding.ASCII.GetString(_RspBfr, aB, (aEol - aB));
try
{ aMsgLength = Int32.Parse(aTemp); }
catch (FormatException)
{ Debug.WriteLine("Invalid Content-Length value."); }
}
}
else if (_RspBfr[aB] == '\r')
{
aB++;
}
} // extract Set-Cookie and Content-Length loop
while (aB < aEnd && (_RspBfr[aB++]) != '\n');
// partial. save the partial request.
// aBeg = Beginning of this message
// aB = Beginning of the body of request
if (aB + aMsgLength > aEnd)
{ // if aBeg has been moved past the beginning of the buffer
// just keep the partial
if (aBeg > 0)
{ // create new buffer
byte[] aNewBfr = new byte[aEnd - aBeg];
Array.Copy(_RspBfr, aBeg, aNewBfr, 0, aNewBfr.Length);
_RspBfr = aNewBfr;
}
aBeg = aB + aMsgLength;
// DO NOT CLEAR BUFFER
aClear = false;
// quit the main loop
break;
}
else
{
ResponseEventArgs aHtmlResponse = new ResponseEventArgs();
aHtmlResponse.ResponseBuffer = new byte[aMsgLength];
aHtmlResponse.CookieBuffer = aCookie;
Array.Copy(_RspBfr, aB, aHtmlResponse.ResponseBuffer, 0, aMsgLength);
// emit response signal
ResponseEvent(this, aHtmlResponse);
// move aBeg to end of body
aBeg += aMsgLength;
}
}
if (aClear)
{
_RspLength = 0;
}
// call asynchronous read again
_RemoteSocket.ReceiveAsync(iEvent);
} // end of process response buffer loop
/// <summary>
/// Handles the XML response.
/// </summary>
/// <param name="iEvent">Socket event arguments object.</param>
private void ProcessXml(SocketAsyncEventArgs iEvent)
{
// resize response buffer if not enough
if ((_RspLength + iEvent.BytesTransferred) < _RspBfr.Length)
{
Array.Resize(ref _RspBfr, _RspLength + iEvent.BytesTransferred);
}
// append new data to response buffer
Array.Copy(iEvent.Buffer, 0, _RspBfr, _RspLength, iEvent.BytesTransferred);
// update new response length
_RspLength += iEvent.BytesTransferred;
Int32 aBeg = 0;
Int32 aB = 0;
Int32 aEnd = _RspLength;
String aTemp = String.Empty;
bool aClear = true;
// process response buffer loop
while (aBeg < aEnd)
{ // skip whitespaces
while ((Char.IsWhiteSpace((char)_RspBfr[aBeg])) && (aBeg < aEnd))
{
aBeg++;
}
// buffer overflow protection
if (aBeg == aEnd)
{
aClear = false;
break; // not enough bytes
}
// make sure we can read the protocol header
if (aBeg + XML_HDR.Length > aEnd)
{
aClear = false;
break; // not enough bytes
}
// read the protocol header
aTemp = System.Text.Encoding.ASCII.GetString(_RspBfr, aBeg, XML_HDR.Length);
if (aTemp != XML_HDR)
{ // EMIT PROTOCOL ERROR
SocketErrorEventArgs aSocketError = new SocketErrorEventArgs();
aSocketError.Error = "Unknown Protocol";
SocketErrorEvent(this, aSocketError);
break;
}
for (aB = aBeg; aB < aEnd && _RspBfr[aB] > MSG_TERM; aB++)
{
;
}
// if read past the last character
if (aB == aEnd)
{ // DO NOT CLEAR BUFFER
aClear = false;
break;
}
// partial. save partial request.
// aBeg - Beginning of next response
// aB - end of this response
if (_RspBfr[aB] > MSG_TERM)
{ // if aBeg has been moved past the beginning of the buffer
if (aBeg > 0)
{
byte[] aNewBuffer = new byte[aEnd - aBeg];
Array.Copy(_RspBfr, aBeg, aNewBuffer, 0, aNewBuffer.Length);
_RspBfr = aNewBuffer;
}
// DO NOT CLEAR BUFFER
aClear = false;
break;
}
// NULL terminate the response
_RspBfr[aB] = (byte)MSG_NULL;
ResponseEventArgs aResponse = new ResponseEventArgs();
aResponse.ResponseBuffer = new byte[aB + 1];
Array.Copy(_RspBfr, aBeg, aResponse.ResponseBuffer, 0, aB + 1);
// emit response signal
ResponseEvent(this, aResponse);
// move aBeg to
aBeg = aB + 1;
}
if (aClear)
{
_RspLength = 0;
}
// call asynchronous read again
_RemoteSocket.ReceiveAsync(iEvent);
}
/// <summary>
/// Handles the APP response.
/// </summary>
/// <param name="iEvent">Async receive arguments object.</param>
private void ProcessApp(SocketAsyncEventArgs iEvent)
{
byte[] aBuffer = iEvent.Buffer; // buffer reference
String aTemp = String.Empty; // temporary string
String aErrorMessage = String.Empty; // error message
bool aError = false; // error flag
bool aEmit = false; // emit signal flag
switch (_AppReadState)
{
case AppReadState.ReadingResponseLength:
// check if length field was read correctly
// and message delimiter is present
if (iEvent.BytesTransferred == LENGTH_SIZE &&
aBuffer[LENGTH_SIZE - 1] == MSG_DELIM)
{ // convert length field to integer
aTemp = Encoding.ASCII.GetString(aBuffer, 0, LENGTH_SIZE - 1);
try
{ // get the expected size of response
_ResponseSize = Int32.Parse(aTemp);
}
catch (FormatException)
{ // error in number conversion
aErrorMessage = "Invalid response message size format.";
aError = true;
}
// response size is valid
if (_ResponseSize > 0)
{ // set state to reading data length
_AppReadState = AppReadState.ReadingDataLength;
}
else
{ // response size is invalid
aErrorMessage = "Invalid response message size.";
aError = true;
}
}
else
{ // protocol error
aErrorMessage = "Unable to extract response message size.";
aError = true;
}
break;
case AppReadState.ReadingDataLength:
// check if length field was read correctly
if (iEvent.BytesTransferred == LENGTH_SIZE &&
aBuffer[LENGTH_SIZE - 1] == MSG_DELIM)
{ // convert binary data length field to integer
aTemp = Encoding.ASCII.GetString(aBuffer, 0, LENGTH_SIZE - 1);
try
{ // get the expected size of binary data
_DataSize = Int32.Parse(aTemp);
}
catch (FormatException)
{ // error in number conversion
aErrorMessage = "Invalid binary data size format.";
aError = true;
}
if (_DataSize >= 0)
{ // check size of response buffer
if (_RspBfr.Length <= _ResponseSize)
{ // increase buffer size
_RspBfr = new byte[_ResponseSize + 1];
}
// read the response message (including terminator)
_AppReadState = AppReadState.ReadingResponse;
iEvent.SetBuffer(_RspBfr, 0, _ResponseSize + 1);
}
else
{ // binary data size is invalid
aErrorMessage = "Invalid binary data size.";
aError = true;
}
}
else
{ // protocol error
aErrorMessage = "Unable to extract binary data size";
aError = true;
}
break;
case AppReadState.ReadingResponse:
// update the bytes received
_RspLength += iEvent.BytesTransferred;
// if read response is complete
if (_RspLength == _ResponseSize + 1)
{ // check if terminator is present
if (_RspBfr[_ResponseSize] > MSG_TERM)
{ // allow to continue
Debug.WriteLine("Encountered unterminated response in message.");
}
// put null terminator
_RspBfr[_ResponseSize] = (byte)MSG_NULL;
// if binary data is expected
if (_DataSize > 0)
{ // if data buffer not present or not enough
if (_DataBfr == null || _DataBfr.Length < _DataSize)
{
_DataBfr = new byte[_DataSize];
}
// read data
_AppReadState = AppReadState.ReadingData;
iEvent.SetBuffer(_DataBfr, 0, _DataSize);
}
else
{ // read complete, signal response event
aEmit = true;
}
}
else
{ // partial response received
// continue reading the remaining bytes
iEvent.SetBuffer(_RspLength, _ResponseSize - _RspLength + 1);
}
break;
case AppReadState.ReadingData:
// update the bytes received
_DataLength += iEvent.BytesTransferred;
// if read binary data is complete
if (_DataLength == _DataSize)
{ // read complete, signal response event
aEmit = true;
}
else
{ // partial binary data received
// continue reading the remaining bytes
iEvent.SetBuffer(_DataLength, _DataSize - _DataLength);
}
break;
}
// on emit
if (aEmit)
{ // Get ready to emit response to subscribers
ResponseEventArgs aResEvtArgs = new ResponseEventArgs();
aResEvtArgs.ResponseBuffer = new byte[_ResponseSize + 1];
Array.Copy(_RspBfr, aResEvtArgs.ResponseBuffer, _ResponseSize + 1);
// if binary data is available
if (_DataLength > 0)
{
aResEvtArgs.DataBuffer = new byte[_DataSize];
Array.Copy(_DataBfr, aResEvtArgs.DataBuffer, _DataSize);
}
// Signal response event
ResponseEvent(this, aResEvtArgs);
// Reset state variables
_RspLength = 0;
_ResponseSize = 0;
_DataLength = 0;
_DataSize = 0;
_AppReadState = AppReadState.ReadingResponseLength;
iEvent.SetBuffer(_RspBfr, 0, LENGTH_SIZE);
}
// on error
if (aError)
{ // Display error message
Debug.WriteLine(aErrorMessage);
// Clear socket buffer
DumpSocketBuffer();
// Reset read state
_RspLength = 0;
_ResponseSize = 0;
_DataLength = 0;
_DataSize = 0;
_AppReadState = AppReadState.ReadingResponseLength;
iEvent.SetBuffer(_RspBfr, 0, LENGTH_SIZE);
}
// trigger next asynchronous read
_RemoteSocket.ReceiveAsync(iEvent);
}
